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87-437: The MBARI-designed Environmental Sample Processor was the first underwater robotic instrument to provide autonomous detection of both a HAB species and its toxin. This ability allows scientists, in near real-time, to determine whether or not an algal bloom is toxic, thus allowing better prediction and treatment of public or ecosystem health threats. The NOAA Great Lakes Environmental Research Laboratory (GLERL) will deploy

174-409: A cell wall . Newly dead animals may be covered by an exoskeleton . Fragmentation processes, which break through these protective layers, accelerate the rate of microbial decomposition. Animals fragment detritus as they hunt for food, as does passage through the gut. Freeze-thaw cycles and cycles of wetting and drying also fragment dead material. The chemical alteration of the dead organic matter

261-495: A food chain . Real systems are much more complex than this—organisms will generally feed on more than one form of food, and may feed at more than one trophic level. Carnivores may capture some prey that is part of a plant-based trophic system and others that are part of a detritus-based trophic system (a bird that feeds both on herbivorous grasshoppers and earthworms, which consume detritus). Real systems, with all these complexities, form food webs rather than food chains which present

348-605: A habitat . Ecosystem ecology is the "study of the interactions between organisms and their environment as an integrated system". The size of ecosystems can range up to ten orders of magnitude , from the surface layers of rocks to the surface of the planet. The Hubbard Brook Ecosystem Study started in 1963 to study the White Mountains in New Hampshire . It was the first successful attempt to study an entire watershed as an ecosystem. The study used stream chemistry as

435-609: A central role over a wide range, for example, in the slow development of soil from bare rock and the faster recovery of a community from disturbance . Disturbance also plays an important role in ecological processes. F. Stuart Chapin and coauthors define disturbance as "a relatively discrete event in time that removes plant biomass". This can range from herbivore outbreaks, treefalls, fires, hurricanes, floods, glacial advances , to volcanic eruptions . Such disturbances can cause large changes in plant, animal and microbe populations, as well as soil organic matter content. Disturbance

522-416: A combination of those. Toxins detected 'in house' are already either just outside the intake or present in the system. The ESP can provide managers earlier warning of blooms and toxicity. Correlations between data collected on toxicity and chlorophyll concentrations will be monitored in an effort to develop an experimental forecast of bloom toxicity. The Lake Erie ESP was purchased by GLERL with funding from

609-507: A critical role in global nutrient cycling and ecosystem function. Phosphorus enters ecosystems through weathering . As ecosystems age this supply diminishes, making phosphorus-limitation more common in older landscapes (especially in the tropics). Calcium and sulfur are also produced by weathering, but acid deposition is an important source of sulfur in many ecosystems. Although magnesium and manganese are produced by weathering, exchanges between soil organic matter and living cells account for

696-517: A faster recovery. More severe and more frequent disturbance result in longer recovery times. From one year to another, ecosystems experience variation in their biotic and abiotic environments. A drought , a colder than usual winter, and a pest outbreak all are short-term variability in environmental conditions. Animal populations vary from year to year, building up during resource-rich periods and crashing as they overshoot their food supply. Longer-term changes also shape ecosystem processes. For example,

783-427: A function-based typology has been proposed to leverage the strengths of these different approaches into a unified system. Human activities are important in almost all ecosystems. Although humans exist and operate within ecosystems, their cumulative effects are large enough to influence external factors like climate. Ecosystems provide a variety of goods and services upon which people depend. Ecosystem goods include

870-698: A general level, for example, tropical forests , temperate grasslands , and arctic tundra . There can be any degree of subcategories among ecosystem types that comprise a biome, e.g., needle-leafed boreal forests or wet tropical forests. Although ecosystems are most commonly categorized by their structure and geography, there are also other ways to categorize and classify ecosystems such as by their level of human impact (see anthropogenic biome ), or by their integration with social processes or technological processes or their novelty (e.g. novel ecosystem ). Each of these taxonomies of ecosystems tends to emphasize different structural or functional properties. None of these

957-492: A luciferin-luciferase reaction to create a blue light emission glow. There are seventeen major types of dinoflagellate toxins, in which the strains, Saxitoxin and Yessotoxin, are both bioluminescent and toxic. These two strains are found to have similar niches in coastal areas. A surplus of Dinoflagellates in the night time creates a blue-green glow, however, in the day, it presents as a red brown color which names algal blooms, Red Tides. Dinoflagellates have been reported to be

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1044-665: A means of monitoring ecosystem properties, and developed a detailed biogeochemical model of the ecosystem. Long-term research at the site led to the discovery of acid rain in North America in 1972. Researchers documented the depletion of soil cations (especially calcium) over the next several decades. Ecosystems can be studied through a variety of approaches—theoretical studies, studies monitoring specific ecosystems over long periods of time, those that look at differences between ecosystems to elucidate how they work and direct manipulative experimentation. Studies can be carried out at

1131-528: A more important role in moving nutrients around. This can be especially important as the soil thaws in the spring, creating a pulse of nutrients that become available. Decomposition rates are low under very wet or very dry conditions. Decomposition rates are highest in wet, moist conditions with adequate levels of oxygen. Wet soils tend to become deficient in oxygen (this is especially true in wetlands ), which slows microbial growth. In dry soils, decomposition slows as well, but bacteria continue to grow (albeit at

1218-406: A number of common, non random properties in the topology of their network. The carbon and nutrients in dead organic matter are broken down by a group of processes known as decomposition. This releases nutrients that can then be re-used for plant and microbial production and returns carbon dioxide to the atmosphere (or water) where it can be used for photosynthesis. In the absence of decomposition,

1305-421: A process known as denitrification . Mycorrhizal fungi which are symbiotic with plant roots, use carbohydrates supplied by the plants and in return transfer phosphorus and nitrogen compounds back to the plant roots. This is an important pathway of organic nitrogen transfer from dead organic matter to plants. This mechanism may contribute to more than 70 Tg of annually assimilated plant nitrogen, thereby playing

1392-696: A significant portion of ecosystem fluxes. Potassium is primarily cycled between living cells and soil organic matter. Biodiversity plays an important role in ecosystem functioning. Ecosystem processes are driven by the species in an ecosystem, the nature of the individual species, and the relative abundance of organisms among these species. Ecosystem processes are the net effect of the actions of individual organisms as they interact with their environment. Ecological theory suggests that in order to coexist, species must have some level of limiting similarity —they must be different from one another in some fundamental way, otherwise, one species would competitively exclude

1479-408: A slower rate) even after soils become too dry to support plant growth. Ecosystems are dynamic entities. They are subject to periodic disturbances and are always in the process of recovering from past disturbances. When a perturbation occurs, an ecosystem responds by moving away from its initial state. The tendency of an ecosystem to remain close to its equilibrium state, despite that disturbance,

1566-464: A small effect on ecosystem function. Ecologically distinct species, on the other hand, have a much larger effect. Similarly, dominant species have a large effect on ecosystem function, while rare species tend to have a small effect. Keystone species tend to have an effect on ecosystem function that is disproportionate to their abundance in an ecosystem. An ecosystem engineer is any organism that creates, significantly modifies, maintains or destroys

1653-468: A variety of approaches—theoretical studies, studies monitoring specific ecosystems over long periods of time, those that look at differences between ecosystems to elucidate how they work and direct manipulative experimentation. Biomes are general classes or categories of ecosystems. However, there is no clear distinction between biomes and ecosystems. Ecosystem classifications are specific kinds of ecological classifications that consider all four elements of

1740-443: A variety of goods and services upon which people depend, and may be part of. Ecosystem goods include the "tangible, material products" of ecosystem processes such as water, food, fuel, construction material, and medicinal plants . Ecosystem services , on the other hand, are generally "improvements in the condition or location of things of value". These include things like the maintenance of hydrological cycles , cleaning air and water,

1827-522: A variety of scales, ranging from whole-ecosystem studies to studying microcosms or mesocosms (simplified representations of ecosystems). American ecologist Stephen R. Carpenter has argued that microcosm experiments can be "irrelevant and diversionary" if they are not carried out in conjunction with field studies done at the ecosystem scale. In such cases, microcosm experiments may fail to accurately predict ecosystem-level dynamics. Biomes are general classes or categories of ecosystems. However, there

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1914-431: Is a system that environments and their organisms form through their interaction. The biotic and abiotic components are linked together through nutrient cycles and energy flows. Ecosystems are controlled by external and internal factors . External factors such as climate , parent material which forms the soil and topography , control the overall structure of an ecosystem but are not themselves influenced by

2001-454: Is an international synthesis by over 1000 of the world's leading biological scientists that analyzes the state of the Earth's ecosystems and provides summaries and guidelines for decision-makers. The report identified four major categories of ecosystem services: provisioning, regulating, cultural and supporting services. It concludes that human activity is having a significant and escalating impact on

2088-442: Is consumed by animals while still alive and enters the plant-based trophic system. After plants and animals die, the organic matter contained in them enters the detritus-based trophic system. Ecosystem respiration is the sum of respiration by all living organisms (plants, animals, and decomposers) in the ecosystem. Net ecosystem production is the difference between gross primary production (GPP) and ecosystem respiration. In

2175-658: Is deployed on a custom-built, underwater stationary mooring assembly. It samples the surface and in the water column, allowing the detection of microcystins as they relate to recreational risk (surface concentrations) or drinking water intake risk (at depth concentrations). After QC/QA, data is uploaded to NOAA’s Great Lakes Environmental Research Laboratory (GLERL) "HABs and Hypoxia" page to inform decision making by water managers and other stakeholders in near real-time. Managers without access to ESP data rely on 'in house' toxin testing, weekly sampling, surrogates (i.e. using algal pigment concentrations to infer risk of microcystins), or

2262-569: Is followed by succession, a "directional change in ecosystem structure and functioning resulting from biotically driven changes in resource supply." The frequency and severity of disturbance determine the way it affects ecosystem function. A major disturbance like a volcanic eruption or glacial advance and retreat leave behind soils that lack plants, animals or organic matter. Ecosystems that experience such disturbances undergo primary succession . A less severe disturbance like forest fires, hurricanes or cultivation result in secondary succession and

2349-554: Is governed by three sets of factors—the physical environment (temperature, moisture, and soil properties), the quantity and quality of the dead material available to decomposers, and the nature of the microbial community itself. Temperature controls the rate of microbial respiration; the higher the temperature, the faster the microbial decomposition occurs. Temperature also affects soil moisture, which affects decomposition. Freeze-thaw cycles also affect decomposition—freezing temperatures kill soil microorganisms, which allows leaching to play

2436-405: Is no clear distinction between biomes and ecosystems. Biomes are always defined at a very general level. Ecosystems can be described at levels that range from very general (in which case the names are sometimes the same as those of biomes) to very specific, such as "wet coastal needle-leafed forests". Biomes vary due to global variations in climate . Biomes are often defined by their structure: at

2523-531: Is primarily achieved through bacterial and fungal action. Fungal hyphae produce enzymes that can break through the tough outer structures surrounding dead plant material. They also produce enzymes that break down lignin , which allows them access to both cell contents and the nitrogen in the lignin. Fungi can transfer carbon and nitrogen through their hyphal networks and thus, unlike bacteria, are not dependent solely on locally available resources. Decomposition rates vary among ecosystems. The rate of decomposition

2610-485: Is termed its resistance . The capacity of a system to absorb disturbance and reorganize while undergoing change so as to retain essentially the same function, structure, identity, and feedbacks is termed its ecological resilience . Resilience thinking also includes humanity as an integral part of the biosphere where we are dependent on ecosystem services for our survival and must build and maintain their natural capacities to withstand shocks and disturbances. Time plays

2697-422: Is the "best" classification. Ecosystem classifications are specific kinds of ecological classifications that consider all four elements of the definition of ecosystems : a biotic component, an abiotic complex, the interactions between and within them, and the physical space they occupy. Different approaches to ecological classifications have been developed in terrestrial, freshwater and marine disciplines, and

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2784-563: Is very common from the exposure of algal blooms. Water-borne diseases are also present as our drinking waters can be contaminated by cyanotoxins. If the HAB event results in a high enough concentration of algae the water may become discoloured or murky, varying in colour from purple to almost pink, normally being red or green. Not all algal blooms are dense enough to cause water discolouration. Dinoflagellate s are microbial eukaryotes that link bioluminesce and toxin production in algal blooms. They use

2871-612: The EPA's Great Lakes Restoration Initiative . NOAA's National Centers for Coastal Ocean Science (NCCOS)] leads development of algal toxin sensors for ESPs. The technology to detect microcystins by ELISA assay ) was developed by NCCOS, GLERL, and the Cooperative Institute for Limnology and Ecosystems Research . The viability of ESP technology to assist in monitoring and forecasting of marine HABs and their related toxins in California and

2958-592: The Gulf of Maine has been supported by NCCOS funding. Algal bloom An algal bloom or algae bloom is a rapid increase or accumulation in the population of algae in fresh water or marine water systems. It is often recognized by the discoloration in the water from the algae's pigments. The term algae encompasses many types of aquatic photosynthetic organisms, both macroscopic multicellular organisms like seaweed and microscopic unicellular organisms like cyanobacteria .   Algal bloom commonly refers to

3045-428: The photic , or sunlit zone of the ocean. Along coastal regions and in freshwater systems, agricultural, city, and sewage runoff can cause algal blooms. Algal blooms, especially large algal bloom events, can reduce the transparency of the water and can discolor the water. The photosynthetic pigments in the algal cells, like chlorophyll and photoprotective pigments, determine the color of the algal bloom. Depending on

3132-555: The resource inputs are generally controlled by external processes like climate and parent material, the availability of these resources within the ecosystem is controlled by internal factors like decomposition, root competition or shading. Other factors like disturbance, succession or the types of species present are also internal factors. Primary production is the production of organic matter from inorganic carbon sources. This mainly occurs through photosynthesis . The energy incorporated through this process supports life on earth, while

3219-435: The "tangible, material products" of ecosystem processes such as water, food, fuel, construction material, and medicinal plants . They also include less tangible items like tourism and recreation, and genes from wild plants and animals that can be used to improve domestic species. Ecosystem services , on the other hand, are generally "improvements in the condition or location of things of value". These include things like

3306-597: The ability to provide water managers with bloom location, projected direction, intensity, AND toxicity before the water reaches the intake. Initial deployments of the ESP took place in 2016: the first field tests of the communications and the microcystin detection happened in July. The ESP was re-deployed in August near the Toledo water intake crib for its first full mission. The Lake Erie ESP

3393-481: The absence of disturbance, net ecosystem production is equivalent to the net carbon accumulation in the ecosystem. Energy can also be released from an ecosystem through disturbances such as wildfire or transferred to other ecosystems (e.g., from a forest to a stream to a lake) by erosion . In aquatic systems , the proportion of plant biomass that gets consumed by herbivores is much higher than in terrestrial systems. In trophic systems, photosynthetic organisms are

3480-472: The air that contain toxins. Because human exposure can take place by consuming seafood products that contain the toxins expelled by HAB algae, food-borne diseases are present and can affect the nervous, digestive, respiratory, hepatic, dermatological, and cardiac systems in the body. Beach users have often experienced upper respiratory diseases, eye and nose irritation, fever, and have often needed medical care in order to be treated. Ciguatera fish poisoning (CFP)

3567-506: The algae species concentration simply deviates from its normal growth. Blooms are the result of a nutrient needed by the particular algae being introduced to the local aquatic system. This growth-limiting nutrient is typically nitrogen or phosphorus, but can also be iron, vitamins, or amino acids. There are several mechanisms for the addition of these nutrients in water. In the open ocean and along coastlines, upwelling from both winds and topographical ocean floor features can draw nutrients to

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3654-402: The amount of energy available to the ecosystem. Parent material determines the nature of the soil in an ecosystem, and influences the supply of mineral nutrients. Topography also controls ecosystem processes by affecting things like microclimate , soil development and the movement of water through a system. For example, ecosystems can be quite different if situated in a small depression on

3741-504: The amount of light available, the amount of leaf area a plant has to capture light (shading by other plants is a major limitation of photosynthesis), the rate at which carbon dioxide can be supplied to the chloroplasts to support photosynthesis, the availability of water, and the availability of suitable temperatures for carrying out photosynthesis. Energy and carbon enter ecosystems through photosynthesis, are incorporated into living tissue, transferred to other organisms that feed on

3828-523: The benign feeding of higher trophic levels to more harmful effects like blocking sunlight from reaching other organisms, causing a depletion of oxygen levels in the water, and, depending on the organism, secreting toxins into the water. Blooms that can injure animals or the ecology, especially those blooms where toxins are secreted by the algae, are usually called " harmful algal blooms " (HAB), and can lead to fish die-offs, cities cutting off water to residents, or states having to close fisheries. The process of

3915-408: The carbon makes up much of the organic matter in living and dead biomass, soil carbon and fossil fuels . It also drives the carbon cycle , which influences global climate via the greenhouse effect . Through the process of photosynthesis, plants capture energy from light and use it to combine carbon dioxide and water to produce carbohydrates and oxygen . The photosynthesis carried out by all

4002-413: The cause of seafood poisoning from the neurotoxins. There are three major categories for management of algal blooms consisting of mitigation, prevention, and control. Within mitigation, routine monitoring programs are implemented for toxins in shellfish and an overall surveillance of the area. The HAB levels of the shellfish will be determined and can manage restrictions to keep contaminated shellfish off

4089-432: The combustion of fossil fuels, ammonia gas which evaporates from agricultural fields which have had fertilizers applied to them, and dust. Anthropogenic nitrogen inputs account for about 80% of all nitrogen fluxes in ecosystems. When plant tissues are shed or are eaten, the nitrogen in those tissues becomes available to animals and microbes. Microbial decomposition releases nitrogen compounds from dead organic matter in

4176-445: The concentration of photosynthetic pigment, quantification of the bloom's negative effect, or relative concentration of the algae compared to the rest of the microbial community. For example, definitions of blooms have included when the concentration of chlorophyll exceeds 100 ug/L, when the concentration of chlorophyll exceeds 5 ug/L, when the species considered to be blooming exceeds concentrations of 1000 cells/mL, and when

4263-418: The concept to draw attention to the importance of transfers of materials between organisms and their environment. He later refined the term, describing it as "The whole system, ... including not only the organism-complex, but also the whole complex of physical factors forming what we call the environment". Tansley regarded ecosystems not simply as natural units, but as "mental isolates". Tansley later defined

4350-403: The dead organic matter would accumulate in an ecosystem, and nutrients and atmospheric carbon dioxide would be depleted. Decomposition processes can be separated into three categories— leaching , fragmentation and chemical alteration of dead material. As water moves through dead organic matter, it dissolves and carries with it the water-soluble components. These are then taken up by organisms in

4437-447: The definition of ecosystems : a biotic component, an abiotic complex, the interactions between and within them, and the physical space they occupy. Biotic factors of the ecosystem are living things; such as plants, animals, and bacteria, while abiotic are non-living components; such as water, soil and atmosphere. Plants allow energy to enter the system through photosynthesis , building up plant tissue. Animals play an important role in

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4524-643: The ecosystem or to gradual disruption of biotic processes and degradation of abiotic conditions of the ecosystem. Once the original ecosystem has lost its defining features, it is considered "collapsed ". Ecosystem restoration can contribute to achieving the Sustainable Development Goals . An ecosystem (or ecological system) consists of all the organisms and the abiotic pools (or physical environment) with which they interact. The biotic and abiotic components are linked together through nutrient cycles and energy flows. "Ecosystem processes" are

4611-528: The ecosystem. Internal factors are controlled, for example, by decomposition , root competition, shading, disturbance, succession, and the types of species present. While the resource inputs are generally controlled by external processes, the availability of these resources within the ecosystem is controlled by internal factors. Therefore, internal factors not only control ecosystem processes but are also controlled by them. Ecosystems are dynamic entities—they are subject to periodic disturbances and are always in

4698-587: The first ever freshwater ESP in Lake Erie . This ESP will measure concentrations of particulate microcystins in the western basin of the lake, every other day. It can also genetically detect Microcystis and archive samples for future processing. With the addition of information from the ESPs, NOAA's suite of Lake Erie HAB products, (i.e. weekly Lake Erie HAB bulletin), and the Experimental HAB Tracker]), will have

4785-421: The flow of energy through a lake was the primary driver of the ecosystem. Hutchinson's students, brothers Howard T. Odum and Eugene P. Odum , further developed a "systems approach" to the study of ecosystems. This allowed them to study the flow of energy and material through ecological systems. Ecosystems are controlled by both external and internal factors. External factors, also called state factors, control

4872-427: The food market. Moving fish pens away from algal blooms is also another form of mitigation. Within prevention, this category is less known but policy changes are implemented to control sewage and waste. Within control, there are mechanical, biological, chemical, genetic and environmental controls. Mechanical control involves dispersing clay into the water to aggregate with the HAB leading to less of these HAB to go through

4959-452: The forests of eastern North America still show legacies of cultivation which ceased in 1850 when large areas were reverted to forests. Another example is the methane production in eastern Siberian lakes that is controlled by organic matter which accumulated during the Pleistocene . Ecosystems continually exchange energy and carbon with the wider environment . Mineral nutrients, on

5046-691: The landscape, versus one present on an adjacent steep hillside. Other external factors that play an important role in ecosystem functioning include time and potential biota , the organisms that are present in a region and could potentially occupy a particular site. Ecosystems in similar environments that are located in different parts of the world can end up doing things very differently simply because they have different pools of species present. The introduction of non-native species can cause substantial shifts in ecosystem function. Unlike external factors, internal factors in ecosystems not only control ecosystem processes but are also controlled by them. While

5133-423: The living and dead plant matter, and eventually released through respiration. The carbon and energy incorporated into plant tissues (net primary production) is either consumed by animals while the plant is alive, or it remains uneaten when the plant tissue dies and becomes detritus . In terrestrial ecosystems , the vast majority of the net primary production ends up being broken down by decomposers . The remainder

5220-689: The location and abundance of phytoplankton by detecting the amount of chlorophyll present in coastal and open waters—the higher the concentration, the larger the bloom. Observations show blooms typically last until late spring or early summer, when nutrient stocks are in decline and predatory zooplankton start to graze. The visualization on the left immediately below uses NASA SeaWiFS data to map bloom populations. The NAAMES study conducted between 2015 and 2019 investigated aspects of phytoplankton dynamics in ocean ecosystems, and how such dynamics influence atmospheric aerosols , clouds, and climate. In France, citizens are requested to report coloured waters through

5307-408: The maintenance of hydrological cycles, cleaning air and water, the maintenance of oxygen in the atmosphere, crop pollination and even things like beauty, inspiration and opportunities for research. While material from the ecosystem had traditionally been recognized as being the basis for things of economic value, ecosystem services tend to be taken for granted. The Millennium Ecosystem Assessment

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5394-405: The maintenance of oxygen in the atmosphere, crop pollination and even things like beauty, inspiration and opportunities for research. Many ecosystems become degraded through human impacts, such as soil loss , air and water pollution , habitat fragmentation , water diversion , fire suppression , and introduced species and invasive species . These threats can lead to abrupt transformation of

5481-433: The movement of matter and energy through the system, by feeding on plants and on one another. They also influence the quantity of plant and microbial biomass present. By breaking down dead organic matter , decomposers release carbon back to the atmosphere and facilitate nutrient cycling by converting nutrients stored in dead biomass back to a form that can be readily used by plants and microbes. Ecosystems provide

5568-427: The organism, its pigments, and the depth in the water column, algal blooms can be green, red, brown, golden, and purple. Bright green blooms in freshwater systems are frequently a result of cyanobacteria (colloquially known as "blue-green algae") such as Microcystis . Blooms may also consist of macroalgal (non- phytoplanktonic ) species. These blooms are recognizable by large blades of algae that may wash up onto

5655-537: The other hand, are mostly cycled back and forth between plants, animals, microbes and the soil. Most nitrogen enters ecosystems through biological nitrogen fixation , is deposited through precipitation, dust, gases or is applied as fertilizer . Most terrestrial ecosystems are nitrogen-limited in the short term making nitrogen cycling an important control on ecosystem production. Over the long term, phosphorus availability can also be critical. Macronutrients which are required by all plants in large quantities include

5742-509: The other. Despite this, the cumulative effect of additional species in an ecosystem is not linear: additional species may enhance nitrogen retention, for example. However, beyond some level of species richness, additional species may have little additive effect unless they differ substantially from species already present. This is the case for example for exotic species . The addition (or loss) of species that are ecologically similar to those already present in an ecosystem tends to only have

5829-403: The overall structure of an ecosystem and the way things work within it, but are not themselves influenced by the ecosystem. On broad geographic scales, climate is the factor that "most strongly determines ecosystem processes and structure". Climate determines the biome in which the ecosystem is embedded. Rainfall patterns and seasonal temperatures influence photosynthesis and thereby determine

5916-429: The oversupply of nutrients leading to algae growth and oxygen depletion is called eutrophication . Algal and bacterial blooms have persistently contributed to mass extinctions driven by global warming in the geologic past, such as during the end-Permian extinction driven by Siberian Traps volcanism and the biotic recovery following the mass extinction. The term algal bloom is defined inconsistently depending on

6003-405: The plants in an ecosystem is called the gross primary production (GPP). About half of the gross GPP is respired by plants in order to provide the energy that supports their growth and maintenance. The remainder, that portion of GPP that is not used up by respiration, is known as the net primary production (NPP). Total photosynthesis is limited by a range of environmental factors. These include

6090-444: The presence of nutrients. When phosphates are introduced into water systems, higher concentrations cause increased growth of algae and plants. Algae tend to grow very quickly under high nutrient availability, but each alga is short-lived, and the result is a high concentration of dead organic matter which starts to decompose. Natural decomposers present in the water begin decomposing the dead algae, consuming dissolved oxygen present in

6177-585: The primary nutrients (which are most limiting as they are used in largest amounts): Nitrogen, phosphorus, potassium. Secondary major nutrients (less often limiting) include: Calcium, magnesium, sulfur. Micronutrients required by all plants in small quantities include boron, chloride, copper, iron, manganese, molybdenum, zinc. Finally, there are also beneficial nutrients which may be required by certain plants or by plants under specific environmental conditions: aluminum, cobalt, iodine, nickel, selenium, silicon, sodium, vanadium. Until modern times, nitrogen fixation

6264-413: The primary producers. The organisms that consume their tissues are called primary consumers or secondary producers — herbivores . Organisms which feed on microbes ( bacteria and fungi ) are termed microbivores . Animals that feed on primary consumers— carnivores —are secondary consumers. Each of these constitutes a trophic level. The sequence of consumption—from plant to herbivore, to carnivore—forms

6351-419: The process of recovering from some past disturbance. The tendency of an ecosystem to remain close to its equilibrium state, despite that disturbance, is termed its resistance . The capacity of a system to absorb disturbance and reorganize while undergoing change so as to retain essentially the same function, structure, identity, and feedbacks is termed its ecological resilience . Ecosystems can be studied through

6438-586: The process of sedimentation. Biological control varies largely and can be used through pheromones or releasing sterile males to reduce reproduction. Chemical control uses toxic chemical release. However, it may cause problems of mortality of other non targeted organisms. Genetic control involves genetically engineering species in their environmental tolerances and reproduction processes. However, there are problems of harming indigenous organisms. For environmental control, it can use water circulation and aeration. Ecosystem An ecosystem (or ecological system )

6525-917: The project PHENOMER. This helps to understand the occurrence of marine blooms. Wildfires can cause phytoplankton blooms via oceanic deposition of wildfire aerosols. A harmful algal bloom (HAB) is an algal bloom that causes negative impacts to other organisms via production of natural toxins, mechanical damage to other organisms, or by other means. The diversity of these HABs make them even harder to manage, and present many issues, especially to threatened coastal areas. HABs are often associated with large-scale marine mortality events and have been associated with various types of shellfish poisonings . Due to their negative economic and health impacts, HABs are often carefully monitored. HAB has been proved to be harmful to humans. Humans may be exposed to toxic algae by direct consuming seafood containing toxins, swimming or other activities in water, and breathing tiny droplets in

6612-446: The rapid growth of microscopic unicellular algae, not macroscopic algae. An example of a macroscopic algal bloom is a kelp forest . Algal blooms are the result of a nutrient, like nitrogen or phosphorus from various sources (for example fertilizer runoff or other forms of nutrient pollution ), entering the aquatic system and causing excessive growth of algae. An algal bloom affects the whole ecosystem . Consequences range from

6699-399: The result of an excess of nutrients , particularly some phosphates . Excess nutrients may originate from fertilizers that are applied to land for agricultural or recreational purposes and may also originate from household cleaning products containing phosphorus . The reduction of phosphorus inputs is required to mitigate blooms that contain cyanobacteria. In lakes that are stratified in

6786-443: The scientific field and can range from a "minibloom" of harmless algae to a large, harmful bloom event. Since algae is a broad term including organisms of widely varying sizes, growth rates, and nutrient requirements, there is no officially recognized threshold level as to what is defined as a bloom. Because there is no scientific consensus, blooms can be characterized and quantified in several ways: measurements of new algal biomass,

6873-760: The shoreline. Once the nutrient is present in the water, the algae begin to grow at a much faster rate than usual. In a mini bloom, this fast growth benefits the whole ecosystem by providing food and nutrients for other organisms. Of particular note are the harmful algal blooms (HABs), which are algal bloom events involving toxic or otherwise harmful phytoplankton. Many species can cause harmful algal blooms. For example, Gymnodinium nagasakiense can cause harmful red tides , dinoflagellates Gonyaulax polygramma can cause oxygen depletion and result in large fish kills, cyanobacteria Microcystis aeruginosa can make poisonous toxins, and diatom Chaetoceros convolutus can damage fish gills. Freshwater algal blooms are

6960-572: The situation can be corrected by changing the water in the tank and then reducing the amount of food given. Turbulent storms churn the ocean in summer, adding nutrients to sunlit waters near the surface. This sparks a feeding frenzy each spring that gives rise to massive blooms of phytoplankton. Tiny molecules found inside these microscopic plants harvest vital energy from sunlight through photosynthesis. The natural pigments, called chlorophyll, allow phytoplankton to thrive in Earth's oceans and enable scientists to monitor blooms from space. Satellites reveal

7047-611: The soil, react with mineral soil, or are transported beyond the confines of the ecosystem (and are considered lost to it). Newly shed leaves and newly dead animals have high concentrations of water-soluble components and include sugars , amino acids and mineral nutrients. Leaching is more important in wet environments and less important in dry ones. Fragmentation processes break organic material into smaller pieces, exposing new surfaces for colonization by microbes. Freshly shed leaf litter may be inaccessible due to an outer layer of cuticle or bark , and cell contents are protected by

7134-511: The soil, where plants, fungi, and bacteria compete for it. Some soil bacteria use organic nitrogen-containing compounds as a source of carbon, and release ammonium ions into the soil. This process is known as nitrogen mineralization . Others convert ammonium to nitrite and nitrate ions, a process known as nitrification . Nitric oxide and nitrous oxide are also produced during nitrification. Under nitrogen-rich and oxygen-poor conditions, nitrates and nitrites are converted to nitrogen gas ,

7221-483: The spatial extent of ecosystems using the term " ecotope ". G. Evelyn Hutchinson , a limnologist who was a contemporary of Tansley's, combined Charles Elton 's ideas about trophic ecology with those of Russian geochemist Vladimir Vernadsky . As a result, he suggested that mineral nutrient availability in a lake limited algal production . This would, in turn, limit the abundance of animals that feed on algae. Raymond Lindeman took these ideas further to suggest that

7308-463: The summer, autumn turnover can release substantial quantities of bio-available phosphorus potentially triggering algal blooms as soon as sufficient photosynthetic light is available. Excess nutrients can enter watersheds through water runoff. Excess carbon and nitrogen have also been suspected as causes. Presence of residual sodium carbonate acts as catalyst for the algae to bloom by providing dissolved carbon dioxide for enhanced photosynthesis in

7395-421: The transfers of energy and materials from one pool to another. Ecosystem processes are known to "take place at a wide range of scales". Therefore, the correct scale of study depends on the question asked. The term "ecosystem" was first used in 1935 in a publication by British ecologist Arthur Tansley . The term was coined by Arthur Roy Clapham , who came up with the word at Tansley's request. Tansley devised

7482-424: The water during the process. This can result in a sharp decrease in available dissolved oxygen for other aquatic life. Without sufficient dissolved oxygen in the water, animals and plants may die off in large numbers. This may also be known as a dead zone . Blooms may be observed in freshwater aquariums when fish are overfed and excess nutrients are not absorbed by plants. These are generally harmful for fish, and

7569-679: Was the major source of nitrogen for ecosystems. Nitrogen-fixing bacteria either live symbiotically with plants or live freely in the soil. The energetic cost is high for plants that support nitrogen-fixing symbionts—as much as 25% of gross primary production when measured in controlled conditions. Many members of the legume plant family support nitrogen-fixing symbionts. Some cyanobacteria are also capable of nitrogen fixation. These are phototrophs , which carry out photosynthesis. Like other nitrogen-fixing bacteria, they can either be free-living or have symbiotic relationships with plants. Other sources of nitrogen include acid deposition produced through

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