Zheng Cheng, Yuan Liuhuan, Shi Haijing, Duan Gaohui, Liu Yangyang, Wen Zhongming
College of Grassland Agriculture, Northwest A&F University, Yangling, Shaanxi, China.
Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, Yangling, Shaanxi, China.
Front Plant Sci. 2024 Nov 21;15:1472439. doi: 10.3389/fpls.2024.1472439. eCollection 2024.
Depending on specific environmental conditions, plantations can have a positive or negative impact on ecosystem function. Numerous studies have demonstrated that plantations on the Loess Plateau has decreased the water levels in this area, increasing the risks of water resource security. Understanding the ecosystem function of the plantations is thought to be critical to vegetation restoration in the Loess Plateau. However, no consensus exists on the mechanism by which afforestation affects moisture regulation under varying environmental conditions nor on how to manage plantations to maintain the ecosystem function. In this study, we used the response-effect trait approach to examine the evolving relationship between community functional composition and water regulation by collecting community samples from plantations and natural ecosystems across three vegetation zones (steppe, forest-steppe, and forest). Our goal was to clarify how the afforestation of impacts functional composition and, consequently, moisture regulation. The findings indicated that negatively impacts community structure and moisture regulation in the drier steppe and forest-steppe (<0.05). Afforestation of increases specific leaf area (SLA), leaf nitrogen content (LNC), and plant height (H), while weakening the trait correlations within the community, which is the main cause of the negative effect. Furthermore, we discovered that response and effect traits overlapped (leaf tissue density, LTD) in natural ecosystems but not in afforested ecosystems within the response-effect traits framework. In conclusion, our findings indicated that the functional structure of communities and moisture regulation are impacted plantations in drier habitats. Additionally, because response-effect traits do not overlap and trait coordination declines, afforestation increases instability in the moisture regulation maintenance. The introduction of weakens the coordination and coupling relationships between traits. We advise giving preference to native species over for restoration in the dry steppe and forest-steppe zones. Trait-based restoration approaches can enhance the efficacy of restoration measure in achieving desired ecosystem functions.
根据特定的环境条件，人工林可能对生态系统功能产生积极或消极影响。大量研究表明，黄土高原的人工林降低了该地区的地下水位，增加了水资源安全风险。了解人工林的生态系统功能被认为对黄土高原的植被恢复至关重要。然而，对于造林在不同环境条件下影响水分调节的机制以及如何管理人工林以维持生态系统功能，目前尚无共识。在本研究中，我们采用响应-效应性状方法，通过收集三个植被带（草原、森林草原和森林）的人工林和自然生态系统的群落样本，研究群落功能组成与水分调节之间的演变关系。我们的目标是阐明造林如何影响功能组成，进而影响水分调节。研究结果表明，在较干旱的草原和森林草原地区（<0.05），造林对群落结构和水分调节产生负面影响。造林增加了比叶面积（SLA）、叶片氮含量（LNC）和株高（H），同时削弱了群落内的性状相关性，这是产生负面影响的主要原因。此外，我们发现在响应-效应性状框架内，自然生态系统中的响应和效应性状（叶组织密度，LTD）存在重叠，而在造林生态系统中则不存在。总之，我们的研究结果表明，较干旱生境中的人工林会影响群落的功能结构和水分调节。此外，由于响应-效应性状不重叠且性状协调性下降，造林增加了水分调节维持的不稳定性。外来物种的引入削弱了性状之间的协调和耦合关系。我们建议在干旱草原和森林草原地区的恢复中，优先选择本地物种而非外来物种。基于性状的恢复方法可以提高恢复措施实现预期生态系统功能的效果。
