1.
Ecological succession
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Ecological succession is the process of change in the species structure of an ecological community over time. The time scale can be decades, or even millions of years after a mass extinction, the community begins with relatively few pioneering plants and animals and develops through increasing complexity until it becomes stable or self-perpetuating as a climax community. The ʺengineʺ of succession, the cause of change, is the impact of established species upon their own environments. A consequence of living is the subtle and sometimes overt alteration of ones own environment. It is a phenomenon or process by which an ecological community undergoes more or less orderly, Succession was among the first theories advanced in ecology. The study of remains at the core of ecological science. Ecological succession was first documented in the Indiana Dunes of Northwest Indiana which led to efforts to preserve the Indiana Dunes, exhibits on ecological succession are displayed in the Hour Glass, a museum in Ogden Dunes. Precursors of the idea of ecological succession go back to the beginning of the 19th century, the French naturalist Adolphe Dureau de la Malle was the first to make use of the word succession concerning the vegetation development after forest clear-cutting. In 1859 Henry David Thoreau wrote an address called The Succession of Forest Trees in which he described succession in an oak-pine forest. It has long known to observers that squirrels bury nuts in the ground. The Austrian botanist Anton Kerner published a study about the succession of plants in the Danube river basin in 1863, Henry Chandler Cowles, at the University of Chicago, developed a more formal concept of succession. Inspired by studies of Danish dunes by Eugen Warming, Cowles studied vegetation development on sand dunes on the shores of Lake Michigan and he recognized that vegetation on dunes of different ages might be interpreted as different stages of a general trend of vegetation development on dunes. He first published work as a paper in the Botanical Gazette in 1899. Clements and his followers developed a taxonomy of communities and successional pathways. Henry Gleason offered a contrasting framework as early as the 1920s, the Gleasonian model was more complex and much less deterministic than the Clementsian. It differs most fundamentally from the Clementsian view in suggesting a greater role of chance factors and in denying the existence of coherent. Gleason argued that species distributions responded individualistically to environmental factors, gleasons ideas, first published in 1926, were largely ignored until the late 1950s. Two quotes illustrate the contrasting views of Clements and Gleason, Clements wrote in 1916, The developmental study of vegetation necessarily rests upon the assumption that the unit or climax formation is an organic entity
2.
Kettle (landform)
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A kettle is a shallow, sediment-filled body of water formed by retreating glaciers or draining floodwaters. The kettles are formed as a result of blocks of ice calving from glaciers, another source is the sudden drainage of an ice-dammed lake. When the block melts, the hole it leaves behind is a kettle, as the ice melts, ramparts can form around the edge of the kettle hole. The lakes that fill these holes are seldom more than 10 m deep, in acid conditions, a kettle bog may form but in alkaline conditions, it will be kettle peatland. Kettles are fluvioglacial landforms occurring as the result of blocks of ice calving from the front of a receding glacier, glacial outwash is generated when streams of meltwater flow away from the glacier and deposit sediment to form broad outwash plains called sandurs. When the ice melt, kettle holes are left in the sandur. When the development of kettle holes disrupt sandur surfaces, a jumbled array of ridges and mounds form, resembling kame. Kettle holes can also occur in ridge shaped deposits of rock fragments called till. Kettle holes can form as the result of floods caused by the drainage of an ice-dammed lake. These floods, called jökulhlaups, often rapidly deposit large quantities of sediment onto the sandur surface, the kettle holes are formed by the melting blocks of sediment-rich ice that were transported and consequently buried by the jökulhlaups. It was found in observations and laboratory simulations done by Maizels in 1992 that ramparts form around the edge of kettle holes generated by jökulhlaups. The development of types of ramparts depends on the concentration of rock fragments contained in the melted ice block. Most kettle holes are less than two kilometres in diameter, although some in the U. S. Midwest exceed ten kilometres, puslinch Lake in Ontario, Canada, is the largest kettle lake in Canada spanning 160 hectares. Fish Lake in the north-central Cascade Mountains of the U. S. state of Washington is 200 hectares, the depth of most kettles is less than ten meters. In most cases, kettle holes eventually fill with water, sediment, if the kettle is fed by surface or underground rivers or streams, it becomes a kettle lake. If the kettle receives its water from precipitation, the groundwater table, Kettle ponds that are not affected by the groundwater table will usually become dry during the warm summer months, in which case they are deemed ephemeral. Kettle bogs are closed ecosystems because they have no water other than precipitation. Both acidic kettle bogs and fresh water kettles are important ecological niches for some species of flora
3.
Woodland
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Woodland /ˈwʊdlənd/ is a low-density forest forming open habitats with plenty of sunlight and limited shade. Woodlands may support an understory of shrubs and herbaceous plants including grasses, woodland may form a transition to shrubland under drier conditions or during early stages of primary or secondary succession. Higher density areas of trees with a closed canopy that provides extensive. Conservationists have worked hard to preserve woodlands, because people are destroying animals habitats when building homes, for example, the woodlands in Northwest Indiana have been preserved as part of the Indiana Dunes. The term ancient woodland is used in British nature conservation to refer to any wooded land that has existed since 1600, woodlot is a closely related American term, which refers to a stand of trees generally used for firewood. While woodlots often technically have closed canopies, they are so small that light penetration from the edge makes them ecologically closer to woodland than forest, in Australia, a woodland is defined as an area with sparse cover of trees, and an open woodland has very sparse cover. Woodlands are also subdivided into tall woodlands, or low woodlands and this contrasts with forests, which have greater than 30% cover by trees
4.
Swamp
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A swamp is a wetland that is forested. Many swamps occur along rivers where they are critically dependent upon natural water level fluctuations. Other swamps occur on the shores of large lakes, some swamps have hammocks, or dry-land protrusions, covered by aquatic vegetation, or vegetation that tolerates periodic inundation. The two main types of swamp are true or swamp forests and transitional or shrub swamps, in the boreal regions of Canada, the word swamp is colloquially used for what is more correctly termed a bog or muskeg. The water of a swamp may be water, brackish water or seawater. Some of the worlds largest swamps are found along rivers such as the Amazon, the Mississippi. Swamps are characterized by slow-moving to stagnant waters and they are usually associated with adjacent rivers or lakes. Swamps are features of areas with very low topographic relief, historically, humans have drained swamps to provide additional land for agriculture and to reduce the threat of diseases borne by swamp insects and similar animals. Many swamps have also undergone intensive logging, requiring the construction of drainage ditches and these ditches and canals contributed to drainage and, along the coast, allowed salt water to intrude, converting swamps to marsh or even to open water. Large areas of swamp were therefore lost or degraded, louisiana provides a classic example of wetland loss from these combined factors. Europe has probably lost nearly half its wetlands, New Zealand lost 90 percent of its wetlands over a period of 150 years. Ecologists recognise that swamps provide valuable ecological services including flood control, fish production, water purification, carbon storage, in many parts of the world authorities protect swamps. In parts of Europe and North America, swamp restoration projects are becoming widespread, often the simplest steps to restoring swamps involve plugging drainage ditches and removing levees. Swamps and other wetlands have traditionally held a very low property value compared to fields, prairies and they have a reputation for being unproductive land that cannot easily be utilized for human activities, other than perhaps hunting and trapping. Farmers, for example, typically drained swamps next to their fields so as to more land usable for planting crops. Many societies now realize that swamps are important to providing fresh water and oxygen to all life. Indeed, floodplain swamps are important in fish production. Government environmental agencies are taking steps to protect and preserve swamps, in Europe, major effort is being invested in the restoration of swamp forests along rivers
5.
Marsh
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A marsh is a wetland that is dominated by herbaceous rather than woody plant species. Marshes can often be found at the edges of lakes and streams and they are often dominated by grasses, rushes or reeds. If woody plants are present they tend to be low-growing shrubs, Marshes provide a habitat for many species of plants, animals, and insects that have adapted to living in flooded conditions. The plants must be able to survive in wet mud with low oxygen levels, many of these plants therefore have aerenchyma, channels within the stem that allow air to move from the leaves into the rooting zone. Marsh plants also tend to have rhizomes for underground storage and reproduction, familiar examples include cattails, sedges, papyrus and sawgrass. Aquatic animals, from fish to salamanders, are able to live with a low amount of oxygen in the water. Some can obtain oxygen from the air instead, while others can live indefinitely in conditions of low oxygen, Marshes provide habitats for many kinds of invertebrates, fish, amphibians, waterfowl and aquatic mammals. Marshes have extremely high levels of production, some of the highest in the world. Marshes also improve water quality by acting as a sink to filter pollutants, Marshes are able to absorb water during periods of heavy rainfall and slowly release it into waterways and therefore reduce the magnitude of flooding. The pH in marshes tends to be neutral to alkaline, as opposed to bogs, Marshes differ depending mainly on their location and salinity. Both of these factors influence the range and scope of animal and plant life that can survive. The three main types of marsh are salt marshes, freshwater marshes, and freshwater marshes. These three can be found worldwide and each contains a different set of organisms, saltwater marshes are found around the world in mid to high latitudes, wherever there are sections of protected coastline. They are located close enough to the shoreline that the motion of the tides affects them and they flourish where the rate of sediment buildup is greater than the rate at which the land level is sinking. Salt marshes are dominated by specially adapted rooted vegetation, primarily salt-tolerant grasses, salt marshes are most commonly found in lagoons, estuaries, and on the sheltered side of shingle or sandspit. The currents there carry the fine particles around to the side of the spit. These locations allow the marshes to absorb the nutrients from the water running through them before they reach the oceans. Coastal development and urban sprawl has caused significant loss of these essential habitats, although considered a freshwater marsh, this form of marsh is affected by the ocean tides
6.
Mute swan
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The mute swan is a species of swan and a member of the waterfowl family Anatidae. It is native to much of Eurasia, and the far north of Africa and it is an introduced species in North America, Australasia and southern Africa. The name mute derives from it being less vocal than other swan species, measuring 125 to 170 cm in length, this large swan is wholly white in plumage with an orange beak bordered with black. It is recognisable by its pronounced knob atop the beak, which is larger in males, the mute swan was first formally described by the German naturalist Johann Friedrich Gmelin as Anas olor in 1789, and was transferred by Johann Matthäus Bechstein to the new genus Cygnus in 1803. It is the species of the genus Cygnus. Both cygnus and olor mean swan in Latin, cygnus is a variant form of cycnus, a borrowing from Greek κύκνος kyknos, a word of the same meaning. Despite its Eurasian origin, its closest relatives are the black swan of Australia, the species is monotypic with no living subspecies. Mute swan subfossils,6,000 years old, have found in post-glacial peat beds of East Anglia. They have been recorded from Ireland east to Portugal and Italy, the paleosubspecies Cygnus olor bergmanni, which differed only in size from the living bird, is known from fossils found in Azerbaijan. Fossils of swan ancestors more distantly allied to the mute swan have been found in four U. S. states, California, Arizona, Idaho, the timeline runs from the Miocene to the late Pleistocene, or 10,000 BP. The latest find was in Anza Borrego Desert, a park in California. Adults of this large swan typically range from 140 to 160 cm long, although can range in extreme cases from 125 to 170 cm, males are larger than females and have a larger knob on their bill. On average, this is the second largest waterfowl species after the trumpeter swan, among standard measurements of the mute swan, the wing chord measures 53–62.3 cm, the tarsus is 10–11.8 cm and the bill is 6. 9–9 cm. The mute swan is one of the heaviest flying birds, young birds, called cygnets, are not the bright white of mature adults, and their bill is dull greyish-black, not orange, for the first year. The down may range from white to grey to buff. The white cygnets have a leucistic gene, cygnets grow quickly, reaching a size close to their adult size in approximately three months after hatching. Cygnets typically retain their grey feathers until they are at least one year old, all mute swans are white at maturity, though the feathers are often stained orange-brown by iron and tannins in the water. The morph immutabilis has pinkish legs and dull white cygnets, as with white domestic geese, polish swans carry a copy of a gene responsible for leucism
7.
Siltation
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Siltation or siltification is the pollution of water by particulate terrestrial clastic material, with a particle size dominated by silt or clay. It refers both to the concentration of suspended sediments, and to the increased accumulation of fine sediments on bottoms where they are undesirable. Siltation is most often caused by erosion or sediment spill. Siltation is the term for being unambigiuous, even if not entirely stringent since it also includes other particle sizes than silt. The origin of the sediment transport into an area may be erosion on land. In rural areas the erosion source is typically soil degradation due to intensive or inadequate agricultural practices, leading to soil erosion, the result will be an increased amount of silt and clay in the water bodies that drain the area. In water the main source is sediment spill from dredging, from the transportation of dredged material on barges. Such deposition may be made to get rid of unwanted material, such as the dumping of material dredged from harbours. The deposition may also have as purpose to build up the coastline, artificial islands, climate change also affect siltation rates. While the sediment in transport is in suspension, it acts as a pollutant for those who require clean water and this includes uses such as for cooling or in industrial processes, and it includes aquatic life that are sensitive to suspended material in the water. While nekton have been found to avoid spill plumes in the water, among the most sensitive organisms are coral polyps. Generally speaking, hard bottom communities and mussel banks are more sensitive to siltation than sand, unlike in the sea, in a stream the plume will cover the entire channel, except possibly for backwaters, which is why fish will also be directly affected in most cases. Siltation can also affect navigation channels, or irrigation channels and it refers to the undesired accumulation of sediments in channels intended for vessels, or for distributing water. One may distinguish between measurements at the source, during transport, and within the affected area, source measurements of erosion may be very difficult, since the lost material may be a fraction of a millimeter per year.5 kg/s. Also sediment spill is better measured in transport than at the source, to distinguish the spill contribution, the background turbidity is subtracted from the spill plume turbidity. Since the spill plume in open water varies in space and time, an integration over the plume is required. These measurements are close to the source, in the order of a few hundred meters. Anything beyond a work area buffer zone for sediment spill is considered the impact area
8.
Phytoplankton
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Phytoplankton /ˌfaɪtoʊˈplæŋktən/ are the autotrophic components of the plankton community and a key part of oceans, seas and freshwater basin ecosystems. The name comes from the Greek words φυτόν, meaning plant, most phytoplankton are too small to be individually seen with the unaided eye. Phytoplankton are photosynthesizing microscopic organisms that inhabit the upper layer of almost all oceans. They are agents for primary production, the creation of organic compounds from carbon dioxide dissolved in the water, Phytoplankton obtain energy through the process of photosynthesis and must therefore live in the well-lit surface layer of an ocean, sea, lake, or other body of water. Phytoplankton account for half of all activity on Earth. Their cumulative energy fixation in carbon compounds is the basis for the vast majority of oceanic, the effects of anthropogenic warming on the global population of phytoplankton is an area of active research. Additionally, changes in the mortality of phytoplankton due to rates of zooplankton grazing may be significant, as a side note, one of the more remarkable food chains in the ocean – remarkable because of the small number of links – is that of phytoplankton-feeding krill feeding baleen whales. Phytoplankton are also dependent on minerals. However, across large regions of the World Ocean such as the Southern Ocean and this has led to some scientists advocating iron fertilization as a means to counteract the accumulation of human-produced carbon dioxide in the atmosphere. Large-scale experiments have added iron to the oceans to promote phytoplankton growth, however, controversy about manipulating the ecosystem and the efficiency of iron fertilization has slowed such experiments. Phytoplankton depend on other substances to survive as well, in particular, Vitamin B is crucial. Areas in the ocean have been identified as having a lack of Vitamin B. While almost all species are obligate photoautotrophs, there are some that are mixotrophic and other. Of these, the best known are dinoflagellate genera such as Noctiluca and Dinophysis, the term phytoplankton encompasses all photoautotrophic microorganisms in aquatic food webs. Phytoplankton serve as the base of the food web, providing an essential ecological function for all aquatic life. However, unlike terrestrial communities, where most autotrophs are plants, phytoplankton are a group, incorporating protistan eukaryotes. There are about 5,000 known species of marine phytoplankton, how such diversity evolved despite scarce resources is unclear. In terms of numbers, the most important groups of phytoplankton include the diatoms, cyanobacteria and dinoflagellates, one group, the coccolithophorids, is responsible for the release of significant amounts of dimethyl sulfide into the atmosphere
9.
Spore
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In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavorable conditions. Spores form part of the cycles of many plants, algae, fungi. Bacterial spores are not part of a sexual cycle but are resistant structures used for survival under unfavourable conditions, spores are usually haploid and unicellular and are produced by meiosis in the sporangium of a diploid sporophyte. Under favourable conditions the spore can develop into a new organism using mitotic division, producing a multicellular gametophyte, two gametes fuse to form a zygote which develops into a new sporophyte. This cycle is known as alternation of generations, the term spore derives from the ancient Greek word σπορά spora, meaning seed, sowing, related to σπόρος sporos, sowing, and σπείρειν speirein, to sow. Spores germinate to give rise to haploid gametophytes, while seeds germinate to give rise to diploid sporophytes, vascular plant spores are always haploid. Vascular plants are either homosporous or heterosporous, plants that are homosporous produce spores of the same size and type. Spores can be classified in several ways, In fungi and fungus-like organisms, spores are often classified by the structure in which meiosis, since fungi are often classified according to their spore-producing structures, these spores are often characteristic of a particular taxon of the fungi. Sporangiospores, spores produced by a sporangium in many such as zygomycetes. Zygospores, spores produced by a zygosporangium, characteristic of zygomycetes, ascospores, spores produced by an ascus, characteristic of ascomycetes. Basidiospores, spores produced by a basidium, characteristic of basidiomycetes, aeciospores, spores produced by an aecium in some fungi such as rusts or smuts. Urediniospores, spores produced by a uredinium in some such as rusts or smuts. Teliospores, spores produced by a telium in some such as rusts or smuts. Oospores, spores produced by an oogonium, characteristic of oomycetes, carpospores, spores produced by a carposporophyte, characteristic of red algae. Tetraspores, spores produced by a tetrasporophyte, characteristic of red algae, chlamydospores, thick-walled resting spores of fungi produced to survive unfavorable conditions. Parasitic fungal spores may be classified into internal spores, which germinate within the host, meiospores, spores produced by meiosis, they are thus haploid, and give rise to a haploid daughter cell or a haploid individual. Examples are the cells of gametophytes of seed plants found in flowers or cones. Microspores, meiospores that give rise to a male gametophyte, megaspores, meiospores that give rise to a female gametophyte
10.
Zooplankton
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Plankton are organisms drifting in oceans, seas, and bodies of fresh water. The word zooplankton is derived from the Greek zoon, meaning animal, individual zooplankton are usually microscopic, but some are larger and visible with the naked eye. Zooplankton is a categorization spanning a range of organism sizes including small protozoans, although zooplankton are primarily transported by ambient water currents, many have locomotion, used to avoid predators or to increase prey encounter rate. Ecologically important protozoan zooplankton groups include the foraminiferans, radiolarians and dinoflagellates and this wide phylogenetic range includes a similarly wide range in feeding behavior, filter feeding, predation and symbiosis with autotrophic phytoplankton as seen in corals. Zooplankton feed on bacterioplankton, phytoplankton, other zooplankton, detritus, as a result, zooplankton are primarily found in surface waters where food resources are abundant. Just as any species can be limited within a geographical region, however, species of zooplankton are not dispersed uniformly or randomly within a region of the ocean. As with phytoplankton, ‘patches’ of zooplankton species exist throughout the ocean, zooplankton patchiness can also be influenced by biological factors, as well as other physical factors. Biological factors include breeding, predation, concentration of phytoplankton, the physical factor that influences zooplankton distribution the most is mixing of the water column that affects nutrient availability and, in turn, phytoplankton production. Since they are small, zooplankton can respond rapidly to increases in phytoplankton abundance, for instance. Zooplankton can also act as a disease reservoir, crustacean zooplankton have been found to house the bacterium Vibrio cholerae, which causes cholera, by allowing the cholera vibrios to attach to their chitinous exoskeletons. This symbiotic relationship enhances the ability to survive in an aquatic environment, as the exoskeleton provides the bacterium with carbon. A global coverage database of zooplankton biomass and abundance data
