My current research aims to understand what influences biodiversity (the number of species) on islands in the Greater Caribbean region. This work is trying to increase the predictive power of classical ecological theory for the current era of human activity and influence in the world. Named the Anthropocene, the current time period that we are in is characterized by the immense influence humans have on natural processes at the global scale. While climate change and species extinctions get a lot of attention, humans are influencing many processes, through for example trade and land development (see first picture in the slider below), and ecological theory needs to be contemporized so that we can fully understand and predict how these effects influence the diversity of species. In a recent paper (link below) published in the journal Global Ecology and Biogeography, my collaborators and I contemporize island biogeography theory (see second and thrid pictures in the slider below). This theory states that the number of species on islands is a product of the island's area and isolation (distance) from the mainland. This theory, first proposed by E. O. Wilson and Robert H. MacArthur in the 1960s and 70s, was transformative for the field of ecology and conservation science. Much of what we know about the diversity of species, not only on islands but across the world, was built on this theory and took ecology from a descriptive science (just describing patterns) to a predictive one that could be applied to the conservation of species.
Our paper takes the theory inspired and built from Wilson's and MacArthur's work and applies it to the Anthropocene so that the effects of human activity can be incorporated into island biogeography theory. With this contemporized theory and the framework we propose, ecologists and conservationists will be able to understand and predict how human activity will influence the diversity of species on islands. We show this utility by testing expectations built from this theory with the reptile and amphibians of the Greater Caribbean region (see map below) and found that the expectations from the contemporized theory are overall supported.
We made two main observations during the contemporization of island biogeography theory. First, the role of geographic island isolation (the distance from where species immigrate) is becoming weaker and is being replaced by how isolated the island is economically. This is because the
primary path through which species immigrate is no longer natural dispersal and is instead through the introduction of species by humans, largely by stowaways on maritime trade. Second, because the immigration of species is no longer limited by island isolation, the role of island area in driving the diversity of species on islands is now much stronger. These changes in the processes that lead to the diversity on islands can have great implications for species conservation. Stay tuned for upcoming research into this aspect!
Link to paper: https://onlinelibrary.wiley.com/doi/10.1111/geb.13623
(or you can download the pdf below)
Comments