Ecosystem health is a metaphor used to describe the condition of an ecosystem. Ecosystem condition can vary as a result of fire, flooding, drought, extinctions, invasive species, climate change, mining, overexploitation in fishing, farming or logging, chemical spills, and a host of other reasons. There is no universally accepted benchmark for a healthy ecosystem, rather the apparent health status of an ecosystem can vary depending upon which health metrics are employed in judging it and which societal aspirations are driving the assessment. Advocates of the health metaphor argue for its simplicity as a communication tool. "Policy-makers and the public need simple, understandable concepts like health." Critics worry that ecosystem health, a "value-laden construct", is often "passed off as science to unsuspecting policy makers and the public."
The health metaphor applied to the environment has been in use at least since the early 1800s and the great American conservationist Aldo Leopold (1887–1948) spoke metaphorically of land health, land sickness, mutilation, and violence when describing land use practices. The term "ecosystem management" has been in use at least since the 1950s. The term "ecosystem health" has become widespread in the ecological literature, as a general metaphor meaning something good, and as an environmental quality goal in field assessments of rivers, lakes, seas, and forests.
Recently however this metaphor has been subject of quantitative formulation using complex systems concepts such as criticality, meaning that a healthy ecosystem is in some sort of balance between adaptability (randomness) and robustness (order) . Nevertheless the universality of criticality is still under examination and is known as the Criticality Hypothesis, which states that systems in a dynamic regime shifting between order and disorder, attain the highest level of computational capabilities and achieve an optimal trade-off between robustness and flexibility. Recent results in cell and evolutionary biology, neuroscience and computer science have great interest in the criticality hypothesis, emphasizing its role as a viable candidate general law in the realm of adaptive complex systems (see  and references therein).
The term ecosystem health has been employed to embrace some suite of environmental goals deemed desirable. Edward Grumbine's highly cited paper "What is ecosystem management?" surveyed ecosystem management and ecosystem health literature and summarized frequently encountered goal statements:
Grumbine describes each of these goals as a "value statement" and stresses the role of human values in setting ecosystem management goals.
It is the last goal mentioned in the survey, accommodating humans, that is most contentious. "We have observed that when groups of stakeholders work to define … visions, this leads to debate over whether to emphasize ecosystem health or human well-being … Whether the priority is ecosystems or people greatly influences stakeholders' assessment of desirable ecological and social states." and, for example, "For some, wolves are critical to ecosystem health and an essential part of nature, for others they are a symbol of government overreach threatening their livelihoods and cultural values."
Measuring ecosystem health requires extensive goal-driven environmental sampling. For example, a vision for ecosystem health of Lake Superior was developed by a public forum and a series of objectives were prepared for protection of habitat and maintenance of populations of some 70 indigenous fish species. A suite of 80 lake health indicators was developed for the Great Lakes Basin including monitoring native fish species, exotic species, water levels, phosphorus levels, toxic chemicals, phytoplankton, zooplankton, fish tissue contaminants, etc.
Some authors have attempted broad definitions of ecosystem health, such as benchmarking as healthy the historical ecosystem state "prior to the onset of anthropogenic stress." A difficulty is that the historical composition of many human-altered ecosystems is unknown or unknowable. Also, fossil and pollen records indicate that the species that occupy an ecosystem reshuffle through time, so it is difficult to identify one snapshot in time as optimum or "healthy.".
A commonly cited broad definition states that a healthy ecosystem has three attributes:
While this captures significant ecosystem properties, a generalization is elusive as those properties do not necessarily co-vary in nature. For example, there is not necessarily a clear or consistent relationship between productivity and species richness. Similarly, the relationship between resilience and diversity is complex, and ecosystem stability may depend upon one or a few species rather than overall diversity. And some undesirable ecosystems are highly productive.
"Resilience is not desirable per se. There can be highly resilient states of ecosystems which are very undesirable from some human perspectives , such as algal-dominated coral reefs." Ecological resilience is a "capacity" that varies depending upon which properties of the ecosystem are to be studied and depending upon what kinds of disturbances are considered and how they are to be quantified. Approaches to assessing it "face high uncertainties and still require a considerable amount of empirical and theoretical research."
Other authors have sought a numerical index of ecosystem health that would permit quantitative comparisons among ecosystems and within ecosystems over time. One such system employs ratings of the three properties mentioned above: Health = system vigor x system organization x system resilience. Ecologist Glenn Suter argues that such indices employ "nonsense units," the indices have "no meaning; they cannot be predicted, so they are not applicable to most regulatory problems; they have no diagnostic power; effects of one component are eclipsed by responses of other components, and the reason for a high or low index value is unknown."
Health metrics are determined by stakeholder goals, which drive ecosystem definition. An ecosystem is an abstraction. "Ecosystems cannot be identified or found in nature. Instead, they must be delimited by an observer. This can be done in many different ways for the same chunk of nature, depending on the specific perspectives of interest."
Ecosystem definition determines the acceptable range of variability (reference conditions) and determines measurement variables. The latter are used as indicators of ecosystem structure and function, and can be used as indicators of "health".
An indicator is a variable, such as a chemical or biological property, that when measured, is used to infer trends in another (unmeasured) environmental variable or cluster of unmeasured variables (the indicandum). For example, rising mortality rate of canaries in a coal mine is an indicator of rising carbon monoxide levels. Rising chlorophyll-a levels in a lake may signal eutrophication.
Ecosystem assessments employ two kinds of indicators, descriptive indicators and normative indicators. "Indicators can be used descriptively for a scientific purpose or normatively for a political purpose."
Used descriptively, high chlorophyll-a is an indicator of eutrophication, but it may also be used as an ecosystem health indicator. When used as a normative (health) indicator, it indicates a rank on a health scale, a rank that can vary widely depending on societal preferences as to what is desirable. A high chlorophyll-a level in a natural successional wetland might be viewed as healthy whereas a human-impacted wetland with the same indicator value may be judged unhealthy.
Estimation of ecosystem health has been criticized for intermingling the two types of environmental indicators. A health indicator is a normative indicator, and if conflated with descriptive indicators "implies that normative values can be measured objectively, which is certainly not true. Thus, implicit values are insinuated to the reader, a situation which has to be avoided."
It can be argued that the very act of selecting indicators of any kind is biased by the observer's perspective but separation of goals from descriptions has been advocated as a step toward transparency: "A separation of descriptive and normative indicators is essential from the perspective of the philosophy of science … Goals and values cannot be deduced directly from descriptions … a fact that is emphasized repeatedly in the literature of environmental ethics … Hence, we advise always specifying the definition of indicators and propose clearly distinguishing ecological indicators in science from policy indicators used for decision-making processes."
And integration of multiple, possibly conflicting, normative indicators into a single measure of "ecosystem health" is problematic. Using 56 indicators, "determining environmental status and assessing marine ecosystems health in an integrative way is still one of the grand challenges in marine ecosystems ecology, research and management"
Another issue with indicators is validity. Good indicators must have an independently validated high predictive value, that is high sensitivity (high probability of indicating a significant change in the indicandum) and high specificity (low probability of wrongly indicating a change). The reliability of various health metrics has been questioned and "what combination of measurements should be used to evaluate ecosystems is a matter of current scientific debate." Most attempts to identify ecological indicators have been correlative rather than derived from prospective testing of their predictive value and the selection process for many indicators has been based upon weak evidence or has been lacking in evidence.
In some cases no reliable indicators are known: "We found no examples of invertebrates successfully used in [forest] monitoring programs. Their richness and abundance ensure that they play significant roles in ecosystem function but thwart focus on a few key species." And, "Reviews of species-based monitoring approaches reveal that no single species, nor even a group of species, accurately reflects entire communities. Understanding the response of a single species may not provide reliable predictions about a group of species even when the group is comprised of a few very similar species."
A trade-off between human health and the "health" of nature has been termed the "health paradox" and it illuminates how human values drive perceptions of ecosystem health.
Human health has benefited by sacrificing the "health" of wild ecosystems, such as dismantling and damming of wild valleys, destruction of mosquito-bearing wetlands, diversion of water for irrigation, conversion of wilderness to farmland, timber removal, and extirpation of tigers, whales, ferrets, and wolves.
There has been an acrimonious schism among conservationists and resource managers over the question of whether to "ratchet back human domination of the biosphere" or whether to embrace it. These two perspectives have been characterized as utilitarian vs protectionist.
The utilitarian view treats human health and well-being as criteria of ecosystem health. For example, destruction of wetlands to control malaria mosquitoes "resulted in an improvement in ecosystem health." The protectionist view treats humans as an invasive species: "If there was ever a species that qualified as an invasive pest, it is Homo sapiens,"
Proponents of the utilitarian view argue that "healthy ecosystems are characterized by their capability to sustain healthy human populations," and "healthy ecosystems must be economically viable," as it is "unhealthy" ecosystems that are likely to result in increases in contamination, infectious diseases, fires, floods, crop failures and fishery collapse.
Protectionists argue that privileging of human health is a conflict of interest as humans have demolished massive numbers of ecosystems to maintain their welfare, also disease and parasitism are historically normal in pre-industrial nature. Diseases and parasites promote ecosystem functioning, driving biodiversity and productivity, and parasites may constitute a significant fraction of ecosystem biomass.
The very choice of the word "health" applied to ecology has been questioned as lacking in neutrality in a BioScience article on responsible use of scientific language: "Some conservationists fear that these terms could endorse human domination of the planet … and could exacerbate the shifting cognitive baseline whereby humans tend to become accustomed to new and often degraded ecosystems and thus forget the nature of the past."
Criticism of ecosystem health largely targets the failure of proponents to explicitly distinguish the normative dimension from the descriptive dimension, and has included the following:
Alternatives have been proposed for the term ecosystem health, including more neutral language such as ecosystem status, ecosystem prognosis, and ecosystem sustainability. Another alternative to the use of a health metaphor is to "express exactly and clearly the public policy and the management objective", to employ habitat descriptors and real properties of ecosystems. An example of a policy statement is "The maintenance of viable natural populations of wildlife and ecological functions always takes precedence over any human use of wildlife." An example of a goal is "Maintain viable populations of all native species in situ." An example of a management objective is "Maintain self-sustaining populations of lake whitefish within the range of abundance observed during 1990-99."
Kurt Jax presented an ecosystem assessment format that avoids imposing a preconceived notion of normality, that avoids the muddling of normative and descriptive, and that gives serious attention to ecosystem definition. (1) Societal purposes for the ecosystem are negotiated by stakeholders, (2) a functioning ecosystem is defined with emphasis on phenomena relevant to stakeholder goals, (3) benchmark reference conditions and permissible variation of the system are established, (4) measurement variables are chosen for use as indicators, and (5) the time scale and spatial scale of assessment are decided.
Ecological health has been used as a medical term in reference to human allergy and multiple chemical sensitivity and as a public health term for programs to modify health risks (diabetes, obesity, smoking, etc.). Human health itself, when viewed in its broadest sense, is viewed as having ecological foundations. It is also an urban planning term in reference to "green" cities (composting, recycling), and has been used loosely with regard to various environmental issues, and as the condition of human-disturbed environmental sites. Ecosystem integrity implies a condition of an ecosystem exposed to a minimum of human influence. Ecohealth is the relationship of human health to the environment, including the effect of climate change, wars, food production, urbanization, and ecosystem structure and function. Ecosystem management and ecosystem-based management refer to the sustainable management of ecosystems and in some cases may employ the terms ecosystem health or ecosystem integrity as a goal.
COASST (Coastal Observation and Seabird Survey Team) is a citizen science project of the University of Washington, Seattle, WA, USA, with a vision of monitoring marine ecosystem health with the support of citizens within coastal communities. With the help of hundreds of volunteers from different locations spanning the entire U.S. west coast from Washington to California and into the northern state of Alaska, COASST assesses beach conditions and identifies and tracks any carcasses of dead seabirds found. Data on the carcass of a seabird contributes to creation of a baseline record for the death rates of various species of seabirds including which beaches birds are found at and in what density. Any irregularities can be identified and evaluated so the cause of any increased mortality can be identified. COASST believes citizen scientists partnered with trained scientists create an invaluable relationship that benefits our ability to track and understand marine ecosystems. COASST works closely with state, tribal and federal agencies, environmental organizations and community groups to help this vision of monitoring, and successfully establish marine conservation solutions.Carposinidae
Carposinidae, the "fruitworm moths", is a family of insects in the order Lepidoptera. These moths are narrower winged than Copromorphidae, with less rounded forewing tips. Males often have conspicuous patches of scales on either surface (Dugdale et al., 1999). The mouthparts are quite diagnostic, usually with prominent, upcurved "labial palps", the third segment long (especially in females), and the second segment covered in large scales. Unlike Copromorphidae, the "M2" and sometimes "M1" vein on the hindwings is absent. The relationship of Carposinidae relative to Copromorphidae needs further investigation. It is considered possible that the family is artificial, being nested within Copromorphidae (Dugdale et al., 1999). The Palearctic species have been revised by Alexey Diakonoff (1989).Centennial Biomedical Campus of North Carolina State University
The Centennial Biomedical Campus is 250 acres (1.0 km2) of property owned and operated by North Carolina State University in Raleigh, North Carolina, United States. It is located five minutes west of the NC State’s main campus and is considered part of Centennial Campus, the university’s research and educational campus footprint.
Centennial Biomedical Campus is home to NC State’s College of Veterinary Medicine (CVM). Ranked 5th among the nation's 28 colleges of veterinary medicine in the current (2007) listing by U.S. News & World Report, the College of Veterinary Medicine offers graduate courses three departments — Clinical Sciences, Molecular Biomedical Sciences, and Population Health & Pathobiology. In addition, the College focuses on six specific program areas: Companion Animal Medicine, Food Supply Medicine, Biomedical Research, Ecosystem Health, Equine Medicine, and Animal Welfare. CMV treats and diagnoses more than 20,000 patients each year. The College opened in 1981 with an initial enrollment of 40 students. The College now boasts a student enrollment of over 450.The Centennial Biomedical Campus also houses the Veterinary Teaching Hospital, a major referral center for veterinarians from throughout the Southeast, where more than 20,000 animals a year are treated.
In 2011, the Randall B. Terry, Jr. Companion Animal Veterinary Medical Center opened. The 110,000 square-foot Terry Center is expected to be a national model for excellence in companion animal medicine. Also located on campus is the 100,000-square-foot (9,300 m2) CVM Research Building, which holds the Center for Comparative Medicine and Translational Research and houses research activities in genomic sciences, gene therapy, vaccine development, creation of diagnostic tests, new cancer immuno-therapy, and genetic research to prevent inherited and acquired diseases in livestock and comparative animals.
Future plans call for the 47,500-square-foot (4,410 m2) Flexible Biosciences Lab Building (or Flex Building), which will hold “wet lab” space for corporate and institutional tenants who intend to collaborate with NC State researchers.David Waltner-Toews
David Waltner-Toews (born 1948) is a Canadian epidemiologist, essayist, poet, fiction writer, veterinarian, and a specialist in the epidemiology of food and waterborne diseases, zoonoses and ecosystem health. He is best known for his work on animal and human infectious diseases in relation to complexity.Ecological effects of biodiversity
The diversity of species and genes in ecological communities affects the functioning of these communities. These ecological effects of biodiversity in turn are affected by both climate change through enhanced greenhouse gases, aerosols and loss of land cover, and biological diversity, causing a rapid loss of biodiversity and extinctions of species and local populations. The current rate of extinction is sometimes considered a mass extinction, with current species extinction rates on the order of 100 to 1000 times as high as in the past.The two main areas where the effect of biodiversity on ecosystem function have been studied are the relationship between diversity and productivity, and the relationship between diversity and community stability. More biologically diverse communities appear to be more productive (in terms of biomass production) than are less diverse communities, and they appear to be more stable in the face of perturbations.
Also animals that inhabit an area may alter the surviving conditions by factors assimilated by climate.Ecological health
Ecological health is a term that has been used in relation to both human health and the condition of the environment.
In medicine, ecological health has been used to refer to multiple chemical sensitivity, which results from exposure to synthetic chemicals (pesticides, smoke, etc.) in the environment, hence the term ecological.
The term has also been used in medicine with respect to management of environmental factors (taxes, health insurance surcharges) that may reduce the risk of unhealthy behavior such as smoking.
As an urban planning term, ecological health refers to the "greenness" of cities, meaning composting, recycling, and energy efficiency.
With respect to broader environmental issues, ecological health has been defined as "the goal for the condition at a site that is cultivated for crops, managed for tree harvest, stocked for fish, urbanized, or otherwise intensively used."Ecological health differs from ecosystem health, the condition of ecosystems, which have particular structural and functional properties, and it differs from ecological integrity, which refers to environments with minimal human impact, although the term ecological health has also been used loosely in reference to a range of environmental issues. Human health, in its broadest sense, is recognized as having ecological foundations.The term health is intended to evoke human environmental health concerns, which are often closely related (but as a part of medicine not ecology). As with ecocide, that term assumes that ecosystems can be said to be alive (see also Gaia philosophy on this issue). While the term integrity or damage seems to take no position on this, it does assume that there is a definition of integrity that can be said to apply to ecosystems. The more political term ecological wisdom refers not only to recognition of a level of health, integrity or potential damage, but also, to a decision to do nothing (more) to harm that ecosystem or its dependents. An ecosystem has a good health if it is capable of self-restoration after suffering external disturbances. This is termed resilience.
Measures of broad ecological health, like measures of the more specific principle of biodiversity, tend to be specific to an ecoregion or even to an ecosystem. Measures that depend on biodiversity are valid indicators of ecological health as stability and productivity (good indicators of ecological health) are two ecological effects of biodiversity. Dependencies between species vary so much as to be difficult to express abstractly. However, there are a few universal symptoms of poor health or damage to system integrity:
The buildup of waste material and the proliferation of simpler life forms (bacteria, insects) that thrive on it - but no consequent population growth in those species that normally prey on them;
The loss of keystone species, often a top predator, causing smaller carnivores to proliferate, very often overstressing herbivore populations;
A higher rate of species mortality due to disease rather than predation, climate, or food scarcity;
The migration of whole species into or out of a region, contrary to established or historical patterns;
The proliferation of a bioinvader or even a monoculture where previously a more biodiverse species range existed.Some practices such as organic farming, sustainable forestry, natural landscaping, wild gardening or precision agriculture, sometimes combined into sustainable agriculture, are thought to improve or at least not to degrade ecological health, while still keeping land usable for human purposes. This is difficult to investigate as part of ecology, but is increasingly part of discourse on agricultural economics and conservation.
Ecotage is another tactic thought to be effective by some in protecting the health of ecosystems, but this is hotly disputed. In general, low confrontation and much attention to political virtues is thought to be important to maintaining ecological health, as it is far faster and simpler to destroy an ecosystem than protect it—thus wars on behalf of ecosystem integrity may simply lead to more rapid despoliation and loss due to competition.
Deforestation and the habitat destruction of deep-sea coral reef are two issues that prompt deep investigation of what makes for ecological health, and fuels a great many debates. The role of clearcuts, plantations, and trawler nets is often portrayed as negative in the extreme, held akin to the role of weapons on human life. (See Human impact on the environment.)Ecological threshold
Ecological threshold is the point at which a relatively small change or disturbance in external conditions causes a rapid change in an ecosystem. When an ecological threshold has been passed, the ecosystem may no longer be able to return to its state by means of its inherent resilience . Crossing an ecological threshold often leads to rapid change of ecosystem health. Ecological threshold represent a non-linearity of the responses in ecological or biological systems to pressures caused by human activities or natural processes.Critical load, tipping point and regime shift are examples of other closely related terms.Functional ecology
Functional ecology is a branch of ecology that focuses on the roles, or functions, that species play in the community or ecosystem in which they occur. In this approach, physiological, anatomical, and life history characteristics of the species are emphasized. The term "function" is used to emphasize certain physiological processes rather than discrete properties, describe an organism's role in a trophic system, or illustrate the effects of natural selective processes on an organism. This sub-discipline of ecology represents the crossroads between ecological patterns and the processes and mechanisms that underlie them. It focuses on traits represented in large number of species and can be measured in two ways. The first being screening, which involves measuring a trait across a number of species, and the second being empiricism, which provides quantitative relationships for the traits measured in screening. Functional ecology often emphasizes an integrative approach, using organism traits and activities to understand community dynamics and ecosystem processes, particularly in response to the rapid global changes occurring in earth's environment.
Functional ecology sits at the nexus of several disparate disciplines and serves as the unifying principle between evolutionary ecology, evolutionary biology, genetics and genomics, and traditional ecological studies, and attempts to understand species' "competitive abilities, patterns of species co-occurrence, community assembly, and the role of different traits on ecosystem functioning".International Seafood Sustainability Foundation
International Seafood Sustainability Foundation (ISSF) was formed in 2009 as a global, non-profit partnership among the tuna industry, scientists and World Wide Fund for Nature. The group states its mission is to undertake science-based initiatives for the long-term conservation and sustainable use of tuna stocks, reducing bycatch and promoting ecosystem health. Regional Fisheries Management Organizations (RFMOs) are primarily responsible for managing the world’s tuna stocks—skipjack, yellowfin and albacore tuna, the species most commonly processed for canned and shelf-stable tuna products, but their parliamentary procedures too often allow the short-term economic and political interests of nations to prevent sustainable measures from being adopted. ISSF works to ensure that effective international management practices are in place to maintain the health of all the tuna stocks.
While ISSF is not generally involved in the bluefin segment of the industry, which primarily supplies the sashimi market, the board has enacted a statement of concern urging the adoption of policies supporting proper management of bluefin in the Atlantic – one of the most threatened of all tuna stocks, and they now include bluefin populations in their Status of the Stocks Reports.Large marine ecosystem
Large marine ecosystems (LMEs) are regions of the world's oceans, encompassing coastal areas from river basins and estuaries to the seaward boundaries of continental shelves and the outer margins of the major ocean current systems. They are relatively large regions on the order of 200,000 km² or greater, characterized by distinct bathymetry, hydrography, productivity, and trophically dependent populations. Productivity in LME protected areas is generally higher than in the open ocean.
The system of LMEs has been developed by the US National Oceanic and Atmospheric Administration (NOAA) to identify areas of the oceans for conservation purposes. The objective is to use the LME concept as a tool for enabling ecosystem-based management to provide a collaborative approach to management of resources within ecologically-bounded transnational areas. This will be done in an international context and consistent with customary international law as reflected in 1982 UN Convention on the Law of the Sea.Although the LMEs cover mostly the continental margins and not the deep oceans and oceanic islands, the 66 LMEs produce about 80% of global annual marine fishery biomass. In addition, LMEs contribute $12.6 trillion in goods and services each year to the global economy. Due to their close proximity to developed coastlines, LMEs are in danger of ocean pollution, overexploitation, and coastal habitat alteration. NOAA has conducted studies of principal driving forces affecting changes in biomass yields for 33 of the 66 LMEs, which have been peer-reviewed and published in ten volumes.LME-based conservation is based on recognition that the world’s coastal ocean waters are degraded by unsustainable fishing practices, habitat degradation, eutrophication, toxic pollution, aerosol contamination, and emerging diseases, and that positive actions to mitigate these threats require coordinated actions by governments and civil society to recover depleted fish populations, restore degraded habitats and reduce coastal pollution. Five modules are considered when assessing LMEs: productivity, fish and fisheries, pollution and ecosystem health, socioeconomics, and governance. Periodically assessing the state of each module within a marine LME is encouraged to ensure maintained health of the ecosystem and future benefit to managing governments.Lobaria
Lobaria is a genus of lichens commonly known as "lung wort" or "lungmoss" as their physical shape somewhat resembles a lung, and their ecological niche is similar to that of moss.
Lobaria are unusual in that they have a three-part symbiosis, containing a fungus, and an alga (as other lichens do), but also a cyanobacterium which fixes nitrogen.
Lichen have no roots, no leaves, no flowers. The fungus provides the basic structure, known as the thallus, and is adept at drawing minerals from the surrounding environment, as well as trapping water. The alga are individuals lodged in the fungus, and produce sugar from photosynthesis, using the water which it could not retain itself.
Navajo herbalists have described this mutually symbiotic relationship as "a marriage", and moss biologist Robin Wall Kimmerer describes this "marriage" as "Lichens are a couple in which the whole is more than the sum of the parts". Their sensitivity to toxins makes them an excellent indicator of ecosystem health. They are often found in ecological climax communities, such as the few remaining remnants of old growth forest in northwestern North America and Eurasia.
Under the doctrine of signatures, Lobaria pulmonaria is sometimes used to treat respiratory infections, although there is no peer-reviewed data to support the efficacy of this treatment.
Lobaria pulmonaria has been found to have moderate anti-inflammatory effects, and strong anti-ulcerative effects in rats.Meadows Center for Water and the Environment
The Meadows Center for Water and the Environment, formerly Aquarena Springs and later the Aquarena Center, is an educational center in San Marcos, Texas, dedicated to the preservation of the unique archeological and biological resources of Spring Lake. Visitors can take glass-bottomed boat tours of Spring Lake and view live native animals and fish in the Discovery Center.
The function of the Meadows Center for Water and the Environment is to develop and promote programs and techniques for ensuring sustainable water resources for human needs, ecosystem health, and economic development. At Texas State University-San Marcos, the Meadows Center serves as an integrating mechanism for the university’s multidisciplinary departments that are involved with aquatic resources. Texas State is home to several departments and research centers engaged in critical scholarly work on water management issues. The Meadows Center at Spring Lake Hall houses the Texas Stream Team, a volunteer program that monitors the water quality of freshwater systems through the state.
Aquarena Center was established in 1994 when Southwest Texas State University purchased land previously used as an amusement park, including Spring Lake, an artificial freshwater reservoir which contains several of the San Marcos Springs.Normative science
In the applied sciences, normative science is a type of information that is developed, presented, or interpreted based on an assumed, usually unstated, preference for a particular policy or class of policies. Regular or traditional science does not presuppose a policy preference, but normative science, by definition, does. Common examples of such policy preferences are arguments that pristine ecosystems are preferable to human altered ones, that native species are preferable to nonnative species, and that higher biodiversity is preferable to lower biodiversity.In more general philosophical terms, normative science is a form of inquiry, typically involving a community of inquiry and its accumulated body of provisional knowledge, that seeks to discover good ways of achieving recognized aims, ends, goals, objectives, or purposes. Many political debates revolve around arguments over which of the many "good ways" shall be selected. For example, when presented as scientific information, words such as ecosystem health, biological integrity, and environmental degradation are typically examples of normative science because they each presuppose a policy preference and are therefore a type of policy advocacy.Photochemical Reflectance Index
The Photochemical Reflectance Index (PRI) is a reflectance measurement developed by John Gamon during his tenure as a postdoctorate fellow supervised by Christopher Field at the Carnegie Institution for Science at Stanford University. The PRI is sensitive to changes in carotenoid pigments (e.g. xanthophyll pigments) in live foliage. Carotenoid pigments are indicative of photosynthetic light use efficiency, or the rate of carbon dioxide uptake by foliage per unit energy absorbed. As such, it is used in studies of vegetation productivity and stress. Because the PRI measures plant responses to stress, it can be used to assess general ecosystem health using satellite data or other forms of remote sensing. Applications include vegetation health in evergreen shrublands, forests, and agricultural crops prior to senescence. PRI is defined by the following equation using reflectance (ρ) at 531 and 570 nm wavelength:
Some authors use
The values range from –1 to 1.Plant health
Plant health is concerned with
Ecosystem health with a special focus on plants
The control of plant pests and plant pathology, e.g. by plant disease forecasting and taking necessary countermeasures
Tree healthRedside dace
The redside dace (Clinostomus elongatus) is a species of ray-finned fish in the family Cyprinidae, found in the United States and Canada. It is unique among minnows, being the only species to routinely feed on flying insects by leaping from water. Thus, it acts as a conduit for nutrient transfers between terrestrial and aquatic environments. The species can be used as an ecosystem health indicator, as it is sensitive to environmental disturbances.State of the Environment
The term State of the Environment normally relates to an analysis of trends in the environment of a particular place. This analysis can encompass aspects such as water quality, air quality, land use, ecosystem health and function, along with social and cultural matters.University of Wisconsin–Milwaukee School of Freshwater Sciences
University of Wisconsin–Milwaukee School of Freshwater Sciences (SFS) is an academic division of the University of Wisconsin–Milwaukee focusing on freshwater research and graduate education.
Located at the edge of the Great Lakes, SFS is the only graduate school of freshwater science in the U.S. and the third in the world. It offers Doctor of Philosophy (Ph.D.) and Master of Science (M.S.) of Freshwater Sciences in Freshwater System Dynamics, Human and Ecosystem Health, Freshwater Technology and Freshwater Economics, Policy and Management.The school was built upon the Great Lakes WATER Institute, a freshwater research institution of the University of Wisconsin System administered by the Graduate School of University of Wisconsin–Milwaukee.Xerces Society
The Xerces Society is a non-profit environmental organization that focuses on the conservation of invertebrates considered to be essential to biological diversity and ecosystem health. The name is in honor of the extinct California butterfly, the Xerces blue (Glaucopsyche xerces).
The Society collaborates with federal and state agencies including the US Department of Agriculture, as well as scientists, land managers, educators, and citizens to promote invertebrate conservation, applied research, advocacy, public outreach and education.
Examples of Xerces Society activities include advocating for invertebrates and their habitats, petitioning for the designation of endangered status for applicable species such as the monarch butterfly,
and public education projects. Ongoing projects include the rehabilitation of habitat for endangered species, public education about the importance of native pollinators, and the restoration and protection of watersheds.