Abstract:
Higher biodiversity is often assumed to be a more desirable scenario for maintaining the functioning of ecosystems, but whether species-richer communities are also more disturbance-tolerant remains controversial. In this study, we investigated the bacterial communities based on 472 soil samples from 28 forests across China with associated edaphic and climatic properties. We developed two indexes (i.e., community mean tolerance breadth [CMTB] and community mean response asynchrony [CMRA]) to explore the relationship between diversity and community resistance potential. Moreover, we examined this resistance potential along the climatic and latitudinal gradients. We revealed that CMTB was significantly and negatively related to species richness, resulting from the changes in balance between relative abundances of putative specialists and generalists. In comparison, we found a unimodal relationship between CMRA and richness, suggesting that higher biodiversity might not always lead to higher community resistance. Moreover, our results showed differential local patterns along latitude. In particular, local patterns in the northern region mainly followed general relationships rather than those for the southern forests, which may be attributed to the differences in annual means and annual variations of climate conditions. Our findings highlight that the community resistance potential depends on the composition of diverse species with differential environmental tolerance and responses. This study provides a new, testable evaluation by considering tolerance breadth and response asynchrony at the community level, which will be helpful in assessing the influence of disturbance under rapid shifts in biodiversity and species composition as a result of global environmental change.
摘要:
更高的生物多样性通常被认为是维持生态系统功能的更理想的方案,但是物种丰富的社区是否也更容受干扰仍然存在争议。在这项研究中,我们调查了来自中国28个森林的472个土壤样品的细菌群落,这些土壤样品具有相关的土壤和气候特性。我们开发了两个指标(即,社区平均耐受宽度[CMTB]和社区平均响应异步[CMRA]),以探索多样性与社区抵抗潜力之间的关系。此外,我们沿着气候和纬度梯度检查了这种阻力潜力。我们发现CMTB与物种丰富度显著负相关,由于假定的专家和通才的相对丰富之间的平衡变化。相比之下,我们发现CMRA和丰富度之间存在单峰关系,这表明更高的生物多样性可能并不总是导致更高的社区抵抗力。此外,我们的结果显示了沿纬度的不同局部模式。特别是,北部地区的当地模式主要遵循一般关系,而不是南部森林的模式,这可能归因于气候条件的年度均值和年度变化的差异。我们的发现强调,社区的抗性潜力取决于具有不同环境耐受性和响应的不同物种的组成。这项研究提供了一种新的,通过在社区一级考虑容忍度和响应异步性的可测试评估,这将有助于评估全球环境变化导致的生物多样性和物种组成快速变化下的干扰影响。