Colombo, Environment

Desertification and Biodiversity

Photo courtesy NASA

The link between land degradation and desertification has been made abundantly clear in studies conducted in Africa and Australia. A loss of natural vegetation, a loss in soil organic matter and a loss of soil stability contribute greatly to the process.  These processes are often interlinked.  Vegetation encourages soil stability by providing cover, the binding action of roots, providing root exudates and by the contribution of its biomass to the soil.  A loss of vegetation results in a corresponding loss of soil organic matter and stability.

Soil organic matter and soil stability are often linked.  A soil that becomes depauperate in its content of organic matter looses the glue that holds soil particles together and becomes easily erodible.  The more a soil erodes the more difficult it becomes for the soil microorganisms to glue the particles together.  The process is analogous to a spider’s web in the wind.  A whole web can withstand the pressure.  If one of the threads that anchor it is broken the spider can repair it, but if the rate of damage is slowly increased, there will come a time when the spider cannot repair the damage and the web will be destroyed by the wind.

Every environment has a threshold beyond which damage cannot be repaired by the natural system.  In arid and semi arid environments this threshold is very low.  This does not mean that these environments are unusable. Merely that management has to be sensitive to these constraints.  The lessons of mismanagement are thick about us.  The forests of Lebanon and the forests of central China have been replaced by deserts as a consequence of poor management. In other places, humanity has used such lands for time immemorial and still does today.  It means that good land management is critical in addressing arid and semi arid lands.

Studies of arid and semi-arid ecosystems indicate that the original ecosystems are uniquely adapted to the harsh climate, when they are disturbed or destroyed, the ecosystem moves towards desertification.  These ecosystems are rich in biodiversity and have distinctive associations of plants and animals when stable.  Biodiversity, it must be noted is the measure of the variability of living organisms at any spatio-temporal point.  It does not mean wild, endemic, rare or even native, merely the measure of variability.

Thus a certain suite of species will represent the biodiversity of a wild area in a given environment, while a different suite of species will represent a human managed area in the same environment.  Degradation is usually accompanied by the loss of biodiversity in either environment.  Therefore, biodiversity is a good indicator of land degradation.  As land degradation and desertification are closely linked, biodiversity can also serve as a good indicator of desertification.

In all of the much-touted agricultural advances, one fact is clear. There is a loss of biodiversity that accompanies high-energy addicted agriculture. The broadcasting of artificial fertilizer as promoted by the pathetic politicized programs in agriculture, has only resulted in the farmer getting more and more addicted and becoming victims to the chemical suppliers.

History demonstrates that the great soil capital of this nation was lost with the advent of colonial plantation agriculture.  It was hoped that this loss could be dealt with. However, the current ill advised and thoughtless programs in agriculture will destroy the remaining bits of living soil with artificial fertilizers, increasing the phenomenon of dust in the dry season, an indicator of the collapse of the ecosystem and a move towards desertification.

Why dust?  There have been droughts and dry periods before but never with this magnitude of dust.  Dust is generated when soil looses its organic cover and its cohesive strength.  The loss of cover is the loss of stable or perennial vegetation over the surface.  The loss of cohesive strength is the loss of soil binding agents both macroscopically and microscopically created.  The macroscopic binding agents are the roots of plants and plant compounds.  The microscopic agents are the bacterial gums, polysaccharides and humates of a healthy soil.  With an increase of intensive farming there is a corresponding increase in the dust phenomenon.

While traditional management systems maintained the stability of their ecosystems as evidenced by the biodiversity levels in such systems, the modern management systems did not.  This is especially true in many parts of northern Africa where inappropriate and unsustainable agricultural technologies have been implemented.  The ‘new’ agriculture being developed to produce export crops.  The consequence of these technologies in terms of desertification are well documented, its cost in terms of biodiversity loss still waits to be evaluated.

Couple the observation above with the loss of tree biomass throughout the nation and a dismal picture emerges, the average size of harvested trees becomes consistently smaller over the last twenty years. A countryside that was evergreen now changes to green during the rains and brown during the dry. Rivers that once ran clean now flow as turbid drains and the increase in dust!  These are indications of a move towards dryer conditions for those who can see. If they persist without being addressed, we are guilty of eroding the sustainability of this nation.

The loss of social cohesion and traditions through landscape simplification, the loss of biomass and the loss of biodiversity are evidenced in all of industrial agriculture. This ‘development’ process brings about, not only a monoculture of production, but as pointed out by Vandana Shiva ‘ a monoculture of mind.’ A mindset that sees only the need to make money to consume as development, a mindset that has no concern for the land, water or air that is so fundamental to living. As pointed out above, the consequence of this mindset of ‘Idiot Development’ is to create a mass of consumers with no other goal than to consume more. It will disrupt the life support systems that sustain us.

And the dust tells us that for us, the process has begun