Variations in the plasticity of functional traits indicate the differential impacts of abiotic and biotic factors on the structure and growth of trees in tropical dry forest fragments

Ravi Kant Chaturvedi; Santosh Kumar Pandey; Anshuman Tripathi; Laxmi Goparaju; Akhilesh Singh Raghubanshi; J S Singh

doi:10.3389/fpls.2023.1181293

Variations in the plasticity of functional traits indicate the differential impacts of abiotic and biotic factors on the structure and growth of trees in tropical dry forest fragments

Front Plant Sci. 2024 Jan 25:14:1181293. doi: 10.3389/fpls.2023.1181293. eCollection 2023.

Authors

Ravi Kant Chaturvedi¹, Santosh Kumar Pandey², Anshuman Tripathi³, Laxmi Goparaju⁴, Akhilesh Singh Raghubanshi⁵, J S Singh²

Affiliations

¹ Center for Integrative Conservation and Yunnan Key Laboratory for Conservation of Tropical Rainforests and Asian Elephant, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan, China.
² Ecosystems Analysis Laboratory, Department of Botany, Banaras Hindu University, Varanasi, Uttar Pradesh, India.
³ Training, Safety and Environment, National Mineral Development Corporation Limited, Dantewada, Chhattisgarh, India.
⁴ Forest and Remote Sensing, Vindhyan Ecology and Natural History Foundation, Mirzapur, Uttar Pradesh, India.
⁵ Institute of Environment and Sustainable Development, Banaras Hindu University, Varanasi, Uttar Pradesh, India.

Abstract

Abiotic and biotic factors have considerable impact on the plasticity of plant functional traits, which influences forest structure and productivity; however, their inter-relationships have not been quantified for fragmented tropical dry forest (TDF) ecosystems. We asked the following questions: (1) what are the variations in the plasticity of functional traits due to soil moisture availability in TDF fragments? (2) what are the roles of soil nutrients and forest disturbances in influencing variations in the plasticity of functional traits in the TDF fragments? and (3) how do the variations in the plasticity of functional traits influence the structure and productivity of TDF fragments? Based on linear mixed-effects results, we observed significant variations among tree species for soil moisture content (SMC) under the canopy and selected functional traits across forest fragments. We categorized tree species across fragments by principal component analysis (PCA) and hierarchical clustering on principal components (HCPC) analyses into three functional types, viz., low wood density high deciduous (LWHD), high wood density medium deciduous (HWMD), and high wood density low deciduous (HWLD). Assemblage of functional traits suggested that the LWHD functional type exhibits a drought-avoiding strategy, whereas HWMD and HWLD adopt a drought-tolerant strategy. Our study showed that the variations in functional trait plasticity and the structural attributes of trees in the three functional types exhibit contrasting affinity with SMC, soil nutrients, and disturbances, although the LWHD functional type was comparatively more influenced by soil resources and disturbances compared to HWMD and HWLD along the declining SMC and edge distance gradients. Plasticity in functional traits for the LWHD functional type exhibited greater variations in traits associated with the conservation of water and resources, whereas for HWMD and HWLD, the traits exhibiting greater plasticity were linked with higher productivity and water transport. The cumulative influence of SMC, disturbances, and functional trait variations was also visible in the relative abundance of functional types in large and small sized fragments. Our analysis further revealed the critical differences in the responses of functional trait plasticity of the coexisting tree species in TDF, which suggests that important deciduous endemic species with drought-avoiding strategies might be prone to strategic exclusion under expected rises in anthropogenic disturbances, habitat fragmentation, and resource limitations.

Keywords: community structure; fragmentation; plasticity in functional traits; resource-use strategy; tropical dry forest.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. RC, AR, and JS thank the Ministry of Environment and Forests, Govt. of India (project no. 14/26/2005-ERS/RE), for the financial support. RKC is supported under the Council of Scientific and Industrial Research (CSIR), Govt. of India, Research Associate scheme (award no. 09/13(452)/2012-EMR-I), and the National Natural Science Foundation of China (NSFC) (grant No. 31750110466).