Effects of planting Caragana shrubs on soil nutrients and stoichiometries in desert steppe of Northwest China
Effects of planting Caragana shrubs on soil nutrients and stoichiometries in desert steppe of Northwest China
复制标题
西北荒漠草原种植锦鸡儿灌木对土壤养分及化学计量的影响
DOI：
10.1016/j.catena.2019.104213
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发表时间：
2019
期刊：
影响因子：
6.2
通讯作者：
Liu Bingru
中科院分区：
文献类型：
--
作者：
Yang Yang;Liu Bingru
摘要锦鸡儿是我国西北荒漠草原上广泛种植的一种植物，其主要作用是缓解荒漠化的侵蚀。土壤养分和化学计量反映了土壤有机质在生态系统中的循环。因此，在该地区，由于柠条的建立，土壤养分和化学计量之间存在着动态平衡。为探讨西北荒漠草原区种植锦鸡儿对土壤养分和化学计量的影响，采用不同种植密度（高密度4530束/hm 2，中密度3670束/hm 2，低密度2560束/hm 2）对土壤养分和化学计量进行了研究。结果表明，低磷地区土壤速效磷和全磷含量与对照差异不显著（p> 0.05）;土壤有机碳（SOC）、全氮（TN）和碱解氮（AN）含量的大小顺序为HD > MD > LD > CK，表明种植锦鸡儿对土壤养分有增加作用，但对AP和TP的影响不显著（p> 0.05），且这种增加作用沿沿着逐渐减弱。此外，锦鸡儿的种植显著影响土壤化学计量。土壤N/P和C/P随土层深度的增加而逐渐增加，但变化幅度不大，而C/N随土层深度的增加而逐渐减小。土壤含水量、AP、AN和SOC对土壤C/N有较强的正效应，而对C/P和N/P有较强的负效应，说明土壤性质在决定土壤化学计量中的重要性。研究结果表明，种植锦鸡儿可以提高土壤养分水平，HD可以作为荒漠草原植被恢复的最佳种植密度。然而，在该地区特殊的气候条件下，最适宜的种植密度阈值还有待于进一步研究。
Caraganakorshinskiishrubs are widely planted in desert steppe of Northwest China to mitigate desert encroachment. Soil nutrients and stoichiometries reflect the cycling of soil organic matter in ecosystems. Thus, there is a dynamic balance between soil nutrients and stoichiometries due to the establishment ofCaraganashrubs in this region. Here, soil nutrients and stoichiometries were characterized with different planting densities ofCaraganashrubs (HD, high density, 4530 bundle/hm2; MD, mid density, 3670 bundle/hm2; LD, low density, 2560 bundle/hm2) to explore how the planting ofCaraganashrubs affects soil nutrients and stoichiometries in desert steppe of Northwest China. The results showed that soil available phosphorus (AP) and soil total phosphorus (TP) had no significant differences between LD and control (CK) (p> 0.05). Further, soil organic carbon (SOC), soil total nitrogen (TN), and soil alkali-hydrolyzable nitrogen (AN) followed the order of HD > MD > LD > CK, indicating that the planting ofCaraganashrubs had an increasing effect to soil nutrients, with the exception of AP and TP (p< 0.05), and the increasing effect gradually died down along soil profile. In addition, the planting ofCaraganashrubs significantly affected soil stoichiometries. Specifically, soil N/P and C/P gradually increased with soil depth with fluctuation, while soil C/N decreased with soil depth. Besides, soil water content (SW), AP, AN, and SOC had strong positive effects on soil C/N, while they had strong negative effects on soil C/P and N/P, highlighting the importance of soil properties in determining soil stoichiometries. Overall, our results indicated that plantingCaraganashrubs can improve levels of soil nutrients, and HD can be considered the optimal planting density for vegetation restoration in desert steppe. Nevertheless, the threshold of the planting density most favorable for the special climates must be identified through further study in this region.