Urbanization aggravates imbalances in the active C, N and P pools of terrestrial ecosystems
Urbanization aggravates imbalances in the active C, N and P pools of terrestrial ecosystems
复制标题
城市化加剧陆地生态系统活性碳、氮、磷库的失衡
DOI：
10.1016/j.gecco.2019.e00831
复制
发表时间：
2020
影响因子：
4
通讯作者：
Fang Xiang-Min
中科院分区：
文献类型：
--
作者：
Wan Song-Ze;Chen Fu-Sheng;Hu Xiao-Fei;Zhang Yang;Fang Xiang-Min
城市化导致温度升高，改变土壤碳（C）、氮（N）和磷（P）循环，但这些过程在温度敏感性方面的变化程度沿着城乡梯度尚不清楚。在南昌市沿城市-郊区-乡村梯度沿着选择3种典型植被类型（森林、灌木和草坪），采集表层土壤（0-15 cm），采用土壤培养法测定土壤C、N和P矿化速率。这分别在5 ° C、15 ° C、25 ° C、35 ° C和45 ° C的环境温度下进行。结果表明，土壤微生物C、N含量以及土壤C矿化速率、硝化速率和P矿化速率均沿着城乡梯度呈下降趋势（P < 0.05）。土壤C矿化的温度敏感性（Q（10））城市最高，郊区次之，农村最低。与此相反，氨化作用的Q（10）值在城市低于郊区和农村网站，和硝化反应的差异，温度变化只发现在城市网站。磷矿化率在不同培养温度下变化最小。两者合计，我们发现，土壤C和养分通量在温度升高的反应可能是更异步的城市比农村网站，因此城市化可能会加剧陆地生态系统的活性C，N和P池的不平衡。因此，全球变暖可能有助于加速中国亚热带城市植被土壤有机C分解，N淋溶和P富集。(C)2019年，任作家。由爱思唯尔公司出版
Urbanization causes increases in temperature and alters soil carbon (C), nitrogen (N), and phosphorus (P) cycles, but the degree to which these processes vary in temperature sensitivity along the urban-rural gradient are unclear. We selected three typical vegetation types (forests, shrub, and lawn) along an urban-subruban-rural gradient in Nanchang, China, and collected topsoil (at 0-15 cm depth) from 27 plots in each to measure the C, N, and P mineralization rates using thermostatic incubation. This was performed at ambient temperatures of 5 degrees C, 15 degrees C, 25 degrees C, 35 degrees C and 45 degrees C, respectively. Our results showed that soil microbial C and N content, as well as the rates of soil C mineralization, nitrification, and P mineralization generally decreased along the urban-rural gradient (P < 0.05). Moreover, the temperature sensitivity (Q(10)) of soil C mineralization was highest at urban sites, followed by suburban, then at rural sites. In contrast, the Q(10) value of ammonification was lower in urban than suburban and rural sites, and a difference in nitrification response to temperature alteration was only found at urban sites. The phosphorus mineralization rate showed minimal variation across incubation temperatures. Taken together, we found that soil C and nutrient fluxes in response to elevated temperature might be more asynchronous in urban than in rural sites, and thus urbanization may aggravate imbalances in the active C, N and P pools of terrestrial ecosystems. Global warming may thus help accelerate soil organic C decomposition, N leaching, and P enrichment in urban vegetations in subtropical China. (C) 2019 The Authors. Published by Elsevier B.V.