文献类型：期刊文献

英文题名：Changes in Plant-Soil-Microbe C-N-P Contents and Stoichiometry During Poplar Shelterbelt Degradation

作者：Wang, Guan[1] Xiao, Huijie[1] Xin, Zhiming[2,3] Luo, Minfeng[2,3] Jin, Yuxi[1] Liu, Mingming[1] Li, Junran[4]

第一作者：Wang, Guan

机构：[1] School of Soil and Water Conservation, Beijing Forestry University, Beijing, 100083, China; [2] Experimental Center of Desert Forestry, Chinese Academy of Forestry, Dengkou, 015200, China; [3] Inner Mongolia Dengkou Desert Ecosystem National Observation Research Station, National Forestry and Grassland Administration, Dengkou, 015200, China; [4] Department of Geography, The University of Hong Kong, 999077, Hong Kong

年份：2023

外文期刊名：SSRN

收录：EI(收录号：20230381629)

语种：英文

外文关键词：Bacteria - Deterioration - Nitrogen - Organic carbon - Phosphorus - Plants (botany) - Soils - Stoichiometry

摘要：Extensive poplar shelterbelts are experiencing degradation, yet the consequences of this deterioration on plant-soil-microbe stoichiometry remain poorly understood. We selected three distinct types of pure poplar shelterbelts and examined the dynamics of tree leaf, soil, and microbial biomass carbon (C), nitrogen (N), and phosphorus (P) contents, as well as their stoichiometric relationships, at different stages of shelterbelt degradation. Our results show a consistent reduction in foliar N:P ratio throughout the degradation process for all shelterbelts, implying an amplified nitrogen limitation on tree growth as degradation ensued. However, the underlying mechanisms behind this phenomenon varied. For Populus alba shelterbelts, the diminished soil organic carbon and total nitrogen contents during degradation suggest a reduction in the availability of substrates and energy sources for nitrogen mineralization, which combines with the higher microbial nitrogen assimilation reflected by elevated soil microbial biomass carbon (SMBC) content, contributing to the comparatively lower nitrogen absorption by trees in relation to phosphorus. In Lombardy poplar shelterbelts, the inconsistent trends among reduced foliar N, stable soil TN, and unaltered SMBC and SMBC: SMBN ratio underscore either microbial activity decreased as degradation advanced or trees reallocated more N into tissues like roots to fight against harsh conditions like severe droughts and strong winds, leaving leaves with deficient N. Within Populus popular's shelterbelts, the diminished foliar N content signifies nitrogen deficiency. This is accompanied by an augmented foliar C:N ratio and reduced soil N:P ratio, indicating the potentially deteriorated litter quality, which then contributes to a detrimental cycle involving N deficit soil organic matter, limited soil nitrogen availability, decreased nitrogen absorption by trees, and subsequently reduced foliar nitrogen content. Our study highlights the distinctive responses of plant-soil-microbe C-N-P stoichiometry to shelterbelt degradation, contingent on tree species, underscoring the diverse strategies that poplar shelterbelts employ when confronted with harsh internal and external conditions. ? 2023, The Authors. All rights reserved.