E-Thesis 475 views 160 downloads
Local effects of spatial environmental heterogeneity on ecosystem structure and functioning in rocky shores / JORDI CODINA
Swansea University Author: JORDI CODINA
-
PDF | E-Thesis – open access
Copyright: The Author, Jordi Sola Codina, 2023 Distributed under the terms of a Creative Commons Attribution-ShareAlike 4.0 International License (CC BY-SA 4.0).
Download (7.17MB)
DOI (Published version): 10.23889/SUThesis.66720
Abstract
Ongoing anthropogenic and climate change impacts result in habitat loss around the world, removing complex physical structures with negative consequences for biodiversity. At the local scale (i.e., the scale at which species interact), spatial environmental heterogeneity originates from biotic and a...
| Published: |
Swansea University, Swansea, UK
2024
|
|---|---|
| Institution: | Swansea University |
| Degree level: | Doctoral |
| Degree name: | Ph.D |
| Supervisor: | Griffin, J., N.; and Bull, J., C. |
| URI: | https://cronfa.swan.ac.uk/Record/cronfa66720 |
| Abstract: |
Ongoing anthropogenic and climate change impacts result in habitat loss around the world, removing complex physical structures with negative consequences for biodiversity. At the local scale (i.e., the scale at which species interact), spatial environmental heterogeneity originates from biotic and abiotic complex physical structures such as canopies and substrate rugosity and is a key local factor promoting species diversity. However, more recent assessments have found substantial variability in Heterogeneity-Diversity Relationships (HDRs) across plots, sites, and studies. Such variability may originate from the role of external environmental factors, limited temporal (e.g., <5 time points) and spatial within plot) scales considered in heterogeneity studies. This thesis aims at expanding our knowledge of heterogeneity effects on the structure and functioning of ecosystems by a) assessing how heterogeneity effects on the diversity, structure and functioning of species communities vary across environmental contexts worldwide and b) explores mechanisms (i.e., ecological causes) explaining how heterogeneity effects on species communities are maintained at larger temporal and spatial scales. Using rocky reef literature, I found that positive saturating heterogeneity effects on diversity and abundance were generally common and changed across several context-dependent variables from the type of heterogeneity considered (i.e., heterogeneity facet) and substrate to organismal group, ecological process, latitude, and depth (intertidal and subtidal). Second, using experimental data over three years from an intertidal rocky shore, I found that despite positive heterogeneity effects on community diversity and structure, heterogeneity did not increase temporal cover stability within the species community due to several counteracting mechanisms (e.g., increasing mean temporal population stability but decreasing temporal species asynchrony) and even reduced temporal compositional stability. Finally, also using the experimental data, I found that local and landscape heterogeneity effects competed to promote landscape or regional (gamma) diversity through effects on local (alpha) richness and species turnover, respectively. In addition, they presented combined effects that helped maintain community cover and diversity across seasons and species groups. Overall, results help reveal the key role that environmental context has in determining the strength of heterogeneity effects and uncovers temporal and spatial mechanisms that maintain heterogeneity effects over time and space. Given that heterogeneity effects on ecosystems are not as linear and straightforward as previously thought, improving our understanding of the mechanisms behind heterogeneity effects is crucial to better predict when and where heterogeneity will benefit ecosystems and help mitigate for habitat loss |
|---|---|
| Item Description: |
A selection of content is redacted or is partially redacted from this thesis to protect sensitive and personal information. |
| Keywords: |
Biodiversity, Marine Ecology, Habitat complexity, Heterogeneity |
| College: |
Faculty of Science and Engineering |
| Funders: |
SURESCOS scholarship |