Climate Change and Edaphic Specialists: Irresistible Force Meets Immovable Object?

Current approaches to predicting responses to climate change often assume that species will move to track their climate envelopes, but edaphic specialists restricted to globally rare and fragmented substrates cannot easily do this. Some edaphically extreme habitats have acted as refugia during past periods of climate change, as a result of environmental heterogeneity and/or the stress-tolerant functional traits of their biotas, but past climates were usually cooler than today and rates of warming slower. Species distribution models used to predict climate change responses can include edaphic factors, but these are rarely mapped at a high enough spatial resolution. Using low-resolution edaphic data for predictions is likely to give misleading results. Many edaphic islands are now also threatened by other human impacts, including mining, nitrogen deposition, and invasive species. Species exposed to anthropogenic climate change can acclimate, adapt, move, or be extirpated. It is often assumed that movement will be the dominant response, with populations tracking their climate envelopes in space, but the numerous species restricted to specialized substrates cannot easily move. In warmer regions of the world, such edaphic specialists appear to have accumulated in situ over millions of years, persisting despite climate change by local movements, plastic responses, and genetic adaptation. However, past climates were usually cooler than today and rates of warming slower, while edaphic islands are now exposed to multiple additional threats, including mining. Modeling studies that ignore edaphic constraints on climate change responses may therefore give misleading results for a significant proportion of all taxa. Species exposed to anthropogenic climate change can acclimate, adapt, move, or be extirpated. It is often assumed that movement will be the dominant response, with populations tracking their climate envelopes in space, but the numerous species restricted to specialized substrates cannot easily move. In warmer regions of the world, such edaphic specialists appear to have accumulated in situ over millions of years, persisting despite climate change by local movements, plastic responses, and genetic adaptation. However, past climates were usually cooler than today and rates of warming slower, while edaphic islands are now exposed to multiple additional threats, including mining. Modeling studies that ignore edaphic constraints on climate change responses may therefore give misleading results for a significant proportion of all taxa. also known as managed translocation, this is the deliberate movement of a species to a new habitat which it could not reach without human assistance. In the context of climate change, assisted migration means establishing a new population in an area where the climate has newly become suitable or is anticipated to become suitable in the near future. a Portuguese term meaning rocky fields, applied to shrubby vegetation on shallow, nutrient-poor soils with rock outcrops in Southeastern Brazil. this describes the range of climatic conditions under which a species currently exists. while most plants that grow on soils with high concentrations of available metal cations exclude them from their above-ground parts, a minority of species accumulate concentrations in their tissues that are far above what would be toxic to most plants. Metal hyperaccumulation is best studied for aluminum and nickel, but other species accumulate Cd, Cr, Mn, Se, or Zn. isolated hills or mountains rising abruptly from a plain, like islands in the sea. the input of reactive nitrogen (as opposed to the abundant, unreactive, gaseous nitrogen) to a habitat in the rain or as dry deposition. This nitrogen comes ultimately from fossil fuel combustion and agricultural sources. in the context of climate change, refugia (singular: refugium) are places with a relatively stable local climate, and/or with high climatic heterogeneity, which can allow species to persist when the regional climate becomes unsuitable. these are isolated, flat-topped mountains on the Guiana Shield of Northern South America, in Venezuela, Guyana, Suriname, and Brazil. Typical tepuis have a basal slope, emerging from the surrounding lowlands, a vertical cliff, and a largely flat summit.