The importance of different spatial scales in determining structural and functional characteristics of deep-sea infauna communities

[摘要] The urge to understand spatial distributions of species and communities andtheir causative processes has continuously instigated the development andtesting of conceptual models in spatial ecology. For the deep sea, there isevidence that structural and functional characteristics of benthiccommunities are regulated by a multitude of biotic and environmentalprocesses that act in concert on different spatial scales, but the spatialpatterns are poorly understood compared to those for terrestrial ecosystems.Deep-sea studies generally focus on very limited scale ranges, therebyimpairing our understanding of which spatial scales and associated processesare most important in driving structural and functional diversity ofcommunities. Here, we used an extensive integrated dataset of free-livingnematodes from deep-sea sediments to unravel the importance of differentspatial scales in determining benthic infauna communities. Multiple-factormultivariate permutational analyses were performed on different sets ofcommunity descriptors (structure, structural and functional diversity,standing stock). The different spatial scales investigated cover two marginsin the northeast Atlantic, several submarine canyons/channel/slope areas, abathymetrical range of 700–4300 m, different sampling locations at eachstation, and vertical sediment profiles. The results indicated that the mostimportant spatial scale for structural and functional diversity and standingstock variability is the smallest one; infauna communities changedsubstantially more with differences between sediment depth layers than withdifferences associated to larger geographical or bathymetrical scales.Community structure differences were greatest between stations at bothmargins. Important regulating ecosystem processes and the scale on which theyoccur are discussed. The results imply that, if we are to improve ourunderstanding of ecosystem patterns of deep-sea infauna and the relevantprocesses driving their structure, structural and functional diversity, andstanding stock, we must pay particular attention to the small-scaleheterogeneity or patchiness and the causative mechanisms acting on thatscale.

[学科分类] 地球化学与岩石