Need Sample Biome Answers/Notes - Geography 2009 Papers Homework

karaokeman

Ok so my teacher gave us three questions in each section to do for Easter. I've done the regional and I plan on having a shot at the biome questions tomorrow.

Problem is, I've only had time to practice the general biome questions, which is just describing the different characteristics.
The questions are as follows;

1. With reference to one soil type you have studied, examine how parent material, climate and organic matter influence the soil

2. Discuss how human activitiescan accelerate soil erosion

3. Assess how biomes have been altered by human activities

If anyone can help, please PM me with some notes that might help with these questions (if you have any typed notes). Sample answers might help also, just ask for my email address so you can send them.
The biomes my teacher told us to revise are the Tropical Rainforest and the North American biomes. So notes/sample answers for any of these two would do.

Thanks.

karaokeman

Hello, can anyone help me with sample answers?

These are desperately needed so any posts would be appreciated.

conormccarthy92

just finished typing this baby up i hope it helps .


Geoecology - Composition and Characteristics of soil

The scientific study of soil is called pedology . Soil is composed of both organic and inorganic matter , and it is essential for life on earth to exist . The soil type that i have studied is brown earths . Brown earths are the most common soil type in Ireland and are very fertile . Soils are a composition of mineral particles 45% , organic matter 5% , air 25% , and water 25% .

Mineral Particles :
Mineral particles are the largest ingredient and make up approx 45% of soils . They are the original rock that got broken down by weathering and erosion to form the basis of soil . The type of rock that was broken down to form it is called the parent rock . The broken down rock produces minerals such as calcium , phosphorus , and potassium in the soil on which the plants feed . The parent material influences the soil colour , depth , texture and ph value

Organic Matter:
Organic matter is decayed vegetation that is broken down by micro organisms in the soil to form humus . Humus is a dark jelly like substance that binds the soil together and improves its texture . It increases the soils ability to retain moisture . Brown earths develop in area of deciduous woodland where there is an abundance of plant litter available to decay . Brown earth soils are also found where temperatures average zero for less than 3 months of the year and rarely exceed 21 degrees . These conditions allow for micro organisms to thrive . The colour of the soil is an indication of the amount of organic material it contains with darker soils having more organic content . Humus is plentiful in brown earths

Air and Water :
Air is vital for the survival of micro-organisms and without theses , there would be a shortage of humus . Brown earths have a granular structure which allow for good aeration . Plants cannot survive without water present in the soil .Mineral particles are soluble in water and the roots of plants can only absorb the nutrients of them after they have been dissolved
Characteristics of brown earths :
Brown earths are usually 2 metres deep and have 4 horizons . The A horizon has a thick layer of dark humus . There is a plentiful supply of micro organisms which mix the soil well and leave no distinct boundary between the A and B horizons . The B horizon is similar but with a lighter brown colour . The C horizon has a n accumulation of clay and broken down rock . The bottom layer is the bedrock

Brown earths are fertile and very suitable for agriculture . their suitability for agriculture are due to their characteristics of good texture , dark colour , and ph value .
Texture :
Texture is how a sol feels when you touch it . The proportions of sand silt and clay determines the soils texture . The texture determines how well moisture and roots can penetrate the soil and how well excess moisture can drain away . The ideal combination for soil texture is roughly 40% sand , 40% silt , and 20% clay creating what is known as a loam soil . Brown earths fall into this category . They have a well developed crumb structure which allows water air and organisms pass through it easily , and roots can spread out in it easily . Water retention is good as it is soaked up by the crumbs of the soil and nutrient retention is good also . They also have good drainage and aeration properties. Loam soils such as brown earths are ideal for cultivation

Colour :
Lighter coloured soils deflect sunlight while darked soils absorb more light . This allows the soil to heat up much more quickly and encourages seed germination and crop growth , Heat is also important in the humification process . Brown earths have a high humus content which make it a darker soil and thus supports good crop growth

PH Value :
PH scale measure the acidity of a substance . The ideal PH value for agriculture is 6.5 which is slightly acidic . A soil whih is too acidic lacks calcium and potassium which are essential for growth and has low levels of organisms which are vital for humification . Soils which are quite acidca are peaty soils which have a ph value of less than 4and are found mainly in the mountainous areas of the west . They have suffered from leaching and tend to be waterlogged also . Brown earths have a ph value of between 5 and 7 , ideal values that are knon to be very fertile supporting a wide variety of plant life