Landscape limnology

Landscape limnology is the spatially explicit study of lakes, streams, and wetlands as they interact with freshwater, terrestrial, and human landscapes to determine the effects of pattern on ecosystem processes across temporal and spatial scales. Limnology is the study of inland water bodies inclusive of rivers, lakes, and wetlands; landscape limnology seeks to integrate all of these ecosystem types.

The terrestrial component represents spatial hierarchies of landscape features that influence which materials, whether solutes or organisms, are transported to aquatic systems; aquatic connections represent how these materials are transported; and human activities reflect features that influence how these materials are transported as well as their quantity and temporal dynamics.[1]

Foundation

The core principles or themes of landscape ecology provide the foundation for landscape limnology. These ideas can be synthesized into a set of four landscape ecology themes that are broadly applicable to any aquatic ecosystem type, and that consider the unique features of such ecosystems.

A landscape limnology framework begins with the premise of Thienemann (1925). Wiens (2002):[2] freshwater ecosystems can be considered patches. As such, the location of these patches and their placement relative to other elements of the landscape is important to the ecosystems and their processes. Therefore, the four main themes of landscape limnology are:

(1) Patch characteristics: The characteristics of a freshwater ecosystem include its physical morphometry, chemical, and biological features, as well as its boundaries. These boundaries are often more easily defined for aquatic ecosystems than for terrestrial ecosystems (e.g., shoreline, riparian zones, and emergent vegetation zone) and are often a focal-point for important ecosystem processes linking terrestrial and aquatic components.

(2) Patch context: The freshwater ecosystem is embedded in a complex terrestrial mosaic (e.g., soils, geology, and land use/cover) that has been shown to drive many within-ecosystem features and processes such as water chemistry, species richness, and primary and secondary productivity.

(3) Patch connectivity and directionality: The complex freshwater mosaic is connected to the particular patch of interest and defines the degree to which materials and organisms move across the landscape through freshwater connections. For freshwater ecosystems, these connections often display a strong directionality component that must be explicitly considered.[3][4] For example, a specific wetland can be connected through groundwater to other wetlands or lakes, or through surface water connections directly to lakes and rivers, or both, and the directionality of those connections will strongly impact the movement of nutrients and biota.

(4) Spatial scale and hierarchy: Interactions among terrestrial and freshwater elements occur at multiple spatial scales that must be considered hierarchically. The explicit integration of hierarchy into landscape limnology is important because (a) many freshwater ecosystems are hierarchically organized and controlled by processes that are hierarchically organized,[5][6][7] (b) most freshwater ecosystems are managed at multiple spatial scales, from policy set at the national level, to land management conducted at local scales, and (c) the degree of homogeneity among freshwater ecosystems can change in relation to the scale of observation.

Contributions to other fields

Findings from landscape limnology research are contributing to many facets of aquatic ecosystem research, management, and conservation. Landscape limnology is especially relevant for geographical areas with thousands of ecosystems (i.e. lake-rich regions of the world), in situations with a range of human disturbances, or when considering lakes, streams, and wetlands that are connected to other such ecosystems. For example, landscape limnology perspectives have contributed to the development of nutrient criteria for lakes,[8] formation of classification systems that can be used to monitor the health of aquatic ecosystems,[9] understanding ecosystem responses to environmental stressors,[10] or explaining biogeographic patterns of community composition.[6]

See also

Notes

  1. ^ Soranno, P.A., K.E. Webster, K.S. Cheruvelil and M.T. Bremigan. 2009. The lake landscape-context framework: linking aquatic connections, terrestrial features and human effects at multiple spatial scales. Verhandlungen Internationale Vereinigung für theoretische und angewandte Limnologie. 30:695-700
  2. ^ Wiens, J.A. 2002. Riverine landscapes: taking landscape ecology into the water. Freshwater Biology 47:501-515
  3. ^ Kling, G.W., G.W. Kipphut, M.M. Miller, and J. O’Briens. 2000. Integration of lakes and streams in a landscape perspective: the importance of material processing on spatial patterns and temporal coherence. Freshwater Biology 43: 477-497
  4. ^ Marcarelli, A.M. and W.A. Wurtsbaugh. 2007. Effects of upstream lakes and nutrient limitation on periphytic biomass and nitrogen fixation in Oligotrophic, subalpine streams. Freshwater Biology 52:2211-2225
  5. ^ Frissell, C.A., W.J. Liss, C.E. Warren & M.D. Hurley. 1986. A hierarchical framework for stream habitat classification: viewing streams in a watershed context. Environmental Management 10: 199–214
  6. ^ a b Tonn, W.M. 1990. Climate change and fish communities: A conceptual framework. Transactions of the American Fisheries Society 119:337-352
  7. ^ Poff, N.L. 1997. Landscape filters and species traits: towards mechanistic understanding and prediction in stream ecology. Journal of the North American Benthological Society 16: 391–409
  8. ^ Soranno, P.A., K.S. Cheruvelil, R.J. Stevenson, S.L. Rollins, S.W. Holden, S. Heaton, and E.K. Torng. 2008. A framework for developing ecosystem-specific nutrient criteria: Integrating biological thresholds with predictive modeling. Limnology and Oceanography 53(2): 773-787
  9. ^ Cheruvelil, K.S., P.A. Soranno, M.T. Bremigan, T. Wagner, and S.L. Martin. 2008. Grouping lakes for water quality assessment and monitoring: the roles of regionalization and spatial scale. Environmental Management. 41:425-440
  10. ^ Baker, L. A., A.T. Herlihy, P.R. Kaufmann, and J.M. Eilers. 1991. Acidic lakes and streams in the United States: The role of acidic deposition. Science (Wash.) 252: 1151-1154
Bacterivore

Bacterivores are free-living, generally heterotrophic organisms, exclusively microscopic, which obtain energy and nutrients primarily or entirely from the consumption of bacteria. Many species of amoeba are bacterivores, as well as other types of protozoans. Commonly, all species of bacteria will be prey, but spores of some species, such as Clostridium perfringens, will never be prey, because of their cellular attributes.

Copiotroph

A copiotroph is an organism found in environments rich in nutrients, particularly carbon. They are the opposite to oligotrophs, which survive in much lower carbon concentrations.

Copiotrophic organisms tend to grow in high organic substrate conditions. For example, copiotrophic organisms grow in Sewage lagoons. They grow in organic substrate conditions up to 100x higher than oligotrophs.

Decomposer

Decomposers are organisms that break down dead or decaying organisms, and in doing so, they carry out the natural process of decomposition. Like herbivores and predators, decomposers are heterotrophic, meaning that they use organic substrates to get their energy, carbon and nutrients for growth and development. While the terms decomposer and detritivore are often interchangeably used, detritivores must ingest and digest dead matter via internal processes while decomposers can directly absorb nutrients through chemical and biological processes hence breaking down matter without ingesting it. Thus, invertebrates such as earthworms, woodlice, and sea cucumbers are technically detritivores, not decomposers, since they must ingest nutrients and are unable to absorb them externally.

Depensation

In population dynamics, depensation is the effect on a population (such as a fish stock) whereby, due to certain causes, a decrease in the breeding population (mature individuals) leads to reduced production and survival of eggs or offspring. The causes may include predation levels rising per offspring (given the same level of overall predator pressure) and the allee effect, particularly the reduced likelihood of finding a mate.

Dominance (ecology)

Ecological dominance is the degree to which a taxon is more numerous than its competitors in an ecological community, or makes up more of the biomass.

Most ecological communities are defined by their dominant species.

In many examples of wet woodland in western Europe, the dominant tree is alder (Alnus glutinosa).

In temperate bogs, the dominant vegetation is usually species of Sphagnum moss.

Tidal swamps in the tropics are usually dominated by species of mangrove (Rhizophoraceae)

Some sea floor communities are dominated by brittle stars.

Exposed rocky shorelines are dominated by sessile organisms such as barnacles and limpets.

Energy Systems Language

The Energy Systems Language, also referred to as Energese, Energy Circuit Language, or Generic Systems Symbols, was developed by the ecologist Howard T. Odum and colleagues in the 1950s during studies of the tropical forests funded by the United States Atomic Energy Commission. They are used to compose energy flow diagrams in the field of systems ecology.

Feeding frenzy

In ecology, a feeding frenzy occurs when predators are overwhelmed by the amount of prey available. For example, a large school of fish can cause nearby sharks, such as the lemon shark, to enter into a feeding frenzy. This can cause the sharks to go wild, biting anything that moves, including each other or anything else within biting range. Another functional explanation for feeding frenzy is competition amongst predators. This term is most often used when referring to sharks or piranhas. It has also been used as a term within journalism.

Landscape epidemiology

Landscape epidemiology draws some of its roots from the field of landscape ecology. Just as the discipline of landscape ecology is concerned with analyzing both pattern and process in ecosystems across time and space, landscape epidemiology can be used to analyze both risk patterns and environmental risk factors. This field emerges from the theory that most vectors, hosts and pathogens are commonly tied to the landscape as environmental determinants control their distribution and abundance. In 1966, Evgeniy Pavlovsky introduced the concept of natural nidality or focality, defined by the idea that microscale disease foci are determined by the entire ecosystem. With the recent availability of new computing technologies such as geographic information systems, remote sensing, statistical methods including spatial statistics and theories of landscape ecology, the concept of landscape epidemiology has been applied analytically to a variety of disease systems, including malaria, hantavirus, Lyme disease and Chagas' disease.

Limnology

Limnology ( lim-NOL-ə-jee; from Greek λίμνη, limne, "lake" and λόγος, logos, "knowledge"), is the study of inland aquatic ecosystems.

The study of limnology includes aspects of the biological, chemical, physical, and geological characteristics and functions of inland waters (running and standing waters, fresh and saline, natural or man-made). This includes the study of lakes, reservoirs, ponds, rivers, springs, streams, wetlands, and groundwater. A more recent sub-discipline of limnology, termed landscape limnology, studies, manages, and seeks to conserve these ecosystems using a landscape perspective, by explicitly examining connections between an aquatic ecosystem and its watershed. Recently, the need to understand global inland waters as part of the Earth System created a sub-discipline called global limnology. This approach considers processes in inland waters on a global scale, like the role of inland aquatic ecosystems in global biogeochemical cycles.Limnology is closely related to aquatic ecology and hydrobiology, which study aquatic organisms and their interactions with the abiotic (non-living) environment. While limnology has substantial overlap with freshwater-focused disciplines (e.g., freshwater biology), it also includes the study of inland salt lakes.

Lithoautotroph

A lithoautotroph or chemolithoautotroph is a microbe which derives energy from reduced compounds of mineral origin. Lithoautotrophs are a type of lithotrophs with autotrophic metabolic pathways. Lithoautotrophs are exclusively microbes; macrofauna do not possess the capability to use mineral sources of energy. Most lithoautotrophs belong to the domain Bacteria, while some belong to the domain Archaea. For lithoautotrophic bacteria, only inorganic molecules can be used as energy sources. The term "Lithotroph" is from Greek lithos (λίθος) meaning "rock" and trōphos (τροφοσ) meaning "consumer"; literally, it may be read "eaters of rock". Many lithoautotrophs are extremophiles, but this is not universally so.

Lithoautotrophs are extremely specific in using their energy source. Thus, despite the diversity in using inorganic molecules in order to obtain energy that lithoautotrophs exhibit as a group, one particular lithoautotroph would use only one type of inorganic molecule to get its energy.

Mesotrophic soil

Mesotrophic soils are soils with a moderate inherent fertility. An indicator of soil fertility is its base status, which is expressed as a ratio relating the major nutrient cations (calcium, magnesium, potassium and sodium) found there to the soil's clay percentage. This is commonly expressed in hundredths of a mole of cations per kilogram of clay, i.e. cmol (+) kg−1 clay.

Mycotroph

A mycotroph is a plant that gets all or part of its carbon, water, or nutrient supply through symbiotic association with fungi. The term can refer to plants that engage in either of two distinct symbioses with fungi:

Many mycotrophs have a mutualistic association with fungi in any of several forms of mycorrhiza. The majority of plant species are mycotrophic in this sense. Examples include Burmanniaceae.

Some mycotrophs are parasitic upon fungi in an association known as myco-heterotrophy.

Organotroph

An organotroph is an organism that obtains hydrogen or electrons from organic substrates. This term is used in microbiology to classify and describe organisms based on how they obtain electrons for their respiration processes. Some organotrophs such as animals and many bacteria, are also heterotrophs. Organotrophs can be either anaerobic or aerobic.

Antonym: Lithotroph, Adjective: Organotrophic.

Overpopulation

Overpopulation occurs when a species' population exceeds the carrying capacity of its ecological niche. It can result from an increase in births (fertility rate), a decline in the mortality rate, an increase in immigration, or an unsustainable biome and depletion of resources. When overpopulation occurs, individuals limit available resources to survive.

The change in number of individuals per unit area in a given locality is an important variable that has a significant impact on the entire ecosystem.

Planktivore

A planktivore is an aquatic organism that feeds on planktonic food, including zooplankton and phytoplankton.

Population cycle

A population cycle in zoology is a phenomenon where populations rise and fall over a predictable period of time. There are some species where population numbers have reasonably predictable patterns of change although the full reasons for population cycles is one of the major unsolved ecological problems. There are a number of factors which influence population change such as availability of food, predators, diseases and climate.

Recruitment (biology)

In biology, especially marine biology, recruitment occurs when a juvenile organism joins a population, whether by birth or immigration, usually at a stage whereby the organisms are settled and able to be detected by an observer.There are two types of recruitment: closed and open.In the study of fisheries, recruitment is "the number of fish surviving to enter the fishery or to some life history stage such as settlement or maturity".

Relative abundance distribution

In the field of ecology, the relative abundance distribution (RAD) or species abundance distribution describes the relationship between the number of species observed in a field study as a function of their observed abundance. The graphs obtained in this manner are typically fitted to a Zipf–Mandelbrot law, the exponent of which serves as an index of biodiversity in the ecosystem under study.

Species homogeneity

In ecology, species homogeneity is a lack of biodiversity. Species richness is the fundamental unit in which to assess the homogeneity of an environment. Therefore, any reduction in species richness, especially endemic species, could be argued as advocating the production of a homogenous environment.

General
Producers
Consumers
Decomposers
Microorganisms
Food webs
Example webs
Processes
Defense,
counter
Ecology: Modelling ecosystems: Other components
Population
ecology
Species
Species
interaction
Spatial
ecology
Niche
Other
networks
Other
Aquatic ecosystems

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