Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales, 2052, Australia.
Ecology. 2018 Sep;99(9):1964-1974. doi: 10.1002/ecy.2408. Epub 2018 Aug 7.
Habitat complexity is accepted as a general mechanism for increasing the abundance and diversity of communities. However, the circumstances under which complexity has the strongest effects are not clear. Over 20 degrees of Australia's east coast, we tested whether the effects of within-site structural habitat complexity on the diversity and community structure of sessile marine invertebrates was consistent over a latitudinal gradient where environmental conditions and species composition vary. We used experimental arrays with varied structural treatments to detect whether community cover, species richness, diversity and community composition (β-diversity) changed with increasing complexity. Community response to complexity varied over latitude due to differences in species richness and community development. Increased complexity had the greatest positive effects on community cover and species richness at higher latitudes where recruitment and growth were low. At lower latitudes, community cover and species richness were higher overall and did not vary substantially between complexity treatments. Latitudinal variation in within-treatment β-diversity relative to complexity further suggest divergent community responses. At higher latitudes, increased similarity in more complex treatments suggests community dominance of successful taxonomic groups. Despite limited effects on species richness and community cover at lower latitudes, β-diversity was higher in more complex treatments, signifying potential positive effects of increased complexity at these sites. These results demonstrate the context-dependency of complexity effects in response to variation in species richness and community development and should be taken into consideration to help direct conservation and restoration efforts.
生境复杂性被认为是增加群落丰富度和多样性的一般机制。然而，复杂性影响最强的情况尚不清楚。在澳大利亚东海岸的 20 多度地区，我们测试了在环境条件和物种组成变化的纬度梯度上，场地内结构生境复杂性对固着海洋无脊椎动物多样性和群落结构的影响是否一致。我们使用具有不同结构处理的实验阵列来检测群落盖度、物种丰富度、多样性和群落组成（β-多样性）是否随复杂性的增加而变化。由于物种丰富度和群落发育的差异，群落对复杂性的响应随纬度而变化。在高纬度地区，由于繁殖和生长缓慢，增加复杂性对群落盖度和物种丰富度的积极影响最大。在较低的纬度，群落盖度和物种丰富度总体较高，并且在复杂处理之间没有很大差异。相对于复杂性的处理内β-多样性的纬度变化进一步表明了不同的群落响应。在高纬度地区，更复杂的处理中相似性增加表明成功分类群的群落优势。尽管在较低纬度地区对物种丰富度和群落盖度的影响有限，但更复杂的处理中的β-多样性更高，表明在这些地点增加复杂性可能具有积极影响。这些结果表明，复杂性效应的背景依赖性是对物种丰富度和群落发育变化的响应，应该考虑这些因素，以帮助指导保护和恢复工作。
