The lack of diversity can seriously damage the soil. The image above is of a soil that has lost its structure through the over-use of artificial fertilizers and the almost complete lack of any organic matter. Going back to the Pine Tree Plantation, this is not a crop that can be harvested after only one season. Although it will be ‘thinned’ at various stages of its overall life, once the canopy has closed and the lack of daylight has suppressed the growth of anything else, so the previously supporting Bird, Animal and Insect life will also be lost to the area. Others which are better suited to Pine woodland will come in, but they are significantly fewer and less diverse than beforehand.
The major change that will occur over the 80 year period between initial planting and final harvesting is that the condition of the soil will have changed significantly. Leaf litter falling from the trees will be acid. The soil fauna – the Earthworms and other soil dwelling creatures will not have been able to cope with the changing conditions and so over time the soil profile will change from what’s known as a ‘Brown Earth’ to a ‘Podsol’ . (see my earlier blog ‘Soil – The Basics’) And this change will significantly change what type of plants can follow on afterwards.