Biogeomorphology

What is it and Why is it Important?

Biogeomorphology (also commonly referred to as ecogeomorphology) is the branch of geomorphology which focuses on the interactions between ecological and geomorphic processes. As such, it covers a very wide range of subject matter, from the mutual interdependence of microorganisms and weathering on bare rock surfaces to the interactions between forest cover and fluvial dynamics within whole catchments. Biogeomorphic interactions occur in all terrestrial environments, from the hyper-arid zone to the wet tropics, and are also heavily affected by human impacts on the environment. Thus, biogeomorphology has a very broad canvas, one which has global reach and covers many different scales. Biogeomorphology also has many practical applications in terms of environmental management. Geomorphic theory has recently started to take on board ideas about biogeomorphic interactions, following the earlier incorporation by ecological theory of ideas such as ecosystem engineering. Biogeomorphic interactions play key roles in the overall Earth System over a range of timescales and are thus of importance more widely than just to geomorphology. For example, changes in plant and animal communities on Earth over tectonic timescales have been associated with alterations in soils and geomorphology as well as with changing climate.

Because of the wide scope of biogeomorphology, and the difficulty of observing, quantifying and modelling many biogeomorphic interactions, this branch of geomorphology is extremely diverse and disparate. Unlike many other sub-fields of geomorphology, for example, it does not have its own journal. Most people who research on biogeomorphic interactions would not call themselves biogeomorphologists. Furthermore, research in this area is increasingly carried out by inter-disciplinary teams involving hydrologists, geochemists, geomorphologists and ecologists thus contributing to the eclectic nature of much biogeomorphological research. Such eclecticism is reflected in extensive cross-fertilization of methods and ideas.

History of Biogeomorphological Research and Theory

Like much of today's geomorphology, the origins of biogeomorphic research can be traced back to the 19th century. Natural historians such as Charles Darwin, Charles Lyell and Archibald and James Geikie wrote widely and passionately about a range of interactions between the living world and the underlying soils and rocks. However, their work built upon much earlier observations of potential links between the organic and inorganic worlds which have become largely forgotten. During the 19th century many detailed studies were made of the role of individual organisms in various earth surface processes. For example, Julius Sachs made experimental studies of the role of plant roots in chemical weathering of minerals in the 1860s and 1870s (Mottershead and Viles, 2004). Perhaps the most famous work of this sort was the intensive studies made by Charles Darwin into the role of earthworms in denudation, in which he attempted to quantify their role in [Page 247]bioturbation and erosion of sediment. As Darwin expressed it: