#527: Gersmehl Diagrams

Check out this TES Resource which includes an animated Gersmehl diagram option.

Gersmehl diagrams were developed by Phil Gersmehl

They are particularly important when explaining the relative stores and flows of nutrients within an ecosystem. The thickness of the arrows or connectors and the size of the circles relates to the transfer or storage. For a rainforest, the nutrients are stored in the biomass for example, and nutrients move from the litter into the soil by decomposition and the work of detritivores.

I would imagine that they may end up being in the draft specification - perhaps only for UK based ecosystems e.g. deciduous woodland, heathland etc. but you never know.

e.g. a Tropical Rainforest.

Image source:

https://thatbiothing.wixsite.com/ecologyconservation/single-post/2015/12/07/the-gersmehl-cycles-nutrient-cycles

#409: Soil and its parents

Soil is one of the most important substances on the planet, and there will definitely be a focus on soils in some way in the final specification as the soil partly determines the climax vegetation, along with other factors.

A definition from Encyclopaedia Britannica:

Soil is the biologically active and porous medium that has developed in the uppermost layer of Earth’s crust. It serves as the reservoir of water and nutrients and a medium for the filtration and breakdown of injurious wastes. It also helps in the cycling of carbon and other elements through the global ecosystem.

The study of soil is called pedology.

Soil is also an important carbon store.

A short film on soil from the Royal Society.

Any look at Natural History will need to concern itself with the soil beneath our feet, and the rocks (parent material) that lie below that. I would imagine that the specification will refer to biomes, ecosystems and various other options which will require an understanding of the abiotic and biotic components.

Soil is made from four ingredients: weathered rock, organic material, water and air.

Soil is a nutrient store and is featured on Gersmehl diagrams of ecosystems.