Diversity and Patch-Size Distributions of Biological Soil Crusts Regulate Dryland Ecosystem Multifunctionality
Diversity and Patch-Size Distributions of Biological Soil Crusts Regulate Dryland Ecosystem Multifunctionality
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DOI：
10.1007/s10021-013-9644-5
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发表时间：
2013-09-01
期刊：
影响因子：
3.7
通讯作者：
Mau, Rebecca L.
中科院分区：
文献类型：
--
作者：
Bowker, Matthew A.;Maestre, Fernando T.;Mau, Rebecca L.
最近的研究表明，旱地的多功能性——同时提供多种生态系统功能——取决于生物多样性。其他报告指出，植被斑块的具体大小分布表明了整个生态系统的健康和功能。利用生物痂（苔藓、地衣和蓝藻的微植被）模型系统和多元模型，我们确定了生物多样性、斑块大小分布和总丰度对养分循环和多功能性的相对重要性。在大多数情况下，我们解释了至少20%到65%的生态系统功能变化，以及42%的多功能性变化。物种丰富度是C循环最重要的决定因素，在非实验野外环境中构成了多样性与功能之间罕见的明确联系。关于石膏质土壤中的碳循环，我们发现，相对于非常小的斑块，小到中等斑块的频率更高的斑块大小分布具有更强的功能。在两种土壤类型中，氮循环主要是生物覆盖的功能，而在石膏质土壤中，越集中的斑块大小分布对氮循环的作用越弱。这三个社区属性对于多功能来说同样重要。我们的研究结果强调了生物多样性以外的生物属性的功能作用，并表明必须同时达到高覆盖和多样性，以及特定的斑块大小分布，才能最大限度地发挥多功能。结果也与其他陆地和水生群落观察到的趋势一致，即与独立考虑的单一功能相比，维持多功能需要更多的生物多样性。
Recent studies report that multifunctionality-the simultaneous provision of multiple ecosystem functions-in drylands depends on biodiversity. Others report that specific size distributions of vegetation patches indicate overall ecosystem health and function. Using a biocrust (micro-vegetation of mosses, lichens, and cyanobacteria) model system, and multivariate modeling, we determined the relative importance of biodiversity, patch-size distribution, and total abundance to nutrient cycling and multifunctionality. In most cases we explained at least 20%, and up to 65%, of the variation in ecosystem functions, and 42% of the variation in multifunctionality. Species richness was the most important determinant of C cycling, constituting an uncommonly clear link between diversity and function in a non-experimental field setting. Regarding C cycling in gypsiferous soils, we found that patch size distributions with a greater frequency of small to medium patches, as opposed to very small patches, were more highly functional. Nitrogen cycling was largely a function of biocrust cover in two soil types, whereas in gypsiferous soils, more central-tending patch size distributions were less functional with regards to N cycling. All three community properties were about equally important to multifunctionality. Our results highlight the functional role of biotic attributes other than biodiversity, and indicate that high cover and diversity, together with a particular patch-size distribution, must be attained simultaneously to maximize multifunctionality. The results also agree with trends observed with other terrestrial and aquatic communities that more biodiversity is needed to sustain multifunctionality compared to single functions considered independently.