Evaluation of soil fertility in the succession of karst rocky desertification using principal component analysis

Abstract

Abstract. Expanding of karst rocky desertification (RD) area in southwestern China has led to destructed ecosystem and local economic development lagging behind. It is important to understand the soil fertility at RD regions for the sustainable management of karst lands. The effects of the succession of RD on soil fertility were studied by investigating the stands and analyzing the soil samples with different RD grades in the central Hunan province, China, using the principal component analysis method. The results showed that the succession of RD had different impacts on soil fertility indicators. The changing trend of total organic carbon (TOC), total nitrogen (TN), available phosphorous (AP), microbial biomass carbon (MBC), and microbial biomass nitrogen (MBN) out of 19 selected indicators in different RD regions was: potential RD (PRD) > light RD (LRD) > moderate RD (MRD) > intensive RD (IRD), whereas the changing trend of other indicators was not entirely consistent with the succession of RD. The degradation trend of soil fertility was basically parallel to the aggravation of RD, and the strength of integrated soil fertility was in the order of PRD > MRD > LRD > IRD. The TOC, total phosphorus (TP), cation exchange capacity (CEC), MBC, MBN, microbial mass phosphorous (MBP), and bulk density (BD) could be regarded as the key indicators to evaluate the soil fertility due to their close correlations to the integrated fertility.

A Knowledge‐Based Approach for Mapping Land Degradation in the Arid Rangelands of North Africa

“…Indicators of rangeland degradation provide information that should improve the understanding of complex phenomena such as desertification and ecosystem changes. The selection of relevant indicators is therefore a crucial step in providing measurable criteria for monitoring, managing and providing policy support on land degradation (Van Lynden et al ., ; Izzo et al ., ; Liu et al ., ; Xie et al ., ).…”

Changes in soil microbial biomasses and their quotients over the succession of karst rocky desertification

“…The aggravation of RD is not only caused by anthropogenic factor (land overuse) , but also by climate change [19]. For all investigated stands, we found that degradation of phytocommunity (tree → tree/shrub → shrub → shrub/grass → grass) results in the homogenization of community structure, decrease of biomass and litter fall, and reduction of plant nutrition [8]. The destroyed soil ecosystem leads to soil microorganism population reducing and microbial activity on discomposing litter fall decreasing, so that the C, N, and P fixation of soil decreases [20].…”

“…Succession of RD refers to the changing process of karst land from one grade to another here and elsewhere [7], which means an observable process of changes of karst ecosystem such as vegetation type, vegetation coverage, bedrock exposure, and soil depth from potential RD to intensive RD orderly or vice versa [8]. In karst ecosystem, in order to find sensitive indicators to evaluate soil fertility, many researches discussed the interactions among vegetation, soil physical and chemical conditions, and soil microbial properties.…”

Key Role of Desert–Oasis Transitional Area in Avoiding Oasis Land Degradation from Aeolian Desertification in Dunhuang, Northwest China

“…According to the Millennium Ecosystem Assessment (MEA, 2005), 10-20% of the drylands are already moderately degraded. Desertification becomes one of the most important social, economic and environmental problems in the world today (da Silva Pinto Vieira et al, 2014;Xie et al, 2014;Easdale, 2015). Desertification has developed rapidly in oases of northern China over the last 50 years, which is a major obstacle to the sustainable development of oases (Wang et al, 2015a).…”