|
Connell–Slatyer Model Of Ecological Succession
Ecological succession can be understood as a process of changing species composition within a community due to an ecological disturbance, and varies largely according to the initial disturbance prompting the succession. Joseph Connell and Ralph Slatyer further developed the understanding of successional mechanisms in their 1977 paper and proposed that there were 3 main modes of successional development. These sequences could be understood in the context of the specific life-history theories of the individual species within an ecological community. The 1977 study Connell and Slatyer chose to focus on autogenic succession, which occurs on newly exposed landforms and is initiated by changes from within the community rather than a geophysical transformation.Connell & Slatyer They targeted plant and immobile aquatic organisms that demanded the greatest surface area within an environment and could modify the physical landscape. They defined community as "the set of organisms that occur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecological Succession
Ecological succession is the process of change in the species structure of an ecological community over time. The time scale can be decades (for example, after a wildfire) or more or less. Bacteria allows for the cycling of nutrients such as carbon, nitrogen and sulphur. 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 "engine" of succession, the cause of ecosystem change, is the impact of established organisms upon their own environments. A consequence of living is the sometimes subtle and sometimes overt alteration of one's own environment. Succession is a process by which an ecological community undergoes more or less orderly and predictable changes following a disturbance or the initial colonization of a new habitat. Succession may be initiated either by formation of new, unoccupied habitat, such as from a lava flow or a severe lan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S., it borders the Canadian province of British Columbia and the Yukon territory to the east; it also shares a maritime border with the Russian Federation's Chukotka Autonomous Okrug to the west, just across the Bering Strait. To the north are the Chukchi and Beaufort Seas of the Arctic Ocean, while the Pacific Ocean lies to the south and southwest. Alaska is by far the largest U.S. state by area, comprising more total area than the next three largest states (Texas, California, and Montana) combined. It represents the seventh-largest subnational division in the world. It is the third-least populous and the most sparsely populated state, but by far the continent's most populous territory located mostly north of the 60th parallel, with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sponges
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells. Sponges have unspecialized cells that can transform into other types and that often migrate between the main cell layers and the mesohyl in the process. Sponges do not have nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food and oxygen and to remove wastes. Sponges were first to branch off the evolutionary tree from the last common ancestor of all animals, making them the sister group of all other animals. Etymology The term ''sponge'' derives from the Ancient Greek word ( 'sponge'). Overview Sponges are similar to other animals in that they are multicellular, h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tunicates
A tunicate is a marine invertebrate animal, a member of the subphylum Tunicata (). It is part of the Chordata, a phylum which includes all animals with dorsal nerve cords and notochords (including vertebrates). The subphylum was at one time called Urochordata, and the term urochordates is still sometimes used for these animals. They are the only chordates that have lost their myomeric segmentation, with the possible exception of the 'seriation of the gill slits'. Some tunicates live as solitary individuals, but others replicate by budding and become colonies, each unit being known as a zooid. They are marine filter feeders with a water-filled, sac-like body structure and two tubular openings, known as siphons, through which they draw in and expel water. During their respiration and feeding, they take in water through the incurrent (or inhalant) siphon and expel the filtered water through the excurrent (or exhalant) siphon. Most adult tunicates are sessile, immobile and perman ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bryozoa
Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about long, they have a special feeding structure called a lophophore, a "crown" of tentacles used for filter feeding. Most marine bryozoans live in tropical waters, but a few are found in oceanic trenches and polar waters. The bryozoans are classified as the marine bryozoans (Stenolaemata), freshwater bryozoans (Phylactolaemata), and mostly-marine bryozoans (Gymnolaemata), a few members of which prefer brackish water. 5,869living species are known. At least two genera are solitary (''Aethozooides'' and ''Monobryozoon''); the rest are colonial. The terms Polyzoa and Bryozoa were introduced in 1830 and 1831, respectively. Soon after it was named, another group of animals was discovered whose filtering mechanism looked similar, so it was included in Bryozoa until 1869, when the two groups were no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Priority Effect
In ecology, a priority effect is an impact that a particular species can have on community development due to prior arrival at a site. There are two basic types: An ''inhibitory priority effect'' which occurs when a species that arrives first at a site negatively impacts a species that arrives later by reducing the availability of space or resources. A ''facilitative priority effect'' occurs when a species that arrives first at a site alters abiotic or biotic conditions in ways that positively impact a species arriving later. Priority effects are a central and pervasive element of ecological community development which have important implications for natural systems as well as ecological restoration efforts. Theoretical foundation Community succession theory Early in the 20th century, Frederic Clements and other plant ecologists suggested that ecological communities develop in a linear, directional manner towards a final, stable end-point: the climax community. Clements indicate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bothriochloa Ischaemum
''Bothriochloa ischaemum'' is a species of perennial grass in the family Poaceae, found throughout much of the world. It is commonly known as yellow bluestem. Two varieties are recognized, of which ''Bothriochloa ischaemum'' var. ''ischaemum'' is native to Europe, Asia, and Africa and naturalized elsewhere, and var. ''songarica'' is native to Asia and naturalized elsewhere. Var. ''songarica'' is an invasive weed in Texas, where it is known as "King Ranch bluestem"; it has displaced native grasses in large areas of central and south Texas. The species name come from the Ancient Greek ''ischaemum'', a styptic (causing ischemia). References External links Grassbase - The World Online Grass FloraGBIF entryUSDA Plants Profile entry ''Bothriochloa ischaemum'' var. ''ischaemum''USDA Plants Profile entry ''Bothriochloa ischaemum'' var. ''songarica'' ischaemum ''Ischaemum'' is a taxonomically one of the most formidable genera in a huge tribe Andropogoneae belonging to the gras ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Artemisia Scoparia
''Artemisia scoparia'' is a Eurasian species in the genus ''Artemisia (plant), Artemisia'', in the Asteraceae, sunflower family. It is widespread across much of Eurasia from France to Japan, including China, India, Russia, Germany, Poland, central + southwest Asia, etc. The English common name of ''Artemisia scoparia'' is virgate wormwood, capillary wormwood, or redstem wormwood. In Mandarin Chinese it is known as yīn chén (Traditional: 茵陳) and it is an important traditional Chinese medicine, and is considered interchangeable with ''Artemisia capillaris'' for that purpose. Its pollen can be allergenic. Chemical constituents # Capillarisin #Chlorogenic acid butyl ester #6,7-Dimethylesculetin #Isosabandin #Magnolioside (isoscopoletin-β-D-glucopyranoside) #7-Methoxycoumarin #7-Methylesculetin #Sabandin A # Sabandin B # Scoparone (6,7-dimethoxycoumarin) #Scopoletin #beta-Sitosterol, β-Sitosterol #Capillin References Artemisia (genus), scoparia Plants used in trad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and borders fourteen countries by land, the most of any country in the world, tied with Russia. Covering an area of approximately , it is the world's third largest country by total land area. The country consists of 22 provinces, five autonomous regions, four municipalities, and two Special Administrative Regions (Hong Kong and Macau). The national capital is Beijing, and the most populous city and financial center is Shanghai. Modern Chinese trace their origins to a cradle of civilization in the fertile basin of the Yellow River in the North China Plain. The semi-legendary Xia dynasty in the 21st century BCE and the well-attested Shang and Zhou dynasties developed a bureaucratic political system to serve hereditary monarchies, or dyna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loess Plateau
The Chinese Loess Plateau, or simply the Loess Plateau, is a plateau in north-central China formed of loess, a clastic silt-like sediment formed by the accumulation of wind-blown dust. It is located southeast of the Gobi Desert and is surrounded by the Yellow River. It includes parts of the Chinese provinces of Gansu, Shaanxi and Shanxi. The depositional setting of the Chinese Loess Plateau was shaped by the tectonic movement in the Neogene period, after which strong southeast winds caused by the East Asian Monsoon transported sediment to the plateau during the Quaternary period. The three main morphological types in the Loess Plateau are loess platforms, ridges and hills, formed by the deposition and erosion of loess. Most of the loess comes from the Gobi Desert and other nearby deserts. The sediments were transported to the Loess Plateau during interglacial periods by southeasterly prevailing winds and winter monsoon winds. After the deposition of sediments on the plateau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
R/K Selection Theory
In ecology, ''r''/''K'' selection theory relates to the selection of combinations of traits in an organism that trade off between quantity and quality of offspring. The focus on either an increased quantity of offspring at the expense of individual parental investment of ''r''-strategists, or on a reduced quantity of offspring with a corresponding increased parental investment of ''K''-strategists, varies widely, seemingly to promote success in particular environments. The concepts of quantity or quality offspring are sometimes referred to as "cheap" or "expensive", a comment on the expendable nature of the offspring and parental commitment made. The stability of the environment can predict if many expendable offspring are made or if fewer offspring of higher quality would lead to higher reproductive success. An unstable environment would encourage the parent to make many offspring, because the likelihood of all (or the majority) of them surviving to adulthood is slim. In contrast ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saguaro
The saguaro (, ) (''Carnegiea gigantea'') is a tree-like cactus species in the monotypic genus ''Carnegiea'' that can grow to be over tall. It is native to the Sonoran Desert in Arizona, the Mexican state of Sonora, and the Whipple Mountains and Imperial County areas of California. The saguaro blossom is the state wildflower of Arizona. Its scientific name is given in honor of Andrew Carnegie. In 1994, Saguaro National Park, near Tucson, Arizona, was designated to help protect this species and its habitat. Saguaros have a relatively long lifespan, often exceeding 150 years. They may grow their first side arm around 75–100 years of age, but some never grow any arms. Arms are developed to increase the plant's reproductive capacity, as more apices lead to more flowers and fruit. A saguaro can absorb and store considerable amounts of rainwater, visibly expanding in the process, while slowly using the stored water as needed. This characteristic enables the saguaro to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
