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.

Status of China's Land Resources in 2013

On 22nd April 2014,with the approach of the 45th World Earth Day,the Chinese Ministry of Land and Resources announced the status of China＇s land resources in 2013,putting forward the implementation of strict farmland protection measures to ensure the 1.8 billion acres of arable land.This laid a solid foundation for achieving a ＂ten even increase＂ of food production and ensuring China＇s food security.

基于Landsat影像的广东省重点生态功能区生态功能状况及其变化评价

针对重点生态功能区开展监测与评价对于生态保护和环境治理的意义重大。以广东省第一批被纳入生态补偿区域的11个国家重点生态功能区为研究区,采用2011年至2015年的5期Landsat卫星遥感影像,通过目视解译的方法提取研究区的土地利用/覆盖类型,并结合野外核查及统计资料,分析了该11个县域的生态功能状况现状及其变化。结果表明:(1)2015年全部11个县域的生态功能状况均为优或良级别,但相互之间具有一定的区域差异性。生态功能状况指数(FEI)最高的是乳源瑶族自治县,为71.11,最低的是南雄市,为61.20。(2)2015年与2011年相比,广东省11个国家重点生态功能区的功能状况指数变化幅度(ΔFEI)为–0.50—2.50。仁化县、乳源瑶族自治县、南雄市、平远县、蕉岭县、龙川县和连平县等7个县域的生态功能状况无明显变化(|ΔFEI|<1);始兴县、兴宁县及和平县等3个县域的生态功能状况略微变化(1≤|ΔFEI|<2),其中,始兴县和兴宁县2015年的生态功能状况略微优于2011年(1≤ΔFEI<2),而和平县2015年的生态功能状况略微变差(–1≥ΔFEI>–2);另外,乐昌市2015年的生态功能状况明显变好(2≤ΔFEI<4)。(3)2011年至2015年期间,全部县域的生态功能状况保持稳定,其变化趋势均不显著(|Rs|≤0.9)。