River corridor plants revisited: What drives their unique distribution patterns?

The phenomenon whereby some plant species display a river corridor distribution pattern has long been recognized but is still poorly understood. The goals of this study were to supplement the list of river corridor plants for Central Europe, analyze their habitats and compare their ecological features with those of their widely distributed counterparts. The ATPOL (Atlas of Poland) database was used to compile a list of river corridor plants of Poland and calculate their river-specificity indices. The Ellenberg indicator values, dispersal modes and life forms of river corridor and widely distributed species were compared using generalized linear mixed models. Eighty five species were classified as river corridor species. The most numerous habitat groups were meadow species (19%), wet-habitat therophytes (15%), riverside tall-herbs (13%) and species of dry, sandy soils (12%). These species had requirements for a higher temperature, alkalinity, light and moisture than widespread species. Among river corridor plants there were few eurytopic species. Corridor species had usually only one life form and less dispersal modes than widespread species. Hence, specific demands of corridor plants and lower phenotypic plasticity may explain their restricted geographical distribution. The definition of the river corridor plant species needs modification.

部分植物物种呈现河流廊道分布格局的现象早已为学界所认知，但至今仍未得到充分阐释。本研究旨在补充中欧河流廊道植物名录，解析其生境特征，并将其生态特性与广布同类物种进行对比分析。本研究依托ATPOL（Atlas of Poland，波兰地图集）数据库，整理波兰境内河流廊道植物名录并计算其河流特异性指数；采用广义线性混合模型，对比河流廊道植物与广布物种的埃伦伯格指示值（Ellenberg indicator values）、扩散方式及生活型。本研究共筛选出85种河流廊道植物，占比最高的生境类群依次为草甸物种（19%）、湿生一年生植物（15%）、河岸高大草本植物（13%）以及干旱砂质土壤物种（12%）。相较于广布物种，此类植物对温度、碱度、光照与湿度的需求更高，且广适性物种占比极低。河流廊道植物通常仅具备单一生活型，且扩散方式较广布物种更为有限。因此，廊道植物的特异性生境需求与较低的表型可塑性，或可解释其受限的地理分布格局。当前河流廊道植物物种的定义亟待修订完善。