Segrestin Jules, Lisner Aleš, Götzenberger Lars, Hájek Tomáš, Janíková Eva, Jílková Veronika, Konečná Marie, Švancárová Tereza, Lepš Jan
Department of Botany, Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic.
Institute of Botany of the Czech Academy of Sciences, Třeboň, Czech Republic.
Ecology. 2025 May;106(5):e70091. doi: 10.1002/ecy.70091.
Biodiversity loss poses a significant threat to ecosystem functioning. However, much of the empirical evidence for these effects is based on artificial experiments that often fail to simulate the structure of natural communities. Hence, it is still unclear whether natural diversity losses would significantly affect the functioning of "real-world" ecosystems. As subordinate and rare species constitute most of the diversity in natural communities and are often more vulnerable to local extinction, we evaluated their contribution to ecosystem functioning in a naturally species-rich grassland. We focused on two mechanisms by which they can support ecosystem functions: redundancy and complementarity. We conducted two long-term field experiments (>6 years) simulating contrasting biodiversity loss scenarios through the manual removal of plant species and measured the consequences of species loss on various ecosystem functions related to carbon dynamics. The latter were examined seasonally to explore diversity effects outside the typical peak of vegetation. We found that dominant removal led to substantial reductions in aboveground phytomass and litter production and altered the annual carbon fixation capacity of the vegetation, highlighting the pivotal role of dominant species in driving ecosystem functioning. Despite high species diversity, other species could not fully compensate for the loss of a single dominant even after more than 25 years, challenging assumptions about redundancy. Complementarity effects were not detected at the peak of vegetation but were evident in early spring and autumn when subordinate and rare species enhanced ecosystem functions. Surprisingly, belowground phytomass, soil organic carbon content, and litter decomposition were unaffected by species removal, suggesting complex interactions in belowground processes. These findings underscore the importance of dominant species in maintaining ecosystem functioning and emphasize the need for nuanced approaches to studying biodiversity loss in real-world communities. Comprehensive seasonal measurements are essential for accurately discerning the effects of biodiversity on ecosystem dynamics and informing effective conservation strategies that maintain ecosystem functioning.
生物多样性丧失对生态系统功能构成重大威胁。然而，这些影响的许多实证证据都基于人工实验，而这些实验往往无法模拟自然群落的结构。因此，目前仍不清楚自然多样性丧失是否会显著影响 “现实世界” 生态系统的功能。由于从属物种和稀有物种构成了自然群落中的大部分多样性，且往往更容易受到局部灭绝的影响，我们评估了它们在一个物种丰富的天然草原中对生态系统功能的贡献。我们关注它们支持生态系统功能的两种机制：冗余和互补。我们进行了两项长期野外实验（超过6年），通过人工去除植物物种来模拟对比生物多样性丧失情景，并测量了物种丧失对与碳动态相关的各种生态系统功能的影响。对后者进行季节性监测，以探究植被典型高峰期之外的多样性效应。我们发现，去除优势物种导致地上植物生物量和凋落物产量大幅下降，并改变了植被的年固碳能力，突出了优势物种在驱动生态系统功能方面的关键作用。尽管物种多样性很高，但即使在25年多之后，其他物种也无法完全弥补单一优势物种的损失，这对关于冗余的假设提出了挑战。在植被高峰期未检测到互补效应，但在早春和秋季，当从属物种和稀有物种增强生态系统功能时，互补效应很明显。令人惊讶的是，地下植物生物量、土壤有机碳含量和凋落物分解不受物种去除的影响，这表明地下过程中存在复杂的相互作用。这些发现强调了优势物种在维持生态系统功能方面的重要性，并强调需要采用细致入微的方法来研究现实世界群落中的生物多样性丧失。全面的季节性测量对于准确识别生物多样性对生态系统动态的影响以及为维持生态系统功能的有效保护策略提供依据至关重要。
