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Measurement, spatial spillover and influencing factors of agricultural carbon emissions efficiency in China
WU Haoyue, HUANG Hanjiao, HE Yu, CHEN Wenkuan
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Effects of tillage and straw returning method on the distribution of carbon and nitrogen in soil aggregates
ZHANG Yuming, HU Chunsheng, CHEN Suying, WANG Yuying, LI Xiaoxin, DONG Wenxu, LIU Xiuping, PEI Lin, ZHANG Hui
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Relationship between policy incentives, ecological cognition, and organic fertilizer application by farmers: Based on a moderated mediation model
SANG Xiance, LUO Xiaofeng, HUANG Yanzhong, TANG Lin
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Spatio-temporal evolution of carbon stocks in the Yellow River Basin based on InVEST and CA-Markov models
YANG Jie, XIE Baopeng, ZHANG Degang
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Effects of straw returning and fertilization on soil bacterial and fungal community structures and diversities in rice-wheat rotation soil
ZHANG Hanlin, BAI Naling, ZHENG Xianqing, LI Shuangxi, ZHANG Juanqin, ZHANG Haiyun, ZHOU Sheng, SUN Huifeng, LYU Weiguang
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2013 Vol. 21, No. 7
Display Method:
2013, 21(7): 787-794.
doi: 10.3724/SP.J.1011.2013.00787
Abstract:
Although China has become the first major country with facility cultivation in the world, soil degradation has become a bottleneck to sustainable development of modern facility agriculture. To understand the causes of soil degradation and facility agriculture characteristics, the development of appropriate measures for promoting healthy agricultural progress is important. This article reviewed five aspects of soil degradation under current facility agriculture in China. The reviewed aspects included the characteristics and causes of secondary salinization, acidification, micro-flora destroy, nutrient dislocation and harmful substance accumulation. Three major control (biological, agricultural and engineering) measures for improving facility agriculture soils were discussed. In view of the issues of facility agriculture soils in China, research was less at the exploration stage of formative reasons and control mechanisms; original technologies for soil improvement and control were still scarce; long-term large-scale greenhouse soil quality research and dynamic monitoring lagged behind other research activities; and soil degradation factors and interaction mechanisms had not been adequately evolved. The four key components of future research in facility agriculture included the construction of quality standard system of greenhouse soil; understanding soil quality degradation and evolution mechanisms, and establishing regulatory techniques; studying interaction among different degradation ways; and expanding new technology applications.
Although China has become the first major country with facility cultivation in the world, soil degradation has become a bottleneck to sustainable development of modern facility agriculture. To understand the causes of soil degradation and facility agriculture characteristics, the development of appropriate measures for promoting healthy agricultural progress is important. This article reviewed five aspects of soil degradation under current facility agriculture in China. The reviewed aspects included the characteristics and causes of secondary salinization, acidification, micro-flora destroy, nutrient dislocation and harmful substance accumulation. Three major control (biological, agricultural and engineering) measures for improving facility agriculture soils were discussed. In view of the issues of facility agriculture soils in China, research was less at the exploration stage of formative reasons and control mechanisms; original technologies for soil improvement and control were still scarce; long-term large-scale greenhouse soil quality research and dynamic monitoring lagged behind other research activities; and soil degradation factors and interaction mechanisms had not been adequately evolved. The four key components of future research in facility agriculture included the construction of quality standard system of greenhouse soil; understanding soil quality degradation and evolution mechanisms, and establishing regulatory techniques; studying interaction among different degradation ways; and expanding new technology applications.
2013, 21(7): 795-800.
doi: 10.3724/SP.J.1011.2013.00795
Abstract:
Soil C/N ratio is a critical soil nitrogen cycle factor. Two-year old apple trees (Borkh. cv. 'Fuji'/ Malus hupehensis) were used to study the effect of soil C/N ratio [6.21 (CK), 10, 15, 20, 25, 30, 35 and 40] on nitrogen utilization/loss and apple growth using the 15N trace technique. The results showed that with increasing soil C/N ratio, apple shoot length and fresh weight initially increased and then decreased. The highest apple shoot length and fresh weight were under the treatments of 15, 20 and 25 C/N ratio. Although no significant differences were noted among the three treatments, the shoot length and fresh weight of apple tree under these three C/N ratios treatments were significantly higher than those under the other treatments. Statistical analysis revealed significant difference in nitrogen utilization rate among different treatments. The highest nitrogen utilization rate was in soils with C/N ratio of 25, which value was 22.87%, not significantly different from that in soils with C/N ratio of 20. However, the nitrogen utilization under both the two treatments was significantly higher than those under the other treatments. Soil C/N ratio of 40 showed the lowest nitrogen utilization rate (15.43%), which was even lower than that of CK (16.65%). The proportion of plant absorbed fertilizer nitrogen was much higher under treatments of soil C/N ratio range of 15~25. But proportion of plant absorbed soil nitrogen was much higher under too low (<15) or high (>25) soil C/N ratio. Soil residual nitrogen increased gradually with increasing soil C/N ratio. Soil residual nitrogen under C/N ratio of 40 was 1.32 times that of CK. With increasing soil C/N ratio, fertilizer nitrogen loss initially dropped and then increased. Fertilizer nitrogen loss was minimum (49.87%) under soil C/N ratio of 25 and the maximum (61.54%) under CK. Therefore regarding nitrogen utilization and apple growth, soil C/N ratio range of 15~25 was favorable. It increased soil nitrogen fixation efficiency, reduced nitrogen loss, and enhanced nitrogen utilization rate.
Soil C/N ratio is a critical soil nitrogen cycle factor. Two-year old apple trees (Borkh. cv. 'Fuji'/ Malus hupehensis) were used to study the effect of soil C/N ratio [6.21 (CK), 10, 15, 20, 25, 30, 35 and 40] on nitrogen utilization/loss and apple growth using the 15N trace technique. The results showed that with increasing soil C/N ratio, apple shoot length and fresh weight initially increased and then decreased. The highest apple shoot length and fresh weight were under the treatments of 15, 20 and 25 C/N ratio. Although no significant differences were noted among the three treatments, the shoot length and fresh weight of apple tree under these three C/N ratios treatments were significantly higher than those under the other treatments. Statistical analysis revealed significant difference in nitrogen utilization rate among different treatments. The highest nitrogen utilization rate was in soils with C/N ratio of 25, which value was 22.87%, not significantly different from that in soils with C/N ratio of 20. However, the nitrogen utilization under both the two treatments was significantly higher than those under the other treatments. Soil C/N ratio of 40 showed the lowest nitrogen utilization rate (15.43%), which was even lower than that of CK (16.65%). The proportion of plant absorbed fertilizer nitrogen was much higher under treatments of soil C/N ratio range of 15~25. But proportion of plant absorbed soil nitrogen was much higher under too low (<15) or high (>25) soil C/N ratio. Soil residual nitrogen increased gradually with increasing soil C/N ratio. Soil residual nitrogen under C/N ratio of 40 was 1.32 times that of CK. With increasing soil C/N ratio, fertilizer nitrogen loss initially dropped and then increased. Fertilizer nitrogen loss was minimum (49.87%) under soil C/N ratio of 25 and the maximum (61.54%) under CK. Therefore regarding nitrogen utilization and apple growth, soil C/N ratio range of 15~25 was favorable. It increased soil nitrogen fixation efficiency, reduced nitrogen loss, and enhanced nitrogen utilization rate.
2013, 21(7): 801-809.
doi: 10.3724/SP.J.1011.2013.00801
Abstract:
To simultaneously enhance maize yield and phosphorus fertilizer efficiency, the effects of phosphorus application on maize phosphorus uptake and utilization, yield, and the dynamic changes of rhizosphere phosphorus were studied in a field experiment. The study was conducted in low soil phosphorus (Olsen-P 4.9 mg·kg-1) condition at Henan Province with two maize varieties - "Ludan 9002" (LD9002) and "Xianyu 335" (XY335). The application rates of the P fertilizers were 0 (T0), 50 kg(P2O5)·hm-2 (T1) ,100 kg(P2O5)·hm-2 (T2), 200 kg(P2O5)·hm-2 (T3) and 1 000 kg(P2O5)·hm-2 (T4), respectively. The results showed that the order of available phosphorus contents in rhizosphere and non-rhizosphere soils of the two maize varieties at different growth stages was T1 < T2 < T3 < T4. The highest phosphorus transformation rate from non-rhizosphere to rhizosphere soils was at 61 d after maize planting under 200 kg(P2O5)·hm-2 (T3). Also treatment T3 had the highest biomass, grain yield and phosphorus transformation rate. Under 1 000 kg(P2O5)·hm-2 phosphorus fertilizer application (T4), no significant increase was noted in biomass and grain yield compared to intermediate phosphorus level. However, maize phosphorus uptake was much higher under treatment T. Phosphorus transformation rate of XY335 after flowering was lower than that of LD9002, suggesting higher phosphorus use efficiency by LD9002. Correlation analysis showed significant relationships among available phosphorus contents of rhizosphere and non-rhizosphere soils and phosphorus accumulation in stems and leaves of LD9002, especially at 79 d after planting. Also significant relationships were noted among available phosphorus content of rhizosphere and non-rhizosphere soils and those of stems and leaves of XY335, especially at 47 d after planting. This suggested that 79 d and 47 d after planting were key phosphorus demand periods after planting in LD9002 and XY335, respectively. Available phosphorus content of rhizosphere and non-rhizosphere soils reflected the capacity of the soils to release phosphorus. Suitable phosphorus concentration of rhizosphere and non-rhizosphere soils for the highest phosphorus uptake were respectively 54.95 mg·kg-1 and 32.99 mg·kg-1 at 79 d after planting LD9002. The corresponding values for XY335 were respectively 51.24 mg·kg-1 and 35.35 mg·kg-1 at 47 d after planting. When phosphorus application rate increased to 1 000 kg(P2O5)·hm -2, no significant difference existed in terms of yield, biomass and phosphorus uptake compared with those under phosphorus application rate of 100~200 kg(P2O5)·hm-2.
To simultaneously enhance maize yield and phosphorus fertilizer efficiency, the effects of phosphorus application on maize phosphorus uptake and utilization, yield, and the dynamic changes of rhizosphere phosphorus were studied in a field experiment. The study was conducted in low soil phosphorus (Olsen-P 4.9 mg·kg-1) condition at Henan Province with two maize varieties - "Ludan 9002" (LD9002) and "Xianyu 335" (XY335). The application rates of the P fertilizers were 0 (T0), 50 kg(P2O5)·hm-2 (T1) ,100 kg(P2O5)·hm-2 (T2), 200 kg(P2O5)·hm-2 (T3) and 1 000 kg(P2O5)·hm-2 (T4), respectively. The results showed that the order of available phosphorus contents in rhizosphere and non-rhizosphere soils of the two maize varieties at different growth stages was T1 < T2 < T3 < T4. The highest phosphorus transformation rate from non-rhizosphere to rhizosphere soils was at 61 d after maize planting under 200 kg(P2O5)·hm-2 (T3). Also treatment T3 had the highest biomass, grain yield and phosphorus transformation rate. Under 1 000 kg(P2O5)·hm-2 phosphorus fertilizer application (T4), no significant increase was noted in biomass and grain yield compared to intermediate phosphorus level. However, maize phosphorus uptake was much higher under treatment T. Phosphorus transformation rate of XY335 after flowering was lower than that of LD9002, suggesting higher phosphorus use efficiency by LD9002. Correlation analysis showed significant relationships among available phosphorus contents of rhizosphere and non-rhizosphere soils and phosphorus accumulation in stems and leaves of LD9002, especially at 79 d after planting. Also significant relationships were noted among available phosphorus content of rhizosphere and non-rhizosphere soils and those of stems and leaves of XY335, especially at 47 d after planting. This suggested that 79 d and 47 d after planting were key phosphorus demand periods after planting in LD9002 and XY335, respectively. Available phosphorus content of rhizosphere and non-rhizosphere soils reflected the capacity of the soils to release phosphorus. Suitable phosphorus concentration of rhizosphere and non-rhizosphere soils for the highest phosphorus uptake were respectively 54.95 mg·kg-1 and 32.99 mg·kg-1 at 79 d after planting LD9002. The corresponding values for XY335 were respectively 51.24 mg·kg-1 and 35.35 mg·kg-1 at 47 d after planting. When phosphorus application rate increased to 1 000 kg(P2O5)·hm -2, no significant difference existed in terms of yield, biomass and phosphorus uptake compared with those under phosphorus application rate of 100~200 kg(P2O5)·hm-2.
2013, 21(7): 810-816.
doi: 10.3724/SP.J.1011.2013.00810
Abstract:
Long-term waterlogging with large amounts of reducing toxic substances of cold waterlogged soils and nutrient unavailability has often resulted in deteriorated rice growth, reduced rice resistance to adversities, inhibited root growth/activity and reduced rice yield. To explore feasible means of suppressing the negative effects of cold waterlogged paddy soils, a location experiment consisting an open-ditch drainage was conducted to study the effects of different soil amendments (self-developed desulphurization ash, biomass charcoal; and marketed lime, silicon-calcium fertilizer and humic acid) on soil Eh and respiration intensity, microbial quantity and population structure, and rice yield and yield components. The results showed that different soil amendments enhanced soil available nutrients contents and pH, while they did not significantly affected Eh except desulphurization ash treatment. All soil amendments increased respiration intensity and soil microbes at different growth stages of rice, with a significant (P < 0.05) increase in actinomycete population over CK. The respiration intensity and actinomycete population under biomass charcoal treatment were increased by 67.6% and 127.6% respectively. All soil amendments increased rice leaf SPAD, tiller number, dry matter accumulation, panicle number, grain number per panicle, yield, and root bleeding rate. Desulfurization ash and biomass charcoal treatments presented most obvious effects. At 29 days after heading, the rate of root bleeding under desulfurization ash and biomass charcoal treatments increased by 45.4% and 39.1%, respectively. Also leaf SPAD at 29 days after heading was 27.4% and 22.5% higher under desulfurization ash and biomass charcoal treatments over that under CK respectively. Dry matter accumulation increased by 68.5% and 50.5%, panicle number by 12.1% and 10.7%, and yield by 12.8% and 10.3% at maturity stage under desulfurization ash and biomass charcoal treatments over those under CK, respectively. In conclusion, different soil amendments differently improved soil properties and rice quality. Desulphurization ash and biomass charcoal amendments had the best effects.
Long-term waterlogging with large amounts of reducing toxic substances of cold waterlogged soils and nutrient unavailability has often resulted in deteriorated rice growth, reduced rice resistance to adversities, inhibited root growth/activity and reduced rice yield. To explore feasible means of suppressing the negative effects of cold waterlogged paddy soils, a location experiment consisting an open-ditch drainage was conducted to study the effects of different soil amendments (self-developed desulphurization ash, biomass charcoal; and marketed lime, silicon-calcium fertilizer and humic acid) on soil Eh and respiration intensity, microbial quantity and population structure, and rice yield and yield components. The results showed that different soil amendments enhanced soil available nutrients contents and pH, while they did not significantly affected Eh except desulphurization ash treatment. All soil amendments increased respiration intensity and soil microbes at different growth stages of rice, with a significant (P < 0.05) increase in actinomycete population over CK. The respiration intensity and actinomycete population under biomass charcoal treatment were increased by 67.6% and 127.6% respectively. All soil amendments increased rice leaf SPAD, tiller number, dry matter accumulation, panicle number, grain number per panicle, yield, and root bleeding rate. Desulfurization ash and biomass charcoal treatments presented most obvious effects. At 29 days after heading, the rate of root bleeding under desulfurization ash and biomass charcoal treatments increased by 45.4% and 39.1%, respectively. Also leaf SPAD at 29 days after heading was 27.4% and 22.5% higher under desulfurization ash and biomass charcoal treatments over that under CK respectively. Dry matter accumulation increased by 68.5% and 50.5%, panicle number by 12.1% and 10.7%, and yield by 12.8% and 10.3% at maturity stage under desulfurization ash and biomass charcoal treatments over those under CK, respectively. In conclusion, different soil amendments differently improved soil properties and rice quality. Desulphurization ash and biomass charcoal amendments had the best effects.
2013, 21(7): 817-823.
doi: 10.3724/SP.J.1011.2013.00817
Abstract:
Despite the fact of a strong linkage has been noted between xylem water transport capacity and photosynthesis in several woody plant species, not much research has studied such linkage in herbaceous plants. Herbaceous plants could be more vulnerable to drought-induced embolism than woody plants due to their lower xylem structure. Hence in a pot experiment, this paper investigated the coordination between stem water transport capacity and photosynthesis in corn cultivars ("Shaandan 21" and "Zhengdan 958") and sorghum cultivars ("Jinzhong 405" and "Jinza 12") during progressive soil drying. The aim of the study was to demonstrate the differences in sensitivity of photosynthesis to drought-induced embolism in maize and sorghum cultivars and the related hydro-physiological mechanisms of drought resistance. The results indicated that: (1) Drought-resistant corn cultivar "Zhengdan 958" had higher leaf water potential, net photosynthetic rate (Pn), maximum photochemical quantarum efficiency (Fv/Fm), maximum actual quantarum efficiency (ΦPSⅡ) and lower stomatal conductance (Gs) and transpiration rate (Tr) than drought-sensitive corn cultivar "Shaandan 21". Also drought-resistant sorghum cultivar "Jinza 12" had higher Pn and ΦPSⅡ than drought-sensitive sorghum cultivar "Jinzhong 405". This suggested that "Zhengdan 958" corn cultivar and "Jinza 12" sorghum cultivar had relatively stronger drought-resistance. (2) Drought induced different degrees of decreases in leaf water potential, photosynthetic gas exchange (Pn, Gs and Tr) and in chlorophyll fluorescence parameters (Fv/Fm and ΦPSⅡ) in both corn and sorghum cultivars. Gas exchange decreased earlier than fluorescence parameters during progressive soil drying. This implied that stomata closed earlier to prevent drought-induced damage to PSⅡ activity. (3) Drought-resistant corn cultivar "Zhengdan 958" and sorghum cultivar "Jinza 12" had higher water transport capacities and stronger cavitation resistance than drought-sensitive "Shaandan 21" and "Jinzhong 405", respectively. Sorghum had a weaker cavitation resistance than corn, suggesting that sorghum cultivars reduced water loss through rapid embolism. (4) Pn and Gs in corn cultivars showed greater sensitivity to declining water transport capacity than those in sorghum cultivars. Also Gs in drought-resistant corn and sorghum cultivars showed greater sensitivity to declining water transport capacity than those in drought-sensitive cultivars. Sorghum maintained certain photosynthesis at low water potential compared with maize, reflecting its higher conservative water use strategy.
Despite the fact of a strong linkage has been noted between xylem water transport capacity and photosynthesis in several woody plant species, not much research has studied such linkage in herbaceous plants. Herbaceous plants could be more vulnerable to drought-induced embolism than woody plants due to their lower xylem structure. Hence in a pot experiment, this paper investigated the coordination between stem water transport capacity and photosynthesis in corn cultivars ("Shaandan 21" and "Zhengdan 958") and sorghum cultivars ("Jinzhong 405" and "Jinza 12") during progressive soil drying. The aim of the study was to demonstrate the differences in sensitivity of photosynthesis to drought-induced embolism in maize and sorghum cultivars and the related hydro-physiological mechanisms of drought resistance. The results indicated that: (1) Drought-resistant corn cultivar "Zhengdan 958" had higher leaf water potential, net photosynthetic rate (Pn), maximum photochemical quantarum efficiency (Fv/Fm), maximum actual quantarum efficiency (ΦPSⅡ) and lower stomatal conductance (Gs) and transpiration rate (Tr) than drought-sensitive corn cultivar "Shaandan 21". Also drought-resistant sorghum cultivar "Jinza 12" had higher Pn and ΦPSⅡ than drought-sensitive sorghum cultivar "Jinzhong 405". This suggested that "Zhengdan 958" corn cultivar and "Jinza 12" sorghum cultivar had relatively stronger drought-resistance. (2) Drought induced different degrees of decreases in leaf water potential, photosynthetic gas exchange (Pn, Gs and Tr) and in chlorophyll fluorescence parameters (Fv/Fm and ΦPSⅡ) in both corn and sorghum cultivars. Gas exchange decreased earlier than fluorescence parameters during progressive soil drying. This implied that stomata closed earlier to prevent drought-induced damage to PSⅡ activity. (3) Drought-resistant corn cultivar "Zhengdan 958" and sorghum cultivar "Jinza 12" had higher water transport capacities and stronger cavitation resistance than drought-sensitive "Shaandan 21" and "Jinzhong 405", respectively. Sorghum had a weaker cavitation resistance than corn, suggesting that sorghum cultivars reduced water loss through rapid embolism. (4) Pn and Gs in corn cultivars showed greater sensitivity to declining water transport capacity than those in sorghum cultivars. Also Gs in drought-resistant corn and sorghum cultivars showed greater sensitivity to declining water transport capacity than those in drought-sensitive cultivars. Sorghum maintained certain photosynthesis at low water potential compared with maize, reflecting its higher conservative water use strategy.
2013, 21(7): 824-830.
doi: 10.3724/SP.J.1011.2013.00824
Abstract:
Drip irrigation under mulch, as an important water-saving irrigation technique, has been a common potato production practice in Inner Mongolia. However, the advantage of drip irrigation under mulch has dropped due to over-irrigation or non-timing irrigation in the past few years. A field experiment was conducted in Wuchuan County of Inner Mongolia Autonomous Region to evaluate the optimal irrigation frequency of drip irrigation under mulch with the total irrigation of 120 mm. In the study, irrigation frequencies of "Kexin-I" potato cultivar were one time every 4 days, 8 days and 12 days, respectively. Plant average height, leaf SPAD and leaf area index were measured at different plant growth stages. Also tuber yield, starch content and water use efficiency were measured at harvest. Results showed that the depth of moist soil layer was 0~40 cm under the 8 days irrigation treatment. This corresponded with potato root concentration layer, which favored potato growth. Under this irrigation treatment, average plant height, plant dry accumulation, tuber starch content and water use efficiency were 40.8 cm, 8 683.0 kg·hm-2 , 13.9% and 11.2 kg·mm-1, respectively. The values were respectively higher by 3.1%, 8.9%, 37.2% and 26.3% compared with the 4 days irrigation treatment; and by 4.1%, 10.1%, 9.3% and 33.3% compared with 12 days irrigation treatment. The highest tuber yield (35 398.5 kg·hm-2) was under the 4 days irrigation treatment, which was 12.1% higher than that under 8 days irrigation treatment and then 15.4% higher than that under 12 days irrigation treatment. Potato irrigation frequency of drip irrigation under mulch in Wuchuan area was recommended one time every 8 days due to the higher tuber yield and water use efficiency.
Drip irrigation under mulch, as an important water-saving irrigation technique, has been a common potato production practice in Inner Mongolia. However, the advantage of drip irrigation under mulch has dropped due to over-irrigation or non-timing irrigation in the past few years. A field experiment was conducted in Wuchuan County of Inner Mongolia Autonomous Region to evaluate the optimal irrigation frequency of drip irrigation under mulch with the total irrigation of 120 mm. In the study, irrigation frequencies of "Kexin-I" potato cultivar were one time every 4 days, 8 days and 12 days, respectively. Plant average height, leaf SPAD and leaf area index were measured at different plant growth stages. Also tuber yield, starch content and water use efficiency were measured at harvest. Results showed that the depth of moist soil layer was 0~40 cm under the 8 days irrigation treatment. This corresponded with potato root concentration layer, which favored potato growth. Under this irrigation treatment, average plant height, plant dry accumulation, tuber starch content and water use efficiency were 40.8 cm, 8 683.0 kg·hm-2 , 13.9% and 11.2 kg·mm-1, respectively. The values were respectively higher by 3.1%, 8.9%, 37.2% and 26.3% compared with the 4 days irrigation treatment; and by 4.1%, 10.1%, 9.3% and 33.3% compared with 12 days irrigation treatment. The highest tuber yield (35 398.5 kg·hm-2) was under the 4 days irrigation treatment, which was 12.1% higher than that under 8 days irrigation treatment and then 15.4% higher than that under 12 days irrigation treatment. Potato irrigation frequency of drip irrigation under mulch in Wuchuan area was recommended one time every 8 days due to the higher tuber yield and water use efficiency.
LEI Feng-Jin,
WEN Xiang-Zhen,
LI Ya-Ling,
WANG Xiao-Min,
LI Ling-Zhi,
LIU Xiu-Li,
LIU Qing-Hua,
HAN Li-Li
2013, 21(7): 831-837.
doi: 10.3724/SP.J.1011.2013.00831
Abstract:
Dwarf and semi-dwarf varieties of summer squashes are two domestic types in China and semi-dwarf varieties are mainly cultivated under greenhouse conditions. To study the effect of density on canopy and source-sink relationship in summer squash, key high-yield factors of summer squash were tested in large plastic houses by using two semi-dwarf varieties ("Donghu No.4" and "Dongyu") and two dwarf varieties ("Changqingwang No.3" and "Zaoqing"). The results showed that as planting densities increased from low to high, the changes in canopy indicators of semi-dwarf varieties were far greater than those in dwarf varieties. The trends of change in LAI (leaf area index), source capacity and sink capacity tracked quadratic-type curves. Transmittance had an inverse trend of change with LAI. The trend of change in source-sink ratio was linear and the highest yield was at optimum source-sink ratio. Lower LAI and higher light transmittance, and lower source supply, sink capacity and source-sink ratio were noted under lower density. Lower summer squash yield was associated with lower sink capacity under lower density. Light transmittance for all tested varieties was lower under medium density treatment with mean values of 12.4% for semi-dwarf and 13.2% for dwarf varieties. However, LAI was higher under medium density treatment with maximum LAI of 4.4 for semi-dwarf and 3.3 for dwarf varieties. The higher yield under medium density was associated with higher capacities of source and sink and source-sink ratio. The maximum source supply was 1 169.8 g·m-2 for semi-dwarf varieties and 736.9 g·m-2 for dwarf varieties. Also the maximum sink capacity was 422.4 g·m-2 for semi-dwarf and 333.0 g·m-2 for dwarf vine. Then the almost optimal source-sink ratio was 2.62 for semi-dwarf and 1.96 for dwarf varieties. Summer squash LAI under high density treatment increased rapidly at early growth stage with lower light transmittance especially at maximum LAI. However, LAI decreased rapidly due to rapid senescence of lower position leaves at late stage, resulting in larger light transmittance. Under high density, source supply was the dominant limiting factor of yield. Semi-dwarf varieties yield was higher than dwarf yield varieties because of higher and more stable source supply. The largest source supply capacity of semi-dwarf variety was 1.6 times that of dwarf variety. It was concluded that semi-dwarf variety of summer squash was a better choice for protected fields.
Dwarf and semi-dwarf varieties of summer squashes are two domestic types in China and semi-dwarf varieties are mainly cultivated under greenhouse conditions. To study the effect of density on canopy and source-sink relationship in summer squash, key high-yield factors of summer squash were tested in large plastic houses by using two semi-dwarf varieties ("Donghu No.4" and "Dongyu") and two dwarf varieties ("Changqingwang No.3" and "Zaoqing"). The results showed that as planting densities increased from low to high, the changes in canopy indicators of semi-dwarf varieties were far greater than those in dwarf varieties. The trends of change in LAI (leaf area index), source capacity and sink capacity tracked quadratic-type curves. Transmittance had an inverse trend of change with LAI. The trend of change in source-sink ratio was linear and the highest yield was at optimum source-sink ratio. Lower LAI and higher light transmittance, and lower source supply, sink capacity and source-sink ratio were noted under lower density. Lower summer squash yield was associated with lower sink capacity under lower density. Light transmittance for all tested varieties was lower under medium density treatment with mean values of 12.4% for semi-dwarf and 13.2% for dwarf varieties. However, LAI was higher under medium density treatment with maximum LAI of 4.4 for semi-dwarf and 3.3 for dwarf varieties. The higher yield under medium density was associated with higher capacities of source and sink and source-sink ratio. The maximum source supply was 1 169.8 g·m-2 for semi-dwarf varieties and 736.9 g·m-2 for dwarf varieties. Also the maximum sink capacity was 422.4 g·m-2 for semi-dwarf and 333.0 g·m-2 for dwarf vine. Then the almost optimal source-sink ratio was 2.62 for semi-dwarf and 1.96 for dwarf varieties. Summer squash LAI under high density treatment increased rapidly at early growth stage with lower light transmittance especially at maximum LAI. However, LAI decreased rapidly due to rapid senescence of lower position leaves at late stage, resulting in larger light transmittance. Under high density, source supply was the dominant limiting factor of yield. Semi-dwarf varieties yield was higher than dwarf yield varieties because of higher and more stable source supply. The largest source supply capacity of semi-dwarf variety was 1.6 times that of dwarf variety. It was concluded that semi-dwarf variety of summer squash was a better choice for protected fields.
2013, 21(7): 838-843.
doi: 10.3724/SP.J.1011.2013.00838
Abstract:
Rice-crab culture system is a new ecological complex that combines rice culture with that of Eriocheir sinensis. Zoobenthos communities play a critical role in this complex ecological system. To our knowledge, however, there little research has been conducted on zoobenthos diversity in rice-crab culture systems. Much research has been directed towards the rational selection of rice variety, cultivation and management measures of rice-crab culture systems. To determine the effects of rice-crab culture systems on zoobenthos diversity in paddy fields, periodic sampling was conducted in rice-crab culture systems with different crab densities (10 ind·m-2, LD; 30 ind·m-2, HD) and in conventional paddy field (CK) at four key growth stages (tillering stage, elongation stage, flowering stage and maturity stage). The samples (a total of four per time) were analyzed for species composition, average density and diversity. At tillering stage, the results revealed no significant difference in species number, average density, diversity index and Pielou evenness index of zoobenthos faunal groups in the three treatments (P > 0.05). At elongation and flowering stages, zoobenthos species number and average density were inversely related with crab density. Species number and average density of zoobenthos under LD and HD treatments was lower than those under conventional treatment. Shannon-Wiener diversity index of conventional treatment was significantly higher than that of HD treatment in both periods (P< 0.05). However, the Shannon-Wiener diversity index and Pielou evenness index of conventional treatment were only significantly higher than those of LD treatment at elongation stage (P < 0.05). At maturity stage, species number and average density of zoobenthos under three treatments were at the lowest levels. The Shannon-Wiener diversity index revealed no significant difference among the three treatments (P> 0.05) and the Pielou evenness index of HD treatment was significantly higher than that of the conventional treatment (P < 0.05). The study provided additional theoretical guidance about zoobenthos diversity protection and sustainable development of rice-crab culture systems. It provided another means of promoting the development of rice-crab culture technology.
Rice-crab culture system is a new ecological complex that combines rice culture with that of Eriocheir sinensis. Zoobenthos communities play a critical role in this complex ecological system. To our knowledge, however, there little research has been conducted on zoobenthos diversity in rice-crab culture systems. Much research has been directed towards the rational selection of rice variety, cultivation and management measures of rice-crab culture systems. To determine the effects of rice-crab culture systems on zoobenthos diversity in paddy fields, periodic sampling was conducted in rice-crab culture systems with different crab densities (10 ind·m-2, LD; 30 ind·m-2, HD) and in conventional paddy field (CK) at four key growth stages (tillering stage, elongation stage, flowering stage and maturity stage). The samples (a total of four per time) were analyzed for species composition, average density and diversity. At tillering stage, the results revealed no significant difference in species number, average density, diversity index and Pielou evenness index of zoobenthos faunal groups in the three treatments (P > 0.05). At elongation and flowering stages, zoobenthos species number and average density were inversely related with crab density. Species number and average density of zoobenthos under LD and HD treatments was lower than those under conventional treatment. Shannon-Wiener diversity index of conventional treatment was significantly higher than that of HD treatment in both periods (P< 0.05). However, the Shannon-Wiener diversity index and Pielou evenness index of conventional treatment were only significantly higher than those of LD treatment at elongation stage (P < 0.05). At maturity stage, species number and average density of zoobenthos under three treatments were at the lowest levels. The Shannon-Wiener diversity index revealed no significant difference among the three treatments (P> 0.05) and the Pielou evenness index of HD treatment was significantly higher than that of the conventional treatment (P < 0.05). The study provided additional theoretical guidance about zoobenthos diversity protection and sustainable development of rice-crab culture systems. It provided another means of promoting the development of rice-crab culture technology.
ZHOU Hai-Yan,
SU Fei,
SUN Jun-Wei,
XUAN Shu-Zhang,
ZHOU Chun-Ming,
SUN Hong-Lian,
EI Yue-Hui,
WU Jiang,
SHI Hong-Zhi
2013, 21(7): 844-852.
doi: 10.3724/SP.J.1011.2013.00844
Abstract:
To explore the effects of ecological environment on the quality of burley tobacco during air-curing process, burley leaves cultivated in Binchuan and Yunlong Counties of Yunnan Province were put into both counties for air-curing, respectively. Temperature and relative humidity of barns were investigated during the curing process. HPLC and GC/MS were used to analyze plastid pigment and neutral aroma components of burley tobacco leaves. Results showed no apparent differences in temperature between the two areas. However, the differences in relative humidity between the two areas were very significant. Relative humidity in Yunlong County was higher by 4.42%~16.54% than in Binchuan County throughout the air-curing process. Air-curing duration of tobacco leaves in Binchuan County was 9 days shorter that in Yunlong County. The differences in leaves cured in the two ecological environments were evident in terms of physical appearance and internal quality. β-carotenoid of leaves cured in Binchuan County produced in Yunlong County was 6.44% higher than that produced in Binchuan County, while β-carotenoid contents in leaves cured in Yunlong County produced in Binchuan County was 14.45% higher than that produced in Yunlong County. Neutral aroma components of leaves cured in Yunlong County was higher than that of leaves cured in Binchuan County. Leaves produced in the two counties and cured in Yunlong County respectively had 47.31% and 20.37% higher aroma components over those cured in Binchuan County. For leaves produced in the same area but cured in Binchuan County had significantly more contents of nicotine and total sugar than those cured in Yunlong County. However, the contents of total nitrogen of leaves cured in Yunlong County were significantly higher than those cured in Binchuan County. Strong correlations were noted between eco-environment and the contents of plastid pigment, neutral aroma components and the main chemical compositions of burley tobacco. It was therefore significant to make reasonable scientific measures based on local situations during curing process in order to increase the content of aroma and improve the quality of leaves in agricultural and manufactured burley tobacco.
To explore the effects of ecological environment on the quality of burley tobacco during air-curing process, burley leaves cultivated in Binchuan and Yunlong Counties of Yunnan Province were put into both counties for air-curing, respectively. Temperature and relative humidity of barns were investigated during the curing process. HPLC and GC/MS were used to analyze plastid pigment and neutral aroma components of burley tobacco leaves. Results showed no apparent differences in temperature between the two areas. However, the differences in relative humidity between the two areas were very significant. Relative humidity in Yunlong County was higher by 4.42%~16.54% than in Binchuan County throughout the air-curing process. Air-curing duration of tobacco leaves in Binchuan County was 9 days shorter that in Yunlong County. The differences in leaves cured in the two ecological environments were evident in terms of physical appearance and internal quality. β-carotenoid of leaves cured in Binchuan County produced in Yunlong County was 6.44% higher than that produced in Binchuan County, while β-carotenoid contents in leaves cured in Yunlong County produced in Binchuan County was 14.45% higher than that produced in Yunlong County. Neutral aroma components of leaves cured in Yunlong County was higher than that of leaves cured in Binchuan County. Leaves produced in the two counties and cured in Yunlong County respectively had 47.31% and 20.37% higher aroma components over those cured in Binchuan County. For leaves produced in the same area but cured in Binchuan County had significantly more contents of nicotine and total sugar than those cured in Yunlong County. However, the contents of total nitrogen of leaves cured in Yunlong County were significantly higher than those cured in Binchuan County. Strong correlations were noted between eco-environment and the contents of plastid pigment, neutral aroma components and the main chemical compositions of burley tobacco. It was therefore significant to make reasonable scientific measures based on local situations during curing process in order to increase the content of aroma and improve the quality of leaves in agricultural and manufactured burley tobacco.
2013, 21(7): 853-859.
doi: 10.3724/SP.J.1011.2013.00853
Abstract:
Photosynthesis is the most important factor influencing the growth and development of fruit trees. Using field data to model the three-dimensional (3-D) distribution of photosynthesis in hedgerow tree crops in hourly time steps is critical for the accurately estimation of orchard yield and quality. Here in this study, a coupled model was used to simulate the 3-D distribution and diurnal variations of net photosynthetic rate of four canopy structures of apple trees. The four apple tree canopy structures were small and sparse canopy (APS-Ⅰ), dispersed stratified canopy (APS-Ⅱ), spindle canopy (APS-Ⅲ), and open-center canopy (APS-Ⅳ). The experiment was conducted in four "Fuji" apple (Malus domestica Borkh. cv. "Fuji") orchards during the 2010-2012 growth seasons. While the coupled model was based the 3-D distributions of canopy radiation and leaf area from direct field measurements, the leaf photosynthesis model was based on mechanistic knowledge of C3 plants. Experiential equations best described foliage photosynthetic capacity for different canopy positions. The results showed that 3-D distribution of leaf net photosynthetic rate (Pn) was similar to that of relative radiation. A flat curve was observed for canopy top of the 3-D Pn distribution, decreasing rapidly with decreasing photosynthetically active radiation (PAR). However, the 3-D distribution of total photosynthetic rate of a unit cell depended mainly on leaf area density pattern. Average Pn of the four apple tree canopy structures determined by the coupled model were 6.72 μmol·m-2·s-1 for APS-Ⅰ, 7.52 μmol·m-2·s-1 for APS-Ⅱ, 7.24 μmol·m-2·s-1 for APS-Ⅲ and 9.88 μmol·m-2·s-1 for APS-Ⅳ, and with canopy top PAR of 1 500 μmol·m -2·s-1. The diurnal variation in Pn was largely driven by PAR, depicted in di-peak curves. Differences in canopy Pn were related to the differences in leaf area index (LAI) of the tree canopy. Under clear day conditions, total photosynthesis per unit ground area was 665.5 mmol·m-2·d-1 for APS-I, 791.7 mmol·m-2·d-1 for APS-Ⅱ, 752.6 mmol·m-2·d-1 for APS-Ⅲ and 601.1 mmol·m-2·d-1 for APS-Ⅳ. There was strong agreement between the measured and simulated Pn for the different tree canopy structures. This showed that the coupled model reliably predicted Pn for the different tree canopy structures. The results also showed that the open-center apple tree canopy enhanced fruit quality with bigger Pn while the other canopies enhanced yield with high canopy photosynthetic rate. The main aim of tree pruning was to remove useless shoots and leaves, which parts were easily identified by 3-D plots. Overall, the coupled model performed well in predicting instantaneous photosynthetic rates for different apple tree canopy structures in 3-D space.
Photosynthesis is the most important factor influencing the growth and development of fruit trees. Using field data to model the three-dimensional (3-D) distribution of photosynthesis in hedgerow tree crops in hourly time steps is critical for the accurately estimation of orchard yield and quality. Here in this study, a coupled model was used to simulate the 3-D distribution and diurnal variations of net photosynthetic rate of four canopy structures of apple trees. The four apple tree canopy structures were small and sparse canopy (APS-Ⅰ), dispersed stratified canopy (APS-Ⅱ), spindle canopy (APS-Ⅲ), and open-center canopy (APS-Ⅳ). The experiment was conducted in four "Fuji" apple (Malus domestica Borkh. cv. "Fuji") orchards during the 2010-2012 growth seasons. While the coupled model was based the 3-D distributions of canopy radiation and leaf area from direct field measurements, the leaf photosynthesis model was based on mechanistic knowledge of C3 plants. Experiential equations best described foliage photosynthetic capacity for different canopy positions. The results showed that 3-D distribution of leaf net photosynthetic rate (Pn) was similar to that of relative radiation. A flat curve was observed for canopy top of the 3-D Pn distribution, decreasing rapidly with decreasing photosynthetically active radiation (PAR). However, the 3-D distribution of total photosynthetic rate of a unit cell depended mainly on leaf area density pattern. Average Pn of the four apple tree canopy structures determined by the coupled model were 6.72 μmol·m-2·s-1 for APS-Ⅰ, 7.52 μmol·m-2·s-1 for APS-Ⅱ, 7.24 μmol·m-2·s-1 for APS-Ⅲ and 9.88 μmol·m-2·s-1 for APS-Ⅳ, and with canopy top PAR of 1 500 μmol·m -2·s-1. The diurnal variation in Pn was largely driven by PAR, depicted in di-peak curves. Differences in canopy Pn were related to the differences in leaf area index (LAI) of the tree canopy. Under clear day conditions, total photosynthesis per unit ground area was 665.5 mmol·m-2·d-1 for APS-I, 791.7 mmol·m-2·d-1 for APS-Ⅱ, 752.6 mmol·m-2·d-1 for APS-Ⅲ and 601.1 mmol·m-2·d-1 for APS-Ⅳ. There was strong agreement between the measured and simulated Pn for the different tree canopy structures. This showed that the coupled model reliably predicted Pn for the different tree canopy structures. The results also showed that the open-center apple tree canopy enhanced fruit quality with bigger Pn while the other canopies enhanced yield with high canopy photosynthetic rate. The main aim of tree pruning was to remove useless shoots and leaves, which parts were easily identified by 3-D plots. Overall, the coupled model performed well in predicting instantaneous photosynthetic rates for different apple tree canopy structures in 3-D space.
LI Sheng-Yu,
XU Xin-Wen,
LEI Jia-Qiang,
ZHOU Hong-Wei,
LI Ying-Gang,
JIN Zheng-Zhong,
CHANG Qing,
WANG Lu-Hai,
ZHANG Jian-Lin,
LIU Yao-Zhong
2013, 21(7): 860-866.
doi: 10.3724/SP.J.1011.2013.00860
Abstract:
Wind erosion, especially via blown sands, is hazardous to fragile ecosystems in desert regions. It is critical for ecological constructions in desert regions to determine the resistance thresholds of different plant species to wind erosion. In this study, the Tazhong Si Oilfield shelter forest of Calligonum caput-medusae Schrenk in the hinterland of Taklimakan Desert was investigated. The C. caput-medusae plants with different wind erosion depths (range of 1~82 cm) were set as treatments and other plants not affected by wind erosion as the control. The study was conducted in 2007 on a secondary dune that was in the leeward slope of a complex sand-ridge. In the study, the number and length of photosynthetic organs per joint and whole plant were recorded. Photosynthetic organ samples of whole plants that settled in the 40 cm erosion depth were collected along with the control. Conclusion drawn from the analyses were as follows: The number and total length of assimilative branches per joint, average length and weight of single assimilative branch, and fresh weight and surface area of photosynthetic organ per whole plant decreased with increasing wind erosion depth. Photosynthetic organ growth was negatively correlated with wind erosion depth. When wind erosion depth was less than 40 cm, photosynthetic organ growth decreased slightly. However, when wind erosion depth was more than 40 cm, photosynthetic organ growth declined significantly. Then when wind erosion depth exceeded 80 cm, plants withered and finally died. The number, length, diameter of assimilative branches and the surface area of photosynthetic organs reduced in order to adapt to the conditions of wind erosion. The numerical and morphological readjustments constituted an important form of adaption of photosynthetic organs of C. caput-medusae to wind erosion. The number of joints with photosynthetic organs and length and diameter of assimilative branches on plants reduced due to wind erosion to reduce transpirative water consumption. Despite the fewer photosynthetic organs per joint, some amount of photosynthetic organs grew at plant joints to sustain the plants alive. The adaptive strategy was that limited resources were configured at key locations on the plant to enhance plant survival. This research result was significant for theoretical guidance in ecological construction in desert regions.
Wind erosion, especially via blown sands, is hazardous to fragile ecosystems in desert regions. It is critical for ecological constructions in desert regions to determine the resistance thresholds of different plant species to wind erosion. In this study, the Tazhong Si Oilfield shelter forest of Calligonum caput-medusae Schrenk in the hinterland of Taklimakan Desert was investigated. The C. caput-medusae plants with different wind erosion depths (range of 1~82 cm) were set as treatments and other plants not affected by wind erosion as the control. The study was conducted in 2007 on a secondary dune that was in the leeward slope of a complex sand-ridge. In the study, the number and length of photosynthetic organs per joint and whole plant were recorded. Photosynthetic organ samples of whole plants that settled in the 40 cm erosion depth were collected along with the control. Conclusion drawn from the analyses were as follows: The number and total length of assimilative branches per joint, average length and weight of single assimilative branch, and fresh weight and surface area of photosynthetic organ per whole plant decreased with increasing wind erosion depth. Photosynthetic organ growth was negatively correlated with wind erosion depth. When wind erosion depth was less than 40 cm, photosynthetic organ growth decreased slightly. However, when wind erosion depth was more than 40 cm, photosynthetic organ growth declined significantly. Then when wind erosion depth exceeded 80 cm, plants withered and finally died. The number, length, diameter of assimilative branches and the surface area of photosynthetic organs reduced in order to adapt to the conditions of wind erosion. The numerical and morphological readjustments constituted an important form of adaption of photosynthetic organs of C. caput-medusae to wind erosion. The number of joints with photosynthetic organs and length and diameter of assimilative branches on plants reduced due to wind erosion to reduce transpirative water consumption. Despite the fewer photosynthetic organs per joint, some amount of photosynthetic organs grew at plant joints to sustain the plants alive. The adaptive strategy was that limited resources were configured at key locations on the plant to enhance plant survival. This research result was significant for theoretical guidance in ecological construction in desert regions.
2013, 21(7): 867-871.
doi: 10.3724/SP.J.1011.2013.00867
Abstract:
Oaks germinate asynchronously under natural conditions and the difference between first and last germinating acorns can be up to a few weeks. In addition, acorns of the subgenus Erythrobalanus usually exhibit delayed germination. The epicotyls germinate 20 days later than the roots. Thick tap roots of Quercus aliena seed grow down several centimeters into the soil instead of a green shoot in the fall. These characters of acorns negatively affect the quality of seedlings. In the past several decades, some feasible practices and associated mechanisms have been published for some oak species in Europe, North America and Asia. And the researches advanced that removing pericarp or cutting parts of cotyledons increased germination percentage and accelerated germination. Although, the previous studies dealt with acorn germination and seedling emergence, the root and seedling development were little understood, especially root development. To solve the problems of delayed and irregular germination of Q. fabri seeds, acorns were mechanically treated in five ways: CK (without any mechanical treatment), cup scar removal (RS), pericarp removal (RP), pericarp removal and half cotyledon cutting (RHC), pericarp removal and 2/3 cotyledon cutting (RPC). Treated acorns were placed onto petri dishes (11.5 cm diameter) with filter paper moistened by distilled water under 25 ℃ and 8 hours light. As acorns germinated (when the length of radicle was longer than acorn length), root and shoot emergence were investigated every seven days. The length of all roots and shoots were measured at the end of the experiment (137 days). Germination percentage, vigor index, mean germination time and synchronization index of roots and shoots were calculated to probe delay and irregular germination of Q. fabri seeds. The results showed that: (1) The mean root germination time of RP and RHC were respectively 39 d and 36 d shorter, while the mean shoot mean germination time of the two treatments were 52 d and 51 d shorter than that of CK, respectively. The root synchronization indices of RP and RHC were respectively 0.3 and 0.2 higher, and the shoot synchronization indices of the two treatments were all 0.4 greater than that of CK. RP and RHC significantly increased rooting percentage (both 57.8% higher) and sprouting percentage (both 33.3% higher). RP improved root length (3.0 cm longer). (2) Compared with CK, RP and RPC treatments significantly decreased mean root and shoot germination time of Q. fabri seeds by 36 d and 50 d, respectively. Both treatments significantly increased root and shoot synchronization indices by 0.2 and 0.4, and rooting percentage by 26.7% over CK. However, the srpouting percentage, root length and shoot height had no significant difference from those of CK. (3) RS significantly reduced the mean root and shoot germination time by 16 d and 21 d, respectively, compared with CK. No significant differences were detected in root and shoot synchronization indices, rooting and sprouting percentage, root length and shoot height between RS and CK treatments. Therefore, RP and RHC treatments effectively accelerated germination and regulated seedling growth, which had an important actual significance in Q. fabri seedling growing.
Oaks germinate asynchronously under natural conditions and the difference between first and last germinating acorns can be up to a few weeks. In addition, acorns of the subgenus Erythrobalanus usually exhibit delayed germination. The epicotyls germinate 20 days later than the roots. Thick tap roots of Quercus aliena seed grow down several centimeters into the soil instead of a green shoot in the fall. These characters of acorns negatively affect the quality of seedlings. In the past several decades, some feasible practices and associated mechanisms have been published for some oak species in Europe, North America and Asia. And the researches advanced that removing pericarp or cutting parts of cotyledons increased germination percentage and accelerated germination. Although, the previous studies dealt with acorn germination and seedling emergence, the root and seedling development were little understood, especially root development. To solve the problems of delayed and irregular germination of Q. fabri seeds, acorns were mechanically treated in five ways: CK (without any mechanical treatment), cup scar removal (RS), pericarp removal (RP), pericarp removal and half cotyledon cutting (RHC), pericarp removal and 2/3 cotyledon cutting (RPC). Treated acorns were placed onto petri dishes (11.5 cm diameter) with filter paper moistened by distilled water under 25 ℃ and 8 hours light. As acorns germinated (when the length of radicle was longer than acorn length), root and shoot emergence were investigated every seven days. The length of all roots and shoots were measured at the end of the experiment (137 days). Germination percentage, vigor index, mean germination time and synchronization index of roots and shoots were calculated to probe delay and irregular germination of Q. fabri seeds. The results showed that: (1) The mean root germination time of RP and RHC were respectively 39 d and 36 d shorter, while the mean shoot mean germination time of the two treatments were 52 d and 51 d shorter than that of CK, respectively. The root synchronization indices of RP and RHC were respectively 0.3 and 0.2 higher, and the shoot synchronization indices of the two treatments were all 0.4 greater than that of CK. RP and RHC significantly increased rooting percentage (both 57.8% higher) and sprouting percentage (both 33.3% higher). RP improved root length (3.0 cm longer). (2) Compared with CK, RP and RPC treatments significantly decreased mean root and shoot germination time of Q. fabri seeds by 36 d and 50 d, respectively. Both treatments significantly increased root and shoot synchronization indices by 0.2 and 0.4, and rooting percentage by 26.7% over CK. However, the srpouting percentage, root length and shoot height had no significant difference from those of CK. (3) RS significantly reduced the mean root and shoot germination time by 16 d and 21 d, respectively, compared with CK. No significant differences were detected in root and shoot synchronization indices, rooting and sprouting percentage, root length and shoot height between RS and CK treatments. Therefore, RP and RHC treatments effectively accelerated germination and regulated seedling growth, which had an important actual significance in Q. fabri seedling growing.
2013, 21(7): 872-876.
doi: 10.3724/SP.J.1011.2013.00872
Abstract:
Cadmium (Cd) is one of the most toxic heavy metals with a strong inhibitory effect on plant growth. Although the effects of auxin on Cd tolerance and accumulation has been reported, the role of brassinosteroid (BR) on Cd stress response has remained unclear. In this study, the physiological effects of BR on Cd stress in Solanum nigrum seedlings were investigated. Cd toxicity induced oxidative damage and decreased the activities of SOD, CAT, and APX in S. nigrum seedlings. Treatment with epibrassinolide (eBL, a synthetic BR) increased Cd sensitivity in S. nigrum seedlings. On the contrary, supplementation with brassinazole (Brz, a specific inhibitor of BR biosynthesis) increased anti-oxidative enzyme activities and reduced reactive oxygen species (ROS) accumulation and oxidative damage. This improved Cd tolerance in S. nigrum seedlings exposed to Cd stress. After treatment with Brz, plant height and root length increased by 29% and 28%, respectively. Also MDA level and Evans blue staining decreased by 37% and 20%, respectively compared with Cd treatment alone. This suggested that BR increased Cd-induced oxidative damage and growth inhibition in S. nigrum seedlings. The results suggest that enhanced Cd sensitivity by BR was correlated with decreasing activities of anti-oxidative capacity in S. nigrum seedling. These results suggested that manipulation of BR level was an effective approach to improve Cd tolerance in plants. It modulated anti-oxidative enzyme activity and ROS accumulation, and provided detailed insights into novel phytoremediation strategies.
Cadmium (Cd) is one of the most toxic heavy metals with a strong inhibitory effect on plant growth. Although the effects of auxin on Cd tolerance and accumulation has been reported, the role of brassinosteroid (BR) on Cd stress response has remained unclear. In this study, the physiological effects of BR on Cd stress in Solanum nigrum seedlings were investigated. Cd toxicity induced oxidative damage and decreased the activities of SOD, CAT, and APX in S. nigrum seedlings. Treatment with epibrassinolide (eBL, a synthetic BR) increased Cd sensitivity in S. nigrum seedlings. On the contrary, supplementation with brassinazole (Brz, a specific inhibitor of BR biosynthesis) increased anti-oxidative enzyme activities and reduced reactive oxygen species (ROS) accumulation and oxidative damage. This improved Cd tolerance in S. nigrum seedlings exposed to Cd stress. After treatment with Brz, plant height and root length increased by 29% and 28%, respectively. Also MDA level and Evans blue staining decreased by 37% and 20%, respectively compared with Cd treatment alone. This suggested that BR increased Cd-induced oxidative damage and growth inhibition in S. nigrum seedlings. The results suggest that enhanced Cd sensitivity by BR was correlated with decreasing activities of anti-oxidative capacity in S. nigrum seedling. These results suggested that manipulation of BR level was an effective approach to improve Cd tolerance in plants. It modulated anti-oxidative enzyme activity and ROS accumulation, and provided detailed insights into novel phytoremediation strategies.
2013, 21(7): 877-882.
doi: 10.3724/SP.J.1011.2013.00877
Abstract:
Procecidochares utilis Stone is an obligatory parasitic natural enemy widely used to control the highly invasive Eupatorium adenophorum Spreng plant. However, parasitic rate of P. utilis in E. adenophorum has significantly decreased in mining areas polluted with heavy metals. To study bioconcentration effects of Cd, Pb and Zn in soil-E. adenophorum-P. utilis system, soil, E. adenophorum and P. utilis samples were collected at the Lanping Lead-Zinc Mine in Yunnan Province using the concentric circles method. The samples were then analyzed for Cd, Pb and Zn contents. The results showed that Cd, Pb and Zn contents in soil-E. adenophorum-P. utilis system significantly declined from the center outwards. The ranges of bioconcentration factors of Cd, Pb and Zn in the soil-E. adenophorum system were 0.205~0.614, 0.058~0.079 and 0.222~0.398 with corresponding averages of 0.453, 0.067 and 0.315, respectively. The bioconcentration factors of Cd, Pb and Zn in the E. adenophorum-P. utilis were 1.06~7.69, 9.68~20.13 and 1.13~1.56 with corresponding averages of 2.47, 12.83 and 1.42, respectively. Pb was more easily absorbed than Cd and Zn. The results confirmed that Cd, Pb and Zn could be transferred and bioaccumulated in soil-E. adenophorum-P. utilis system. This mainly expanded the mode and trend of heavy metal transfer from soil to E. adenophorum to P. utili. This finding was also helpful in enriching the eco-toxicological effects of heavy metal pollution. It further strengthened the basis for future studies of the mechanism of heavy metal stress control effects on P. utilis.
Procecidochares utilis Stone is an obligatory parasitic natural enemy widely used to control the highly invasive Eupatorium adenophorum Spreng plant. However, parasitic rate of P. utilis in E. adenophorum has significantly decreased in mining areas polluted with heavy metals. To study bioconcentration effects of Cd, Pb and Zn in soil-E. adenophorum-P. utilis system, soil, E. adenophorum and P. utilis samples were collected at the Lanping Lead-Zinc Mine in Yunnan Province using the concentric circles method. The samples were then analyzed for Cd, Pb and Zn contents. The results showed that Cd, Pb and Zn contents in soil-E. adenophorum-P. utilis system significantly declined from the center outwards. The ranges of bioconcentration factors of Cd, Pb and Zn in the soil-E. adenophorum system were 0.205~0.614, 0.058~0.079 and 0.222~0.398 with corresponding averages of 0.453, 0.067 and 0.315, respectively. The bioconcentration factors of Cd, Pb and Zn in the E. adenophorum-P. utilis were 1.06~7.69, 9.68~20.13 and 1.13~1.56 with corresponding averages of 2.47, 12.83 and 1.42, respectively. Pb was more easily absorbed than Cd and Zn. The results confirmed that Cd, Pb and Zn could be transferred and bioaccumulated in soil-E. adenophorum-P. utilis system. This mainly expanded the mode and trend of heavy metal transfer from soil to E. adenophorum to P. utili. This finding was also helpful in enriching the eco-toxicological effects of heavy metal pollution. It further strengthened the basis for future studies of the mechanism of heavy metal stress control effects on P. utilis.
2013, 21(7): 883-890.
doi: 10.3724/SP.J.1011.2013.00883
Abstract:
Pedosphere constitutes an important part of the earth surface and is the base for most lives. Sustaining better quality soil is a prerequisite for healthy ecosystem. In recent decades, however, soil conditions have been heavily affected by rapid agricultural and industry activities. Heavy metal soil contamination and pollution from enhanced human activity have become a major threat to the health of regional ecosystems. As a result, research on heavy metal contamination of soils (e.g., discriminating the sources and evaluating environmental risks of heavy metals) has become a hot-field in geography, pedo-science and environmental science. Located in central Xinjiang Uygur Autonomous Region with relatively plenty rainfall, Tianshan Mountains is an important water source and ecological barrier in China. Variations in ecological and environmental conditions in the mountains have exerted an obvious pressure on the oases in the lower reaches. In August 2011, a field investigation was carried out in order to gain a comprehensive insight into soil heavy metal contamination conditions of Tianshan Mountains. A total of 153 soil samples were collected from three sections - the eastern (Balikun-Yiwu), middle (Xinyuan-Bayinbuluke) and western (Zhaosu-Tekesi)-in that northern slop of Tianshan Mountains. The samples were sent to the laboratory in the Institute of Ecology and Geography, Chinese Academy of Sciences for analysis for heavy metals. Five heavy metals (Cr, Cu, Ni, Pb and Zn) were analyzed using standard methods. Using single factor pollution index and comprehensive pollution index, quantitative comparison was done for soil heavy metal pollution in different sections with the soil background value in Xinjiang and the secondary standard of soil environmental quality (GB15618-1995). Moreover, the distribution features and pollution sources of soil heavy metals in the different sections were analyzed and illustrated using principal component analysis. The results showed that soil heavy metal content and the related single factor pollution index and comprehensive pollution index for the eastern section of the northern slope of Tianshan Mountains (Balikun-Yiwu) were higher than those in the middle (Xinyuan-Bayinbuluke) and western sections (Zhaosu-Tekesi). The soil heavy metal pollution level in the middle section was higher than that in the western section. Heavy metal pollution in the eastern section of the northern slope (Balikun-Yiwu) was caused mainly by human factors such as traffic, industry, agriculture, tourism. Although human factors (traffic and industry) had some effects, soil heavy metal pollution in the middle section (Xinyuan-Bayinbuluke) was mainly from soil parent materials. In the western section (Zhaosu-Tekesi), soil parent materials were main resources of soil heavy pollution with some effects from agriculture.
Pedosphere constitutes an important part of the earth surface and is the base for most lives. Sustaining better quality soil is a prerequisite for healthy ecosystem. In recent decades, however, soil conditions have been heavily affected by rapid agricultural and industry activities. Heavy metal soil contamination and pollution from enhanced human activity have become a major threat to the health of regional ecosystems. As a result, research on heavy metal contamination of soils (e.g., discriminating the sources and evaluating environmental risks of heavy metals) has become a hot-field in geography, pedo-science and environmental science. Located in central Xinjiang Uygur Autonomous Region with relatively plenty rainfall, Tianshan Mountains is an important water source and ecological barrier in China. Variations in ecological and environmental conditions in the mountains have exerted an obvious pressure on the oases in the lower reaches. In August 2011, a field investigation was carried out in order to gain a comprehensive insight into soil heavy metal contamination conditions of Tianshan Mountains. A total of 153 soil samples were collected from three sections - the eastern (Balikun-Yiwu), middle (Xinyuan-Bayinbuluke) and western (Zhaosu-Tekesi)-in that northern slop of Tianshan Mountains. The samples were sent to the laboratory in the Institute of Ecology and Geography, Chinese Academy of Sciences for analysis for heavy metals. Five heavy metals (Cr, Cu, Ni, Pb and Zn) were analyzed using standard methods. Using single factor pollution index and comprehensive pollution index, quantitative comparison was done for soil heavy metal pollution in different sections with the soil background value in Xinjiang and the secondary standard of soil environmental quality (GB15618-1995). Moreover, the distribution features and pollution sources of soil heavy metals in the different sections were analyzed and illustrated using principal component analysis. The results showed that soil heavy metal content and the related single factor pollution index and comprehensive pollution index for the eastern section of the northern slope of Tianshan Mountains (Balikun-Yiwu) were higher than those in the middle (Xinyuan-Bayinbuluke) and western sections (Zhaosu-Tekesi). The soil heavy metal pollution level in the middle section was higher than that in the western section. Heavy metal pollution in the eastern section of the northern slope (Balikun-Yiwu) was caused mainly by human factors such as traffic, industry, agriculture, tourism. Although human factors (traffic and industry) had some effects, soil heavy metal pollution in the middle section (Xinyuan-Bayinbuluke) was mainly from soil parent materials. In the western section (Zhaosu-Tekesi), soil parent materials were main resources of soil heavy pollution with some effects from agriculture.
2013, 21(7): 891-897.
doi: 10.3724/SP.J.1011.2013.00891
Abstract:
Livestock production, especially its intensification around metropolitan areas, has contributed immensely to global warming. The estimation and analysis of spatial and temporal patterns of greenhouse gas emissions from livestock and poultry production were critical for the formulation of mitigation and adaptation strategies of national agricultural sectors. To investigate greenhouse gas emissions from enteric fermentation and manure management of livestock and poultry industry in Beijing area, emissions of methane and nitrous oxide during 1978-2009 were estimated based on regional livestock statistics. The study used the emission factor method recommended by the 2006 IPCC Guidelines and specific emphasis was placed on the trends and spatial distributions of the emissions. The results showed that livestock and poultry emissions in Beijing area started increasing at the early 1990s and peaked in 2004, with an average annual growth rate of 2%. This trend was similar to the increase in livestock and poultry population in Beijing area. Among the emissions, enteric fermentation methane was the most significant, with annual average emission of 0.4 Tg CO2-eq. Cattle was the main contributor to enteric fermentation methane emission, accounting for 54%, followed by swine and sheep. The annual average emissions of methane and nitrous oxide from manure management were 0.2 Tg CO2-eq and 0.3 Tg CO2-eq, respectively. The emissions were mainly from swine, respectively accounting for 73% and 46% of the emitted methane and nitrous oxide. Increase in methane indicated the intensification of livestock and poultry industry in Beijing area during 1978-2009. CR4 (industry concentration index) increased progressively from 1978 to 2009, indicating unceasing enhancement of the intensity of livestock industry in Beijing area. The emissions were mainly from Shunyi, Daxing, Miyun and Tongzhou Districts. The estimated livestock methane and nitrous oxide emissions in Beijing area for 1978-2009 was consistent with the linear growth model. Although an arduous task, it was urgent for the Beijing livestock industry to adopt efficient reduction strategies of greenhouse gases emission.
Livestock production, especially its intensification around metropolitan areas, has contributed immensely to global warming. The estimation and analysis of spatial and temporal patterns of greenhouse gas emissions from livestock and poultry production were critical for the formulation of mitigation and adaptation strategies of national agricultural sectors. To investigate greenhouse gas emissions from enteric fermentation and manure management of livestock and poultry industry in Beijing area, emissions of methane and nitrous oxide during 1978-2009 were estimated based on regional livestock statistics. The study used the emission factor method recommended by the 2006 IPCC Guidelines and specific emphasis was placed on the trends and spatial distributions of the emissions. The results showed that livestock and poultry emissions in Beijing area started increasing at the early 1990s and peaked in 2004, with an average annual growth rate of 2%. This trend was similar to the increase in livestock and poultry population in Beijing area. Among the emissions, enteric fermentation methane was the most significant, with annual average emission of 0.4 Tg CO2-eq. Cattle was the main contributor to enteric fermentation methane emission, accounting for 54%, followed by swine and sheep. The annual average emissions of methane and nitrous oxide from manure management were 0.2 Tg CO2-eq and 0.3 Tg CO2-eq, respectively. The emissions were mainly from swine, respectively accounting for 73% and 46% of the emitted methane and nitrous oxide. Increase in methane indicated the intensification of livestock and poultry industry in Beijing area during 1978-2009. CR4 (industry concentration index) increased progressively from 1978 to 2009, indicating unceasing enhancement of the intensity of livestock industry in Beijing area. The emissions were mainly from Shunyi, Daxing, Miyun and Tongzhou Districts. The estimated livestock methane and nitrous oxide emissions in Beijing area for 1978-2009 was consistent with the linear growth model. Although an arduous task, it was urgent for the Beijing livestock industry to adopt efficient reduction strategies of greenhouse gases emission.
2013, 21(7): 898-903.
doi: 10.3724/SP.J.1011.2013.00898
Abstract:
Land use planning is generally a strategic process. The quality of land use planning directly influences the rational use of land resources and the sustainability of socio-economic development. Current studies have focused mainly on the external effects of land use planning such as comprehensive benefits and environmental impacts, while ignoring the inherited attributes and characteristics of land use. This study in fact showed that even such evaluation studies were incomplete. The empirical relationship between land use and planning was established from the perspective of land use in this paper. A 6-aspect analytical framework was constructed for evaluating land use plan. The aspects of the framework included whether or not (1) land use form was stable; (2) land use structure was rational; (3) land use behavior was orderly; (4) land use degree was changeable; (5) land use function was improvable; and (6) land use layout was reasonable. Based on this 6-aspect framework, a comprehensive evaluation system was proposed and applied to a newly completed general land use planning in Jinkouhe District, Leshan City, Sichuan Province. The analysis showed that each characteristic index for the target year (2010) and near future (2020) was superior to that of the base year (2005). The indexes for 2020 were generally better than those for 2010. This implies that the general land use planning quality was excellent and was broadly able to meet the objectives of land use in the study area. Implementation of the land use plan was likely to promote optimal allocations of regional land resources with positive effects on regional development. The method was considered to be generally simple, feasible and effective in evaluating land use planning quality. The aim of the study was to provide methodological support to the management practice of general land use planning for improved quality and implementation effects. It was important to note that general land use planning was a multi-link engineering system that was comprehensive with strong policy considerations. Implementation was likely to induce significant changes due to unforeseen effects of regulation adjustment. With therefore the exception of quality analysis, a whole range of tracking management was executed at the implementation stage of planning. Consistently, the gathering of feedback and other relevant information needed thorough screening and evaluation against planning objectives. The recognition attained in the method was comprehensive and detailed.
Land use planning is generally a strategic process. The quality of land use planning directly influences the rational use of land resources and the sustainability of socio-economic development. Current studies have focused mainly on the external effects of land use planning such as comprehensive benefits and environmental impacts, while ignoring the inherited attributes and characteristics of land use. This study in fact showed that even such evaluation studies were incomplete. The empirical relationship between land use and planning was established from the perspective of land use in this paper. A 6-aspect analytical framework was constructed for evaluating land use plan. The aspects of the framework included whether or not (1) land use form was stable; (2) land use structure was rational; (3) land use behavior was orderly; (4) land use degree was changeable; (5) land use function was improvable; and (6) land use layout was reasonable. Based on this 6-aspect framework, a comprehensive evaluation system was proposed and applied to a newly completed general land use planning in Jinkouhe District, Leshan City, Sichuan Province. The analysis showed that each characteristic index for the target year (2010) and near future (2020) was superior to that of the base year (2005). The indexes for 2020 were generally better than those for 2010. This implies that the general land use planning quality was excellent and was broadly able to meet the objectives of land use in the study area. Implementation of the land use plan was likely to promote optimal allocations of regional land resources with positive effects on regional development. The method was considered to be generally simple, feasible and effective in evaluating land use planning quality. The aim of the study was to provide methodological support to the management practice of general land use planning for improved quality and implementation effects. It was important to note that general land use planning was a multi-link engineering system that was comprehensive with strong policy considerations. Implementation was likely to induce significant changes due to unforeseen effects of regulation adjustment. With therefore the exception of quality analysis, a whole range of tracking management was executed at the implementation stage of planning. Consistently, the gathering of feedback and other relevant information needed thorough screening and evaluation against planning objectives. The recognition attained in the method was comprehensive and detailed.
2013, 21(7): 904-912.
doi: 10.3724/SP.J.1011.2013.00904
Abstract:
Spatial interpolation of meteorological data is critical in meteorological and grassland research at macroscopic scales. To improve precision and enhance spatial differentiation effects of the Analytic Method based on Multiple Regression Residues (AMMRR) interpolation for the classification of grassland types, the AMMRR was upgraded by adding micro-topography factors such as slope and aspect, while the Inverse Distance Weighted (IDW) function was replaced with Ordinary Kriging (OK) function. And then the Improved Analytic Method based on Multiple Regression Residues (I-AMMRR) interpolation was established. The I-AMMRR was applied in the spatial interpolation of annual accumulated temperature of > 0 ℃ (Σθ), annual precipitation (r) and humidity (K) in the Inner Mongolia Autonomous Region. Subsequently, the grassland was classified and the corresponding Comprehensive Sequential Classification System (CSCS) of rangeland map produced for the Inner Mongolia Autonomous Region. The CSCS and I-AMMRR technique were used in conjunction with meteorological data from 197 stations for the period from 1961 to 2004. The research results suggested that: (1) The mean absolute error (MAE), mean relative error (RME) and root-mean-square error (RMSE) cross validation indices of the training and test datasets of Σθ and r were lower for I-AMMRR than AMMRR. The R correlation coefficients for Σθ and r between simulated and observed values were 0.969 (P < 0.01) and 0.933 (P < 0.01), respectively. This suggested that the interpolation accuracy of I-AMMRR was higher than that of AMMRR. (2) The spatial distribution patterns of Σθ, r and K simulated by I-AMMRR for the Inner Mongolia Autonomous Region showed horizontal and vertical zonalities, which were strongly agreed with actual distribution of natural zones and natural landscapes in the region. Specifically, Σθ increased from southeast to northwest while r and K had the reverse pattern. (3) Grassland in the Inner Mongolia Autonomous Region was classified into a total of 17 CSCS classes, ranging from the cool temperate-humid mixed coniferous broad leaved forest (ⅢF38) to the cool temperate-extra-arid temperate zonal desert (ⅢA3). The cool temperate-arid temperate zonal semi-desert (ⅢB10) covered the largest area while the smallest was under warm temperate-humid deciduous broad leaved forest (ⅣE32), with approximate areas of 2.42×105 km2 and 0.647 km2, respectively. The landscape types from east to west included forest, forest-rangeland, meadow, steppe, semi-desert and desert in that sequence. With simultaneous increase in altitude, the land cover distribution across the region between Ergun River-Hulun Lake and Da Hinggan Mountains was steppe (ⅢC17), meadow (ⅢD24), montane meadow (ⅢE30) and coniferous forest (ⅢF37) in that successive order. Meadow (ⅢD24), forest-rangeland (ⅢE31), and coniferous and broad-leaved mixed forest (ⅣF38) were orderly distributed in the region from southern Nenjiang Plain to Da Hinggan Mountains. Steppe (ⅢC17), meadow (ⅢD24), forest-rangeland (ⅢE31), and coniferous forest (ⅢF37) were distributed across the area linking Xiliao River Plain to Da Hinggan Mountains. Horizontal and vertical zones were distinct in spatial distribution of grassland vegetation, which well fitted the result of vegetation investigation in Inner Mongolia Autonomous Region. These research results provided theoretical evidence and technical support for dynamic monitoring of the variations in grassland in Inner Mongolia Autonomous Region.
Spatial interpolation of meteorological data is critical in meteorological and grassland research at macroscopic scales. To improve precision and enhance spatial differentiation effects of the Analytic Method based on Multiple Regression Residues (AMMRR) interpolation for the classification of grassland types, the AMMRR was upgraded by adding micro-topography factors such as slope and aspect, while the Inverse Distance Weighted (IDW) function was replaced with Ordinary Kriging (OK) function. And then the Improved Analytic Method based on Multiple Regression Residues (I-AMMRR) interpolation was established. The I-AMMRR was applied in the spatial interpolation of annual accumulated temperature of > 0 ℃ (Σθ), annual precipitation (r) and humidity (K) in the Inner Mongolia Autonomous Region. Subsequently, the grassland was classified and the corresponding Comprehensive Sequential Classification System (CSCS) of rangeland map produced for the Inner Mongolia Autonomous Region. The CSCS and I-AMMRR technique were used in conjunction with meteorological data from 197 stations for the period from 1961 to 2004. The research results suggested that: (1) The mean absolute error (MAE), mean relative error (RME) and root-mean-square error (RMSE) cross validation indices of the training and test datasets of Σθ and r were lower for I-AMMRR than AMMRR. The R correlation coefficients for Σθ and r between simulated and observed values were 0.969 (P < 0.01) and 0.933 (P < 0.01), respectively. This suggested that the interpolation accuracy of I-AMMRR was higher than that of AMMRR. (2) The spatial distribution patterns of Σθ, r and K simulated by I-AMMRR for the Inner Mongolia Autonomous Region showed horizontal and vertical zonalities, which were strongly agreed with actual distribution of natural zones and natural landscapes in the region. Specifically, Σθ increased from southeast to northwest while r and K had the reverse pattern. (3) Grassland in the Inner Mongolia Autonomous Region was classified into a total of 17 CSCS classes, ranging from the cool temperate-humid mixed coniferous broad leaved forest (ⅢF38) to the cool temperate-extra-arid temperate zonal desert (ⅢA3). The cool temperate-arid temperate zonal semi-desert (ⅢB10) covered the largest area while the smallest was under warm temperate-humid deciduous broad leaved forest (ⅣE32), with approximate areas of 2.42×105 km2 and 0.647 km2, respectively. The landscape types from east to west included forest, forest-rangeland, meadow, steppe, semi-desert and desert in that sequence. With simultaneous increase in altitude, the land cover distribution across the region between Ergun River-Hulun Lake and Da Hinggan Mountains was steppe (ⅢC17), meadow (ⅢD24), montane meadow (ⅢE30) and coniferous forest (ⅢF37) in that successive order. Meadow (ⅢD24), forest-rangeland (ⅢE31), and coniferous and broad-leaved mixed forest (ⅣF38) were orderly distributed in the region from southern Nenjiang Plain to Da Hinggan Mountains. Steppe (ⅢC17), meadow (ⅢD24), forest-rangeland (ⅢE31), and coniferous forest (ⅢF37) were distributed across the area linking Xiliao River Plain to Da Hinggan Mountains. Horizontal and vertical zones were distinct in spatial distribution of grassland vegetation, which well fitted the result of vegetation investigation in Inner Mongolia Autonomous Region. These research results provided theoretical evidence and technical support for dynamic monitoring of the variations in grassland in Inner Mongolia Autonomous Region.
Editor-in-chief：LIU Changming
Competent Authorities：Chinese Academy of Sciences
Sponsored by：Institute of Genetics and Developmental Biology, Chinese Academy of Sciences; China Ecological Economics Society
Organizer：Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences
ISSN 2096-6237
CN 13-1432/S
- Chinese core periodicals
- Core Chinese Sci-Tech Periodicals
- China's Top Science and Technology Periodicals
- Covered by Chinese Science Citation Database (CSCD)
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