Plants can be used to prevent desertification. The Great Green Wall in the Sahara is an example, which was an initiative by the UN and the UNCCD (UN Convention for Combatting Desertification). Plants stabilise the soil, fertilise the soil, and can allow for other plants to grow by changing the climate and soil conditions, including the chemical and physical structure of the soil. Using native plants is optimal when possible. The climate can change with trees, which will cool the area - In a model if you remove trees you decrease precipitation and increase temperatures. Trees affect the climate in many aspects, through immediate cooling effects as well as long term CO2 sequestration, which reduces CO2 in the atmosphere.