Soil Composition and Human Impact on Soil Characteristics

These flashcards cover key concepts related to soil composition, effects of climate, human impacts on soil, and desertification as discussed in the lecture.

Overgrazing definition

Overgrazing is when the amount of cattle grazing is greater than the carrying capacity of that area of land.

Soil Characteristics

Organic matter, mineral matter, water content, soil PH, soil texture and colour.

Water and air is 25%. Proportion depends on…

Texture, climate, humus content and relief

East of Ireland experiences…

Rain shadow effect, so less rainfall than the mountainous West of Ireland. 700mm rainfall per year.

What is the consequence of increased rain levels in the West of Ireland on soil development?

Increased leaching and podzolization.

What soil type forms in Galway due to high rainfall and leaching?

Podzolic brown earth soils.

Loamy soil texture of brown earth soil ensures…

Enough water storage to be taken in, not too much to waterlog

How does temperature in upland areas, like the Wicklow Mountains, affect soil microorganisms?

It reduces their activity, leading to less decomposition of organic matter.

What effect does overgrazing have on soil characteristics?

It negatively impacts soil organic matter, mineral content, and overall fertility.

What happens to soil when young trees and shrubs are removed?

The soil becomes loose, loses strength, and decreases in fertility.

What consequence does the trampling by cattle have on soil?

It compacts the soil, preventing water infiltration.

What is desertification?

The formation of aridsols due to soil erosion from human activities.

What are aridsols?

Sandy soils that cannot retain or store water, leading to lack of vegetation.

How does climate change accelerate desertification?

Increased CO2 leads to higher temperatures, increasing evaporation and reducing rainfall.

Desertification involves…

Formation of soils aridsols.

Aridsols are sandy soils that…

Cannot retain or store water, leading to lack of vegetation growth.

Desertification is widespread in…

Sahel region

Results from rising temperatures…

Increased evaporation, lack of rainfall. Unbinds soil and starves them of organic matter.

Deforestation also causes desertification, this results in…

No protective cover, no leaves to decompose, rich layers of humus is lost.