Biosphere is a hugely important component of Physical Geography. Also known as the 'ecosphere', this region of the planet describes where life exists. We know why soils support ecosystems and sustain life, but what are the other benefits of healthy soil?
Agriculture is also reliant upon invertebrate and biota within the soil serve a very important function in mixing the soil horizons up, helping soil support food production systems as an important natural resource. The soil delivers 95 percent of global food supplies but it under stress due to desertification, soil erosion, overpopulation, overcultivation and climate change. Keeping biodiverse ecosystems underground help support and advance human health, catalysing nutrient recycling. Management processes such as tilling (working the soil), soil replenishment, crop rotation and organic farming ensure soil is biologically healthy and functional.
Healthy soil reduces flood risk, to put it simply. Water percolates through the soil as rain infiltrates into the soil surface. The soil then becomes saturated. Other natural (soft-engineering) ways you can increase flood resilience is through afforestation, embankments, restoring mudflats and marshes and creating leaky barriers, all aimed at reducing surface run off.
Nutrient cycling and recycling is also important to consider involving the uptake of nutrients by biota mixing up the soil keeping it fresh. It is a cyclical process involving reservoirs, sources and sinks. Nitrogen (N), phosphorus (P), potassium (K), sulfur (S), magnesium (Mg), and calcium (Ca) are crucial components or organic compounds for ecosystems above the soil.
Sequestering carbon in soil is finally something to consider investing more attention in. Basically we want the soil to retain and store more carbon so less of it is in the atmosphere. Currently, soils remove about 25 percent of the world’s fossil fuel emissions each year. Permafrost is an example. Most of the carbon in soil is a product of dead matter and waste from organisms. When the soil is exposed to draining and deforestation, organic matter within the soil is exposed to oxygen meaning a faster decomposition process takes place.
Flood hydrographs can be used by Geographers to predict when a flood will happen. A gentler hydrographs illustrates a lower flood risk.
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