|The Improvement of Tropical and Subtropical Rangelands (BOSTID)|
|Criteria for plant selection|
When planning any revegetation project or program, the first two questions that should come to mind are: what is the purpose of the project or program, and what are the management tools to be applied? Clear answers to these two questions would eliminate many problems and would restrict plant selection to a relatively limited number of possibilities. In the past, a number of philosophical views have been argued endlessly: for example, the selection of native species versus exotics; herbaceous species versus woody species; the planting of nursery-grown seedlings versus direct sowing; and single species versus mixed plantations (Le Houu, 1984). Many personal biases would be avoided by first answering the two questions posed above.
Once the scope and objectives of the project or program are clearly defined, many controversial issues would solve themselves if a number of other questions were asked:
· What is needed?
· What is available?
· What technologies have proven successful under similar circumstances, if any?
· What are the principal constraints in establishment and in management?
· Is the project or program technically and economically feasible, and is it socially acceptable?
The purpose of a revegetation project may be single or multiple, simple or complex. Some examples are given below:
· To rehabilitate depleted rangelands and
· To establish multiple species for both agroforestry and sylvopastoral uses;
· To establish fodder-shrub plantations as drought buffer reserves;
· To stabilize watersheds, which will achieve a combination of goals;
· To develop a program for the reclamation of salt- or alkaline affected land (in either rainfed or irrigated conditions to produce fodder, fuel, amenities, etc.);
· To provide windbreaks and shelterbelts for the protection of agricultural lands;
· To stabilize sand dunes, preventing encroachment upon productive lands;
· To establish fuelwood plantations;
· To increase the potential for timber production by planting highly productive species and ecotypes;
· To reclaim mined land, quarries, and mine-waste dumps;
· To establish protective plantations that will arrest erosion or sedimentation in order to reduce the maintenance costs of highways, bridges, airports, reservoirs, and settlements, without other envisaged direct benefits; and
· To establish amenity plantings - for example, in association with settlements or highways.