Role of soil and ecosystems Flashcards
what is soil
it is a dynamic natural body composed of minerals and organic solids, gasses, liquids, and living organisms, which can serve and a medium for plant growth
what is soil made up of
Soil solids -mineral fraction (45%) -organic matter (5%) Pore space -water (20%-30%) -air (20%-30%)
what are the properties of a whole soil
- soil is 3D (physical, chemical, and biological properties can vary both vertically and horizontally
- surface location of the deposit cause soil to behave differently from other geological deposits
- it is constantly evolving due to forces of weathering
what is involved in the destructive process of soil formation
the weathering of rock and mineral material and decomposition of organic matter
what is involved in the synthetic process of soil formation
clay mineral and organic matter formation, soil horizon development
what is a soil profile
it is a vertical section of soil through all its soil horizon and extending into the parent material
how does soil help plant growth medium
- anchorage for plant roots
- source of water and nutrients
- indirectly provides humanity with food, fibre, fuel, and building material
how does soil help regulate water supply
- absorbs, stores, and releases precipitation
- provides a more continuous supply of water to plants
- regulates the flow of rivers and streams
- purifies water by filtering, absorbing or decomposing toxic substances in water
what role do organisms have on soil
- a handful of soil houses billions of microorganisms
- soil organisms carry out the important task of nutrient recycling
- many soil organisms are ecosystem engineers; they create burrows and channels affecting water and air movement
- some soil organisms can cause illness, while others are a source of medicine
how does soil help nature recycle
nutrients and carbon in waste products and dead organisms are recycled in the soil and made available for reuse by the next generation of life
what does soil do for the global energy cycle
- it moderates the influence of solar radiation on the earth surface tempature
- soil absorbs and reradiates a large amount of solar energy back into space
how does soil influence atmospheric conditions
- soils take up and release carbon dioxide, oxygen, and other gases
- soil water evaporates into the air
- contributes to dust
- re-radiates heat to the air
how does soil contribute to engineering
it is the primary material for roads, earthen dams, and foundations for roads and bridges
what is an ecosystem
a dynamic complex of plant, animal, and microbial communities, interacting within the non-living environment and may include human beings
are soils renewable
no
how long can it take to form an inch of topsoil
hundreds to thousands of years
what is erosion, how is it caused and what are the adverse effects
erosion: the loss of topsoil from water, wind, tillage, and overgrazing
adverse effects: loss of topsoil
what is compaction and how is it caused and what are the adverse effects
caused by excess vehicle traffic or grazing squishes soil particles together, reducing pore space
effects: increase flooding risks, and erosion and limits root growth
what is nutrient mining, how is it caused and what are the adverse effects
continually removing nutrients in harvested plant material off the field without nutrient replenishment
effects:reduces soil fertility
what is loss of organic matter, how is it caused and what are the adverse effects
caused by the accelerated decomposition of organic matter
effects: reduces soil health
what is salinization, how is it caused and what are the adverse effects
increase in soil salinity
effects: plant toxicity
what is contamination, how is it caused and what are the adverse effects
pollutants spilled or leached into the soil
Effects: plant toxicity
what is provisioning services
products obtained from the ecosystem
- food
- water
- fuelwood
- fiber
- biochemical
what is regulating services
benefits obtained from regulation of ecosystem processes
- climate regulation
- doses regulation
- flood drought regulation
- erosion regulation
- water purification
- pollination
what is cultural services
non-material benefits obtained from ecosystem
- religion and spiritual
- recreation and ecoturism
- aesthetic
- inspirational
- sense of place
- cultural heratage
what is supporting services
services necessary for the production of all other ecosystem services
- soil formation
- nutrient cycling
- primary production
