Biogeochemical cycling and pollutant exposure in tropical rain forest ecosystems

This type of closed biogeochemical cycling is very sensitive to uncontrolled intervention into ecosystems. For instance, clearcutting leads to the entire destruction of the whole ecosystem with its multi-annual history. In other words, the deforestation will leave behind a barren soil with completely destroyed biogeochemical turnover and enforce significantly the exposure to different pollutants. 

For instance, clearing tropical forests in the Amazon basin for pasture alters rates of soil nitrogen cycling (Table 5). 

The pattern of NH4+ and N03 concentrations, and net mineralization and net nitrification rates in soils before and after clearing and burning tropical forest indicate  

The total biomass and its annual distribution for these ecosystems are shown in Table 6. 

As a rule the concentration of chemical species in the trunk and twig wood of tropical trees is a few times lower than that in the leaves (Table 7). 

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