pasture, padang rumput, savanna dan rangeland (bahan mk. Tatalaksana Padang Pengembalaan Tropika)

Pasture

Pasture is land with vegetation cover used for grazing of livestock as part of a farm, or in ranching or other unenclosed pastoral systems or used by wild animals for grazing or browsing. Prior to the advent of factory farming, pasture was the primary source of food for grazing animals such as cattle and horses. It is still used extensively, particularly in arid regions where pasture land is unsuitable for any other agricultural production. In more humid regions, pasture grazing is exploited extensively for free range and organic farming.
Pasture growth can consist of grasses, legumes, other forbs, shrubs or a mixture. Soil type, minimum annual temperature, and rainfall are important factors in pasture management.

Grassland

Grasslands (also called greenswards) are areas where the vegetation is dominated by grasses (Poaceae) and other herbaceous (non-woody) plants (forbs). However, sedge (Cyperaceae) and rush (Juncaceae) families can also be found. Grasslands occur naturally on all continents except Antarctica. In temperate latitudes, such as northwest Europe, grasslands are dominated by perennial species, where as in warmer climates annual species form a greater component of the vegetation.

Grasslands are found in most terrestrial climates. Grassland vegetation can vary in height from very short, as in chalk downland where the vegetation may be less than 30 cm (12 in) high, to quite tall, as in the case of North American tallgrass prairie, South American grasslands and African savanna. Woody plants, shrubs or trees, may occur on some grasslands - forming savannas, scrubby grassland or semi-wooded grassland, such as the African savannas or the Iberian dehesa. Such grasslands are sometimes referred to as wood-pasture or woodland.
Grasslands cover nearly fifty percent of the land surface of the continent of Africa.[2] While grasslands in general support diverse wildlife, given the lack of hiding places for predators, the African Savanna regions support a much greater diversity in wildlife than do temperate grasslands.

The appearance of mountains in the western United States during the Miocene and Pliocene epochs, a period of some 25 million years, created a continental climate favorable to the evolution of grasslands. Existing forest biomes declined, and grasslands became much more widespread. Following the Pleistocene Ice Ages, grasslands expanded in range in the hotter, drier climates, and began to become the dominant land feature worldwide.[2]

As flowering plants, grasses grow in great concentrations in climates where annual rainfall ranges between 500 and 900 mm (20 and 35 in).[1] The root systems of perennial grasses and forbs form complex mats that hold the soil in place. Mites, insect larvae, nematodes and earthworms inhabit deep soil, which can reach 6 metres (20 ft) underground in undisturbed grasslands on the richest soils of the world. These invertebrates, along with symbiotic fungi, extend the root systems, break apart hard soil, enrich it with urea and other natural fertilizers, trap minerals and water and promote growth.[4] Some types of fungi make the plants more resistant to insect and microbial attacks.

Savanna

A savanna, or savannah, is a grassland ecosystem characterized by the trees being sufficiently small or widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of C4 grasses.[1] Some classification systems also recognize a grassland savanna from which trees are absent.[2] This article deals only with savanna under common definition of a grassy woodland with a significant woody plant component.

It is often believed that savannas feature widely spaced, scattered trees, however in many savanna communities tree densities are higher and trees are more regularly spaced than in forest communities. Savannas are also characterized by seasonal water availability, with the majority of rainfall being confined to one season of the year. Savannas can be associated with several types of biomes. Savannas are frequently seen as a transitional zone, occurring between forest and desert or prairie. Savannas cover 20% of the globe not including oceans. The largest amount of Savannah is in Africa.

Rangeland

Rangeland refers to expansive, mostly unimproved lands on which a significant proportion of the natural vegetation is native grasses, grass-like plants, forbs, and shrubs. Rangeland also consists of areas seeded to native or adapted introduced species that are managed like native vegetation. Rangelands include natural grasslands, savannas, shrublands, many deserts, tundra, alpine communities, coastal marshes, and wet meadows. Rangeland is generally arid, semi-arid, sub-humid or otherwise unsuitable for cultivation. Ranches are likely to comprise mainly rangeland.

In the United States, around 399 million acres (1,610,000 km²) of rangeland are privately owned. The Bureau of Land Management manages about 167 million acres (676,000 km²) of publicly owned rangeland, with the United States Forest Service managing approximately 95 million acres (380,000 km²) more. Ranchers may lease portions of this public rangeland and pay a fee based on the number and type of livestock and the period for which they are on the land. Many western states have open range laws. In these states, all land, both public and private, is designated as open range unless it is within city limits. In open range, it becomes the responsibility of the land owner to keep unwanted livestock off their land and the livestock owner is not liable for any damage caused by the livestock.