Ersoy Zeynep, López-Rodríguez Nieves, Acosta Raúl, Soria Maria, Gomà Joan, Gallart Francesc, Múrria Cesc, Latron Jérôme, Llorens Pilar, Fortuño Pau, Quevedo-Ortiz Guillermo, Cid Núria, Prat Narcís, Cañedo-Argüelles Miguel, Bonada Núria
FEHM-Lab (Freshwater Ecology, Hydrology and Management), Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Facultat de Biologia, Universitat de Barcelona, Barcelona, Catalonia, Spain; Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain.
FEHM-Lab (Freshwater Ecology, Hydrology and Management), Departament de Biologia Evolutiva, Ecologia i Ciències Ambientals, Facultat de Biologia, Universitat de Barcelona, Barcelona, Catalonia, Spain; Institut de Recerca de la Biodiversitat (IRBio), Universitat de Barcelona, Barcelona, Spain; SHE2 group (Surface Hydrology, Ecology and Erosion), Institute of Environmental Assessment and Water Research, IDAEA, CSIC, Barcelona, Catalonia, Spain.
Sci Total Environ. 2024 Oct 20;948:174825. doi: 10.1016/j.scitotenv.2024.174825. Epub 2024 Jul 15.
Temporary rivers, forming the majority of river networks worldwide, are key biodiversity hotspots. Despite their great value for maintaining biodiversity and ecosystem functioning, they are often neglected in biomonitoring programs due to several challenges, such as their variable hydromorphology and the difficulty of establishing reference conditions given their dynamic nature, resulting in highly variable communities. Disconnected pools often form in temporary rivers when flow ceases, providing refuge for aquatic taxa. Given their importance for biodiversity conservation, revising and adapting biotic indices are needed. Here, we evaluate the performance of current biological indices designed for perennial rivers (macroinvertebrates, diatoms) and functional metrics (macroinvertebrates) in assessing biological quality of disconnected pools. We sampled 55 disconnected pools in Catalonia, NE Spain, covering local (e.g., physico-chemical variables, water chemistry) and regional (e.g., human influence, hydrological variables at the water body level) natural and anthropogenic gradients. Only a few macroinvertebrate biotic indices (e.g., family richness, EPT/EPT + OCH and OCH) showed strong responses to anthropogenic predictors and were unaffected by natural predictors at both local and regional scales, making them suitable for biomonitoring. Of the newly adopted functional metrics of macroinvertebrate communities tested, only two (i.e., functional redundancy of predators and response diversity based on the total community) responded strongly to anthropogenic predictors. The rest showed varying responses to the interactive effect of anthropogenic and natural predictors, requiring calibration efforts. Models assessing these metrics explained <40 % of the total variation, likely due to the interplay of colonization/extinction dynamics and density-dependent trophic interactions governing community assemblages in disconnected pools. Although some existing biological metrics could potentially be used to monitor the ecological status of disconnected pools, we call for further development of biomonitoring tools specifically designed for these habitats since they will become more widespread with global change.
临时性河流构成了全球大部分的河网，是重要的生物多样性热点地区。尽管它们对于维持生物多样性和生态系统功能具有巨大价值，但由于面临诸多挑战，如水文形态多变，且鉴于其动态性质难以确立参照条件，导致群落高度可变，因而在生物监测项目中常被忽视。当水流停止时，临时性河流中常常会形成孤立的水塘，为水生生物类群提供庇护所。鉴于其对生物多样性保护的重要性，需要对生物指数进行修订和调整。在此，我们评估了当前为常年性河流设计的生物指数（大型无脊椎动物、硅藻）和功能指标（大型无脊椎动物）在评估孤立水塘生物质量方面的表现。我们在西班牙东北部加泰罗尼亚地区对55个孤立水塘进行了采样，涵盖了局部（如物理化学变量、水化学）和区域（如人类影响、水体层面的水文变量）的自然和人为梯度。只有少数大型无脊椎动物生物指数（如科丰富度、EPT/EPT + OCH和OCH）在局部和区域尺度上对人为预测因子表现出强烈响应，且不受自然预测因子影响，使其适合用于生物监测。在所测试的新采用的大型无脊椎动物群落功能指标中，只有两个（即捕食者的功能冗余和基于整个群落的响应多样性）对人为预测因子有强烈响应。其余指标对人为和自然预测因子的交互作用表现出不同的响应，需要进行校准。评估这些指标的模型解释的总变异不到40%，这可能是由于孤立水塘中群落组装过程中定殖/灭绝动态和密度依赖的营养相互作用相互影响所致。尽管一些现有的生物指标可能可用于监测孤立水塘的生态状况，但我们呼吁进一步开发专门针对这些栖息地设计的生物监测工具，因为随着全球变化，它们将变得更加普遍。
