Realized niche width

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Realized niche width is a phrase relating to ecology, is defined by the actual space that an organism inhabits and the resources it can access as a result of limiting pressures from other species (e.g. superior competitors). An organism's ecological niche is determined by the biotic and abiotic factors that make up that specific ecosystem that allow that specific organism to survive there. The width of an organism's niche is set by the range of conditions a species is able to survive in that specific environment.

Contents

Definition

The fundamental niche width of an organism refers to the theoretical range of conditions that an organism could survive and reproduce in without considering interspecific interactions. The fundamental niche exclusively considers limiting biotic and abiotic factors such as appropriate food sources and a suitable climate. The fundamental niche width often differs from the realized niche width (the areas where actually inhabited by a given species). [1] This differentiation is due to interspecific competition with other species within their ecosystem while still considering the biotic and abiotic limiting factors. A species' realized niche is usually much narrower than its fundamental niche width as it is forced to adjust its niche around the superior competing species.

The physical area where a species lives, is its habitat. The set of environmental features essential to that species' survival, is its "niche." (Ecology. Begon, Harper, Townsend)

Importance

The difference between the realized and the fundamental niche is important in understanding how interactions with a variety of different species in one environment affects the fitness of another species. This is not only important in understanding how a species functions in an ecosystem, but it is also important in determining the potential and realized success of invasive species. Invasive species could thrive or be killed off in an environment where they would theoretically be able to exist based on the presence or lack of there of different species. [2] To survive, an invasive species first has to successfully survive the journey to the new area, they then have to be able to survive in that habitat. After this, they then must to be able to successfully compete and reproduce with the other species already in the new, invaded environment. Considering these factors, not all invasive species are devastating to the new environment they inhabit as they must first overcome these other challenges before they can negatively affect their new environment.

In an organism's niche, the abiotic and biotic factors determine the ability of a species to survive; however, both the abiotic and biotic factors of that environment can be changed by that species' existence. A species' impact on its biotic environment in its niche tend to effect not only that species' ability to survive, but the other species it coexists with. Again, these changes are important in understanding the effects of invasive species in a new habitat. The ability of a new species to change an environments abiotic and biotic factors can make a previously habitable environment for a species uninhabitable. The extinction of this species can further change the biotic factors of an environment. Invasive species not only directly affect the biotic environment, but they indirectly effect this environment by affecting the species able to survive in this habitat.

Niche theory states that a species' ranges are limited by their physiological tolerances (fundamental niche) and their biotic limitations (realized niche). The survival rates of organisms facing rapid niche shifts help scientists predict the future effects of climate change and invasive species on current ecological communities. The ability of organisms to shift niches also help scientists understand community formation and speciation. Niche shifts for invasive species in their native environment differ from those in their newly invaded environment. After an invasive species is introduced to their new environment, they have to cope with new biotic factors, environmental constraints, and climate differences. These variables play a role in determining how the organism's niche will evolve. Biophysical models use links between an organism's preferred climate and their functional traits to determine where an organism could survive without taking biotic factors into account. [3]

Experiments

Barnacles

The phenomenon of fundamental and realized niches was documented by the ecologist Joseph Connell in his study of species overlap between barnacles on intertidal rocks. He observed that Chthamalus stellatus and Balanus balanoides inhabited the upper and lower strata of intertidal rocks respectively, but only Chthamalus barnacles could survive both the upper and lower strata without desiccation. The removal of Balanus barnacles from the lower strata, resulted in the Chthamalus barnacles occupying its fundamental niche (both upper and lower strata) which is much larger than its realized niche in the upper strata. [4]

This experiment was conducted on the rocky intertidal because of its accessibility and the large amount of previous research done on the species living there. Many of the species that live here are also sedentary or slow moving, making them easier to study. The different species are also more easily manipulated creating experimental and control groups that can be better studied because of their sedentary or slow moving state. The goal of Connell's experiment was to determine how much physical and biotic competition factors affected community structure in the rocky intertidal ecosystem. Vertical zonation also plays a role in determining the placement of different species in the rocky intertidal ecosystem which was previously thought to be due to the tides. [5]

Invasion biology

A study by Tingley et al. focuses on the invasion of the cane toad (Rhinella marina, formerly Bufo marinus) of Australia. Through thermal acclimation and development of improved movement functions, this toad has expanded its habitat range significantly. Evidence in this study showed that there was a difference between the toad's native niche and its invaded environment niche. A review of 180 case studies showed only 50% of invasive species went through a niche shift; however, niche changes are determined in a variety of different ways making it hard to determine how accurate this study is.

It was also proven that the toad's increased range was only observed in Australia and not in its native environment even though the same physical conditions were present in both. This means that biotic factors and/or dispersal barriers limit the toad in its native environment. Without these constraints in its invaded environment, the toad is able to fill out its fundamental niche. Determining realized niches help with developing biotic control agents for invasive species, and determining an organism's fundamental niche help scientist's conclude how well a species would be able to survive and adapt to climate change. [3]

Pathogens

Another study by Truong et al. reviewed the use of plants as the realized niche for the human pathogen Listeria monocytogenes . This paper focuses on how this pathogen uses a plant as its realized niche. The fundamental niche of this pathogen can be determined through studies where the pathogen is grown aseptically (without other pathogens); however, abiotic and biotic factors limit the ability for this pathogen to exist in nature. This study was not able to clearly determine how this pathogen and plants survive together. However, it was shown that the plants did not defend itself against the presence of this pathogen. This study did support the theory that this pathogen can use plant nutrients to survive and multiply if the plants environment and competition allows. However, more comprehensive research will need to be conducted to determine this pathogen's realized niche. This study further shows how determining an organism's realized niche can help understand this human pathogen's natural history. [6]

Related Research Articles

Abiotic stress is the negative impact of non-living factors on the living organisms in a specific environment. The non-living variable must influence the environment beyond its normal range of variation to adversely affect the population performance or individual physiology of the organism in a significant way.

<span class="mw-page-title-main">Ecosystem</span> Community of living organisms together with the nonliving components of their environment

An ecosystem consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the system through photosynthesis and is incorporated into plant tissue. By feeding on plants and on one another, animals play an important role in the movement of matter and energy through the system. 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.

<span class="mw-page-title-main">Ecological niche</span> Fit of a species living under specific environmental conditions

In ecology, a niche is the match of a species to a specific environmental condition. It describes how an organism or population responds to the distribution of resources and competitors and how it in turn alters those same factors. "The type and number of variables comprising the dimensions of an environmental niche vary from one species to another [and] the relative importance of particular environmental variables for a species may vary according to the geographic and biotic contexts".

This glossary of ecology is a list of definitions of terms and concepts in ecology and related fields. For more specific definitions from other glossaries related to ecology, see Glossary of biology, Glossary of evolutionary biology, and Glossary of environmental science.

Ecotopes are the smallest ecologically distinct landscape features in a landscape mapping and classification system. As such, they represent relatively homogeneous, spatially explicit landscape functional units that are useful for stratifying landscapes into ecologically distinct features for the measurement and mapping of landscape structure, function and change.

In biology and ecology, abiotic components or abiotic factors are non-living chemical and physical parts of the environment that affect living organisms and the functioning of ecosystems. Abiotic factors and the phenomena associated with them underpin biology as a whole. They affect a plethora of species, in all forms of environmental conditions, such as marine or land animals. Humans can make or change abiotic factors in a species' environment. For instance, fertilizers can affect a snail's habitat, or the greenhouse gases which humans utilize can change marine pH levels.

<span class="mw-page-title-main">Aquatic ecosystem</span> Ecosystem in a body of water

An aquatic ecosystem is an ecosystem found in and around a body of water, in contrast to land-based terrestrial ecosystems. Aquatic ecosystems contain communities of organisms—aquatic life—that are dependent on each other and on their environment. The two main types of aquatic ecosystems are marine ecosystems and freshwater ecosystems. Freshwater ecosystems may be lentic ; lotic ; and wetlands.

Ecologically, invader potential is the qualitative and quantitative measures of a given invasive species probability to invade a given ecosystem. This is often seen through climate matching. There are many reasons why a species may invade a new area. The term invader potential may also be interchangeable with invasiveness. Invader potential is a large threat to global biodiversity. It has been shown that there is an ecosystem function loss due to the introduction of species in areas they are not native to.

<span class="mw-page-title-main">Biogeomorphology</span> Study of interactions between organisms and the development of landforms

Biogeomorphology and ecogeomorphology are the study of interactions between organisms and the development of landforms, and are thus fields of study within geomorphology and ichnology. Organisms affect geomorphic processes in a variety of ways. For example, trees can reduce landslide potential where their roots penetrate to underlying rock, plants and their litter inhibit soil erosion, biochemicals produced by plants accelerate the chemical weathering of bedrock and regolith, and marine animals cause the bioerosion of coral. The study of the interactions between marine biota and coastal landform processes is called coastal biogeomorphology.

<span class="mw-page-title-main">Intertidal ecology</span>

Intertidal ecology is the study of intertidal ecosystems, where organisms live between the low and high tide lines. At low tide, the intertidal is exposed whereas at high tide, the intertidal is underwater. Intertidal ecologists therefore study the interactions between intertidal organisms and their environment, as well as between different species of intertidal organisms within a particular intertidal community. The most important environmental and species interactions may vary based on the type of intertidal community being studied, the broadest of classifications being based on substrates—rocky shore and soft bottom communities.

Soil ecology is the study of the interactions among soil organisms, and between biotic and abiotic aspects of the soil environment. It is particularly concerned with the cycling of nutrients, formation and stabilization of the pore structure, the spread and vitality of pathogens, and the biodiversity of this rich biological community.

<span class="mw-page-title-main">Species distribution</span> Geographical area in which a species can be found

Species distribution, or speciesdispersion, is the manner in which a biological taxon is spatially arranged. The geographic limits of a particular taxon's distribution is its range, often represented as shaded areas on a map. Patterns of distribution change depending on the scale at which they are viewed, from the arrangement of individuals within a small family unit, to patterns within a population, or the distribution of the entire species as a whole (range). Species distribution is not to be confused with dispersal, which is the movement of individuals away from their region of origin or from a population center of high density.

The following outline is provided as an overview of and topical guide to ecology:

<span class="mw-page-title-main">Community (ecology)</span> Associated populations of species in a given area

In ecology, a community is a group or association of populations of two or more different species occupying the same geographical area at the same time, also known as a biocoenosis, biotic community, biological community, ecological community, or life assemblage. The term community has a variety of uses. In its simplest form it refers to groups of organisms in a specific place or time, for example, "the fish community of Lake Ontario before industrialization".

Biotic stress is stress that occurs as a result of damage done to an organism by other living organisms, such as bacteria, viruses, fungi, parasites, beneficial and harmful insects, weeds, and cultivated or native plants. It is different from abiotic stress, which is the negative impact of non-living factors on the organisms such as temperature, sunlight, wind, salinity, flooding and drought. The types of biotic stresses imposed on an organism depend the climate where it lives as well as the species' ability to resist particular stresses. Biotic stress remains a broadly defined term and those who study it face many challenges, such as the greater difficulty in controlling biotic stresses in an experimental context compared to abiotic stress.

<span class="mw-page-title-main">Species distribution modelling</span> Algorithmic prediction of the distribution of a species across geographic space

Species distribution modelling (SDM), also known as environmental(or ecological) niche modelling (ENM), habitat modelling, predictive habitat distribution modelling, and range mapping uses computer algorithms to predict the distribution of a species across geographic space and time using environmental data. The environmental data are most often climate data (e.g. temperature, precipitation), but can include other variables such as soil type, water depth, and land cover. SDMs are used in several research areas in conservation biology, ecology and evolution. These models can be used to understand how environmental conditions influence the occurrence or abundance of a species, and for predictive purposes (ecological forecasting). Predictions from an SDM may be of a species’ future distribution under climate change, a species’ past distribution in order to assess evolutionary relationships, or the potential future distribution of an invasive species. Predictions of current and/or future habitat suitability can be useful for management applications (e.g. reintroduction or translocation of vulnerable species, reserve placement in anticipation of climate change).

Forest pathology is the research of both biotic and abiotic maladies affecting the health of a forest ecosystem, primarily fungal pathogens and their insect vectors. It is a subfield of forestry and plant pathology.

Ecological inheritance occurs when organisms inhabit a modified environment that a previous generation created; it was first described in Odling-Smee (1988) and Odling-Smee et al. (1996) as a consequence of niche construction. Standard evolutionary theory focuses on the influence that natural selection and genetic inheritance has on biological evolution, when individuals that survive and reproduce also transmit genes to their offspring. If offspring do not live in a modified environment created by their parents, then niche construction activities of parents do not affect the selective pressures of their offspring. However, when niche construction affects multiple generations, ecological inheritance acts a inheritance system different than genetic inheritance.

<span class="mw-page-title-main">Invasibility</span>

Alien species, or species that are not native, invade habitats and alter ecosystems around the world. Invasive species are only considered invasive if they are able to survive and sustain themselves in their new environment. A habitat and the environment around it has natural flaws that make them vulnerable to invasive species. The level of vulnerability of a habitat to invasions from outside species is defined as its invasibility. One must be careful not to get this confused with invasiveness, which relates to the species itself and its ability to invade an ecosystem.

<span class="mw-page-title-main">Climate change and invasive species</span> Increase of invasive organisms caused by climate change

Climate change and invasive species refers to the process of the environmental destabilization caused by climate change. This environmental change facilitates the spread of invasive species — species that are not historically found in a certain region, and often bring about a negative impact to that region's native species. This complex relationship is notable because climate change and invasive species are also considered by the USDA to be two of the top four causes of global biodiversity loss.

References

  1. Ricklefs, Robert; Relyea, Rick (2014). Ecology The Economy of Nature. W.H Freeman and Company. p. 249. ISBN   978-1-4641-3681-8.
  2. Lounibos, L. Philip; Juliano, Steven A. (2018-08-01). "Where vectors collide: the importance of mechanisms shaping the realized niche for modeling ranges of invasive Aedes mosquitoes". Biological Invasions. 20 (8): 1913–1929. doi:10.1007/s10530-018-1674-7. ISSN   1573-1464. PMC   6133263 . PMID   30220875.
  3. 1 2 Tingley, Reid; Vallinoto, Marcelo; Sequeira, Fernando; Kearney, Michael R. (2014-07-15). "Realized niche shift during a global biological invasion". Proceedings of the National Academy of Sciences. 111 (28): 10233–10238. Bibcode:2014PNAS..11110233T. doi: 10.1073/pnas.1405766111 . ISSN   0027-8424. PMC   4104887 . PMID   24982155.
  4. "Competition". South China Normal University School of Life Sciences. Archived from the original on 10 June 2017. Retrieved 29 January 2014.
  5. Connell, Joseph H. (1972). "Community Interactions on Marine Rocky Intertidal Shores" . Annual Review of Ecology and Systematics. 3: 169–192. doi:10.1146/annurev.es.03.110172.001125. ISSN   0066-4162. JSTOR   2096846.
  6. Truong, Hoai‐Nam; Garmyn, Dominique; Gal, Laurent; Fournier, Carine; Sevellec, Yann; Jeandroz, Sylvain; Piveteau, Pascal (December 2021). "Plants as a realized niche for Listeria monocytogenes". MicrobiologyOpen. 10 (6): e1255. doi:10.1002/mbo3.1255. ISSN   2045-8827. PMC   8710918 . PMID   34964288.