Species’ movement influences responses to habitat fragmentation

Habitat fragmentation is considered a prevalent threat to biodiversity. Many species experience negative impacts in fragmented environments, however, there have been studies showing species benefiting from these changes. This has led to ongoing debate regarding what is causing these different impacts. Some examples include the amount of resources, the movement capabilities of the species in the habitat and external factors such as advection. A growing problem in field research, however, is that it is difficult to control these various factors, and these studies generally take a large amount of time and resources to complete. To overcome these challenges, in my research, I used C. elegans as a model organism to explore the impacts of habitat fragmentation in different scenarios. By using C. elegans we were able to grow strains of worms with different characteristics such as movement speed to see how well low dispersers did compared to high dispersers. Also, we were able to avoid some of the issues with field work, such as controlling the amount of resources and collecting data in a timely fashion. In my first chapter, we explored the habitat amount hypothesis by covering 83% vs 33% of the environment with resources and then splitting the environment to simulate habitat fragmentation while maintaining the same amount of resources. We found that low dispersers were more impacted by the fragmentation than the high dispersers, especially when the amount of resources was lower. For my following chapter, I sought to how external factors such as advection could impact the success of species in fragmented environments. I used 2 columns of resources that were fragmented along a gradient. I then used deionized water to push the C. elegans towards their starting position (left), away from their starting position (right), and along their starting position (down) and compared those results to trials with no advection. We saw that high dispersers saw a wide range of changes in the various environments with different directions of drift, while low dispersers stayed relatively constant. This research highlights the importance of dispersal in fragmented environments and offers a promising alternative to habitat fragmentation research.