Phosphorus Differences in Trunk-Epiphytic and Rock-Epiphytic Habitats Modify Pyrrosia sheareri Root Traits but Not Leaf Photosynthetic Rates in a Karst Forest

• Published in: Forests Vol. 16; no. 6; p. 903
• Main Authors: Zou, Shun, Huang, Chumin, Feng, Tu, Chen, Yang, Bai, Xiaolong, Li, Wangjun, He, Bin
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.06.2025
• Subjects: Acclimatization; Adaptation; Comparative analysis; Energy metabolism; Environmental aspects; Epiphytes; Ferns; Flowers & plants; Forests; Habitat (Ecology); Habitats; Humidity; Karst; Leaves; Measurement; Morphology; Nitrogen; Nutrients; Phosphorus; Phosphorus in the body; Photosynthesis; Physiological aspects; Physiology; Plant growth; Ratios; Rocks; Roots (Botany); Stoichiometry; Testing; Trees; Tropical forests; China
• ISSN: 1999-4907; 1999-4907
• DOI: 10.3390/f16060903

Phosphorus (P) is a pivotal element in plant energy metabolism and growth, and P limitation is widespread among plants in nature. However, our understanding of how epiphytes allocate P and adapt to P-deficient environments remains limited. We selected an obligate epiphyte Pyrrosia sheareri from a subtropical forest as our research subject. We compared its carbon (C)–nitrogen (N)–P ecological stoichiometry, P fractions, and morphological and physiological traits under the two habitats (trunk-epiphytic and rock-epiphytic). We also constructed a plant trait network method (PTN) that includes 62 traits to explore the co-variation characteristics of plant traits across the whole plant and identify the hub traits. We found that the following: (1) Habitat type significantly affects plant P concentration, with trunk-epiphytic plants having higher P concentration than rock-epiphytic plants. Pyrrosia sheareri may be more strongly limited by P according to the results of C-N-P ecological stoichiometry. (2) Epiphytic habitats significantly affect plant P fractions but do not influence the relative allocation of P fractions. (3) Compared with rock-epiphytic plants, trunk-epiphytic plants adopt a root resource-acquisition strategy rather than relying on leaves. (4) P-related indicators link ecological stoichiometry with morphological and physiological traits and are hub traits in PTN. Overall, P. plays a key functional role in the environmental acclimatization of Pyrrosia sheareri, highlighting the morphological and physiological adaptability of epiphytes to various habitats in terms of P availability, allocation, and storage.