COEXISTENCE THEORY & SPECIES PERSISTENCE
Spatial scales of species coexistence (Ph.D. chapter)
We are evaluating how species persistence is shaped across spatial scales. By planting replicate focal seeds in both non-competitive and competitive treatments we can decouple the effects of biotic and abiotic drivers on persistence-area relationships. Across the spatial extent of our study system (McLaughlin Reserve), population growth rates indicate where they can persist, and surveys indicate where they do exist, thereby quantifying source-sink dynamics and dispersal limitation across scales.
This work is supported in part by CNPS.
We are evaluating how species persistence is shaped across spatial scales. By planting replicate focal seeds in both non-competitive and competitive treatments we can decouple the effects of biotic and abiotic drivers on persistence-area relationships. Across the spatial extent of our study system (McLaughlin Reserve), population growth rates indicate where they can persist, and surveys indicate where they do exist, thereby quantifying source-sink dynamics and dispersal limitation across scales.
This work is supported in part by CNPS.
Coexistence mechanisms that facilitate range expansion (Ph.D. chapter)
Our goal is to reveal what future conditions will allow for the sub-alpine species to expand and persist into the alpine. We are exploring the effects of three major global change drivers (GCDs): snow melt, atmospheric warming, and nitrogen deposition. At Niwot Ridge LTER in the Colorado Rockies, we transplanted a sub-alpine perennial (Trollius albiflorus) into the alpine, within each combinations of GCD treatment. Through tracking Trollius population growth, we will be able to mathematically decompose these invasion growth rates into which coexistence mechanisms (no variance, variance of each GCD, and covariances between GCDs) help or hinder range expansion.
Our goal is to reveal what future conditions will allow for the sub-alpine species to expand and persist into the alpine. We are exploring the effects of three major global change drivers (GCDs): snow melt, atmospheric warming, and nitrogen deposition. At Niwot Ridge LTER in the Colorado Rockies, we transplanted a sub-alpine perennial (Trollius albiflorus) into the alpine, within each combinations of GCD treatment. Through tracking Trollius population growth, we will be able to mathematically decompose these invasion growth rates into which coexistence mechanisms (no variance, variance of each GCD, and covariances between GCDs) help or hinder range expansion.
DISPERSAL'S ROLE IN COMMUNITY DYNAMICS
The following work was conducted during my M.Sc. at UBC with the Germain Lab. Find a link to my thesis here.
Role of seedbanks in persistence across habitat boundaries
Patchy populations combat isolation and temporal variability via bet-hedging strategies: dispersal or dormancy. My project explores how dormant populations might simultaneously deal with isolation as well as variability through secondary dispersal as dormant seeds. This method of patch connectivity could be particularly important when movement is facilitated by interactions between landscape features and seed traits.
Patchy populations combat isolation and temporal variability via bet-hedging strategies: dispersal or dormancy. My project explores how dormant populations might simultaneously deal with isolation as well as variability through secondary dispersal as dormant seeds. This method of patch connectivity could be particularly important when movement is facilitated by interactions between landscape features and seed traits.
On the other hand, habitat between serpentine patches is invaded by European grasses. We looked at the effect that invasive species, particularly Avena fatua, has on endemic populations. I am quantifying dispersal pressure into the patches in order to evaluate the persistence of these invasive individuals and determine if they are reproductively transient or stable through population growth rates and germination success.
Multi-trophic approach to nutrient and species movement (NSERC-USRA Mentor)
This project is a collaboration with mentees Kately Nikiforuk and Jenny Mackay. We ask how do herbivores and carnivores reinforce or dilute productivity gradients through plant dispersal and nutrient movement via their scat. Our results suggest that herbivores play a larger role in local nutrient movement, whereas carnivores disperse alien species long distances through consumption and excretion (i.e. endozoochory).
This project is a collaboration with mentees Kately Nikiforuk and Jenny Mackay. We ask how do herbivores and carnivores reinforce or dilute productivity gradients through plant dispersal and nutrient movement via their scat. Our results suggest that herbivores play a larger role in local nutrient movement, whereas carnivores disperse alien species long distances through consumption and excretion (i.e. endozoochory).
Select publications:
Szojka, M & R.M. Germain. Dispersal across habitat boundaries: uncovering the demographic fates of failed dispersers in patchy landscapes. Submitted to Journal of Ecology. BioRxv Preprint https://doi.org/10.1101/2021.03.22.436493 Mackay, J., K. Nikiforuk, M. Szojka, C.J. Little, J.R. Fleri & R.M. Germain. 2021. Animals connect plant species and resources in a meta-ecosystem. Landscape Ecology. https://doi.org/10.1007/s10980-021-01244-4 |
CONSERVATION & RECREATION ECOLOGY
Recreation ecology in the Canadian Rockies with Yellowstone to Yukon Conservation Initiative (Y2Y)
As outdoor recreation is projected to grow, impacts on wildlife may increase along with conflicts among users. To mitigate the risks of unmanaged recreational activities Y2Y collected information on the type of trail-users (e.g., biking, hiking, off-highway vehicles, equestrians), and which trails each of these groups use most frequently in Alberta and British Columbia. With funding from BRITE (link), I joined this recreation project lead by Dr. Karine Pigeon and Dr. Aerin Jacob. I conducted geo-spatial analyses (ArcMaps) to identify relevant trail networks within the study region. The research has the potential to improve the effectiveness of land-use and recreation management plans in Alberta and British Columbia, helping to protect the environment while promoting high-quality outdoor recreation experiences. For updates on this project see here.
As outdoor recreation is projected to grow, impacts on wildlife may increase along with conflicts among users. To mitigate the risks of unmanaged recreational activities Y2Y collected information on the type of trail-users (e.g., biking, hiking, off-highway vehicles, equestrians), and which trails each of these groups use most frequently in Alberta and British Columbia. With funding from BRITE (link), I joined this recreation project lead by Dr. Karine Pigeon and Dr. Aerin Jacob. I conducted geo-spatial analyses (ArcMaps) to identify relevant trail networks within the study region. The research has the potential to improve the effectiveness of land-use and recreation management plans in Alberta and British Columbia, helping to protect the environment while promoting high-quality outdoor recreation experiences. For updates on this project see here.
The role of provisioning and sibling competition on Ferruginous Hawk nestlings
This project was conducted for my Honors Thesis (B.Sc.) in the Bayne Lab at the University of Alberta. I examined how the parent-offspring conflict results in food distribution among nestlings, depending on their hatching order and competitive ability. Ferruginous Hawks are considered at risk (SARA) in their Albertan breeding grounds, and this research was a part of a broader research effort towards understanding to what degree food availability limits nestling success.
This project was conducted for my Honors Thesis (B.Sc.) in the Bayne Lab at the University of Alberta. I examined how the parent-offspring conflict results in food distribution among nestlings, depending on their hatching order and competitive ability. Ferruginous Hawks are considered at risk (SARA) in their Albertan breeding grounds, and this research was a part of a broader research effort towards understanding to what degree food availability limits nestling success.
Select publications:
Szojka, M.C., E.M. Bayne, T.I. Wellicome, C.J. Nordell, & J.W. Ng. 2020. The role of sibling competition and parental provisioning on food distribution among Ferruginous Hawk nestlings. Journal of Raptor Research. 54(4):376-387. DOI: 10.3356/0892-1016-54.4.376 |