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4. Natural Processes

Information source: Allan Savoury Network/Roots of Nature

Natural processes means, a functioning water cycle, mineral cycle, species diversity, and maximising the use of the sun’s energy (photosynthesis) to drive all the processes. They are interrelated so changing one changes all in some way. They are like four windows looking in on the same room.

Improving the ecosystem processes will enhance overall diversity, resilience, flood and drought mitigation, water purity, and health of all organisms in the system - including livestock and humans where applicable. These processes are essential for rich, healthy and functioning land but often get broken down where there is intensive land management and this as a result can lead to sediment and nutrients entering the river.

Water Cycle:

Is your rainfall being absorbed quickly into the soil? Or does the rainfall stay on the surface and either evaporate or cause flooding, soil run off and erosion? Bare, compacted or waterlogged soil is the primary cause of a dysfunctional water cycle. Water always cycles between earth and air – into aquifers, run off, transpiration. Plants absorb water and nutrients through the roots.

Effective water cycle:

• Little water is lost to runoff or evaporation from the soil.
• Most water penetrates the soil, only leaving it through transpiring plants, by flowing down to underground reservoirs or out through rivers and streams.
• A good air-to-water balance exists in the soil, enabling plant roots to absorb water readily, as most plants require oxygen as well as water around their roots to grow.
• Rain soaks in to land and becomes available to plant roots, insects and micro-organisms and then moves downward to replenish aquifers with very little evaporating from or running off the soil surface.
• Reduce flooding and drought and floodwaters are cleaner as they carry less soil.
• A covered soil surface is critical to creating and maintaining an effective water cycle – bare soil can shed more than half the water falling on it which could be available for wildlife/us!
• A rich organic content and therefore well aerated soils and reduced evaporation.

Mineral/nutrient cycle:

Are minerals constantly being cycled from dead organisms to living organisms? Are minerals being lost through soil erosion, leaching, or escaping as gasses? Micro-organisms are the key to the mineral cycle. Movement of mineral nutrients from soil to plants and animals and back into the soil again.

A good mineral cycle implies a biologically active living soil with adequate aeration and energy underground to sustain an abundance of organisms that make up the soil food web.

Minerals are brought up to soil surface by living plants by roots and soil organisms (worms, insects) from deeper layers. Then after they are used they must be returned to the ground by decomposition. The more diverse the vegetation the more access to nutrients from different depths.

Water and animals help to return the nutrients back to the soil depths.

Soil surface is key for mineral cycle, if it is bare/capped this means a harsh environment for micro-organisms and biological breakdown in very slow. A sealed surface inhibits aeration, as aeration decreases so does the abundance of biological life and as the life depletes so does the organic material which decreases soil structure as it decreases so does aeration - becomes nearly impenetrable.

Ideal surface is covered with closey spaced plants with mature, decaying plant material (litter) covering the bare ground in between them – this will hold moisture and regulate surface temperature which will be more hospitable to the decaying microorganisms.

Effective mineral cycle:

• Soil surface is porous and rich in organic matter.
• Surface litter cover is high and mature, decaying mulch rests on soil surface.
• Rapid turnover of plant material – breaks down readily.
• Large numbers of surface insects and micro-organisms present.
• Close plant space very little exposed soil.
• Plant roots are abundant with good penetration on many levels.
• Soil underground is porous with abundant underground life.
• Low surface mineral loss as well as leaching.
• High turnover rate of mineral nutrients.

Community/diversity:

Is biodiversity increasing or decreasing? Is ecological succession moving forwards or backwards? The more diverse an ecosystem the more stable and resilient it tends to be. Plants and animals are continually dying and being replaced.

When soil is bare and exposed the community is generally less complex and therefore less resilient – one species can boom. The more complex the community, the more stable it will be.

Soil compaction, exposure and capping, inadequate drainage, over fertilisation, pesticides all alter the biological community below ground and what happens there will show itself above ground!

The process of change is called succession. As succession advances, complexity, productivity, and stability increase and the micro-environment changes. Local environments e.g. weather, will dictate how it changes but there will always be decay, death, birth to drive the change. The rise and decline of various populations is part of the ever-changing dynamic of succession.

Need communities rich in plant and animal species both above and below ground for resilient healthy landscape.

Energy flow - photosynthesis:

All energy comes from the sun. How efficiently is sunlight being utilised and passed up and down the trophic levels for the benefit of all organisms in the ecosystem? Energy from the sun to green growing plants which convert the energy through photosynthesis to the food that fuels all life.

The natural world runs on solar power. We depend on green plants to capture energy from the sun and convert it into a form we can use – only photosynthesis directly produces food for living organisms, including us.

Healthy water, mineral, and diverse systems enable more solar energy to be captured and utilised. If you have broadleaved plants they capture more energy than thin leaved plants. If you have bare ground this reflects the energy rather than having a diversity of vegetation covering the ground which provides more chance to capture energy. It benefits everyone if plants can capture more energy for our consumption!