Lan Jing, Sun Zijian, Feng Jianyi, Zhao Chunlin, Kang Da, Zhu Wenbo, Zhao Tian, Su Shengqi
College of Fisheries, Southwest University, Chongqing, 400715, China.
CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization and Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, 610041, China.
Front Zool. 2023 Feb 6;20(1):7. doi: 10.1186/s12983-023-00485-0.
Functional diversity is important to maintain ecosystem functioning. Species with different ecomorphological traits may display distinct functional roles in ecosystems. Accordingly, functionally extreme species are more important as they can exhibit specific strategies. However, little is known about the distribution patterns of functionally extreme species at a local scale and whether the prior extinction of extreme species can cause significant effects on functional diversity. In addition, no empirical studies have been conducted on the microhabitat determinants of extreme species to maintain the functional diversity.
This study collected 1470 tadpoles belonging to 6 families and 20 anuran species. These species were subsequently divided into 65 functional entities based on their developmental stages to incorporate intraspecific traits variability. As a result, we detected seven extreme functional entities, accounting for 10.7% of the total number of entities. Moreover, the prior extinction of extreme entities can lead to a significant decrease in functional diversity compared with the random extinction of entities. Microhabitat variables such as conductivity, water depth, and current velocity determined the distribution of extreme entities.
Although the functionally extreme entities only represented a small proportion of the total number of tadpoles, they played irreplaceable roles in maintaining functional diversity. Their extinction may induce high functional vulnerability in tadpole communities. Therefore, anuran species with extreme tadpole traits need to be projected for amphibian conservation.
功能多样性对于维持生态系统功能至关重要。具有不同生态形态特征的物种可能在生态系统中发挥不同的功能作用。因此，功能上极端的物种更为重要，因为它们能够展现出特定的策略。然而，对于功能极端物种在局部尺度上的分布模式，以及极端物种的提前灭绝是否会对功能多样性产生显著影响，我们知之甚少。此外，尚未有关于极端物种微生境决定因素以维持功能多样性的实证研究。
本研究收集了属于6个科和20种无尾目物种的1470只蝌蚪。随后根据它们的发育阶段将这些物种分为65个功能实体，以纳入种内性状变异性。结果，我们检测到7个极端功能实体，占实体总数的10.7%。此外，与实体的随机灭绝相比，极端实体的提前灭绝会导致功能多样性显著下降。电导率、水深和流速等微生境变量决定了极端实体的分布。
尽管功能极端实体仅占蝌蚪总数的一小部分，但它们在维持功能多样性方面发挥了不可替代的作用。它们的灭绝可能会在蝌蚪群落中引发高度的功能脆弱性。因此，具有极端蝌蚪特征的无尾目物种需要被纳入两栖动物保护计划。
