Vernadsky (1926) developed the concept of the biosphere as a planetary membrane that captures, stores, and transforms solar energy. The proportion of solar energy captured by the biosphere is small compared to that represented by climate processes, but large compared to other energy sources for landscape processes A tiny fraction of net primary productivity doing pedologic and geomorphic work (e.g., bioturbation, bioweathering, bioerosion, organic matter formation) is (as a global average) a greater energy input for landscape evolution than geophysical processes (Phillips, 2009a).

The soil and the biosphere have been characterized as an “excited membrane” or skin at the planetary surface stimulated by solar energy (Vernadsky, 1926; Nikiforoff, 1959). Can other aspects of landscapes—particularly landforms and topography—be characterized as an “excited membrane?”

Alluvial rivers are dynamic, and often characterized by lateral migration, formation and eventual abandonment of meander loops, formation of anabranches or distributaries, and relatively abrupt shifts in channel courses. An understanding of river behavior, and effective management of resources in alluvial valleys, requires some understanding of the conditions under which these phenomena occur, and of the relationship between local and broader, reach-scale changes. This can be approached via the concept of dynamical stability.

I’ve been spending a lot of time lately kayaking through tupelo/cypress (Nyssa aquatica and Taxodium distichum) swamps in eastern North Carolina, partly in connection with my continued dabbling in research, but largely for fun. I’ve also become interested in what I call “ravine swamps,” which exist along the valley side slopes of the Neuse River estuary and are dominated by tupelo gum (aka water tupelo, swamp tupelo) and bald cypress. Heck, I even own a little bit of one next to my house. 

Ravine swamp, Craven County, N.C., in winter. The scar on the foreground tree is from a floating log repeatedly bashing against it during a flood event (probably Hurricane Florence).

In my efforts to learn more about these bottomland hardwood swamps I read Status and Trends of Bottomland Hardwood Forests in the Mid-Atlantic Region (Rose and Meadows, 2016), and came across this: 

Landscape Evolution: Landforms, Ecosystems, and Soils has been published in the electronic version, and the hardcopy will be available soon. I have mentioned previously that I wish it was less expensive--$150 list, though you can still get it for 15% less if you preorder from the publisher: https://www.elsevier.com/books/landscape-evolution/phillips/978-0-12-821725-2

The state of an Earth surface system (ESS) is determined by three sets of factors: laws, place, and history. Laws (L=L₁, L₂, . . . , L_n) are the n general principles applicable to any such system at any time. Place factors (P=P₁, P₂, . . . , P_m) are the m relevant characteristics of the local or regional environment. History factors (H = H₁, H₂, . . . , H_q) include the previous evolutionary pathway of the ESS, its stage of development, past disturbance, and initial conditions. Geoscience investigation may focus on laws, place, or history, but ultimately all three are necessary to understand and explain ESS. 

I first started using the law-place-history (LPH) framework as a pedagogic device in my teaching, and as a sort of aide memoire framework in my research. Eventually I began invoking it more explicitly in my research and writing, and expressing it formally, as in the passage above lifted from Phillips, 2018.