The Stoichiometric Characteristics and Nutrient Investment Strategies of Dominant Lianas in a Karst Rocky Mountain Area of Northern Guangxi, China

Background and Aims Ecological stoichiometry provides a framework for understanding plant adaptation to nutrient limitation and environmental stress. Lianas play vital roles in forest structure and function, yet their nutrient strategies in karst ecosystems remain poorly understood. Methods We analyzed 13 dominant liana species from karst rocky mountains in northern Guangxi, China, measuring leaf N, P, K, Ca, Mg, and coarse ash contents and their stoichiometric ratios. Correlation and principal component analyses (PCA) were used to identify nutrient trade-offs and investment strategies. Results The results indicated that, influenced by the Karst soil substrate, leaf Ca and Mg showed strong interspecific variation, while N, P, and their ratios remained stable, indicating physiological homeostasis of metabolic nutrients. The mean N/P ratio (12.45) suggested relative nitrogen limitation, likely influenced by Ca–P antagonism. Correlation and PCA revealed a trade-off axis from "resource acquisition" to "resource conservation": N, P, and K formed a synergistic metabolic module supporting rapid growth and high metabolism, while Ca, Mg, and coarse ash reflected structural reinforcement and environmental tolerance. Further analysis demonstrated that life form is a key driver of this strategic differentiation: herbaceous lianas favored an "acquisitive" strategy, whereas woody lianas tended toward a "conservative" strategy, illustrating niche partitioning and functional complementarity. Conclusions These findings reveal the adaptive trade-offs of Karst lianas across a multi-element dimension, deepen our understanding of their functional ecology, and provide a theoretical basis for vegetation restoration and species selection in regions undergoing rocky desertification regions.