The SRS Corridor Experiment: How habitat fragmentation, landscape connectivity, and climate change impact plant populations and communities

Background/Question/Methods

Landscape corridors – strips of habitat that connect otherwise isolated habitat fragments – are a leading strategy for mitigating negative impacts of habitat fragmentation on biodiversity.  Despite widespread implementation, questions remain about corridor efficacy, particularly how corridors affect dispersal of disparate species, and how they interact with global changes to influence population persistence.  In early 2000, we initiated one of the largest experimental studies of landscape corridors by creating a set of eight ~50 ha landscapes that each contain five ~1.4 ha patches of open habitat that are either connected by corridors or isolated by pine plantation matrix.  Within these landscapes, we have studied how plant populations and communities respond to habitat fragmentation and experimental corridor connectivity.

Results/Conclusions

Over the course of this 13 year experiment, we have shown a strong and persistent influence of corridor connectivity on plant species richness: since ~5 years into this study, there have been ~20% more plant species in connected than in unconnected patches.  This effect has been due to the promotion of native, not exotic plant species.  We have also demonstrated that corridor connectivity can increase rates of seed dispersal for some species and that plant traits related to dispersal can predict temporal changes in species richness due to corridor connectivity.  We are currently investigating: 1) how species traits can predict dispersal of seeds through fragmented, connected, and unconnected landscapes, using a novel stable isotope technique and 2) the influences of climate variability and plant-animal interactions for plant populations living within fragmented and connected landscapes.  Through this work, we seek a trait-based predictive ability to inform connectivity conservation going forward in an era of global change.