Nitrogen mass balance in the Brazilian Amazon: an update

Nitrogen mass balance in the Brazilian Amazon: an update.

The main purpose of this study is to perform a nitrogen budget survey for the entire Brazilian Amazon region. The main inputs of nitrogen to the region are biological nitrogen fixation occurring in tropical forests (7.7 Tg.yr(-1)), and biological nitrogen fixation in agricultural lands mainly due to the cultivation of a large area with soybean, which is an important nitrogen-fixing crop (1.68 T...

What Drives Deforestation in the Brazilian Amazon?

While previous empirical analysis of deforestation focused on population, this paper builds from a model of land use which suggests many determinants of deforestation in the Brazilian Amazon. I derive a deforestation equation from this model and test a number of those factors using county-level data for the period 1978]1988. The data include a satellite deforestation measure which allows improv...

Nitrogen Mass Balance in a High Rate Algal Pond

Mass balance for lead in the California South Coast Air Basin: an update.

A mass balance for lead for the year 1989 in the South Coast Air Basin has inputs to the atmosphere of 600 +/- 190 kg/day and outputs of 580 +/- 160 kg/day, showing rough agreement. Stationary sources are responsible for only about 5% of the total lead emissions. The bulk of the lead is emitted from vehicles using leaded gasoline (37%) and unleaded gasoline (15%), as well as from resuspension o...

Land Use Dynamics in the Brazilian Amazon

The articles presented in this special issue of Ecological Economics address the important theme of land use dynamics as it pertains to the Brazilian Amazon. Much environmental change is an ecological artifact of human agency, and such agency is often manifested in land use impacts, particularly in tropical areas. The critical problem of tropical deforestation is but one example of a land use d...