Duarte CM
Instituto Mediterráneo de Estudios Avanzados, CSIC-Univ. Illes Balears, C/Miquel Marqués 21, 07190, Mallorca, Esporles, Spain
J Exp Mar Biol Ecol. 2000 Jul 30;250(1-2):117-131. doi: 10.1016/s0022-0981(00)00194-5.
Efforts to test the hypothesised positive link between ecosystem services and functions and biodiversity are increasing in order to forecast the consequences of the present erosion of biodiversity on ecosystem functions and to provide an additional basis for the conservation of biodiversity. These efforts have been, however, modest in marine ecosystems. An examination of seagrass communities, which are simple assemblages with a limited membership of about 50 species worldwide and <12 species in any one community, provides, however, strong evidence for the existence of such positive link between species richness and ecosystem functions. Ecosystem functions are, however, dependent on the particular membership of the community, rather that its number, for the functions are species-specific properties. Yet evidence, is provided, that an increasing species richness should be, on average, linked to an increase in the functional repertoire present in the community, will lead to a more efficient use of resources and a greater capacity to ensure the sustainability of ecosystem functions under disturbance or ecosystem change. Closer examination indicates that the functional variability of mixed-species seagrass assemblages is correlated to the variability in species size, whereas species of similar size tend to show similar functional capacities and, therefore, a greater degree of functional redundancy. In addition, the demonstration of positive interactions in seagrass communities, which are also dependent on the presence of engineering species in the community that facilitate the growth of other species, provides increasing grounds to expect an enhanced functional performance of mixed communities over that expected from a simple additive contribution of the community members. Multispecific communities also hold, within the functional repertoire they contain, many unrealised functional potentials that may prove instrumental to ensure the sustainability of ecosystem functions in the presence of disturbance or a changing environment. The arguments offered, illustrated for the comparatively simple seagrass communities, provide strong reasons to expect a strong - if difficult to test experimentally - positive relationship between species diversity and the functions of marine ecosystems and, thereby, the services they yield to humanity.
为了预测当前生物多样性丧失对生态系统功能的影响，并为生物多样性保护提供更多依据，人们越来越多地致力于检验生态系统服务与功能和生物多样性之间假设的正向联系。然而，在海洋生态系统中，这些努力的规模较小。不过，对海草群落的研究提供了有力证据，证明物种丰富度与生态系统功能之间存在这种正向联系。海草群落是简单的组合，全球范围内成员有限，约有50种，任何一个群落中不到12种。然而，生态系统功能取决于群落的特定成员组成，而非其数量，因为这些功能是物种特有的属性。不过，有证据表明，平均而言，物种丰富度的增加应与群落中存在的功能库的增加相关联，这将导致资源利用更高效，并在受到干扰或生态系统变化时更有能力确保生态系统功能的可持续性。进一步研究表明，混合物种海草组合的功能变异性与物种大小的变异性相关，而大小相似的物种往往表现出相似的功能能力，因此功能冗余度更高。此外，海草群落中正向相互作用的证明也依赖于群落中促进其他物种生长的工程物种的存在，这使得人们越来越有理由期望混合群落的功能表现优于仅由群落成员简单相加所预期的表现。多物种群落还在其包含的功能库中拥有许多未实现的功能潜力，这些潜力可能对确保在受到干扰或环境变化时生态系统功能的可持续性起到重要作用。以相对简单的海草群落为例所提出的观点，有力地表明，尽管难以通过实验验证，但物种多样性与海洋生态系统功能之间存在很强的正向关系，进而与它们为人类提供的服务之间也存在正向关系。
