Additive effects of physical stress and herbivores on intertidal seaweed biodiversity.
Additive effects of physical stress and herbivores on intertidal seaweed biodiversity.
复制标题
物理压力和食草动物对潮间带海藻生物多样性的累加效应。
DOI：
10.1890/12-0401.1
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发表时间：
2013
期刊：
影响因子：
4.8
通讯作者：
E. Jones
中科院分区：
文献类型：
--
作者：
Susan L. Williams;M. E. Bracken;E. Jones
岩质潮间带海藻生物多样性格局影响着这些重要初级生产者群落的恢复力和功能。反过来，海藻生物多样性模式是许多生态因素的结果。研究了热胁迫、干旱胁迫、草食和营养物对加利福尼亚北部岩石海岸线上海藻生物多样性的影响。在一个完全交叉的设计中，在波浪保护和暴露的两个潮汐高度，我们部署了屏幕来减少压力，去除食草动物，并添加了18个月的营养物质。这些处理降低了海水和海藻中的温度，增加了相对湿度，降低了草食动物丰度，增加了氮含量。海藻丰度和生物多样性（盖度、生物量、物种丰富度、多样性、均匀度和群落组成）受潮高、生理应激和食草动物的影响。除生物量和均匀度外，波浪暴露影响所有响应变量。胁迫和草食动物对海藻的丰度和多样性有独立的加性影响。物理压力并没有使海藻群落整体上更容易受到食草动物的影响，尽管屏障对食草动物的丰度也有积极影响，但对海藻生物多样性有总体的积极影响。营养物对海藻的生物多样性几乎没有影响，我们观察到营养物添加对草食性密度和生物量没有自下而上的影响。小绿藻和硅藻对整个藻类覆盖和不同处理的组成变化有重要贡献，但较大的大型藻类主导了物种丰富度的响应。压力和草食之间明显缺乏相互作用，这凸显了海藻群落如何能够独立应对生物多样性的重要驱动因素。因此，非加性的、潜在的协同效应不一定会使对海藻生物多样性如何响应环境变化的理解复杂化。
Patterns in rocky intertidal seaweed biodiversity influence the resilience and functioning of these important primary producer communities. In turn, seaweed biodiversity patterns are the result of many ecological factors. We determined the influences of thermal and desiccation stress, herbivory, and nutrients on seaweed biodiversity on a northern California rocky shoreline. In a fully crossed design at two tidal heights at wave-protected and exposed sites, we deployed screens to reduce stress, removed herbivores, and added nutrients for 18 months. The treatments reduced temperature, increased relative humidity, decreased herbivore abundances, and increased nitrogen in both seawater and seaweeds. Seaweed abundance and biodiversity (cover, biomass, species richness, diversity, evenness, and community composition) were influenced by tidal height, physical stress, and herbivores. Wave exposure affected all response variables except biomass and evenness. Stress and herbivores had independent additive effects on seaweed abundance and diversity. Physical stress did not make the community as a whole more susceptible to herbivores, and screens had overarching positive effects on seaweed biodiversity even though they also had positive effects on herbivore abundance. Nutrients had virtually no effect on seaweed biodiversity, and we observed no bottom-up effects of nutrient addition on herbivore density or biomass. Small green algae and diatoms were important contributors to overall algal cover and to changes in composition across treatments, but larger macroalgae dominated the species richness response. The striking absence of interactions between stress and herbivory highlights how seaweed communities can respond independently to important drivers of biodiversity. Thus, nonadditive, potentially synergistic effects do not necessarily complicate the understanding of how seaweed biodiversity responds to environmental change.
影响因子：
14.6
作者：
Martijn Gough
通讯作者：
Martijn Gough