Acquisitive vs. conservative trait networks: how habitat heterogeneity shapes resource availability and functional coordination in deciduous and evergreen trees

Plants coordinate multiple functional traits to survive environmental stress, but the architecture of this coordination-how tightly traits are linked and which traits serve as coordination hubs-remains poorly understood, particularly in karst-heterogenous forest ecosystems.While these relationships are often interpreted within the Leaf Economics Spectrum (LES), this framework may not fully capture the multidimensional structure of trait coordination. In this study, we constructed leaf trait networks (LTNs) for 50 deciduous and 49 evergreen species based on 18 leaf traits measured across 25 forest plots in karst region. We compared LTN architecture between life forms using network parameters and evaluated how habitat heterogeneity and soil resources shape network structure through structural equation modeling (SEM) and Mantel tests. Deciduous species exhibited tighter coordination, characterized by lower network diameters, higher edge density, and shorter average path lengths, whereas evergreen species displayed a looser and more modular network structure. Leaf area (LA) and leaf mass per area (LMA) served as hub traits in deciduous species, while specific leaf carbon (SLC) and LMA played dominant roles in evergreen species. SEM results indicated that habitat heterogeneity influenced LTN architectural indirectly via soil resource availability. Mantel tests further showed that soil organic carbon (SOC) was most strongly associated with deciduous networks, whereas total potassium (TK) was most strongly associated with evergreen network structure. These findings demonstrates that the way plants organize their traits-not just the traits themselves-represents a crucial dimension of ecological strategy, with implications for predicting plant responses to environmental heterogeneity in karst ecosystems.