Tian Jing, Sheng Mao-Yin, Wang Pan, Wen Pei-Cai
Institute of Karst Research, Guizhou Normal University, Guiyang 550001, China.
National Engineering Research Center for Karst Rocky Desertification Control, Guiyang 550001, China.
Huan Jing Ke Xue. 2019 Sep 8;40(9):4278-4286. doi: 10.13227/j.hjkx.201812221.
In this study, the litter and soil under four typical land use patterns of primary forest, shrub, grassland, and sloping land in Huajiang Karst Gorge in Guanling, Guizhou Province, were used to study the effects of land use change on the carbon(C), nitrogen(N), and phosphorus(P) stoichiometry characteristics of karst plant litter and soil as well as the effects on soil enzyme activities and their driving mechanism in Southwest China. The results showed significant differences in the litter-soil C, N, and P contents and soil enzyme activities among the four land use types. Compared with other regions, the litter and soil showed a pattern of high C, low N, high P and low C, low N, high P, respectively. Urease, sucrose, and amylase showed an order of primary forest > shrub forest > grassland > slope farmland, whereas alkaline phosphatase showed primary forest > shrub forest > slope farmland > grassland. The protection of primary forests should be considered in future ecological construction. The soil nutrients were significantly affected by litter C, N, P, and their ratios, although the soil enzyme activities were not significantly associated with the litter. Redundancy analysis showed that soil enzyme activity had extremely significant correlation with the soil total N (TN), water content (SWC), and C:N ratio (<0.01) and relatively significant correlation with pH and the N:P ratio (<0.05). The order of importance was shown to be TN > SWC > C:N > pH > N:P. The research results have significant value for the study of karst rocky desertification and karst ecosystem nutrient cycling.
本研究以贵州省关岭花江喀斯特峡谷区原生林、灌丛、草地和坡耕地4种典型土地利用方式下的凋落物和土壤为研究对象，探讨土地利用变化对西南喀斯特地区植物凋落物和土壤碳（C）、氮（N）、磷（P）化学计量特征的影响，以及对土壤酶活性的影响及其驱动机制。结果表明，4种土地利用类型的凋落物-土壤C、N、P含量及土壤酶活性存在显著差异。与其他地区相比，凋落物和土壤分别呈现高C、低N、高P和低C、低N、高P的特征。脲酶、蔗糖酶和淀粉酶表现为原生林＞灌木林＞草地＞坡耕地，而碱性磷酸酶表现为原生林＞灌木林＞坡耕地＞草地。未来生态建设应考虑对原生林的保护。土壤养分受凋落物C、N、P及其比值的显著影响，尽管土壤酶活性与凋落物无显著相关性。冗余分析表明，土壤酶活性与土壤全氮（TN）、含水量（SWC）和C:N比（<0.01）极显著相关，与pH和N:P比（<0.05）显著相关。重要性顺序为TN＞SWC＞C:N＞pH＞N:P。研究结果对喀斯特石漠化及喀斯特生态系统养分循环研究具有重要价值。
