Pict 1. 100 sq km grass steppe, almost withouthigher life
Pict 2. Land degradation caused by little herbs able to buffer flows and few roots bilding soil.
As I mentioned before there are plans on planting a green belt south of Hewler/Erbil. What effects would it have on the environment - if it becomes big enough?
From studies made abroad there are some effects that we can expect after planting a massive Green Belt on the Makhmor hills:
A. Less accentuated seasonal changes outside the Green Belt.
The seasonal changes considering water run-off, humidity in air and (if the belt is massive enough) temperature, will be less accentuated.
1. Precipitation and water run-off
Barren, grass covered hills have a very limited ability to store larger quantities of water. With a pronounced seasonal rain as in Kurdistan and with a cattle-packed surface is the absorbsion only a few percent. The waters moving in high speed downhill excavate the hillside in a flood of mud. The result is advanced land degradation, see picture. It is common knowledge that a slope with trees and sub-vegetation has a totally different ability to buffer and store water. Water remains long enough to be absorbed by the underlying layer to finally reach the water table. A Spanish study shows that water is lead by pole roots to deeper levels than otherwise. This larger intake of water compensates the used later in the season by the trees for evaporation. We can expect less rapid floods and less land degradation and a deeper penetration of larger amounts of water.
2. Evaporation in dry periods
As said above the trees not only contribute to the absorbsion of precipitation. They consume water for evaporation. That is, the trees ooze out soil stored water and thereby increase the humidity. Data suggest that evaporation from a pasture-mesquite vegetation is an important component in the water balance considering the limited rainfall occurring.[1] The moisture wills condensate on air bore dust that will descend in the direction of the ruling winds. In our case with desert winds it should normally happen on the plain between Makhmoor and Hewler, place depending on the velocity of the winds and the altitude of the dust. We can expect an increasing humidity that is dust binding. and changes in the sub-vegetation, from steppe grasses to herbs and other kind of grasses.
3. Wind break
Another factor that diminishes the air-borne dust is the wind break. As the Green Belt slow down the wind, the ability of the air masses to transport dust will decrease. Behind the Green Belt, and even within it, we can expect downfall of dust. As the velocity of the winds slows down will also the drought of the land behind the Green Belt, caused by hot and dry winds diminish. We can expect higher yields on the fields behind the Belt, maybe hampered by dust shading the photosynthesis.
B. Dramatic changes within the Green Belt
The introduction of shade, humidity and available nitrogen will rather dramatically change the biotype in the Green Belt, over time.
1. In a first stage higher grass
In the beginning the areas will be exposed to sun and drought. With the addition of nitrogen from the growing trees the grasses will grow taller and denser. They have to be held back around the trees by mechanical means. We can expect higher grass in the beginning and increasing amount of insects living on the grass steppe.
2. Replacement of grasses
The increased humidity and shade will benefit a lot of herbs depending on these factors and change the composition and amounts of grasses in the area. We can expect a succession of species were each and every has a golden period with optimal conditions.
3. Stable shade/glade biotype, many microclimates
Within, maybe seven years we will see the development of a shade biotype. Under the trees will grow herbs with little demand on sunlight but high on nitrogen. In the glades between with more light and less nitrogen will grasses have their chance. Instead of the ruling steppe monoculture we can expect a high diversity in microclimates depending on light/shade, humidity and available nitrogen.
4. Insects!
As the biotype changes and the differentiation of microclimates increases, the specialists will colonize different niches and the grass steppe insects will diminish. Species seldom seen before will settle in the Green Belt. We can expect a change in the insect population and a rapid increase in the number of species but less individuals of each and every.
5. Higher wild life
Comparing with the grass hills of today will the change be dramatically. Birds, reptiles as well as mammals will colonize the Green Belt. This will be especially evident if we dig water holes that contain water some months after the rain. We can expect a wealth of animals in the Green Belt!
C. The Green Belt and the surrounding areas
There will be an interaction between the Green Belt and the surrounding areas that I have already briefly treated in climatical terms.
1. The Green Belt leaks life
The borders between the Green Belt and the zone around will not be that sharp. Depending of type of organism we can expect life leaking: Animals moving, birds flying outside the Green Belt will in some cases cause irritation from the farmers around. Some of the species will try to colonize the hills around by themselves. Shall we let the Green Belt grow? We can expect the leaking out of life to influence the areas around the Green Belt.
2. Game and poachers
The wealth of wild life will attract poachers. This is a no man’s land with a long history of hunting, except for the restrictions during the Saddam years. There are several ways of treating this issue that will stop or restrict to a controlled hunting. We will for instance see flocks of wild dogs chasing that we simply must kill. We can expect an increased interest from poachers and from wild dogs that has to be handled in an intelligent way.
3. Visitors
As obvious for everybody that has seen a Kurdish or even more, Arabic picnic area, there is a most irresponsible attitude to nature. Go to the picnic sites in Shaqlawa if you don´t understand what I mean! We can expect human impact that contradicts our intentions with the Green Belt that simply have to be controlled and restricted by Park Wards.
4. Claims of ownership and use
As the park grows in every dimension, concerning beauty and number of visitors and thus its economical value increases all kind of demands will be raised: from families that claim that they have ownership to parts of the Green Belt to business people who want to open a restaurant in the park. This has to be regulated by
a. handling over the rights for 25 years in a legally impeccable manner to the Green Belt Trust.
b. restrict the commerce to business zones by the entrances
c. restricting all entrance to parts of the Green Belt zone that are havens for wild life.
We can expect claims of ownership and use that contradicts the intentions of the Green Belt. This has to be controlled by the Green Belt Trust.
[1] http://adsabs.harvard.edu/abs/2004AGUFM.B51A0932S
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