Wednesday, April 16, 2008

Fragile Ecosystem and Desertification

Wikipedia: "Desertification is the degradation of land in arid, semi arid and dry sub-humid areas resulting primarily from human activities and influenced by climatic variations. Current desertification is taking place much faster worldwide than historically and usually arises from the demands of increased populations that settle on the land in order to grow crops and graze animals."

What we saw in Morocco is that the western edge of the Sahara is moving westwards, swallowing up surrounding land by depositing sand. As gardeners know, it is very difficult to grow things in sand. A reduction in productive arable land means people and animals may go hungry. Since 93% of Morocco is arid, the government is working on stopping the encroachment, but 55,000 acres of arable land is disappearing per year. Can mere humans possibly stop it, not only in Morocco, but in many other countries?

At the end of the 19th Century Morocco had over 15 million date palms. Now there are only 4.5 million. This reduction means a huge drop in income for a large part of the local population.

According to Wikipedia: "It has been determined that the primary reasons for desertification are overgrazing, over cultivation, incorrect irigation methods, deforestation, overdrafting of groundwater, increased soil salinity, and global climate change."

I must admit that when our guide told us about the problem of the expanding desert and showed us sandy areas far from major sand dunes of the Sahara, I was puzzled. It was like there was a sand magnet under the ground.

While I have not found an explanation for pockets of sand (I suppose the wind is the main culprit), it seems that (Wiki) "Desertification does not occur in linear, easily mappable patterns. Deserts advance erratically, forming patches on their borders. Areas far from natural deserts can degrade quickly to barren soil, rock, or sand through poor land management. The presence of a nearby desert has no direct relationship to desertification. Unfortunately, an area undergoing desertification is brought to public attention only after the process is well under way. Often little data are available to indicate the previous state of the ecosystem or the rate of degradation."

You frequently hear the phrase fragile ecosystem. After reading the info on Wikipedia and having seen the edge of the desert in Morocco, I understand it much better. There is nothing like nature's classroom and travelling to broaden our understanding of everything and everyone else.


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