113-703: The Greater Toronto Bioregion represents a unique ecosystem that co-exists with the urban sprawl of the Greater Toronto Area . It is also part of the Oak Ridges Moraine system. 43°38′33″N 79°23′14″W / 43.64250°N 79.38722°W / 43.64250; -79.38722 This Ontario geographical article about a location in the Golden Horseshoe is a stub . You can help Misplaced Pages by expanding it . Ecosystem An ecosystem (or ecological system )
226-409: 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
339-495: 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
452-619: 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
565-780: A 60,000-year-old Neanderthal burial site, " Shanidar IV ", in northern Iraq has yielded large amounts of pollen from eight plant species, seven of which are used now as herbal remedies. Also, a mushroom was found in the personal effects of Ötzi the Iceman , whose body was frozen in the Ötztal Alps for more than 5,000 years. The mushroom was probably used against whipworm . In ancient Sumeria , hundreds of medicinal plants including myrrh and opium are listed on clay tablets from around 3000 BC. The ancient Egyptian Ebers Papyrus lists over 800 plant medicines such as aloe , cannabis , castor bean , garlic , juniper , and mandrake . In antiquity, various cultures across Europe, including
678-609: 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
791-507: 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
904-517: 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,
1017-427: 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
1130-698: 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
1243-482: A healthier labour force. However, development of plants or extracts having potential medicinal uses is blunted by weak scientific evidence, poor practices in the process of drug development , and insufficient financing. All plants produce chemical compounds which give them an evolutionary advantage, such as defending against herbivores or, in the example of salicylic acid , as a hormone in plant defenses. These phytochemicals have potential for use as drugs, and
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#17327720375641356-672: 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
1469-528: 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
1582-510: A network called the International Regulatory Cooperation for Herbal Medicines to try to improve the quality of medical products made from medicinal plants and the claims made for them. In 2015, only around 20% of countries had well-functioning regulatory agencies, while 30% had none, and around half had limited regulatory capacity. In India, where Ayurveda has been practised for centuries, herbal remedies are
1695-406: 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,
1808-431: A policy on traditional medicine in 1991, and since then has published guidelines for them, with a series of monographs on widely used herbal medicines. Medicinal plants may provide three main kinds of benefit: health benefits to the people who consume them as medicines; financial benefits to people who harvest, process, and distribute them for sale; and society-wide benefits, such as job opportunities, taxation income, and
1921-421: 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
2034-423: A pure chemical. Extraction can be practical when the compound in question is complex. Plant medicines are in wide use around the world. In most of the developing world, especially in rural areas, local traditional medicine , including herbalism, is the only source of health care for people, while in the developed world , alternative medicine including use of dietary supplements is marketed aggressively using
2147-599: A result, phytochemicals have frequently proven unsuitable as the lead substances in drug discovery . In the United States over the period 1999 to 2012, despite several hundred applications for new drug status , only two botanical drug candidates had sufficient evidence of medicinal value to be approved by the Food and Drug Administration . The pharmaceutical industry has remained interested in mining traditional uses of medicinal plants in its drug discovery efforts. Of
2260-696: 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
2373-408: 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,
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#17327720375642486-464: 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
2599-401: A substance first discovered in a medicinal plant began with salicylic acid in 1853. Around the end of the 19th century, the mood of pharmacy turned against medicinal plants, as enzymes often modified the active ingredients when whole plants were dried, and alkaloids and glycosides purified from plant material started to be preferred. Drug discovery from plants continued to be important through
2712-410: A succession of medicinal plants, starting with morphine from the poppy in 1806, and soon followed by ipecacuanha and strychnos in 1817, quinine from the cinchona tree, and then many others. As chemistry progressed, additional classes of potentially active substances were discovered in plants. Commercial extraction of purified alkaloids including morphine began at Merck in 1826. Synthesis of
2825-468: 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
2938-443: 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,
3051-522: 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
3164-431: 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
3277-433: Is an antiseptic and was once used as a vermifuge (anti-worm medicine). Medicinal plants demand intensive management. Different species each require their own distinct conditions of cultivation. The World Health Organization recommends the use of rotation to minimise problems with pests and plant diseases. Cultivation may be traditional or may make use of conservation agriculture practices to maintain organic matter in
3390-458: 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
3503-442: 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
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3616-569: 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
3729-554: 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
3842-402: Is increasing in developed countries. This brings attendant risks of toxicity and other effects on human health, despite the safe image of herbal remedies. Herbal medicines have been in use since long before modern medicine existed; there was and often still is little or no knowledge of the pharmacological basis of their actions, if any, or of their safety. The World Health Organization formulated
3955-405: 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
4068-593: Is no reason to presume that because a product comes from nature it must be safe: the existence of powerful natural poisons like atropine and nicotine shows this to be untrue. Further, the high standards applied to conventional medicines do not always apply to plant medicines, and dose can vary widely depending on the growth conditions of plants: older plants may be much more toxic than young ones, for instance. Plant extracts may interact with conventional drugs, both because they may provide an increased dose of similar compounds, and because some phytochemicals interfere with
4181-531: 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
4294-485: 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
4407-422: 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
4520-589: The Sumerian civilization, where hundreds of medicinal plants including opium are listed on clay tablets, c. 3000 BC . The Ebers Papyrus from ancient Egypt , c. 1550 BC , describes over 850 plant medicines. The Greek physician Dioscorides , who worked in the Roman army, documented over 1000 recipes for medicines using over 600 medicinal plants in De materia medica , c. 60 AD ; this formed
4633-554: The apothecary shops of Europe in the 1800s, where pharmacists provided local traditional medicines to customers, which included extracts like morphine, quinine, and strychnine. Therapeutically important drugs like camptothecin (from Camptotheca acuminata , used in traditional Chinese medicine) and taxol (from the Pacific yew, Taxus brevifolia ) were derived from medicinal plants. The Vinca alkaloids vincristine and vinblastine , used as anti-cancer drugs, were discovered in
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4746-555: 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
4859-536: The "Circa Instans," which served as practical guides for herbal remedies. In the Iberian Peninsula, the regions of the North remained independent during the period of Islamic occupation, and retained their traditional and indigenous medical practices. Galicia and Asturias, possessed a rich herbal heritage shaped by its Celtic and Roman influences. The Galician people were known for their strong connection to
4972-435: 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
5085-579: The 1073 small-molecule drugs approved in the period 1981 to 2010, over half were either directly derived from or inspired by natural substances. Among cancer treatments, of 185 small-molecule drugs approved in the period from 1981 to 2019, 65% were derived from or inspired by natural substances. Plant medicines can cause adverse effects and even death, whether by side-effects of their active substances, by adulteration or contamination, by overdose, or by inappropriate prescription. Many such effects are known, while others remain to be explored scientifically. There
5198-513: The 1950s from the Madagascar periwinkle, Catharanthus roseus . Hundreds of compounds have been identified using ethnobotany , investigating plants used by indigenous peoples for possible medical applications. Some important phytochemicals, including curcumin , epigallocatechin gallate , genistein and resveratrol are pan-assay interference compounds , meaning that in vitro studies of their activity often provide unreliable data. As
5311-404: The 20th century and into the 21st, with important anti-cancer drugs from yew and Madagascar periwinkle . Medicinal plants are used with the intention of maintaining health, to be administered for a specific condition, or both, whether in modern medicine or in traditional medicine . The Food and Agriculture Organization estimated in 2002 that over 50,000 medicinal plants are used across
5424-537: The Brazilian Amazon, assisted by researchers, have described 101 plant species used for traditional medicines. Drugs derived from plants including opiates, cocaine and cannabis have both medical and recreational uses . Different countries have at various times made use of illegal drugs , partly on the basis of the risks involved in taking psychoactive drugs . Plant medicines have often not been tested systematically, but have come into use informally over
5537-512: The COVID-19 pandemic, which led to the United States taking action to stop the deceptive marketing of herbal products to combat the virus. Where medicinal plants are harvested from the wild rather than cultivated, they are subject to both general and specific threats. General threats include climate change and habitat loss to development and agriculture. A specific threat is over-collection to meet rising demand for medicines. A case in point
5650-611: The Catalonia region of northeastern Spain, was a hub of cultural exchange during the Middle Ages, fostering the preservation and dissemination of medical knowledge. Catalan herbalists, known as "herbolarios," compiled manuscripts detailing the properties and uses of medicinal plants found in the region. The University of Barcelona, founded in 1450, played a pivotal role in advancing herbal medicine through its botanical gardens and academic pursuits. In Scotland and England, herbalism
5763-559: The Elder's "Naturalis Historia" contains valuable insights into Roman medical plant practices Among the Celtic peoples of ancient Europe, herbalism played a vital role in both medicine and spirituality. Druids, the religious leaders of the Celts, were reputed to possess deep knowledge of plants and their medicinal properties. Although written records are scarce, archaeological evidence, such as
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#17327720375645876-693: The Islamic world, particularly in Baghdad and in Al-Andalus . Among many works on medicinal plants, Abulcasis (936–1013) of Cordoba wrote The Book of Simples , and Ibn al-Baitar (1197–1248) recorded hundreds of medicinal herbs such as Aconitum , nux vomica , and tamarind in his Corpus of Simples . Avicenna included many plants in his 1025 The Canon of Medicine . Abu-Rayhan Biruni , Ibn Zuhr , Peter of Spain , and John of St Amand wrote further pharmacopoeias . The Early Modern period saw
5989-644: The Old World and the Americas in the 15th and 16th centuries. Medicinal herbs arriving in the Americas included garlic, ginger, and turmeric; coffee, tobacco and coca travelled in the other direction. In Mexico, the sixteenth century Badianus Manuscript described medicinal plants available in Central America. The place of plants in medicine was radically altered in the 19th century by the application of chemical analysis . Alkaloids were isolated from
6102-549: The Romans, Celts, and Nordic peoples, also practiced herbal medicine as a significant component of their healing traditions. The Romans had a rich tradition of herbal medicine, drawing upon knowledge inherited from the Greeks and expanding upon it. Notable works include those of Pedanius Dioscorides, whose "De Materia Medica" served as a comprehensive guide to medicinal plants and remained influential for centuries. Additionally, Pliny
6215-481: 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
6328-402: 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
6441-504: 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
6554-524: The astringent rind of the pomegranate , containing polyphenols called punicalagins , is used as a medicine, with no scientific proof of efficacy. Terpenes and terpenoids of many kinds are found in a variety of medicinal plants, and in resinous plants such as the conifers . They are strongly aromatic and serve to repel herbivores. Their scent makes them useful in essential oils , whether for perfumes such as rose and lavender , or for aromatherapy . Some have medicinal uses: for example, thymol
6667-716: The basis of pharmacopoeias for some 1500 years. Drug research sometimes makes use of ethnobotany to search for pharmacologically active substances, and this approach has yielded hundreds of useful compounds. These include the common drugs aspirin , digoxin , quinine , and opium . The compounds found in plants are diverse, with most in four biochemical classes: alkaloids , glycosides , polyphenols , and terpenes . Few of these are scientifically confirmed as medicines or used in conventional medicine. Medicinal plants are widely used as folk medicine in non-industrialized societies, mainly because they are readily available and cheaper than modern medicines. The annual global export value of
6780-804: The biodiversity of the world ecosystems, reducing both their resilience and biocapacity . The report refers to natural systems as humanity's "life-support system", providing essential ecosystem services. The assessment measures 24 ecosystem services and concludes that only four have shown improvement over the last 50 years, 15 are in serious decline, and five are in a precarious condition. Medicinal plant Medicinal plants , also called medicinal herbs , have been discovered and used in traditional medicine practices since prehistoric times. Plants synthesize hundreds of chemical compounds for various functions, including defense and protection against insects , fungi , diseases , and herbivorous mammals . The earliest historical records of herbs are found from
6893-737: The body's systems that metabolise drugs in the liver including the cytochrome P450 system, making the drugs last longer in the body and have a cumulative effect. Plant medicines can be dangerous during pregnancy. Since plants may contain many different substances, plant extracts may have complex effects on the human body. Herbal medicine and dietary supplement products have been criticized as not having sufficient standards or scientific evidence to confirm their contents, safety, and presumed efficacy. Companies often make false claims about their herbal products promising health benefits that aren't backed by evidence to generate more sales. The market for dietary supplements and nutraceuticals grew by 5% during
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#17327720375647006-408: 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
7119-410: The centuries. By 2007, clinical trials had demonstrated potentially useful activity in nearly 16% of herbal extracts; there was limited in vitro or in vivo evidence for roughly half the extracts; there was only phytochemical evidence for around 20%; 0.5% were allergenic or toxic; and some 12% had basically never been studied scientifically. Cancer Research UK caution that there is no reliable evidence for
7232-614: The claims of traditional medicine. As of 2015, most products made from medicinal plants had not been tested for their safety and efficacy, and products that were marketed in developed economies and provided in the undeveloped world by traditional healers were of uneven quality, sometimes containing dangerous contaminants. Traditional Chinese medicine makes use of a wide variety of plants, among other materials and techniques. Researchers from Kew Gardens found 104 species used for diabetes in Central America, of which seven had been identified in at least three separate studies. The Yanomami of
7345-432: 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
7458-418: 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
7571-415: The content and known pharmacological activity of these substances in medicinal plants is the scientific basis for their use in modern medicine, if scientifically confirmed. For instance, daffodils ( Narcissus ) contain nine groups of alkaloids including galantamine , licensed for use against Alzheimer's disease . The alkaloids are bitter-tasting and toxic, and concentrated in the parts of the plant such as
7684-403: 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
7797-447: 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
7910-528: The discovery of medicinal plants at Celtic sites, provides insight into their herbal practices In the Nordic regions, including Scandinavia and parts of Germany, herbal medicine was also prevalent in ancient times. The Norse sagas and Eddic poetry often mention the use of herbs for healing purposes. Additionally, archaeological findings, such as the remains of medicinal plants in Viking-age graves, attest to
8023-655: 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
8136-528: 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
8249-562: The effectiveness of herbal remedies for cancer. A 2012 phylogenetic study built a family tree down to genus level using 20,000 species to compare the medicinal plants of three regions, Nepal, New Zealand and the Cape of South Africa. It discovered that the species used traditionally to treat the same types of condition belonged to the same groups of plants in all three regions, giving a "strong phylogenetic signal". Since many plants that yield pharmaceutical drugs belong to just these groups, and
8362-528: The flourishing of illustrated herbals across Europe, starting with the 1526 Grete Herball . John Gerard wrote his famous The Herball or General History of Plants in 1597, based on Rembert Dodoens , and Nicholas Culpeper published his The English Physician Enlarged . Many new plant medicines arrived in Europe as products of Early Modern exploration and the resulting Columbian Exchange , in which livestock, crops and technologies were transferred between
8475-421: 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
8588-458: 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
8701-452: The groups were independently used in three different world regions, the results were taken to mean 1) that these plant groups do have potential for medicinal efficacy, 2) that undefined pharmacological activity is associated with use in traditional medicine, and 3) that the use of a phylogenetic groups for possible plant medicines in one region may predict their use in the other regions. The World Health Organization (WHO) has been coordinating
8814-676: The importance of herbal remedies in Nordic culture From ancient times to the present, Ayurvedic medicine as documented in the Atharva Veda , the Rig Veda and the Sushruta Samhita has used hundreds of herbs and spices, such as turmeric , which contains curcumin . The Chinese pharmacopoeia , the Shennong Ben Cao Jing records plant medicines such as chaulmoogra for leprosy, ephedra , and hemp . This
8927-437: The land and nature and preserved botanical knowledge, with healers, known as "curandeiros" or "meigas," who relied on local plants for healing purposes The Asturian landscape, characterized by lush forests and mountainous terrain, provided a rich source of medicinal herbs used in traditional healing practices, with "yerbatos," who possessed extensive knowledge of local plants and their medicinal properties Barcelona, located in
9040-691: 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
9153-423: 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
9266-408: 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
9379-405: 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
9492-463: The majority of what are often informal attempted treatments, not tested scientifically. The World Health Organization estimates, without reliable data, that some 80 percent of the world's population depends mainly on traditional medicine (including but not limited to plants); perhaps some two billion people are largely reliant on medicinal plants. The use of plant-based materials including herbal or natural health products with supposed health benefits,
9605-433: 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
9718-491: The original source of most plant medicines. Human settlements are often surrounded by weeds used as herbal medicines , such as nettle , dandelion and chickweed . Humans were not alone in using herbs as medicines: some animals such as non-human primates , monarch butterflies and sheep ingest medicinal plants when they are ill. Plant samples from prehistoric burial sites are among the lines of evidence that Paleolithic peoples had knowledge of herbal medicine. For instance,
9831-537: 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
9944-509: 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
10057-403: 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
10170-417: The plant material in cold wine or distilled spirit to form a tincture . Traditional poultices were made by boiling medicinal plants, wrapping them in a cloth, and applying the resulting parcel externally to the affected part of the body. When modern medicine has identified a drug in a medicinal plant, commercial quantities of the drug may either be synthesised or extracted from plant material, yielding
10283-405: 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
10396-610: The practice of medieval medicine, which combined elements of Ancient Greek and Roman traditions. Catholic monastic orders played a significant role in preserving and expanding herbal knowledge. Manuscripts like the "Tractatus de Herbis" from the 15th century depict French herbal remedies and their uses. Monasteries and convents served as centers of learning, where monks and nuns cultivated medicinal gardens. Likewise, in Italy, herbalism flourished with contribution Italian physicians like Matthaeus Platearius who compiled herbal manuscripts, such as
10509-451: The preparation of herbal medicines include decoction , powdering, and extraction with alcohol, in each case yielding a mixture of substances. Decoction involves crushing and then boiling the plant material in water to produce a liquid extract that can be taken orally or applied topically. Powdering involves drying the plant material and then crushing it to yield a powder that can be compressed into tablets . Alcohol extraction involves soaking
10622-585: 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
10735-413: 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
10848-419: 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
10961-502: The responsibility of a government department, AYUSH , under the Ministry of Health & Family Welfare. WHO has set out a strategy for traditional medicines with four objectives: to integrate them as policy into national healthcare systems; to provide knowledge and guidance on their safety, efficacy, and quality; to increase their availability and affordability; and to promote their rational, therapeutically sound usage. WHO notes in
11074-644: The seventeenth century. During the Middle Ages, herbalism continued to flourish across Europe, with distinct traditions emerging in various regions, often influenced by cultural, religious, indigenous, and geographical factors. In the Early Middle Ages , Benedictine monasteries preserved medical knowledge in Europe , translating and copying classical texts and maintaining herb gardens . Hildegard of Bingen wrote Causae et Curae ("Causes and Cures") on medicine. In France, herbalism thrived alongside
11187-490: The soil and to conserve water, for example with no-till farming systems. In many medicinal and aromatic plants, plant characteristics vary widely with soil type and cropping strategy, so care is required to obtain satisfactory yields. Medicinal plants are often tough and fibrous, requiring some form of preparation to make them convenient to administer. According to the Institute for Traditional Medicine, common methods for
11300-611: 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
11413-511: 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 ,
11526-483: 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
11639-402: The specific threat of over-collection to meet market demand. Plants, including many now used as culinary herbs and spices , have been used as medicines, not necessarily effectively, from prehistoric times. Spices have been used partly to counter food spoilage bacteria, especially in hot climates, and especially in meat dishes that spoil more readily. Angiosperms ( flowering plants ) were
11752-839: The stem most likely to be eaten by herbivores; they may also protect against parasites . Modern knowledge of medicinal plants is being systematised in the Medicinal Plant Transcriptomics Database, which by 2011 provided a sequence reference for the transcriptome of some thirty species. Major classes of plant phytochemicals are described below, with examples of plants that contain them. Alkaloids are bitter-tasting chemicals, very widespread in nature, and often toxic, found in many medicinal plants. There are several classes with different modes of action as drugs, both recreational and pharmaceutical. Medicines of different classes include atropine , scopolamine , and hyoscyamine (all from nightshade ),
11865-404: The strategy that countries are experiencing seven challenges to such implementation, namely in developing and enforcing policy; in integration; in safety and quality, especially in assessment of products and qualification of practitioners; in controlling advertising; in research and development; in education and training; and in the sharing of information. The pharmaceutical industry has roots in
11978-677: The thousands of types of plants with medicinal properties was estimated to be US$ 60 billion per year and growing at the rate of 6% per annum. In many countries, there is little regulation of traditional medicine, but the World Health Organization coordinates a network to encourage safe and rational use. The botanical herbal market has been criticized for being poorly regulated and containing placebo and pseudoscience products with no scientific research to support their medical claims. Medicinal plants face both general threats, such as climate change and habitat destruction , and
12091-686: The traditional medicine berberine (from plants such as Berberis and Mahonia ), caffeine ( Coffea ), cocaine ( Coca ), ephedrine ( Ephedra ), morphine ( opium poppy ), nicotine ( tobacco ), reserpine ( Rauvolfia serpentina ), quinidine and quinine ( Cinchona ), vincamine ( Vinca minor ), and vincristine ( Catharanthus roseus ). Anthraquinone glycosides are found in medicinal plants such as rhubarb , cascara , and Alexandrian senna . Plant-based laxatives made from such plants include senna , rhubarb and Aloe . The cardiac glycosides are powerful drugs from medicinal plants including foxglove and lily of
12204-421: 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
12317-796: The valley . They include digoxin and digitoxin which support the beating of the heart, and act as diuretics . Polyphenols of several classes are widespread in plants, having diverse roles in defenses against plant diseases and predators. They include hormone-mimicking phytoestrogens and astringent tannins . Plants containing phytoestrogens have been administered for centuries for gynecological disorders, such as fertility, menstrual, and menopausal problems. Among these plants are Pueraria mirifica , kudzu , angelica , fennel , and anise . Many polyphenolic extracts, such as from grape seeds , olives or maritime pine bark , are sold as dietary supplements and cosmetics without proof or legal health claims for medicinal effects. In Ayurveda ,
12430-407: The world. The Royal Botanic Gardens, Kew more conservatively estimated in 2016 that 17,810 plant species have a medicinal use, out of some 30,000 plants for which a use of any kind is documented. In modern medicine, around a quarter of the drugs prescribed to patients are derived from medicinal plants, and they are rigorously tested. In other systems of medicine, medicinal plants may constitute
12543-588: Was deeply rooted in folk traditions and influenced by Celtic, Anglo-Saxon, and Norse practices. Herbal knowledge was passed down through generations, often by wise women known as "cunning folk." The "Physicians of Myddfai," a Welsh herbal manuscript from the 13th century, reflects the blending of Celtic and Christian beliefs in herbal medicine. In the Islamic Golden Age , scholars translated many classical Greek texts including Dioscorides into Arabic , adding their own commentaries. Herbalism flourished in
12656-558: Was expanded in the Tang dynasty Yaoxing Lun . In the fourth century BC, Aristotle 's pupil Theophrastus wrote the first systematic botany text, Historia plantarum . In around 60 AD, the Greek physician Pedanius Dioscorides , working for the Roman army, documented over 1000 recipes for medicines using over 600 medicinal plants in De materia medica . The book remained the authoritative reference on herbalism for over 1500 years, into
12769-679: 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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