Geoscience Reference
In-Depth Information
Figure 4.4 Diagram of Asian monsoon. Rains come in summer when warm marine
area moves onto the land.
(Illustration by Jeff Dixon.)
weathered, acidic, red and yellow oxisols. Oxisols are very low in nutrients and
high in iron and aluminum oxides. Ultisols are also common throughout this
biome and are the dominant soil in the tropics of Asia. These soils are derived from
crystalline bedrock. They tend to be marginally fertile and less acidic. Additional
soils found in tropical seasonal forests are well drained and fertile inceptisols and
alfisols (mostly converted to agriculture) derived from basalt or limestone, and rich
alluvial soils deposited from ancient and current rivers. Geology, topography,
moisture, nutrient cycling, and decomposition rates all contribute to the composi-
tion and type of soils found in this biome. In general, soils of the tropical seasonal
