How do convergent plate boundaries that have the same density to convert plate boundaries with different densities compare

The biome pictured above is found in areas such as kenya and south africa. the land is grass-covered with very few trees and gazelles and other grazers are common here. why does this biome have a low population of trees? a) large grazing animals destroy the trees. b) it is a deforested rainforest with poor soil. c) it has high temperatures and low precipitation. d) it has a long rainy season followed by flooding.