当前位置: X-MOL 学术Ecosystems › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Leaf Nutrients and Macroinvertebrates Control Litter Mixing Effects on Decomposition in Temperate Streams
Ecosystems ( IF 3.7 ) Pub Date : 2019-06-25 , DOI: 10.1007/s10021-019-00410-9
Mathieu Santonja , Héctor Rodríguez-Pérez , Nathalie Le Bris , Christophe Piscart

Plant litter decomposition is an essential ecosystem function in temperate streams. Both riparian vegetation and decomposer communities are major determinants of the decomposition efficiency and the interactions occurring within litter mixtures. However, the extent to which such litter mixture interactions are affected by combined shifts in litter traits and decomposer community is not well understood. We used leaf litter from 10 European tree species in order to study litter decomposition and litter mixture effects occurring in two-species litter mixtures in a temperate forested stream of northwestern France. The study distinguished between (1) decomposition involving microorganisms alone or together with invertebrates, and (2) decomposition involving litter mixtures of similar or dissimilar nutrient content. Increasing mean litter nutrient concentration favored both microbial activity and litter decomposition rate. Surprisingly, the highest litter mixture effects occurred in mixtures containing two nutrient-rich litters and occurred mainly in macroinvertebrate presence. Both the “mass ratio hypothesis,” expressed as the community-weighted mean traits (TraitCWM), and the “niche complementarity hypothesis,” expressed as the functional dissimilarity of litter traits (TraitFD), contributed to explain litter mixture effects. However, TraitCWM was found to be a better predictor than TraitFD. Finally, when evaluating the individual contributions of litter nutrients, calcium and magnesium appeared as important drivers of litter mixture effects. Our findings suggest that the mass ratio hypothesis overrules the niche complementarity hypothesis as a driver of litter diversity effects. Our study highlights the key importance of macroinvertebrates and of leaf nutrients, such as Ca and Mg, which are often neglected in decomposition studies in streams.



中文翻译:

叶营养物和大型无脊椎动物控制凋落物混合对温带水流分解的影响

植物凋落物分解是温带河流中重要的生态系统功能。河岸植被和分解者群落都是分解效率和凋落物混合物中相互作用的主要决定因素。但是,人们对这种垫料混合物相互作用受垫料性状和分解者群落组合变化的影响程度尚不十分了解。为了研究法国西北部温带森林流中两种物种凋落物混合物中发生的凋落物分解和凋落物混合物效应,我们使用了10种欧洲树种的叶子凋落物。该研究区分了(1)仅涉及微生物或与无脊椎动物一起分解的微生物,以及(2)营养成分相似或不同的凋落物混合物的分解。平均垫料养分浓度的增加有利于微生物活性和垫料分解率。出人意料的是,最高的凋落物混合物效应发生在含有两个营养丰富的凋落物的混合物中,并且主要发生在大型无脊椎动物中。两种“质量比假设”均以社区加权平均特质表示(特质CWM和“生态位互补性假设”表示为凋落物性状的功能差异(特质FD),这有助于解释凋落物混合效应。但是,发现Trait CWM比Trait FD更好。最后,在评估垫料养分的单独贡献时,钙和镁似乎是垫料混合效应的重要驱动因素。我们的发现表明,质量比假说否定了利基互补性假说作为凋落物多样性效应的驱动因素。我们的研究强调了大型无脊椎动物和叶片营养物质(例如Ca和Mg)的关键重要性,而这些物质在河流的分解研究中通常被忽略。

更新日期:2020-04-21
down
wechat
bug