Species traits and environmental conditions govern the relationship between biodiversity effects across trophic levels
Species traits and environmental conditions govern the relationship between biodiversity effects across trophic levels
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物种特征和环境条件决定不同营养级生物多样性影响之间的关系
DOI：
10.1007/s00442-011-2110-1
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发表时间：
2011
期刊：
影响因子：
2.7
通讯作者：
H. Galbraith
中科院分区：
文献类型：
--
作者：
D. Spooner;C. Vaughn;H. Galbraith
在交替的营养水平上，环境变化对生物多样性-生态系统功能关系的影响是不同的。淡水贻贝通过排泄营养物质为河流食物网施肥，贻贝物种特有的排泄率取决于环境条件。我们询问不同环境中贻贝多样性的差异如何影响初级生产者和消费者之间的动态。在夏季（低流量、高温）和秋季（中等流量和温度）条件下，对贻贝丰富度进行了野外实验，测量了营养限制、藻类生物量和放牧栖鱼丰度，并对数据进行了非海进超产分析和生物多样性三方划分分析。藻类生物量和chironomid丰度的最佳解释是贻贝物种间性状无关的互补性，但不同营养水平（藻类和食草动物）间生物多样性效应的关系取决于贻贝物种性状表达（养分排泄和活动水平）的季节差异。物种身份效应和总体多样性效应都与养分限制的大小有关。我们的研究结果表明，资源供应（营养物质和栖息地）物种群体的生物多样性影响食物网动态，了解物种特征和环境背景对解释生物多样性实验非常重要。
Changing environments can have divergent effects on biodiversity–ecosystem function relationships at alternating trophic levels. Freshwater mussels fertilize stream foodwebs through nutrient excretion, and mussel species-specific excretion rates depend on environmental conditions. We asked how differences in mussel diversity in varying environments influence the dynamics between primary producers and consumers. We conducted field experiments manipulating mussel richness under summer (low flow, high temperature) and fall (moderate flow and temperature) conditions, measured nutrient limitation, algal biomass and grazing chironomid abundance, and analyzed the data with non-transgressive overyielding and tripartite biodiversity partitioning analyses. Algal biomass and chironomid abundance were best explained by trait-independent complementarity among mussel species, but the relationship between biodiversity effects across trophic levels (algae and grazers) depended on seasonal differences in mussel species’ trait expression (nutrient excretion and activity level). Both species identity and overall diversity effects were related to the magnitude of nutrient limitation. Our results demonstrate that biodiversity of a resource-provisioning (nutrients and habitat) group of species influences foodweb dynamics and that understanding species traits and environmental context are important for interpreting biodiversity experiments.