In particular, gathering plays a major role only in villages without rich fish stocks or upland nearby as alternative insurance.
In the case of publicly-owned uplands, this was carried out by private firms who were conceded exploitation rights by the state or local authorities.
A simulation is used to study the impact of environmental payments to upland households in exchange for allocating labour away from the externality-producing activity.
The major limiting factor is the drainage conditions for upland crops, the area near the canal being the most suitable for these crops.
Another, more workable approach to the erosion problem would be to create incentives for the adoption of soil conservation measures on upland farms.
Much of this hired labor consisted of residents of upland farms.
In the 15 plots of 0.1 ha established in the well-drained uplands, 81 families, 310 genera and 1124 species were found.
In two of these upland forests, mortality was restricted to particular understorey species.