A guelta is a pocket of water that forms in drainage canals or wadis in the Sahara. The size and duration will depend on conditions, it may last year-round through the dry season. When a river dries up, there may be pockets of water remaining along its course. In Western Sahara, gueltas correspond with oases; some examples include Guelta d'Archei in Timia in Niger. Billabong - term for a similar type of body of water in Australia
Coniferous swamps are forested wetlands in which the dominant trees are lowland conifers such as northern white cedar. The soil in these swamp areas is saturated for most of the growing season and is inundated by seasonal storms or by winter snow melt; the substrate is organic in nature and may contain peat in varying amounts or be composed of muck. The swamp substrate is nutrient-rich and neutral to alkaline but can be acidic and nutrient-poor. Coniferous swamps vary in composition, with different species of conifer dominating, varying amounts of deciduous hardwoods growing within the swamp. A wide diversity of plants is represented within the swamps, with certain species dominating in a variety of microhabitats dependent on factors such as available sunlight, soil Ph, standing groundwater, differences of elevation within the swamp such as tussocks and nurse logs; the different types of coniferous swamps are referred to according to their dominant trees. Rich conifer swamp is dominated by Northern white-cedar and occurs south of the climatic tension zone throughout the Midwest and northeastern United States and adjacent areas in Canada.
North of the climatic tension zone, tamarack is the dominant species of conifer in minerotrophic wetlands classified as rich tamarack swamp. A equal mix of hardwood trees and conifers is known as a hardwood-conifer swamp. A variety of both evergreen and deciduous trees may be present in the rich conifer swamp in addition to the dominant species. Thuja occidentalis: Northern white cedar, the dominant conifer known as arborvitae, a common landscape specimen in northern U. S. states and Canada. Abies balsamea: Balsam fir Acer rubrum: Red maple Betula papyrifera: Paper birch Cornus stolonifera: Red-osier dogwood Cornus florida: Flowering dogwood Larix laricina: Tamarack Picea mariana: Black spruce Picea glauca: White spruce Pinus strobus: White pine Taxodium distichum: Bald cypress Tsuga canadensis: Hemlock Ulmus americana: American elm Populus tremuloides: Quaking aspen Populus balsamifera: Balsam poplar Nyssa aquatica: Water tupelo Nyssa ogeche: White tupelo Nyssa sylvatica: Black tupelo Alnus glutinosa: Common alder Alnus rugosa Tag elder Ilex verticillata Winterberry Ilex mucronata Mountain holly Sambucus racemosa Red elderberry Gaylussacia baccata Huckleberry Taxus canadensis Canadian yew Lonicera canadensis American fly honeysuckle Lonicera oblongifolia Swamp fly honeysuckle Vaccinium angustifolium Low sweet blueberry Vaccinium myrtilloides Canada blueberry Ribes americanum Wild black currant Ribes triste Swamp red currant Ribes lacustre Swamp black currant Toxicodendron radicans Poison ivy Lonicera dioica Limber honeysuckle Osmunda cinnamomea Cinnamon fern Thelypteris palustris Marsh fern Osmunda spectabilis Royal fern Gymnocarpium dryopteris Oak fern A variety of grasses and sedges may be present including multiple varieties of carex.
Glyceria striata Fowl manna grass Callicladium haldanianum Callicladium moss Sphagnum centrale Cypripedium calceolus Yellow lady’s-slipper Platanthera hyperborea Tall northern bog orchid Aquilegia canadensis Red Columbine Freshwater swamp forest Peat swamp forest Swamp
Blanket bog or blanket mire known as featherbed bog, is an area of peatland, forming where there is a climate of high rainfall and a low level of evapotranspiration, allowing peat to develop not only in wet hollows but over large expanses of undulating ground. The blanketing of the ground with a variable depth of peat gives the habitat type its name. Blanket bogs are found extensively throughout the northern hemisphere - well-studied examples are found in Ireland and Britain, but vast areas of the Russian and North American tundra qualify as blanket bogs. In the southern hemisphere they are less well-developed due to the low latitudes of the main land areas, though similar environments are reported in Patagonia, the Falkland Islands and New Zealand; the blanket bogs known as'featherbeds' on subantarctic Macquarie Island occur on raised marine terraces. It is doubtful whether the impoverished flora of Antarctica is sufficiently well developed to be considered as blanket bogs. In some areas of Europe, the spread of blanket bogs is traced to deforestation by prehistoric cultures.
In many areas peat is cultivated as a fossil fuel and used either in electricity generation or domestic solid fuel for heating. In the Republic of Ireland a state owned agency, Bord na Móna, owns large areas of bog land and harvests peat for electricity generation but that peat is from the raised bogs in the central plains. Bord na Móna used to burn peat in the peat fired generating station at Bellacorick but that closed down many years ago and the area now houses a large windfarm; some blanket bogs are now preserved by government organisations in both Ireland and Britain, as this habitat is now under threat from extensive harvesting. Examples of protected blanket bogs include Sliabh Beagh and Airds Moss. String bog
Beach Meadows are coastal meadows influenced by the presence of the nearby sea. Under this definition, the salinity of the air and wind is high and the meadows are flooded during and after stormy weather; these conditions implies. But that alone does not make a meadow. To be categorized as a meadow in the first place, the plantgrowth has to be low in height, this can only be achieved from wear by general traffic or grazing of the landscape, either artificially or by livestock. Beach meadows are therefore thought of as cultural landscapes or biotopes, requiring some degree of intervention and not being able to sustain itself on its own. If left to their own, beach meadows would transform into a socalled transitional meadow and a shrubby or bushy seashore habitat; as explained, beach meadows are fundamentally an unstable nature type and this condition have an important influence on the flora and fauna found here. Beach meadows are characterized by a number of plants and animals, that could not have thrived, if the habitat was left to a natural development.
The grazing hinders bushes and shrubs to get the upper hand and allows low-growth plants to emerge and dominate. This again attracts and supports a special fauna that would change character, if the beach meadow were left to its own; the specific flora and fauna is of course determined by the general climate and geography of the beach meadow. Beach meadows offers a variety of opportunities to many birds waders and gulls. Many species are resting here during tides and they are feeding in the small ponds. A number of bird species use them as breeding grounds on islands without predators like fox, mustelidae or the like. Introducing small numbers of predators to beach meadow habitats, can wreak havoc on the bird populations, as they have unrestricted access to eggs and birds. Denmark have several beach meadows. Large and well-developed meadows can be found in the Wadden Sea and Isefjord areas and on the islands of Læsø and Lolland, but there are many other smaller beach meadows throughout this lowlying country.
On the Faroese Islands and in Greenland'fell meadows' can be found. They are not flooded by seawater, so it could be argued if they are beach meadows. Iceland and some parts of Sweden, have extensive'fell meadows'. In the Baltic region, there are several beach meadows. Sweden can present true beach meadows on Öland and in some parts of Gotland fx. and Estonia has large beach meadows of international importance to migratory birds. United Kingdom have several beach meadows throughout, they can be found in Cornwall and the country of Wales have several. Here the coast consists of high cliffs, so the meadows are not flooded by seawater and speaking they would be classified as'coastal meadows' or'fell meadows'. Examples can be found on the Llŷn Peninsula. Scotland have many fell meadows. Ireland have large areas of fell meadows with grazing cattle. On the American continent, Canada can present extensive fell meadows on Nova Scotia fx.. As the practices of cattle grazing are diminishing in many places - the industrialized parts -, the stress of overgrowth are endangering them as meadow habitats.
Salt marsh Flood-meadow Water-meadow Wet meadow Coastal prairie Lorenz Ferdinand: "Fuglene i landskabet" (Større danske fuglelokaliteter Bind II.
Endemism is the ecological state of a species being unique to a defined geographic location, such as an island, country or other defined zone, or habitat type. The extreme opposite of endemism is cosmopolitan distribution. An alternative term for a species, endemic is precinctive, which applies to species that are restricted to a defined geographical area; the word endemic is from New Latin endēmicus, from Greek ενδήμος, endēmos, "native". Endēmos is formed of en meaning "in", dēmos meaning "the people"; the term "precinctive" has been suggested by some scientists, was first used in botany by MacCaughey in 1917. It is the equivalent of "endemism". Precinction was first used by Frank and McCoy. Precinctive seems to have been coined by David Sharp when describing the Hawaiian fauna in 1900: "I use the word precinctive in the sense of'confined to the area under discussion'...'precinctive forms' means those forms that are confined to the area specified." That definition excludes artificial confinement of examples by humans in far-off botanical gardens or zoological parks.
Physical and biological factors can contribute to endemism. The orange-breasted sunbird is found in the fynbos vegetation zone of southwestern South Africa; the glacier bear is found only in limited places in Southeast Alaska. Political factors can play a part if a species is protected, or hunted, in one jurisdiction but not another. There are two subcategories of endemism: neoendemism. Paleoendemism refers to species that were widespread but are now restricted to a smaller area. Neoendemism refers to species that have arisen, such as through divergence and reproductive isolation or through hybridization and polyploidy in plants. Endemic types or species are likely to develop on geographically and biologically isolated areas such as islands and remote island groups, such as Hawaii, the Galápagos Islands, Socotra. Hydrangea hirta is an example of an endemic species found in Japan. Endemics can become endangered or extinct if their restricted habitat changes, particularly—but not only—due to human actions, including the introduction of new organisms.
There were millions of both Bermuda petrels and "Bermuda cedars" in Bermuda when it was settled at the start of the seventeenth century. By the end of the century, the petrels were thought extinct. Cedars ravaged by centuries of shipbuilding, were driven nearly to extinction in the twentieth century by the introduction of a parasite. Bermuda petrels and cedars are now rare. Principal causes of habitat degradation and loss in endemistic ecosystems include agriculture, urban growth, surface mining, mineral extraction, logging operations and slash-and-burn agriculture
An aquatic ecosystem is an ecosystem in a body of water. Communities of organisms that are dependent on each other and on their environment live in aquatic ecosystems; the two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems. Marine ecosystems, the largest of all ecosystems, cover 71% of the Earth's surface and contain 97% of the planet's water, they generate 32% of the world's net primary production. They are distinguished from freshwater ecosystems by the presence of dissolved compounds salts, in the water. 85% of the dissolved materials in seawater are sodium and chlorine. Seawater has an average salinity of 35 parts per thousand of water. Actual salinity varies among different marine ecosystems. Marine ecosystems can be divided into many zones depending upon water shoreline features; the oceanic zone is the vast open part of the ocean where animals such as whales and tuna live. The benthic zone consists of substrates below water; the intertidal zone is the area between low tides.
Other near-shore zones can include estuaries, salt marshes, coral reefs and mangrove swamps. In the deep water, hydrothermal vents may occur where chemosynthetic sulfur bacteria form the base of the food web. Classes of organisms found in marine ecosystems include brown algae, corals, cephalopods and sharks. Fishes caught in marine ecosystems are the biggest source of commercial foods obtained from wild populations. Environmental problems concerning marine ecosystems include unsustainable exploitation of marine resources, marine pollution, climate change, building on coastal areas. Freshwater ecosystems inhabit 0.009 % of its total water. They generate nearly 3% of its net primary production. Freshwater ecosystems contain 41% of the world's known fish species. There are three basic types of freshwater ecosystems: Lentic: slow moving water, including pools and lakes. Lotic: faster moving water, for example streams and rivers. Wetlands: areas where the soil is saturated or inundated for at least part of the time.
Lake ecosystems can be divided into zones. One common system divides lakes into three zones; the first, the littoral zone, is the shallow zone near the shore. This is; the offshore is divided into an open water zone and a deep water zone. In the open water zone sunlight supports photosynthetic algae, the species that feed upon them. In the deep water zone, sunlight is not available and the food web is based on detritus entering from the littoral and photic zones; some systems use other names. The off shore areas may be called the pelagic zone, the photic zone may be called the limnetic zone and the aphotic zone may be called the profundal zone. Inland from the littoral zone one can frequently identify a riparian zone which has plants still affected by the presence of the lake—this can include effects from windfalls, spring flooding, winter ice damage; the production of the lake as a whole is the result of production from plants growing in the littoral zone, combined with production from plankton growing in the open water.
Wetlands can be part of the lentic system, as they form along most lake shores, the width of the wetland and littoral zone being dependent upon the slope of the shoreline and the amount of natural change in water levels and among years. Dead trees accumulate in this zone, either from windfalls on the shore or logs transported to the site during floods; this woody debris provides important habitat for fish and nesting birds, as well as protecting shorelines from erosion. Two important subclasses of lakes are ponds, which are small lakes that intergrade with wetlands, water reservoirs. Over long periods of time, lakes, or bays within them, may become enriched by nutrients and fill in with organic sediments, a process called succession; when humans use the watershed, the volumes of sediment entering the lake can accelerate this process. The addition of sediments and nutrients to a lake is known as eutrophication. Ponds are small bodies of freshwater with shallow and still water and aquatic plants.
They can be further divided into four zones: vegetation zone, open water, bottom mud and surface film. The size and depth of ponds varies with the time of year. Food webs are based both upon aquatic plants. There is a diverse array of aquatic life, with a few examples including algae, fish, water bugs, turtles and muskrats. Top predators may include herons, or alligators. Since fish are a major predator upon amphibian larvae, ponds that dry up each year, thereby killing resident fish, provide important refugia for amphibian breeding. Ponds that dry up each year are known as vernal pools; some ponds are produced by animal activity, including alligator holes and beaver ponds, these add important diversity to landscapes. The major zones in river ecosystems are determined by the river bed's gradient or by the velocity of the current. Faster moving turbulent water contains greater concentrations of dissolved oxygen, which supports greater biodiversity than the slow moving water of pools; these distinctions form the basis for the division of rivers into lowland rivers.
The food base of streams within riparian forests is derived from the trees, but wider streams and those that lack a canopy derive the majority