Save the tropical grasslands

A complex community of mammals, birds, reptiles, and invertebrates has evolved in the tropical grasslands. But as these areas dwindle, their wildlife become increasingly threatened.

Land of grass

Grasslands naturally form in tropical regions that get too little rain for forests but are not dry enough to become deserts. Vegetation dies in the dry season but grows during the summer rainy season. Grass-es dominate the area, but drought-resistant trees such as acacias, baobabs, palms, and cassias also grow in the grasslands.

Grasses quickly grow again when their stems are bitten off or trampled. They recover easily after the fires that sweep the terrain in the dry season. Narrow leaves provide dense cover and food for herbivores (plant-eaters). Grass roots bind the earth and provide food for soil animals.

Dwinding resources

Human settlement threatens the ecological balance be-tween soil, vegetation, and animals on the tropical sa-vanna and other grasslands worldwide. Land plowed and tilled for crops or used as pasture for herds of cattle, sheep, and goats take over natural habitats. These do-mestic herds graze more intensively than wild herbi-vores, altering the pattern of vegetation and driving out native plants and animals. Intensive grazing and cul-tivation in drier areas reduce plant cover until it no longer protects and binds the top-soil, leaving it exposed to the wind and rain. The soil blows and washes away, leaving the land uninhabitable for either animals or humans.

Hunting

Varieties of large animals on the open savanna terrain suffer from hunting. Killing fast-running animals is con-sidered an exciting sport, and many make valuable trophies. Hunters kill some animals for food and some because they are predators that might attack domestic livestock.

As a result, large grassland animals have declined over the past few centuries. In India, blackbuck and Asiatic lions have decreased to low levels. African elephants, rhinoceroses, giraffes, zebras, lions, leopards, and cheetahs have all disappeared from their original ranges. Several species, including more than a million springboks, were brought close to extinction in the nineteenth century.

Conservation measures

The impact of farming on grassland worldwide would be difficult to reverse. As human populations grow, the need for farming tropical grassland in the future increases. But for these areas to continue sustaining life, careful efforts to conserve the soil must be made.

Livestock herds need to be reduced to fit the size of the land. Pastures should be left empty some years or planted with crops such as alfalfa to restore soil fertility. Lines of trees should be planted as windbreaks to protect the crops and stem erosion.

Other measures to protect grasslands include laws pro-tecting animals from hunt-ing. The Convention of International Endangered Species (CITES) controls animal trade and products.

National parks

The future of tropical grass-land conservation lies in setting aside land in national parks and reserves. Habitats in selected areas remain as wild as possible without human intervention.

The savannas in eastern and southern Africa have many national parks, includ-ing the large areas in Kenya’s Tsavo or Tanzania’s Serengeti. These parks harbor the largest grazing herds, maintaining wildlife once common in African grasslands.

Yet national parks have been unpopular with local people because of park restrictions. In some parks, antelopes and elephants are killed because the protected herds become too large and destructive. Poachers still penetrate protected areas and hunt endangered species. Despite shoot-to-kill policing in some countries, elephant and rhino poaching has increased.