Range and change

I have been reading a lot about biogeography recently, which has made me realize the importance of the distribution of plants and animals for some pretty influential topics (biodiversity, climate change, infectious disease, invasive species) as well as the large gaps in our abilities to predict these distributions.

Most of biogoegraphy comes back to a simple question: Why are certain plants and animals found in some places while others are not? This question is set in the backdrop of some volatile conditions, as described nicely in Dennis McCarthy's book, Here be Dragons:
"Continents rift along volcanic ridges; oceans flow into gaps; islands spew into existence from volcanoes of the deep; and mountains thrust upward as continental regions converge and plates begin to fold. These earthly upheavals lead to changes in climates: sea levels rise or fall, glaciers advance or retreat; deserts become fertile; or rainforests turn barren. The evolving landscapes and new barriers divide various species of plants and animals, insects and fish, isolating certain groups in new environments, pushing them into different climes, mixing them with new predators and food sources, creating new hazards and eliminating old ones. Organisms must continuously adapt or perish on this always dynamic and often violent Earth."

The environment is always changing, creating risky situations for organisms (Loarie et al. 2009). Individual strategies and responses to cope with change (e.g., moving, adapting, or dying) determine the distribution of the species. The dynamics of these responses in space and time - in other words, the range and change - influence the spread of infectious diseases and invasive species as well as the configuration of local ecosystems.

Range
Organisms have many physiological mechanisms to deal with multiple limiting resources, which define the species niche. The limits of a species distribution are defined by these conditions. However, there is often not a definitive boundary between a suitable environment and an unsuitable environment. In reality, these boundaries are very fuzzy due to individual variation in dispersal, establishment, and survival. Individual variations influence a species niche and how they relate to other species (Clark 2010). Examining the subtle complexities that define the fuzziness at species' limits could be useful for predicting whether an organism will live in one place versus another.

Change
While the distribution of a species is a very spatial issue, the impacts and risks of changes in species distributions for humans are primarily temporal. How quickly and effectively species respond to changes in their environment will determine whether the species will spread or decline. As we increase our understanding of which variables are important for the geographic distribution of a species, we need to continue to ask how predictable are these patterns (Pearson and Dawson 2003)? Examining the distribution of responses within a population could be useful for predicting the species-level response to changes in time. For example, individual responses to short-term weather variation could illuminate population responses to long-term changes in climate.