In this research,the contents of organic carbon in soil profiles in rubber forests in west of Hainan were measured and storage quantity of oganic carbon was estimated.The results indicated that contents of organic car...In this research,the contents of organic carbon in soil profiles in rubber forests in west of Hainan were measured and storage quantity of oganic carbon was estimated.The results indicated that contents of organic carbon in soils of ecosystem of rubber forests at different ages were 6.20-14.36 g/kg;organic carbon in soils of rubber forests reduced upon soil depth;the contents differed signigicantly in soils at 0-60 cm in rubber forest at 33 a,but differed little in soils in rubber forests at other ages;the contents were of significant differences in soils in rubber forests at different ages;organic carbon concentrated in soils at 0-30 cm;the storage quantities of organic carbon in rubber forests at 5,10,19 and 33 a were 76.85,74.48,81.74 and 85.31 t/hm^2.Climate,soil property,accumualtion and decomposition of fallen materials,forest age and management are dominant factors influencing accumulation of organic carbon in soils of rubber forest.展开更多
[Objective] The paper was to analyze the quality of flux observation data of rubber plantation.[Method]Based on the FSAM model,footprint and flux source area were analyzed according to the continuous flux measurement ...[Objective] The paper was to analyze the quality of flux observation data of rubber plantation.[Method]Based on the FSAM model,footprint and flux source area were analyzed according to the continuous flux measurement with the open-path eddy covariance system on the 50 m tower of Danzhou Key Field Station of Observation and Research for Tropical Agricultural Resources and Environments,Ministry of Agriculture from Jan 1 to Jun 30,2010.[Result] Under unstable stratification,source areas were smaller than those under stable conditions,and source areas in the dormant season were larger than those in the growing season at the same level.In the main wind direction 130°-270°,the upwind range of source areas was in the magnitude of 100-758 m and vertical upwind range was-251-251 m at 80% level under unstable stratification in the growing season,and they were some large than those under the unstable stratification in the dormant season.The source areas of the upwind and vertical upwind ranges were 173-1 858,-534-534 m especially under stable stratification in the growing season,and they were smaller than those under stable stratification in the dormant season.In the other wind directions of 0°-130° and 270°-360°,the ranges were similar to those of the growing season in the prevailing wind direction under the same atmospheric conditions.[Conclusion] The study would lay a foundation for the future flux calculation and analysis.展开更多
The term forest transition refers to a change in forest cover over a given area from a period of net forest area loss to a period of net gain. Whether transitioning from deforestation to reforestation can lead to impr...The term forest transition refers to a change in forest cover over a given area from a period of net forest area loss to a period of net gain. Whether transitioning from deforestation to reforestation can lead to improved ecosystem services, depends on the quality and characteristics of the newly established forest cover. Using publicly available data, we examine forest transition in two regions of tropical China: Hainan Island and Xishuangbanna. We found that the overall increase of forest cover in both areas during the1980 s was due to an increase in plantation forests rather than to increases in the area covered by natural forest. We also found a time lag between the increase in overall forest cover and an increase in natural forest. On Hainan Island, natural forest continued to decline beyond the point in time when overall forest cover had started to increase, and only began to recover ten years after the turning point in 1978. In Xishuangbanna, where the transition point occurred ten years later, the decline of natural forest cover is still going on. These divergent trends underlying forest transition are concealed by the continued practice to apply the term "forest" broadly, without distinguishing between natural forests and planted forests.Due to the use of undiscriminating terminology, the loss of natural forest may go unnoticed, increasing the risk of plantation forests displacing natural forests in the course of forest transition. Our findings are important for programs related to forest management and ecosystem services improvement, including reforestation and Payments for Ecosystem Services programs.展开更多
基金Supported by Strategic Priority Research Program,CAS(XDA05050601-01-25)Basic Scientific Research Project of Central Science and Technology Institute(163002-2011013)Project of Danzhou Investigation&Experiment Station of Tropical Crops Ministry of Agriculture~~
文摘In this research,the contents of organic carbon in soil profiles in rubber forests in west of Hainan were measured and storage quantity of oganic carbon was estimated.The results indicated that contents of organic carbon in soils of ecosystem of rubber forests at different ages were 6.20-14.36 g/kg;organic carbon in soils of rubber forests reduced upon soil depth;the contents differed signigicantly in soils at 0-60 cm in rubber forest at 33 a,but differed little in soils in rubber forests at other ages;the contents were of significant differences in soils in rubber forests at different ages;organic carbon concentrated in soils at 0-30 cm;the storage quantities of organic carbon in rubber forests at 5,10,19 and 33 a were 76.85,74.48,81.74 and 85.31 t/hm^2.Climate,soil property,accumualtion and decomposition of fallen materials,forest age and management are dominant factors influencing accumulation of organic carbon in soils of rubber forest.
基金Supported by the Fundamental Research Funds for Rubber Research Institute,CATAS (1630022011013 )Hainan Natural Science Foundation (807045)Running Costs of Danzhou Key Field Station of Observation and Research for Tropical Agricultural Resources and Environments,Ministry of Agriculture~~
文摘[Objective] The paper was to analyze the quality of flux observation data of rubber plantation.[Method]Based on the FSAM model,footprint and flux source area were analyzed according to the continuous flux measurement with the open-path eddy covariance system on the 50 m tower of Danzhou Key Field Station of Observation and Research for Tropical Agricultural Resources and Environments,Ministry of Agriculture from Jan 1 to Jun 30,2010.[Result] Under unstable stratification,source areas were smaller than those under stable conditions,and source areas in the dormant season were larger than those in the growing season at the same level.In the main wind direction 130°-270°,the upwind range of source areas was in the magnitude of 100-758 m and vertical upwind range was-251-251 m at 80% level under unstable stratification in the growing season,and they were some large than those under the unstable stratification in the dormant season.The source areas of the upwind and vertical upwind ranges were 173-1 858,-534-534 m especially under stable stratification in the growing season,and they were smaller than those under stable stratification in the dormant season.In the other wind directions of 0°-130° and 270°-360°,the ranges were similar to those of the growing season in the prevailing wind direction under the same atmospheric conditions.[Conclusion] The study would lay a foundation for the future flux calculation and analysis.
基金funded by the National Natural Science Foundation of China (Grant 31300403)the China Postdoctoral Science Foundation (Grant 2013M540722)+2 种基金part of the CGIAR Research Program 6:Forests, Trees, and Agroforestrypart of the BMZ/GIZ "Green Rubber"(Project No. 13.1432.7-001.00)'SURUMER' (Project No. 01LL0919A) funded by the German Federal Ministry of Education and Research(BMBF) under Grant number FKZ 01LL0919
文摘The term forest transition refers to a change in forest cover over a given area from a period of net forest area loss to a period of net gain. Whether transitioning from deforestation to reforestation can lead to improved ecosystem services, depends on the quality and characteristics of the newly established forest cover. Using publicly available data, we examine forest transition in two regions of tropical China: Hainan Island and Xishuangbanna. We found that the overall increase of forest cover in both areas during the1980 s was due to an increase in plantation forests rather than to increases in the area covered by natural forest. We also found a time lag between the increase in overall forest cover and an increase in natural forest. On Hainan Island, natural forest continued to decline beyond the point in time when overall forest cover had started to increase, and only began to recover ten years after the turning point in 1978. In Xishuangbanna, where the transition point occurred ten years later, the decline of natural forest cover is still going on. These divergent trends underlying forest transition are concealed by the continued practice to apply the term "forest" broadly, without distinguishing between natural forests and planted forests.Due to the use of undiscriminating terminology, the loss of natural forest may go unnoticed, increasing the risk of plantation forests displacing natural forests in the course of forest transition. Our findings are important for programs related to forest management and ecosystem services improvement, including reforestation and Payments for Ecosystem Services programs.
