| The karst rift basin has complicated terrain,scarce available water,and scarce land resources.It has faced various levels of rock desertification for a long time.In addition to the rock desertification control project implemented since 2000,local land management has become more frequent and complicated,and human interference Affects the stability of the ecosystem and the human well-being it provides.In order to objectively assess the impact of land use on the ecological environment and the ecological benefits achieved by the rock desertification control measures,an attempt was made to reflect deeper human-land relationships from changes in ecosystem productivity,based on multi-sequence land vegetation net primary productivity(NPP)and net ecosystem productivity(NEP)in the rift basin,this paper clarifies the temporal and spatial variation of ecosystem productivity in the rift basin,and uses the research methods in the life cycle assessment theory combined with land use data to quantitatively analyze the impact of land occupation and land conversion on ecosystem productivity;combine the spatial and temporal distribution of the rock desertification control project with the net ecosystem productivity,discuss the changes in vegetation carbon source / sink after the rock desertification control project is implemented,and measure various types of different stages The effect of governance measures and their ecological benefits.By studying the impact of human activities on ecosystem services,this paper promotes the rational implementation of land layout and the effective implementation of ecological restoration projects to achieve the sustainable development of the ecological environment of faulted basins.The main research conclusions are as follows:(1)From 2000 to 2015,the interannual changes of NPP in faulted basins exhibited tortuous fluctuations.The western and northern regions showed a concentrated improvement,while the central and southern regions showed sporadic degradation.The areas of NPP decline were weak and persistent.The NEP transitioned from a steady change to a significant increase.The change in the Guizhou rift basin area from 2010 to 2015 was significantly different from the other two provinces.The NEP decline areas were concentrated in the Guizhou rift basin area and eastern Xuanwei County in Yunnan.The multi-year mean values of NPP and NEP have basically the same spatial distribution.(2)The difference between the potential vegetation productivity of forest land occupation and NPP increases gradually from west to east,which has a spatial trend consistent with the decrease of forest land area.The forest land vegetation in the northern part of the study area improves,while the natural forest land in Pan County,Pu’an County,and Luliang County in the east exists.Degenerate.Land conversion occurred frequently in the central and southeastern areas of the study area,the NPP in the Yunnan rift basin region showed a slight gain,and the Guizhou rift basin region suffered significant losses.The 80% land conversion method makes NPP gains,among which the conversion of farmland to forests and grassland conversion areas generally achieve significant NPP gains.(3)Rocky desertification control 2011-2016,mountain closure management is the most effective type of management measures,suitable for most implementation areas,followed by mountain closure forestry(grass),forest and grass measures;agricultural measures are not as effective No governance measures will recover naturally,but it can bring certain economic benefits;the effect of engineering measures is very polarized.The areas in Yunnan rifted basin area that have not yet implemented control measures have certain vegetation self-recovery ability under natural climatic conditions.(4)Rock desertification control In addition to comprehensive control measures,other control measures have been improved to a certain extent from 2000 to 2005;in the recent period of rock desertification control,85% of the control measures have been changed to achieve NEP improvement.Among them,the closure of mountains and forests(grass)-closure of mountains The improvement of the management and protection of vegetation is the most impressive.When there is no control measures,mountain closure management,mountain closure afforestation(grass)conversion to engineering measures,vegetation restoration effects are no longer the same. |
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