关键词: 城市河岸带, 叶片, 细根, 功能性状网络, 生态适应策略

Abstract: Aim：Revealing the regional differentiation patterns of functional traits and adaptation strategies of native spontaneous herbs in riparian zones is of great significance for predicting their survival and adaptation potential under the disturbance of urbanization. Methods：In this study, we took the riparian spontaneous herb Persicaria maculosa as the research object, to analyze the adaptation mechanism of functional traits of its leaves and fine roots to urbanized degraded soils. We set up 72 sampling plots in the riparian zone of the Fuzhou section in the lower reaches of the Min River, measured 22 phenotypic functional traits, and combined them with soil physicochemical indicators including soil bulk density, water content and salinity. Methods such as variance analysis, trait network analysis, principal component analysis (PCA) and linear mixed-effects model (LMM) were adopted to reveal the response pattern of aboveground and belowground organs of P. maculosa to urbanization-induced soil gradients. Important findings：The results show that the leaves and fine roots of P. maculosa did not respond synchronously to urbanized soil. Leaves adopted an overall conservative strategy, reducing resource consumption solely by decreasing leaf area. In contrast, fine roots were more sensitive to soil degradation, with significant declines in root length and water content. In multidimensional trait space, the resource-use strategy of P. maculosa shifted from acquisitive to conservative. Specifically, leaves transitioned from a rapid acquisition mode characterized by high resource turnover to a conservative maintenance strategy centered on dry matter accumulation; fine roots shifted from a resource-expansion strategy relying on high specific root length to a conservative strategy that emphasizes increased tissue density and enhanced structural stability. Soil degradation disrupted cross-organ coordination, driving the plant phenotypic network from whole-plant integration toward modular decoupling between leaves and fine roots. The multiple stresses of urbanized soil weakened the regulatory coordination between aboveground and belowground organs, constrained phenotypic plasticity, and pushed the plant’s response to soil environmental variation toward a more conservative and stable state. This study reveals the conservative adaptive strategy of a native herbaceous species to urban degraded soils, offering theoretical insights and practical guidance for the ecological restoration of urban riparian zones.

Key words: urban riparian, leaves, fine roots, plant trait networks, ecological adaptation strategies