CCMAR, CIMAR Associated Laboratory, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal; Department of Zoology and Entomology, Rhodes University, Grahamstown 6140, South Africa.
Department of Zoology and Entomology, Rhodes University, Grahamstown 6140, South Africa.
Sci Total Environ. 2020 Nov 15;743:140723. doi: 10.1016/j.scitotenv.2020.140723. Epub 2020 Jul 7.
Can intraspecific diversity functionally supersede interspecific diversity? Recent studies have established the ecological effects of intraspecific variation on a number of ecosystem dynamics including resilience and productivity and we hypothesised that they may functionally exceed those of species diversity. We focused on a coastal ecosystem dominated by two coexisting bioengineering mussel species, one of which, Perna perna, displays two distinct phylogeographic lineages. A manipulative field experiment revealed greater habitat structural complexity and a more benign microscale environment within beds of the eastern lineage than those of the western lineage or the second species (Mytilus galloprovincialis); the latter two did not differ. Similarly, while infaunal species abundance and biomass differed significantly between the two lineages of Perna, there was no such difference between Mytilus and the western Perna lineage. The evenness and diversity of associated infaunal assemblages responded differently. Diversity differed relatively weakly between species, while evenness showed a very strong difference between conspecific lineages. Our results show that variation within a species can functionally supersede diversity between species. As the two P. perna lineages have different physiological tolerances, we expect them to react differently to environmental change. Our findings indicate that predicting the ecosystem-level consequences of climate change requires an understanding of the relative strengths of within- and between-species differences in functionality.
种内多样性在功能上可以超越种间多样性吗？最近的研究已经确定了种内变异对许多生态系统动态的生态影响，包括恢复力和生产力，我们假设它们在功能上可能超过物种多样性。我们专注于一个由两种共存的生物工程贻贝物种主导的沿海生态系统，其中一种贻贝，即 Perna perna，表现出两种截然不同的系统发育谱系。一项操纵性野外实验表明，与西部谱系或第二种贻贝（Mytilus galloprovincialis）相比，东部谱系的贻贝床具有更大的生境结构复杂性和更良性的微尺度环境；后两者没有差异。同样，虽然 Perna 的两个谱系之间的底栖动物物种丰度和生物量有显著差异，但 Mytilus 和西部 Perna 谱系之间没有这种差异。相关底栖动物组合的均匀度和多样性的反应不同。物种之间的多样性差异相对较弱，而同种谱系之间的均匀度差异非常大。我们的结果表明，一个物种内的变异在功能上可以超越物种之间的多样性。由于这两个 P. perna 谱系具有不同的生理耐受性，我们预计它们会对环境变化有不同的反应。我们的研究结果表明，预测气候变化对生态系统水平的影响需要了解物种内和物种间功能差异的相对强度。
