Appraisal of arid land status:a holistic assessment pertains to bio-physical indicators and ecosystem values

Background:Appraisal of arid land status is very crucial one to know the extent and factors associated with their degradation.Previous studies from arid regions are mostly qualitative in nature(indicator assessment like good,moderate,severe,and very severe)and generally overlooked the significance of temporal fluctuation.Methods:In this study,the temporal status of 12 Indian arid lands was accessed by using a new integrated approach that includes attributes like relative converge score(RCS),herbaceous component score(HCS),soil quality indexModified(SQI),ecosystem monitoring value(EMV),and a modified bare patch index.From each land,data were collected during three seasonal events(pulse,inter-pulse,and non-pulse),and thus,status was evaluated with 36 observations.Data were analyzed by using frequency distribution,principal component analysis(PCA),student t test,and regression technique.Results:RCS and HCS were recorded minimum(0.005,0.65)during non-pulse event and maximum(0.36,1.79)during pulse event respectively.With this approach,multi-directional temporal status of lands identified that were grouped into lower(7),moderate(14),high(12),and very high(3)quality lands.Conclusion:This integrated study suggested that in arid regions,although rainfall triggers plant community composition,however,sole utilization of this parameter is unable to portray the true status of lands,and other physical(soil)and biotic(livestock and other anthropogenic)parameters are equally important and influential during other events.

Effects of an ecological conservation and restoration project in the Three-River Source Region, China

The first-stage of an ecological conservation and restoration project in the Three-River Source Region（TRSR）, China, has been in progress for eight years. However, because the ecological effects of this project remain unknown, decision making for future project implementation is hindered. Thus, in this study, we developed an index system to evaluate the effects of the ecological restoration project, by integrating field observations, remote sensing, and process-based models. Effects were assessed using trend analyses of ecosystem structures and services. Results showed positive trends in the TRSR since the beginning of the project, but not yet a return to the optima of the 1970 s. Specifically, while continued degradation in grassland has been initially contained, results are still far from the desired objective, ‘grassland coverage increasing by an average of 20%–40%＇. In contrast, wetlands and water bodies have generally been restored, while the water conservation and water supply capacity of watersheds have increased. Indeed, the volume of water conservation achieved in the project meets the objective of a 1.32 billion m^3 increase. The effects of ecological restoration inside project regions was more significant than outside, and, in addition to climate change projects, we concluded that the implementation of ecological conservation and restoration projects has substantially contributed to vegetation restoration. Nevertheless, the degradation of grasslands has not been fundamentally reversed, and to date the project has not prevented increasing soil erosion. In sum, the effects and challenges of this first-stage project highlight the necessity of continuous and long-term ecosystem conservation efforts in this region.