Sunday, 29 April 2018

PLANTS AND SOIL


PLANTS AND SOIL ……


leaf food
fallen leaves provide food for animal and fertilize the soil
Plants take water and nutrients from the soil, only to return them in a never-ending, finely balanced cycle. But this cycle can be destroyed by humans, if we forget to care for our vital forests and fields.

What happen to all the leaves that fall?

Huge quantities of leaves fall from forests trees, but they do not build up on the woodland floor from years to year. The dead leaves are attacked for example by fungi and bacteria, and break down becoming part of the soil. The leaves are also eaten by animals including worms and insects.

How do plants make soil more fertile?

When plants die, they decompose, releasing the chemicals in their tissues into the surrounding soil. The mixture of rooting leaves and other plants material in the soil is called humus, and this make the soil more fertile.

What is overgrazing?
It is livestock such as cows and sheep are allowed to eat the grasses and other plants in one area for too long. The plants are not able to recovery and, in dry areas, the land may become eroded or turn into desert.

How do plants colonized bare ground?
DANDELION
A dandelion's seed are carried by 'parachutes'to take root on bare
ground
Some plants can quickly colonized bare soil by germinating rapidly from lightweight, wild-blown seeds. Some colonizing plants spread by putting out runners, which splits off, becoming new plants.

How can plants be used to help stop erosion?

                      Erosion is when soils is loosened and  removed by the action of nature forces such as wind and water. This can often be reduced or prevented by using plants. This roots of the plants. The roots of the plants trap the loose soil and stop it being blown away. This can be useful on steep slopes or the edges of deserts.



How do plants help us reclaim land ?

           Several types of grass, including marram, can be planted on coastal dunes. Their roots anchor the sand and help to stop it blowing away. Plants can even being to reclaim land contaminated by industrial poisons. Some special have evolved forms that can tolerated toxic substance. They gradually improve the fertility and build up the soils so that other plants can grow there too.