The first trees evolved around 370 mya along a lakeshore at the foot of the caledonian range. how did these trees have a positive impact on plants and animals?

These first trees had a huge importance for the other plants and for the animals, and this was because:

- they managed to change the structure of the atmosphere by consuming, using, and storing carbon dioxide, and releasing oxygen, which made the atmosphere much more suitable for life.

- they managed to influence the climate, by making it more moist, and also making the ground bellow them cooler.

- they were producing large amounts of biomass, which made the soil types much richer in nutrients, which in turn enabled more and more plants to grow.

- they were a food source of the animals.

sand 60

clay 10

silt 30

sandy loam should be dominated by the sand. as the amount of sand increased, the amount of slit needed to anchor the plants' roots to the sand will also be increased. even though the amount is very little, 10% part of clay is still necessary for proper oxidation.