Lessons on Ecology and Evolution from the Study of Edaphic Specialization
ID: 613 / 242
Proposed Symposium Title: Lessons on Ecology and Evolution from the Study of Edaphic Specialization
Nishanta Rajakaruna1, 2
Affiliations: 1 Biological Sciences Department, California Polytechnic State University, San Luis Obispo,CA 93407, United States 2 Unit for Environmental Sciences and Management, North-West University, Potchefstroom, South Africa
Edaphic islands, characterized by sharp abiotic and biotic gradients, mosaic landscapes, patchiness and isolation, and harsh environments, offer exceptional opportunities to test macroecological and evolutionary theory, and conservation and restoration practices. Edaphic islands are often distinguished by unique biotic communities with high proportions of rare and endemic species. These communities, often restricted to fragmented islands of harsh substrates, are model settings to investigate the factors and mechanisms contributing to regional and global patterns of diversity and spatial ecology, including metapopulation and metacommunity theory, as well as cross-kingdom interactions. They also provide model organisms for investigating the drivers of adaptive evolution, including the genetic bases for and architecture of traits conferring adaptation and reproductive isolation. Additionally, they offer opportunities to explore cross-adaptation, which is when a trait that evolved for tolerance to one harsh substrate becomes effective as an adaptation for another, allowing species to show cross-tolerance to multiple harsh substrates characterized by a suite of common stressors (i.e., stress resistance syndrome), including habitat bareness, drought, pH, ionic strength, and specific ions. Biota of harsh and nutrient-poor substrates are especially prone to stressors associated with climate change, including atmospheric deposition of nitrogen. Much of the research on harsh substrate-biota relations has focused on plants of ultramafic and other metal-enriched rock outcrops or saline soils. Recent research on biota of gypsum and other chemically ‘harsh’ substrates can help reexamine the biota-harsh soil relationship, especially commonalities and differences across distinct biota-soil type associations, both within and across biomes. Such efforts will also provide opportunities for productive collaboration across research groups with expertise on edaphically distinct communities (e.g., serpentine vs gypsum) or tools of investigation (e.g. ecophysiological vs phylogenomic) relating to key questions on drivers of diversity and community assembly, ecological and evolutionary theory, and conservation and restoration practices.