Editing Desertification (section)

=== Immediate causes ===
The immediate cause of desertification is the loss of most vegetation. This is driven by a number of factors, alone or in combination, such as drought, climatic shifts, tillage for agriculture, overgrazing and [[Deforestation and climate change|deforestation]] for fuel or construction materials. Though vegetation plays a major role in determining the [[soil biology|biological composition of the soil]], studies have shown that, in many environments, the rate of erosion and runoff decreases exponentially with increased vegetation cover.<ref name=":8">{{cite book|author=Geeson, Nichola|title=Mediterranean desertification: a mosaic of processes and responses|publisher=John Wiley & Sons|year=2002|isbn=978-0-470-84448-9|page=58|url=https://books.google.com/books?id=G_0qg0f49GQC&pg=PA58|display-authors=etal|access-date=2016-05-16|archive-date=2023-07-30|archive-url=https://web.archive.org/web/20230730161049/https://books.google.com/books?id=G_0qg0f49GQC&pg=PA58|url-status=live}}</ref> Unprotected, dry soil surfaces blow away with the wind or are washed away by flash floods, leaving infertile lower soil layers that bake in the sun and become an unproductive hardpan.