Class Notes ~ Resource Sustainability

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School

Radford University *

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Course

101

Subject

Geography

Date

Oct 30, 2023

Type

docx

Pages

Uploaded by Mayes073099

Week Two: Resource Sustainability Resource Sustainability This week the lesson focuses on resource sustainability, which means we need a satisfying definition for the phrase. When we say something is sustainable, we mean that we can use it but that we will not use it all. In this way, there is some remaining, so we have not depleted whatever it is we were using. This brings us to the term resource, which we tend to think of as a supply or a stock. In other words, a resource is some known quantity of something. I know, these are not very specific explanations, but that is because the concept of resource sustainability can cover a great deal of topics. Soil Resources Who remembers the Dust Bowl era? OK, so no one in class remembers it first hand, but certainly the Dust Bowl era can offer us a unique perspective on the importance of sound environmental management. "A nation that destroys its soil, destroys itself” President FD Roosevelt (1937) Letters from President to Governors. White House, Washington, D.C., 26 February 1937 Soil is a complex mixture of minerals, organics, living organisms (~109 microbes/m2 soil!), air, and water. We tend to think of soil creation based on five key factors: time, parent materials, climate, topography, and living organisms. Combined, these factors shape the soils we see and use today. We recognize that soil can be replenished and renewed, but at an incredibly slow rate. On average, we say that about 2.5 cm (1 in) of soil can be produced in some 200-1,500 years, depending on conditions. In this way, we would not consider soil as a renewable resource, at least not in a time frame relevant to a human being. So, why the concern with soil? We can think of soils as providing some key ecosystem services including things like soil structure stabilization and erosion control, soil nutrient bioavailability, soil carbon sequestration, soil tilth for root growth, filtration media and transformation of chemicals, and flood and drought avoidance or remediation. [Tilth is a physical condition of soil relative to plant growth.] If you have ever dug down into the soil, you are familiar with how the soil is not uniform through depth. Instead, soils are layered, and we describe these layers as a soil profile. For background reading on soil profiles, please review the materials on the web from the Natural Resources Conservation Service (NRCS, n.d.). In an interesting (though somewhat dated) review of earth moving, Wilkinson (2005) notes that humans operate as an order of magnitude (that's 10 x's) more important at moving sediments around the planetary surface than all of the natural processes that routinely operate on the surface. In brief, natural geological processes account for lowering the surface of Earth some few tens of meters over a million year. In contrast, anthropogenic geological processes, i.e., when humans act as geologic agents, have moved so much sediment and rock to account for lowering the ice-free continental surfaces a few hundred meters over a million years. Wilkinson (2005) attributes these human activities to construction (30% by volume) and agriculture (70% by volume).

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