Ecosystems

1. Ecosystems

2. ECOSYSTEM • An ecosystem is a natural unit consisting of all plants, animals and micro-organisms (biotic factors) in an area functioning together with all of the non-living physical (abiotic) factors of the environment.[1] • The term ecosystem was coined in 1930 by Roy Clapham, to denote the physical and biological components of an environment considered in relation to each other as a unit. British ecologist Arthur Tansley later refined the term, describing it as the interactive system established between biocoenosis (a group of living creatures) and their biotope (the environment in which they live).

3. TYPES OF ECOSYSTEM Examples of ecosystem include: • Aquatic ecosystem • Chaparral • Coral reef • Desert • Greater Yellowstone Ecosystem • Human ecosystem • Large marine ecosystem • Littoral zone • Marine ecosystem • Rainforest • Savanna • Subsurface Lithoautotrophic Microbial Ecosystem • Taiga • Tundra • Urban ecosystem

4. AQUATIC ECOSYSYTEM • An aquatic ecosystem is an ecosystem located 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.[1] Types of aquatic ecosystems • Aquatic ecosystems can be divided into two general types: marine ecosystems and freshwater ecosystems. • Neritic (the relatively shallow part of the ocean that lies over the continental shelf); profundal (bottom or deep water); benthic (bottom substrates); intertidal (the area between high and low tides); estuaries.

5. MARINE ECOSYSTEM • Marine ecosystems • A coral reef near the Hawaiian islands is an example of a complex marine ecosystem. • Marine ecosystems cover approximately 71% of the Earth's surface and contain approximately 97% of the planet's water. They generate 32% of the world's net primary production.[1] They are distinguished from freshwater ecosystems by the presence of dissolved compounds, especially salts, in the water. Approximately 85% of the dissolved materials in seawater are sodium and chlorine. Seawater has an average salinity of 35 parts per thousand (ppt) of water. Actual salinity varies among different marine ecosystems.[2] • Marine ecosystems can be divided into the following zones: oceanic (the relatively shallow part of the ocean that lies over the continental shelf); profundal (bottom or deep water); benthic (bottom substrates); intertidal (the area between high and low tides); estuaries; salt marshes; coral reefs; and hydrothermal vents (where chemosyntheticsulphurbacteria form the food base).[1] • Classes of organisms found in marine ecosystems include brown algae, dinoflagellates, corals, cephalopods, echinoderms, and sharks. Fish caught in marine ecosystems are the biggest source of commercial foods obtained from wild populations.[1] • Environmental problems concerning marine ecosystems include unsustainable exploitation of marine resources (for example overfishing of certain species), water pollution, and building on coastal areas.[1]

6. RAINFOREST ECOSYSTEM • Rainforests, or rain forests, are forests characterized by high rainfall, with definitions setting minimum normal annual rainfall between 1750 mm and 2000 mm (68 inches to 78 inches). • Rainforests are home to two thirds of all the living animal and plant species on the planet. It has been estimated that many hundreds of millions of new species of plants, insects and microorganisms are still undiscovered. Tropical rain forests are called the "jewels of the earth", and the "world's largest pharmacy" because of the large number of natural medicines discovered there. Tropical rain forests are also often called the "Earth's lungs", however there is no scientific basis for such a claim as tropical rainforests are known to be essentially oxygen neutral, with little or no net oxygen production.[1].[2] • The undergrowth in a rainforest is restricted in many areas by the lack of sunlight at ground level. This makes it possible for people and other animals to walk through the forest. If the leaf canopy is destroyed or thinned for any reason, the ground beneath is soon colonized by a dense tangled growth of vines, shrubs and small trees called jungle.

7. SAVANA ECOSYSTEMS • A savanna or savannah is a tropical or subtropicalwoodlandecosystem. Savannas are characterised by the trees being sufficiently small or widely spaced so that the canopy does not close. In many savanna communities, tree densities are higher and trees are more regularly spaced than in forest communities. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of C4 grasses.[1] Savannas are also characterised 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 regions and desert regions. • Although the term savanna is believed to have originally come from a Native American word describing "land which is without trees but with much grass either tall or short" (Oviedo y Valdes, 1535), by the late 1800s it was used to mean "land with both grass and trees". It now refers to land with grass and either scattered trees or an open canopy of trees.

8. SUBSURFACE LITHOAUTOTROPHIC MICROBIAL ECOSYSTEMS • Subsurface Lithoautotrophic Microbial Ecosystems, or "SLIMEs", are defined by Edward O. Wilson as "unique assemblages of bacteria and fungi that occupy pores in the interlocking mineral grains of igneous rock beneath Earth's surface."[1]

9. TAIGA ECOSYSTEMS • Taiga (pronounced /ˈtaɪgə/, from Mongolian) is a biome characterized by coniferous forests. Covering most of inland Alaska, Canada, Sweden, Finland, inland Norway and Russia (especially Siberia), as well as parts of the extreme northern continental United States (Northern Minnesota, Upstate New York, New Hampshire, and Maine), northern Kazakhstan and Japan (Hokkaidō), the taiga is the world's largest terrestrial biome. In Canada, boreal forest is the term used to refer to the southern part of this biome, while "taiga" is used to describe the more barren northern areas of the Arctictree line.

10. TUNDRA ECOSYSTEMS • In physical geography, tundra is an area where the tree growth is hindered by low temperatures and short growing seasons. The term "tundra" comes from Kildin Samitūndâr 'uplands, tundra, treeless mountain tract'. There are two types of tundra: Arctic tundra (which also occurs in Antarctica), and alpine tundra[1]. In tundra, the vegetation is composed of dwarf shrubs, sedges and grasses, mosses, and lichens. Scattered trees grow in some tundra. The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline.

11. URBAN ECOSYSTEMS • Urban ecosystems are the cities, towns and urban strips constructed by humans. • This growth in the urban population and the supporting built infrastructure has impacted on both urban environments and also on areas which surround urban areas. These include semi or 'peri-urban' environments that fringe cities as well as agricultural and natural landscapes. • Scientists are now developing ways to measure and understand the effects of urbananisation on human and environmental health. • By considered urban areas as part of a broader ecological system, scientists can investigate how urban landscapes function and how they effect other landscapes with which they interact. In this context, urban environments are effected by their surrounding environment but also impact on that environment. Knowing this may provide clues as to which alternative development options will lead to the best overall environmental outcome.

12. FRESHWATER ECOSYSTEM • Freshwater ecosystems cover 0.8% of the Earth's surface and contain 0.009% of its total water. They generate nearly 3% of its net primary production.[1] Freshwater ecosystems contain 41% of the world's known fish species.[3] • There are three basic types of freshwater ecosystems: • Lentic: slow-moving water, including pools, ponds, and lakes. • Lotic: rapidly-moving water, for example streams and rivers. • Wetlands: areas where the soil is saturated or inundated for at least part of the time. • TYPES OF FRESHWATER ECOSYSTEMS • Lake ecosystemscan be divided into zones: pelagic (open offshore waters); profundal; littoral (nearshore shallow waters); and riparian (the area of land bordering a body of water). Two important subclasses of lakes are ponds, which typically are small lakes that intergrade with wetlands, and water reservoirs. Many lakes, or bays within them, gradually become enriched by nutrients and fill in with organic sediments, a process called eutrophication. Eutrophication is accelerated by human activity within the water catchment area of the lake.[1] • 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 typically contains greater concentrations of dissolved oxygen, which supports greater biodiversity than the slow moving water of pools. These distinctions forms the basis for the division of rivers into upland and lowland rivers. The food base of streams within riparian forests is mostly derived from the trees, but wider streams and those that lack a canopy derive the majority of their food base from algae. Anadromous fish are also an important source of nutrients. Environmental threats to rivers include loss of water, dams, chemical pollution and introduced species.[ • Pond Ecosystems • This is a specific type of freshwater ecosystem that is largely based on the autotrophalgae which provide the base trophic level for all life in the area. The largest predator in a pond ecosystem will normally be a fish and in-between range smaller insects and microorganisms. It may have a scale of organisms from small bacteria to big creatures like water snakes, beetles, water bugs, and turtles.

13. TYPES OF FRESHWATER ECOSYSTEMS • Pond Ecosystems • This is a specific type of freshwater ecosystem that is largely based on the autotrophalgae which provide the base trophic level for all life in the area. The largest predator in a pond ecosystem will normally be a fish and in-between range smaller insects and microorganisms. It may have a scale of organisms from small bacteria to big creatures like water snakes, beetles, water bugs, and turtles. • Lake ecosystems can be divided into zones: pelagic (open offshore waters); profundal; littoral (nearshore shallow waters); and riparian (the area of land bordering a body of water). Two important subclasses of lakes are ponds, which typically are small lakes that intergrade with wetlands, and water reservoirs. Many lakes, or bays within them, gradually become enriched by nutrients and fill in with organic sediments, a process called eutrophication. Eutrophication is accelerated by human activity within the water catchment area of the lake.[1] • 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 typically contains greater concentrations of dissolved oxygen, which supports greater biodiversity than the slow moving water of pools. These distinctions forms the basis for the division of rivers into upland and lowland rivers. The food base of streams within riparian forests is mostly derived from the trees, but wider streams and those that lack a canopy derive the majority of their food base from algae. Anadromous fish are also an important source of nutrients. Environmental threats to rivers include loss of water, dams, chemical pollution and introduced species.[

14. CHAPARRAL ECOSYSTEMS • Chaparral is a shrubland or heathlandplant community found primarily in California, USA, that is shaped by a Mediterranean climate (mild, wet winters and hot dry summers) and wildfire. Similar plant communities are found in the five other Mediterranean climate regions around the world, including the Mediterranean Basin (where it is known as maquis), central Chile (where it is called matorral), South African Cape Region (known there as fynbos), and in Western and Southern Australia. • The word chaparral is a loan word from Spanish. The Spanish word comes from the word chaparro, which means both small and dwarf evergreen oak, which itself comes from the Basque word txapar, with the same meaning.

15. CORAL REEF ECOSYSTEM • Coral reefs are aragonite structures produced by living organisms, found in shallow, tropical marine waters with little to no nutrients in the water. High nutrient levels such as that found in runoff from agricultural areas can harm the reef by encouraging the growth of algae.[1] In most reefs, the predominant organisms are stony corals, colonial cnidarians that secrete an exoskeleton of calcium carbonate (limestone). The accumulation of skeletal material, broken and piled up by wave action and bioeroders, produces a massive calcareous formation that supports the living corals and a great variety of other animal and plant life. Although corals are found both in temperate and tropical waters, reefs are formed only in a zone extending at most from 30°N to 30°S of the equator.

16. DESERT ECOSYSTEM • A desert is a landscape form or region that receives very little precipitation. Deserts can be defined as areas that receive an average annual precipitation of less than 250 mm (10 in),[1][2] or as areas in which more water is lost than falls as precipitation.[3] In the Köppen climate classification system, deserts are classed as BWh (hot desert) or BWk (temperate desert).

17. GREATER YELLOWSTONE • Greater Yellowstone is the last remaining large, nearly intact ecosystem in the northern temperate zone of the Earth[1] and is partly located in Yellowstone National Park. Conflict over management has been controversial, and the area is a flagship site among conservation groups that promote ecosystem management. The Greater Yellow Ecosystem (GYE) is one of the world's foremost natural laboratories in landscape ecology and geology and is a world-renowned recreational site. It is also home to the animals of Yellowstone.

18. HUMAN ECOSYSTEM • Human ecosystems are complex cybernetic systems that are increasingly being used by ecologicalanthropologists and other scholars to examine the ecological aspects of human communities in a way that integrates multiple factors as economics, socio-political organization, psychological factors, and physical factors related to the environment.

19. LARGE MARINE ECOSYSTEM • Large marine ecosystems (LMEs) are regions of the world's oceans, encompassing coastal areas from river basins and estuaries to the seaward boundaries of continental shelves and the outer margins of the major ocean current systems. They are relatively large regions on the order of 200,000 km² or greater, characterized by distinct bathymetry, hydrography, productivity, and trophically dependent populations. • The system of LMEs has been developed by the US National Oceanic and Atmospheric Administration (NOAA) to identify areas of the oceans for conservation purposes. • Although the LMEs cover only the continental margins and not the deep oceans and oceanic islands, the 64 LMEs produce 95% of the world's annual marine fishery biomass yields. Most of the global ocean pollution, overexploitation, and coastal habitat alteration occur within their waters. NOAA has conducted studies of principal driving forces affecting changes in biomass yields for 33 of the 64 LMEs, which have been peer-reviewed and published in ten volumes [1].

20. LITTORAL ECOSYSTEM • Littoral refers to the coast of an ocean or sea, or to the banks of a river, lake or estuary. It is usually used as an adjective, but may also be used as a noun. The littoral zone is defined as the area between the high water and low water marks. The word is derived from the Latin noun litus, litoris, meaning "shore". (The doubled 't' is a late mediaeval innovation and the word is sometimes seen in the more classical-looking spelling 'litoral'.) • Dunes in littoral of Buenos Aires province, Argentina. 389 km altitude. Source: NASA • In lakes, where tides are usually negligibly small, other definitions of "littoral" must be used. The MinnesotaDepartment of Natural Resources defines littoral as that portion of the lake that is less than 15 feet in depth.[1] This zone is home to most of the aquatic plantlife (both rooted and floating) in a pond or lake because the high amount of sunlight reaching it allows for significant photosynthetic activity.