Myers Elisabeth M V, Anderson Marti J, Liggins Libby, Harvey Euan S, Roberts Clive D, Eme David
New Zealand Institute for Advanced Study (NZIAS) Massey University Auckland New Zealand.
School of Natural and Computational Sciences Massey University Auckland New Zealand.
Ecol Evol. 2021 Jul 8;11(15):10600-10612. doi: 10.1002/ece3.7871. eCollection 2021 Aug.
Variation in both inter- and intraspecific traits affects community dynamics, yet we know little regarding the relative importance of external environmental filters versus internal biotic interactions that shape the functional space of communities along broad-scale environmental gradients, such as latitude, elevation, or depth. We examined changes in several key aspects of functional alpha diversity for marine fishes along depth and latitude gradients by quantifying intra- and interspecific richness, dispersion, and regularity in functional trait space. We derived eight functional traits related to food acquisition and locomotion and calculated seven complementary indices of functional diversity for 144 species of marine ray-finned fishes along large-scale depth (50-1200 m) and latitudinal gradients (29°-51° S) in New Zealand waters. Traits were derived from morphological measurements taken directly from footage obtained using Baited Remote Underwater Stereo-Video systems and museum specimens. We partitioned functional variation into intra- and interspecific components for the first time using a PERMANOVA approach. We also implemented two tree-based diversity metrics in a functional distance-based context for the first time: namely, the variance in pairwise functional distance and the variance in nearest neighbor distance. Functional alpha diversity increased with increasing depth and decreased with increasing latitude. More specifically, the dispersion and mean nearest neighbor distances among species in trait space and intraspecific trait variability all increased with depth, whereas functional hypervolume (richness) was stable across depth. In contrast, functional hypervolume, dispersion, and regularity indices all decreased with increasing latitude; however, intraspecific trait variation increased with latitude, suggesting that intraspecific trait variability becomes increasingly important at higher latitudes. These results suggest that competition within and among species are key processes shaping functional multidimensional space for fishes in the deep sea. Increasing morphological dissimilarity with increasing depth may facilitate niche partitioning to promote coexistence, whereas abiotic filtering may be the dominant process structuring communities with increasing latitude.
种间和种内性状的变异都会影响群落动态，但对于外部环境过滤与内部生物相互作用的相对重要性，我们知之甚少，而正是这些因素沿着纬度、海拔或深度等大尺度环境梯度塑造了群落的功能空间。我们通过量化功能性状空间中的种内和种间丰富度、离散度和规则性，研究了沿深度和纬度梯度的海洋鱼类功能α多样性几个关键方面的变化。我们得出了八个与食物获取和运动相关的功能性状，并计算了新西兰海域144种海洋硬骨鱼类沿大尺度深度（50 - 1200米）和纬度梯度（南纬29° - 51°）的七个功能多样性互补指数。这些性状来自直接从使用诱饵远程水下立体视频系统获得的影像以及博物馆标本中进行的形态测量。我们首次使用PERMANOVA方法将功能变异划分为种内和种间成分。我们还首次在基于功能距离的背景下实施了两种基于树的多样性度量：即成对功能距离的方差和最近邻距离的方差。功能α多样性随深度增加而增加，随纬度增加而降低。更具体地说，性状空间中物种间的离散度和平均最近邻距离以及种内性状变异性均随深度增加，而功能超体积（丰富度）在整个深度范围内保持稳定。相比之下，功能超体积、离散度和规则性指数均随纬度增加而降低；然而，种内性状变异随纬度增加，这表明种内性状变异性在高纬度地区变得越来越重要。这些结果表明，物种内部和物种之间的竞争是塑造深海鱼类功能多维空间的关键过程。随着深度增加形态差异增大可能有助于生态位划分以促进共存，而随着纬度增加非生物过滤可能是构建群落的主导过程。
