Chapter 2
Imperata  Grassland Ecology

2.4 Microsites: more than just grass

There is a great variety in Imperata  grassland landscapes. Summarized here are features to look for and how to use them in agroforestry or assisted natural regeneration.

Springs and streams: Springs often occur in gullies, small valleys, or at the base of steep slopes. They often occupy the same relative elevation or position throughout the landscape. They may also be found by looking for the trees and shrubs that often grow near them.

• Locate springs for water sources for nursery seedlings and livestock.

• Observe levels of flow between rainstorms and during the dry season; a spring that dries up or a site that floods will not be useful for a nursery.

Existing fuelbreaks: The spread of a grass fire may stop at streams, rocky outcrops, roads, moist forests, and other areas with little grass or highly flammable fuel.

• Begin Imperata  rehabilitation next to existing fuelbreaks that will help protect one side of the planting from fire.

• Plan a system of fuelbreaks that widen and extend existing fuelbreaks (see Section 3.3.2).

Gallery forest vegetation: Within Imperata  grasslands, trees and shrubs may continue to grow in gullies and along streams. Even where there is no stream, trees and shrubs may grow in depressions and below springs: wherever there are moist conditions that keep the vegetation less flammable. Such forests are often called gallery forests (or gully forests).

• Begin Imperata  rehabilitation next to existing gallery vegetation, where conditions may be relatively favorable. The vegetation and the moist soil conditions will help protect one side of the planting from fire.

• Gallery forests may be a source of seeds and wildings for ANR.

• Gallery vegetation is a potential source of mycorrhizae for nursery seedlings.

• Gallery forests may serve as corridors for wildlife that help spread seeds.

Pioneer vegetation: Small shrubs and tree saplings are often scattered throughout Imperata  grasslands. Observe where these are most common or occur in clusters, because they may indicate where conditions are favorable, due to fire patterns, moisture and drainage, protection from wind and sun, or other factors. Often, trees and shrubs cluster along steep slopes on one side of ridges.

• Begin Imperata  rehabilitation in areas with clusters of pioneer vegetation, where conditions may be better for planting.

• Pioneer vegetation may be a source of seeds and naturally regenerated seedlings ("wildlings") of fire-resistant species for ANR.

• Pioneer vegetation is a source of mycorrhizae for nursery seedlings.

Fire-resistant grass: On mountain tops there may be fire-resistant grass in monoculture stands or mixed with Imperata . These grass species may be indicators of drought-prone, shallow, or nutrient deficient soils. Few or no trees grow in these areas, apparently due to the low water supply. These grasslands often occupy similar topographic positions and elevations throughout a landscape.

• If these areas are important, test tree and crop species on these sites before making recommendations or beginning full-scale planting.

Grazing areas: Sparse cropped grass and trampled paths zig-zagging across the slope are visible signs of grazing.

• Work with livestock owners to provide for forage needs, either by setting aside adequate Imperata  areas or providing alternate forage.

• Anticipate that grazing areas will be burned to stimulate new growth of tender young grass. Control fires so they do not escape (see Sections 3.2.2 on fire regulations and 3.3.2 on fuelbreaks).

Cattle trails: Observe cattle trails from a high point and follow them through the Imperata.

• Cattle trails may reveal good routes for graded trails from high to low positions within the area, since cattle usually follow the easiest path.

• Trails may lead to waterholes that can be good sites for nurseries.

• Cattle trails often lead to relatively easy gully crossings, where gully banks are not too steep. The gullies often have water and shade and are often good sites for nurseries.

• Trails can serve as starting points for fuelbreak construction.