Araújo Francisco Gerson, Uehara Wagner, Azevedo Márcia Cristina Costa de, Guedes Gustavo Henrique Soares
Laboratório de Ecologia de Peixes, Departamento de Biologia Animal, Universidade Federal Rural do Rio de Janeiro, 23897-000, Seropédica, RJ, Brazil.
Mar Environ Res. 2025 Sep;210:107360. doi: 10.1016/j.marenvres.2025.107360. Epub 2025 Jul 11.
Understanding how deterministic niche (traits and environment-driven) and stochastic neutral (randomness and dispersal-driven) processes shape communities is essential for predicting biodiversity. We investigated taxonomic and functional β-diversity in fish assemblages from oceanic and estuarine beaches along the Brazilian coast to test assembly processes. We hypothesized that: (H1) Community assembly varies latitudinally, influenced by temperature, regional factors, and beach type. Niche processes are expected to dominate in estuarine beaches due to environmental gradients, while neutral processes should prevail on oceanic beaches where physical and chemical conditions are more stable and connectivity with the sea is higher; (H2) Niche processes dominate in the Transition and Warm Temperate regions, where steeper environmental gradients are present. In contrast, neutral processes prevail in the Tropical region, driven by temperature stability and greater species dispersal. Using Mantel tests and null model simulations, we found that niche-based processes predominated at latitudinal scale in both beach types, partially rejecting H1. High taxonomic turnover and functional nestedness indicate species replacement with reduced functional diversity. Oceanic beaches, characterized by high water dynamism, showed niche-driven patterns based on β-diversity components. In estuarine beaches, strong local environmental gradients drove niche-based turnover, although nestedness suggested some neutral influence. At regional scale, niche processes were stronger in oceanic beaches of the Transition and Warm Temperate regions, while neutral dynamics dominated in the Tropical region, supporting H2. In estuarine beaches, niche-based processes predominated regionally, though less intensely. These findings show that niche and neutral processes jointly shape fish communities, varying by region and habitat, and underscore the need for region-specific conservation strategies. Estuarine beaches require protection for disturbance-sensitive species, while oceanic beaches benefit from maintaining connectivity. Niche-driven communities are more vulnerable to local impacts, whereas neutral-driven ones are more resilient but still rely on dispersal. Effective coastal management should prioritize connectivity in tropical regions and focus on local conditions and habitat diversity in temperate and transitional zones, supporting targeted, evidence-based conservation under climate and human pressures.
了解确定性生态位（由性状和环境驱动）和随机中性（由随机性和扩散驱动）过程如何塑造群落对于预测生物多样性至关重要。我们调查了巴西海岸沿线海洋和河口海滩鱼类群落的分类学和功能β多样性，以测试群落构建过程。我们假设：（H1）群落构建随纬度变化，受温度、区域因素和海滩类型影响。由于环境梯度，生态位过程预计在河口海滩占主导地位，而中性过程应在物理和化学条件更稳定且与海洋连通性更高的海洋海滩上占优势；（H2）生态位过程在存在更陡峭环境梯度的过渡区和暖温带地区占主导地位。相比之下，中性过程在热带地区占主导地位，受温度稳定性和更大的物种扩散驱动。使用Mantel检验和空模型模拟，我们发现基于生态位的过程在两种海滩类型的纬度尺度上占主导地位，部分否定了H1。高分类学周转率和功能嵌套表明物种替代且功能多样性降低。以高水动力为特征的海洋海滩基于β多样性成分呈现出生态位驱动的模式。在河口海滩，强烈的局部环境梯度驱动了基于生态位的周转率，尽管嵌套性表明存在一些中性影响。在区域尺度上，生态位过程在过渡区和暖温带地区的海洋海滩更强，而中性动态在热带地区占主导地位，支持了H2。在河口海滩，基于生态位的过程在区域上占主导地位，尽管强度较小。这些发现表明，生态位和中性过程共同塑造鱼类群落，随区域和栖息地而变化，并强调了针对特定区域的保护策略的必要性。河口海滩需要保护对干扰敏感的物种，而海洋海滩则受益于保持连通性。由生态位驱动的群落更容易受到局部影响，但由中性驱动的群落更具恢复力，但仍依赖扩散。有效的海岸管理应优先考虑热带地区的连通性，并关注温带和过渡带的当地条件和栖息地多样性，在气候和人类压力下支持有针对性的、基于证据的保护。
