A spatial stream-network approach assists in managing the remnant genetic diversity of riparian forests

作者：Patricia María Rodríguez‐González, Cristina García, António Albuquerque, Tiago Monteiro‐Henriques, Carla Faria, Joana Bagoin Guimarães, Diogo Mendonça, Fernanda Simões, María Teresa Ferreira, Ana Mendes, José Saldanha Matos, Maria Helena Almeida · 发表于：Scientific Reports · 年份：2019 · DOI：10.1038/s41598-019-43132-7 · 被引用次数：21 · 研究领域：Genetic diversity and population structure、Genetic and phenotypic traits in livestock、Fish Ecology and Management Studies

Quantifying the genetic diversity of riparian trees is essential to understand their chances to survive hydroclimatic alterations and to maintain their role as foundation species modulating fluvial ecosystem processes. However, the application of suitable models that account for the specific dendritic structure of hydrographic networks is still incipient in the literature. We investigate the roles of ecological and spatial factors in driving the genetic diversity of Salix salviifolia, an Iberian endemic riparian tree, across the species latitudinal range. We applied spatial stream-network models that aptly integrate dendritic features (topology, directionality) to quantify the impacts of multiple scale factors in determining genetic diversity. Based on the drift hypothesis, we expect that genetic diversity accumulates downstream in riparian ecosystems, but life history traits (e.g. dispersal patterns) and abiotic or anthropogenic factors (e.g. drought events or hydrological alteration) might alter expected patterns. Hydrological factors explained the downstream accumulation of genetic diversity at the intermediate scale that was likely mediated by hydrochory. The models also suggested upstream gene flow within basins that likely occurred through anemophilous and entomophilous pollen and seed dispersal. Higher thermicity and summer drought were related to higher population inbreeding and individual homozygosity, respectively, suggesting that increased aridity might disrupt the...