The pie chart below shows the main reasons why agricultural land becomes less productive. The table how these causes affected three regions of the world during the 1990s.

The charts provide information on four factors that led to the decline in agricultural land productivity in the 1990s,

as well as

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the areas impacted. As is presented, land degradation was dominantly caused by over-grazing, deforestation, and over-cultivation,

although

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salinization accounted for a small share.

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, Europe was the most affected area,

along with

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Oceania and North America. Regarding the reasons for desertification,

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over-pasturing had a significant amount with just over a third proportion, the increasing salt concentration in soil was the lowest cause with 7%. Both forest clearance and over-planting constituted similar

portion

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at 30% and 28%, respectively. Of the three regions, Europe had the highest number of habitat destruction during the 1990s, at 23%, with over-logging as the main reason at a tenth percentage.

On the other hand

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, Oceania and North America had 18% in total of land degradation.

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over-foraging was the primary cause for the former at 11.3%, over-farming was for the latter at 3.3%.