As has been well documented in the literature, human activity, such as agriculture, mining and large infrastructure projects, has considerably affected ecological, hydrological and socioeconomic connectivity. In riverine settings, dams drastically interrupt the longitudinal, lateral and vertical connectivity of the water, material and organisms being transferred from one geomorphic compartment to another. While searching the literature for a comprehensive review on the connectivity disruption in the Amazon (e.g. Castello et al., 2013; Finer & Jenkins, 2012) I stumbled upon a special issue of Geomorphology entitled “Connectivity in Geomorphology” a result of the 47th annual Binghamton Geomorphology Symposium that came out this month, January 2017. After finding this, I decided to breeze over some of the work published here for this week’s blog post.
In the introductory editorial for the special issue, Wohl et al. (2017) introduced connectivity as an important conceptual framework, defined by the transfer of matter, energy or organisms between landscape compartments, which has been used by geomorphologists and ecologists for decades. In her introduction, Wohl et al. (2017) introduces the following themes addressed in the special edition: Sediments Connectivity, Hydrologic Connectivity, Geochemical Connectivity, Riverine Connectivity, Landscape Connectivity and Modeling of connectivity. For those interested in ecology, geomorphology connectivity is tied to ecological and biological connectivity in the papers focused on the landscape and watershed scales, biogeochemistry and modeling.
Important synthesis points from the special issue and symposium include i) leakiness between compartments should be considered in any connectivity framework; ii) fluxes between geomorphic compartment should be positioned/conceptualized along a connectivity continuum across space and time rather than on connected-disconnected switch; and iii) the lack of studies focused on the role of natural and anthropogenic discontinuities.
Finally, with the purpose of sticking with the central interdisciplinary focus of the Amazon Dams Network, it is important to highlight that as geomorphologists and hydrologists (and I might venture to expand this generalization to biophysical scientists) we tend to focus only on the fluxes of nutrients, sediments or organisms when considering connectivity. To this point, the intro cites Kondolf and Pinto (2017) who remind us “connectivity can also refer to the communication and movement of people, goods, ideas, and culture along and across river and may exhibit the same dimensions of longitudinal, lateral, and vertical connectivity. Moreover, as they show in their expansive international coverage, the social fabric of rivers has been significantly affected by human alterations of the channel and the broader riparian zone, further suggesting that reconnecting rivers geomorphically may have important social implications” Wohl et al. (2017).
If anything, for those interested, this special edition, found through links here, might provide a few papers to add to your spring reading and ideas to contemplate lists.
Castello, L., Mcgrath, D. G., Hess, L. L., Coe, M. T., Lefebvre, P. a., Petry, P., … Arantes, C. C. (2013). The vulnerability of Amazon freshwater ecosystems. Conservation Letters, 6(4), 217–229. http://doi.org/10.1111/conl.12008
Finer, M., & Jenkins, C. N. (2012). Proliferation of hydroelectric dams in the andean amazon and implications for andes-amazon connectivity. PLoS ONE, 7(4), 1–9. http://doi.org/10.1371/journal.pone.0035126
Wohl, E., Magilligan, F. J., & Rathburn, S. L. (2017). Geomorphology Introduction to the special issue : Connectivity in Geomorphology. Geomorphology, 277, 1–5. http://doi.org/10.1016/j.geomorph.2016.11.005