A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur naturally on all continents except Antarctica and are found in most ecoregions of the Earth. Furthermore, grasslands are one of the largest biomes on earth and dominate the landscape worldwide. There are different types of grasslands: natural grasslands, semi-natural grasslands, and agricultural grasslands. They cover 31–69% of the Earth's land area.
This glossary of ecology is a list of definitions of terms and concepts in ecology and related fields. For more specific definitions from other glossaries related to ecology, see Glossary of biology, Glossary of evolutionary biology, and Glossary of environmental science.
A meadow is an open habitat or field, vegetated by grasses, herbs, and other non-woody plants. Trees or shrubs may sparsely populate meadows, as long as these areas maintain an open character. Meadows can occur naturally under favourable conditions, but are often artificially created from cleared shrub or woodland for the production of hay, fodder, or livestock. Meadow habitats, as a group, are characterized as "semi-natural grasslands", meaning that they are largely composed of species native to the region, with only limited human intervention.
Bromus tectorum, known as downy brome, drooping brome or cheatgrass, is a winter annual grass native to Europe, southwestern Asia, and northern Africa, but has become invasive in many other areas. It now is present in most of Europe, southern Russia, Japan, South Africa, Australia, New Zealand, Iceland, Greenland, North America and western Central Asia. In the eastern US B. tectorum is common along roadsides and as a crop weed, but usually does not dominate an ecosystem. It has become a dominant species in the Intermountain West and parts of Canada, and displays especially invasive behavior in the sagebrush steppe ecosystems where it has been listed as noxious weed. B. tectorum often enters the site in an area that has been disturbed, and then quickly expands into the surrounding area through its rapid growth and prolific seed production.
In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to roam around and consume wild vegetations in order to convert the otherwise indigestible cellulose within grass and other forages into meat, milk, wool and other animal products, often on land unsuitable for arable farming.
Rangelands are grasslands, shrublands, woodlands, wetlands, and deserts that are grazed by domestic livestock or wild animals. Types of rangelands include tallgrass and shortgrass prairies, desert grasslands and shrublands, woodlands, savannas, chaparrals, steppes, and tundras. Rangelands do not include forests lacking grazable understory vegetation, barren desert, farmland, or land covered by solid rock, concrete and/or glaciers.
The puna grassland ecoregion, of the montane grasslands and shrublands biome, is found in the central Andes Mountains of South America. It is considered one of the eight Natural Regions in Peru, but extends south, across Chile, Bolivia, and western northwest Argentina. The term puna encompasses diverse ecosystems of the high Central Andes above 3200–3400 m.
Human impact on the nitrogen cycle is diverse. Agricultural and industrial nitrogen (N) inputs to the environment currently exceed inputs from natural N fixation. As a consequence of anthropogenic inputs, the global nitrogen cycle (Fig. 1) has been significantly altered over the past century. Global atmospheric nitrous oxide (N2O) mole fractions have increased from a pre-industrial value of ~270 nmol/mol to ~319 nmol/mol in 2005. Human activities account for over one-third of N2O emissions, most of which are due to the agricultural sector. This article is intended to give a brief review of the history of anthropogenic N inputs, and reported impacts of nitrogen inputs on selected terrestrial and aquatic ecosystems.
Barren vegetation describes an area of land where plant growth may be sparse, stunted, and/or contain limited biodiversity. Environmental conditions such as toxic or infertile soil, high winds, coastal salt-spray, and climatic conditions are often key factors in poor plant growth and development. Barren vegetation can be categorized depending on the climate, geology, and geographic location of a specific area.
Pseudoroegneria spicata is a species of grass known by the common name bluebunch wheatgrass. This native western North American perennial bunchgrass is also known by the scientific synonyms Elymus spicatus and Agropyron spicatum. The grass can be found in the United States, Canada, and Mexico from Alaska and Yukon south as far as Sonora and Nuevo León.
Grazing pressure is defined as the number of grazing animals of a specified class per unit weight of herbage. It is well established in general usage.
Holistic Management in agriculture is an approach to managing resources that was originally developed by Allan Savory for grazing management. Holistic Management has been likened to "a permaculture approach to rangeland management". Holistic Management is a registered trademark of Holistic Management International.
Grassland degradation, also called vegetation or steppe degradation, is a biotic disturbance in which grass struggles to grow or can no longer exist on a piece of land due to causes such as overgrazing, burrowing of small mammals, and climate change. Since the 1970s, it has been noticed to affect plains and plateaus of alpine meadows or grasslands, most notably being in the Philippines and in the Tibetan and Inner Mongolian region of China, where 2,460 km2 (950 sq mi) of grassland is degraded each year. Across the globe it is estimated that 23% of the land is degraded. It takes years and sometimes even decades, depending on what is happening to that piece of land, for a grassland to become degraded. The process is slow and gradual, but so is restoring degraded grassland. Initially only patches of grass appear to die and appear brown in nature; but the degradation process, if not addressed, can spread to many acres of land. As a result, the frequency of landslides and dust storms may increase. The degraded land's less fertile ground cannot yield crops, nor can animals graze in these fields. With a dramatic decrease in plant diversity in this ecosystem, more carbon and nitrogen may be released into the atmosphere. These results can have serious effects on humans such as displacing herders from their community; a decrease in vegetables, fruit, and meat that are regularly acquired from these fields; and a catalyzing effect on global warming.
The fungal loop hypothesis suggests that soil fungi in arid ecosystems connect the metabolic activity of plants and biological soil crusts which respond to different soil moisture levels. Compiling diverse evidence such as limited accumulation of soil organic matter, high phenol oxidative and proteolytic enzyme potentials due to microbial activity, and symbioses between plants and fungi, the fungal loop hypothesis suggests that carbon and nutrients are cycled in biotic pools rather than leached or effluxed to the atmosphere during and between pulses of precipitation.
The key characteristic of dry grasslands is that they have low-growing plants, causing the area to be quite open. They also have a mottled structure, which leads to a biome with sunny or semi-shaded areas. On top of that, their soil is relatively dry and nutrient-poor. There are, however, types of grasslands with a higher humus and nutrient content. The soil of these areas overlie acid rocks or deposits such as sands and gravels. Dry grasslands belong to different zones such as: the natural zonal or azonal/extrazonal vegetation and the semi-natural vegetation. Overall, there are 13 classes that fall under dry grasslands.
Woody plant encroachment is a natural phenomenon characterised by the increase in density of woody plants, bushes and shrubs, at the expense of the herbaceous layer, grasses and forbs. It predominantly occurs in grasslands, savannas and woodlands and can cause biome shifts from open grasslands and savannas to closed woodlands. The term bush encroachment refers to the expansion of native plants and not the spread of alien invasive species. It is thus defined by plant density, not species. Bush encroachment is often considered an ecological regime shift and can be a symptom of land degradation. The phenomenon is observed across different ecosystems and with different characteristics and intensities globally.
Carbon farming is a name for a variety of agricultural methods aimed at sequestering atmospheric carbon into the soil and in crop roots, wood and leaves. The aim of carbon farming is to increase the rate at which carbon is sequestered into soil and plant material with the goal of creating a net loss of carbon from the atmosphere. Increasing a soil's organic matter content can aid plant growth, increase total carbon content, improve soil water retention capacity and reduce fertilizer use. Carbon farming is one component of climate smart agriculture.
The Tibetan Plateau alpine shrublands and meadows ecoregion covers the middle transition zone between the northern and southern regions of the Tibetan Plateau. The region supports both cold alpine steppe and meadows across a broad expanse of the plateau. Wild deer, antelope, and sheep roam the grasslands, but the habitat is increasingly being used to graze domestic livestock.
Annual grasslands are a type of grassland ecosystem characterized by the dominance of annual grasses and forbs. They are most commonly found in regions with Mediterranean climates, such as California, and provide important habitats for a variety of wildlife species.
