A Spatio-temporal Phylogenetic Approach to Community Ecology

Ecologists seek to explain the causes and consequences of species diversity patterns through the interactions of species with each other and their shared environment. Species diversity is however inherently complex because various processes influence species at different spatial and temporal scales. To examine the contribution of both evolutionary and ecological processes, ecologists often measure the phylogenetic relationships between interacting species. However since various processes drive species assembly at different scales, phylogenetic relationships vary with spatial and phylogenetic scale. In my thesis, I address how phylogenetic relationships at different spatial and temporal scales can inform both the ecological and evolutionary processes which affect assembly patterns. For montane plant communities in Colorado, I show that different spatial and phylogenetic scales produce different phylogenetic patterns for the trait, "elevational range size". From my findings, I caution against the use of a single spatial or phylogenetic scale, as it may lead to different conclusions about the data. For angiosperms in a plant community in Toronto, I show that species trait and phylogenetic relationships are spatially-dependent within the community level. For my system, multiple processes likely co-occur within the community and influence species assembly patterns at different spatial scales. I find evidence of competitive interactions at small spatial scales, which then transitions to environmental filtering at broad spatial scales. Therefore studies which select communities at a fixed spatial size are biased toward observing certain patterns and may subsequently overlook spatially-dependent processes. Finally, for angiosperm plant communities in Colorado, I demonstrate how phylogenetic relationships within communities can provide insights on macroevolutionary events. I find patterns consistent with niche conservatism and adaptive radiation, where the environmental gradient associated more with turnover of recently diverged lineages than with ancestral lineages.

Department dc:contributor.department

Ecology and Evolutionary Biology

Year dc:date.issued

2015

Author dc:creator

• Jin, Lanna

Advisors dc:contributor.advisor

• Cadotte, Marc W
• Fortin, Marie-Josée

• angiosperms
• coexistence
• community assembly
• community phylogenetics
• plant diversity
• spatial scale

Handle dc:identifier.uri

http://hdl.handle.net/1807/70854

OAI identifier oai:identifier

oai:utoronto.scholaris.ca:1807/70854