- Library Home /
- Search Collections /
- Open Collections /
- Browse Collections /
- UBC Theses and Dissertations /
- Shifts in plant functional phenotypes reflect resource-use...
Open Collections
UBC Theses and Dissertations
UBC Theses and Dissertations
Shifts in plant functional phenotypes reflect resource-use strategies across an experimental nitrogen gradient Malamud, Nathan David
Abstract
Trait-based ecology seeks to understand how environmental variation influences organismal performance and fitness via functional traits. The morphology-performance-fitness (MPF) framework hypothesizes directional causal relationships linking functional traits, performance traits, and fitness. However, the mediating role of functional traits in linking environmental variation to performance has not been fully articulated or tested within this framework. To address this gap, I extended the MPF framework by explicitly incorporating causal links between environmental variation and functional traits. I tested these hypotheses using data for three leaf economics traits — leaf mass per area (LMA), leaf dry matter content (LDMC), and chlorophyll content (CHL) — and a performance trait (aboveground growth rate) in three plant species grown across a broad nitrogen addition gradient. Leaf traits responded strongly to nitrogen addition, with variation structured primarily along a leaf economics axis and secondarily along a photosynthetic pigment axis. Increasing nitrogen drove phenotypic convergence, shifting trait expression toward a common region of multivariate trait space at high nitrogen levels. Structural equation modeling strongly supported MPF hypotheses, demonstrating that nitrogen addition influenced growth rates primarily through its effects on chlorophyll content and LDMC, as well as unmeasured functional traits. By clarifying the pathways linking environmental variation to plant functional and performance traits, these findings enhance our understanding of plant responses to nutrient gradients and their broader implications for global change ecology.
Item Metadata
Title |
Shifts in plant functional phenotypes reflect resource-use strategies across an experimental nitrogen gradient
|
Creator | |
Supervisor | |
Publisher |
University of British Columbia
|
Date Issued |
2025
|
Description |
Trait-based ecology seeks to understand how environmental variation influences organismal performance and fitness via functional traits. The morphology-performance-fitness (MPF) framework hypothesizes directional causal relationships linking functional traits, performance traits, and fitness. However, the mediating role of functional traits in linking environmental variation to performance has not been fully articulated or tested within this framework. To address this gap, I extended the MPF framework by explicitly incorporating causal links between environmental variation and functional traits. I tested these hypotheses using data for three leaf economics traits — leaf mass per area (LMA), leaf dry matter content (LDMC), and chlorophyll content (CHL) — and a performance trait (aboveground growth rate) in three plant species grown across a broad nitrogen addition gradient. Leaf traits responded strongly to nitrogen addition, with variation structured primarily along a leaf economics axis and secondarily along a photosynthetic pigment axis. Increasing nitrogen drove phenotypic convergence, shifting trait expression toward a common region of multivariate trait space at high nitrogen levels. Structural equation modeling strongly supported MPF hypotheses, demonstrating that nitrogen addition influenced growth rates primarily through its effects on chlorophyll content and LDMC, as well as unmeasured functional traits. By clarifying the pathways linking environmental variation to plant functional and performance traits, these findings enhance our understanding of plant responses to nutrient gradients and their broader implications for global change ecology.
|
Genre | |
Type | |
Language |
eng
|
Date Available |
2025-04-25
|
Provider |
Vancouver : University of British Columbia Library
|
Rights |
Attribution-NonCommercial-NoDerivatives 4.0 International
|
DOI |
10.14288/1.0448606
|
URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
|
Graduation Date |
2025-05
|
Campus | |
Scholarly Level |
Graduate
|
Rights URI | |
Aggregated Source Repository |
DSpace
|
Item Media
Item Citations and Data
Rights
Attribution-NonCommercial-NoDerivatives 4.0 International