Ecosystem‐level decoupling in response to reduced precipitation frequency and degradation in steppe grassland
Ecosystem‐level decoupling in response to reduced precipitation frequency and degradation in steppe grassland
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草原草原降水频率减少和退化对生态系统水平解耦的响应
DOI：
10.1111/1365-2435.14425
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发表时间：
2023-09
影响因子：
5.2
通讯作者：
Tianxue Yang;Xiaoyue Zhong;Junda Chen;Uffe N Nielsen;R. Ochoa‐Hueso;Yanan Qu;Yushu Sui;
中科院分区：
文献类型：
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作者：
Tianxue Yang;Xiaoyue Zhong;Junda Chen;Uffe N Nielsen;R. Ochoa‐Hueso;Yanan Qu;Yushu Sui;
预计干旱和半干旱地区的草原降水频率将减少。此外，在许多这些地区，草地退化已经成为一个严重的问题。尽管越来越多的证据表明这些同步变化对生物和非生物生态系统成分的复合效应，但我们仍然不知道它们将如何影响生态系统成分之间的耦合及其对生态系统功能的影响。在此，我们评估了降水频率减少和草地退化对生态系统耦合的影响，基于多物种群落及其物理化学环境、个体功能和生态系统多功能的平均两两相关强度进行了量化，并在植物-线虫-微生物-土壤相互作用的机制框架内报告了它们之间的关系。降水频率降低导致生态系统耦合不良，地上植物生物量、土壤含水量、土壤养分水平、土壤生物群丰度和多功能性降低。而减少降水频率的处理则增加了地下植物生物量和土壤潜在酶活性。严重的退化导致生态系统解耦，抑制了大部分单个功能和多功能。利用结构方程模型，我们发现耦合对多功能性有很强的直接正向影响（标准化总效应：0.74），而土壤水分变化较大（- 0.54）和土壤pH值较高（- 0.53）会削弱多功能性。生态系统耦合对降水变化和退化的高度敏感性突出了在预测变化环境下早期生态影响时考虑生物和非生物组分之间相互作用的重要性。此外，生态系统耦合与功能之间的正相关关系表明，通过加强生态相互作用可以实现退化草地的恢复。在《华尔街日报》博客上阅读免费的《简明语言摘要》。
Grasslands across arid and semi‐arid regions are predicted to experience reductions in precipitation frequency. Besides, grassland degradation has become a serious problem in many of these areas. Despite increasing evidence suggesting compound effects of these synchronous alterations on biotic and abiotic ecosystem constituents, we still do not know how they will impact the coupling among ecosystem constituents and its consequences on ecosystem functioning. Here, we assessed the effects of decreased precipitation frequency and grassland degradation on ecosystem coupling, quantified based on the mean strength of pairwise correlations among multispecies communities and their physicochemical environment, individual functions and ecosystem multifunctionality, and reported their relationships within a mechanistic plant–nematode–micro‐organism–soil interactions framework. Decreased precipitation frequency led to poorly coupled ecosystems, and reduced aboveground plant biomass, soil water content, soil nutrient levels, soil biota abundance and multifunctionality. By contrast, belowground plant biomass and soil potential enzyme activities increased under decreased precipitation frequency treatment. Severe degradation resulted in decoupled ecosystems and suppressed most of individual functions and multifunctionality. Using structural equation modelling, we showed that coupling had a strong direct positive effect on multifunctionality (standardized total effect: 0.74), while multifunctionality was weakened by greater soil water variation (−0.54) and higher soil pH (−0.53). The great sensitivity of ecosystem coupling to altered precipitation regimes and degradation highlights the importance of considering interactions among biotic and abiotic components when predicting early ecological impacts under changing environments. Moreover, the positive relationship between ecosystem coupling and functioning suggests that restoration of degraded grasslands may be achieved by intensifying ecological interactions. Read the free Plain Language Summary for this article on the Journal blog.