Southern Research Station, USDA Forest Service, Oxford, Mississippi, United States.
Department of Biology, University of Mississippi, University, Mississippi, United States.
PeerJ. 2024 Sep 24;12:e18006. doi: 10.7717/peerj.18006. eCollection 2024.
Understanding the relationship between multi-scale processes driving community- and population-level diversity can guide conservation efforts. While the importance of population-level genetic diversity is widely recognized, it is not always assessed for conservation planning, and positive correlations with community-level diversity are sometimes assumed, such that only the latter is measured. We surveyed species richness and cumulative multispecies abundance of crayfishes in impounded and unimpounded streams in the southern Appalachian Mountains (Alabama, USA). We simultaneously assessed levels of population genetic diversity within two focal crayfishes ( and ) using nuclear (nDNA; inter-simple sequence repeat (ISSR)) and mitochondrial DNA (mtDNA; mitochondrial DNA cytochrome oxidase subunit I (mtCOI)) markers. We then tested for species-genetic diversity correlations (SGDCs), species diversity-abundance correlations (., more individuals hypothesis, MIH), and abundance-genetic diversity correlations (AGDCs) across sites. We also examined the relationship between each of the three different types of correlation (., species richness, cumulative multispecies abundance, and population genetic diversity) and stream habitat characteristics and fragmentation. Surprisingly, based on mtDNA data, sites with the greatest multispecies abundance had the lowest genetic diversity, indicating a negative AGDC. However, no AGDC was evident from nDNA. There was no evidence of SGDCs for based on either of the two genetic data types. For , there was no evidence for SGDC or AGDC. When considering the community-level data only, there was no support for the MIH. Stream width was positively correlated with genetic diversity, but negatively correlated with multispecies abundance. Similarly, species richness was positively correlated with stream width in unimpounded streams but negatively correlated with width in impounded streams. These findings indicate that community-level diversity cannot be indiscriminately used as a proxy for population-level diversity without empirically testing this correlation on the focal group. As such, community- and population-level assessments for multiple crayfish species are needed to better understand drivers of diversity and eco-evolutionary processes which will aid in the conservation of this vulnerable taxonomic group.
理解驱动群落和种群水平多样性的多尺度过程之间的关系，可以指导保护工作。虽然种群水平遗传多样性的重要性得到了广泛的认可，但在保护规划中并不总是对其进行评估，并且有时会假设与群落水平多样性呈正相关，以至于只测量后者。我们调查了美国南部阿巴拉契亚山脉（阿拉巴马州）有坝和无坝溪流中的螯虾物种丰富度和累积多物种丰度。我们同时使用核（nDNA；简单重复序列间的相互简单序列重复（ISSR））和线粒体 DNA（mtDNA；线粒体 DNA 细胞色素氧化酶亚基 I（mtCOI））标记，评估了两个焦点螯虾（和）的种群遗传多样性水平。然后，我们在各个地点测试了物种-遗传多样性相关性（SGDC）、物种多样性-丰度相关性（.,更多个体假设，MIH）和丰度-遗传多样性相关性（AGDC）。我们还检查了三种不同类型的相关性（.,物种丰富度、累积多物种丰度和种群遗传多样性）与溪流生境特征和破碎化之间的关系。令人惊讶的是，基于 mtDNA 数据，多物种丰度最大的地点遗传多样性最低，表明存在负 AGDC。然而，nDNA 没有显示出任何 AGDC。基于两种遗传数据类型，均未发现针对的 SGDC。对于 ，没有 SGDC 或 AGDC 的证据。当仅考虑群落水平数据时，MIH 没有得到支持。溪流宽度与 遗传多样性呈正相关，但与多物种丰度呈负相关。同样，在无坝溪流中，物种丰富度与溪流宽度呈正相关，但在有坝溪流中与宽度呈负相关。这些发现表明，如果没有在焦点群体中对这种相关性进行实证检验，就不能将群落水平多样性不加区分地用作种群水平多样性的代理。因此，需要对多种螯虾物种进行群落和种群评估，以更好地了解多样性的驱动因素和生态进化过程，这将有助于保护这个脆弱的分类群。
