244 high land
P1: highland were once forested. 1. all mammalian species are forest dwelling 2. subfossils recovered with trunks3. Ps forest vegetation
P2: B grassland reflects changing climate. D: mosaic(马赛克,拼凑而成的东西)of forest and grassland because lack of rainfall R:not rainfall, long dry season and winds. However, microclimatic character of M highland. Closed forest can maintain itself in a wet-dry climatic regime(气候型)
P1: many evidences support that the highland were once a forest. All living animals there are forest dwelling, including 28 kinds of lemurs. Then introduced a few animals fossils to support this view.
P2: some researchers have different opinions. Bourgeat believed the grassland reflects a changing climate. Dewar argues a highland mosaic of forest and grassland as a response to seasonal lack of rainfall. Raisin thinks the mosaic is because of a long dry season and easterly winds. But, seasonal drought explanation ignores two factors. One, mosses on the forest floor hold large quantities of waters. Two, fog drip and dew condensation contribute the water balance. So, the seasonal drought explanation is not convincing.
Author's opinion: can not see a clear opinion of the author from the text. But the author did not oppose the highland used to be a forest. But the author indeed point out that the seasonal drought explanation is not sold for the grassland there.