Tree community assembly and biogeochemical processes along an elevational gradient in western Panama

Prada Cordero, Cecilia M.

Permalink

https://hdl.handle.net/2142/112960 Copy

Description

Title

Tree community assembly and biogeochemical processes along an elevational gradient in western Panama

Author(s)

Prada Cordero, Cecilia M.

Issue Date

2021-06-14

Director of Research (if dissertation) or Advisor (if thesis)

Dalling, James W

Doctoral Committee Chair(s)

Yang, Wendy

Committee Member(s)

• Yannarell, Anthony
• Fraterrigo, Jennifer

Department of Study

Plant Biology

Discipline

Plant Biology

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• biogeochemical processes
• elevational gradient
• mycorrhizal associations
• nutrient limitation
• tropical montane forests
• Volcan Baru National Park

Abstract

Tropical montane forests (TMF) are unique ecosystems with remarkable contributions to global diversity and C cycle regulation. Understanding factors responsible of TMF dynamics are critical to predicting their plant community response to global change. Elevational and environmental gradients are key elements in our understanding of the effect of climate, edaphic and biotic interactions in plant community assembly and biogeochemical processes. Changes in environmental and biotic conditions are expected to influence tree diversity, floristic composition, nutrient and C cycling. My dissertation evaluates how edaphic factors, climate, and mycorrhizal associations drive tree community assembly, C storage, and biogeochemical processes along environmental gradients. Using a set of twelve plots in a premontane forest established along a natural fertility gradient, I was able to determine that soil fertility, geology, and annual rainfall account for tree species compositional variation in these forests. In a set of nine plots along an elevational gradient, within which forest patches are dominated by either ectomycorrhizal (EM) or arbuscular mycorrhiza (AM) trees, I show that variation in tree species composition is in part explained by the tree species’ mycorrhizal associations, even when controlling for elevation. I further evaluate how climate, edaphic factors and mycorrhizal associations influence biomass and soil C stocks. I report an exceptionally high C stock attributed to the presence of Quercus species at upper elevations and to recent geological history. Finally, I found Quercus-dominated forests are depleted in available N compared to mixed forests, resulting in low N foliar concentrations and low seedling growth rates. This dissertation highlights the importance of incorporating both abiotic and biotic interactions in our understanding of the effects of climate change on forest dynamics. Specifically, I emphasize the role of oak forests on species composition, C stocks and nutrient availability.

Graduation Semester

2021-08

Type of Resource

Thesis

Permalink

http://hdl.handle.net/2142/112960

Copyright and License Information

Copyright 2021 Cecilia Prada Cordero

Owning Collections