Could top-down forces, such as predation, really be the driving force behind the incredible diversity on the planet? Really nice essay by John Terborgh in PNAS attempts to convince us that this is the case – thanks to ConservationBytes for the link (below). I agree that competition has been over-emphasized as the defining mechanism for diversity. However, it did cover old territory as diversity obviously is an interplay between bottom-up (competition) and top-down forces such as predation. I feel that coexistence theory has moved on from this dichotomy. I also think that environmental change and habitat heterogeneity could’ve been added to the discussion as these forces also important mechanisms. Parasites and pathogens (also top down forces) could’ve been mentioned explicitly too as they are often ignored in the literature and are of obvious importance. Nonetheless it is a really interesting and well written read and I totally agree with Corey Bradshaw that conservation of the predator guild is damn important.
The originl article: http://www.pnas.org/content/112/37/11415.abstract
Animal and parasite community ecology always seems to lag well behind plant ecology in terms of theoretical developments and understanding. This is particularly the case for incorporating functional and phylogenetic perspectives to better understand communities, even though these perspectives can provide insights into these communities impossible to achieve with more traditional approaches. Plants communities are obviously much easier to sample and manipulate so this is not surprising, but animal communities can provide, for example, so many extra trophic dimensions and feed-backs that can give us a more complete picture of ecosystem function than just sampling plants alone. Particularly for poorly understood invertebrate and parasite/pathogen groups.
Anyway, I read the plant journal Vegetation Science and I feel like I’m seeing into the future for some of the directions where animal and parasite community ecology should go. Nearly every paper in this issue: http://onlinelibrary.wiley.com/doi/10.1111/jvs.2015.26.issue-5/issuetoc, for example, is important for thinking about animal/parasite community ecology. Not that I think we should replicate plant ideas directly, but use them to help formulate animal/pathogen specific theory and learn off plant community trials and tribulations with things such as trait databases.