Submission Type
Poster
Abstract
Environmental stressors shape life history strategies and biodiversity across the globe. Stress is particularly important in coastal sand dune habitats where nutrients and water are extremely limiting. However human-driven nutrient enrichment and climate change may alter these factors in sand dune habitats, with cascading effects on plant communities and ecosystem functioning. In 2022, we established monitoring plots in four sand dune sites along the western Michigan coast to examine the impacts of climatic and nutrient stress on vegetation. These sites spanned an increasing gradient of climatic and nutrient stress from south to north. We hypothesized that increasing climatic and nutrient stress would increase total belowground allocation to roots and mycorrhizae in Ammophila breviligulata—a key dune-building species. From each site, we collected fifteen A. breviligulata tillers and measured biomass, root traits, and mycorrhizal colonization. Root biomass and length were negatively associated with stress, while mycorrhizal colonization did not differ. These results suggest that A. breviligulata decreases allocation to roots in response to stress but does not alter allocation to mycorrhizae. These results differ both from our expectations and from hypothesized tradeoffs in which plants may allocate fewer resources to roots and more to mycorrhizal associations when stress is high, and vice versa. These data indicate that belowground allocation in response to global change may differ from hypothesized expectations in A. breviligulata. Because A. breviligulata is a dominant species of dune habitats, belowground response at the plant community level may further differ from expectations with implications for future coastal ecosystem function.
Included in
Divergent patterns of belowground allocation in response to stress in a key coastal grass
Environmental stressors shape life history strategies and biodiversity across the globe. Stress is particularly important in coastal sand dune habitats where nutrients and water are extremely limiting. However human-driven nutrient enrichment and climate change may alter these factors in sand dune habitats, with cascading effects on plant communities and ecosystem functioning. In 2022, we established monitoring plots in four sand dune sites along the western Michigan coast to examine the impacts of climatic and nutrient stress on vegetation. These sites spanned an increasing gradient of climatic and nutrient stress from south to north. We hypothesized that increasing climatic and nutrient stress would increase total belowground allocation to roots and mycorrhizae in Ammophila breviligulata—a key dune-building species. From each site, we collected fifteen A. breviligulata tillers and measured biomass, root traits, and mycorrhizal colonization. Root biomass and length were negatively associated with stress, while mycorrhizal colonization did not differ. These results suggest that A. breviligulata decreases allocation to roots in response to stress but does not alter allocation to mycorrhizae. These results differ both from our expectations and from hypothesized tradeoffs in which plants may allocate fewer resources to roots and more to mycorrhizal associations when stress is high, and vice versa. These data indicate that belowground allocation in response to global change may differ from hypothesized expectations in A. breviligulata. Because A. breviligulata is a dominant species of dune habitats, belowground response at the plant community level may further differ from expectations with implications for future coastal ecosystem function.
Comments
Vincent Cafazo, Undergraduate, Biology Department, University of Louisville (co-author)
Dr. Sarah M. Emery, Professor, Biology Department, University of Louisville (co-author)