Leaf Anatomical Plasticity of Phyllostachys glauca McClure in Limestone Mountains Was Associated with Both Soil Water and Soil Nutrients

Abstract

Little is known on how karst plants adapt to highly heterogeneous habitats via adjusting leaf anatomical structures. Phyllostachys glauca McClure is a dominant species that grow across different microhabitats in the limestone mountains of Jiangxi Province, China. We investigated the leaf anatomical structures, plant biomass, soil water content, soil total nitrogen (TN), and soil total phosphorus (TP) from three habitats characterized by different rock exposure, including high rock exposure (HRE), medium rock exposure (MRE) and low rock exposure (LRE), and aimed to discern the relationships between the leaf anatomical plasticity and edaphic factors. The leaves of P. glauca in different habitats showed significant anatomical plasticity in two aspects. First, the leaves adjusted cuticle thickness, papillae length, bulliform cell size and mesophyll thickness to lower water loss and then adapt to the water-deficient habitats (HRE). Second, the leaves enlarged vessels and vascular bundles (first-order and second-order parallel veins) to improve water and nutrient transportation and then enhance plant growth in nitrogen-rich habitats (HRE). Soil water and soil nutrients purely explained the total variation of leaf anatomical traits by 21.7% and 15.7%, respectively, and had a shared proportion of 15.8%. Our results indicated that the leaf anatomical variations in different habitats were associated with both soil water and soil nutrients. Moreover, we found that leaf anatomical structures were more affected by TN than TP. The present study advanced the current understanding of the strategies employed by karst plants to cope with highly heterogeneous habitats via leaf anatomical plasticity.