Restoration ecology


Restoration ecology is the scientific study and practice of renewing and restoring degraded, damaged, or destroyed ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....

s and habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...

s in the environment
Natural environment
The natural environment encompasses all living and non-living things occurring naturally on Earth or some region thereof. It is an environment that encompasses the interaction of all living species....

 by active human intervention and action, within a short time frame. Restoration ecology emerged as a separate field in ecology
Ecology is the scientific study of the relations that living organisms have with respect to each other and their natural environment. Variables of interest to ecologists include the composition, distribution, amount , number, and changing states of organisms within and among ecosystems...

 in the 1980s.

The Society for Ecological Restoration defines ecological restoration as an "intentional activity that initiates or accelerates the recovery of an ecosystem with respect to its health, integrity and sustainability". The practice of ecological restoration includes wide scope of projects including: erosion
Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

 control, reforestation
Reforestation is the natural or intentional restocking of existing forests and woodlands that have been depleted, usually through deforestation....

, the use of genetically local native species, removal of non-native species and weeds, revegetation
Revegetation is the process of replanting and rebuilding the soil of disturbed land. This may be a natural process produced by plant colonization and succession, or an artificial , accelerated process designed to repair damage to a landscape due to wildfire, mining, flood, or other cause...

 of disturbed areas, daylighting streams
Daylighting (streams)
In urban design and urban planning, daylighting is the redirection of a stream into an above-ground channel. Typically, the goal is to restore a stream of water to a more natural state...

, reintroduction of native species, as well as habitat and range improvement for targeted species. The term "ecological restoration" refers to the practice of the discipline of "restoration ecology".

The term restoration ecology is used for the academic study of the process, whereas "ecological restoration" is the term used for the actual project or process by the commercial practitioners.

The process of ecological restoration is unique in land management perspectives, in that the goal is to restore the original or historic native ecosystem of a site, utilizing local native plant species, excluding exotic plants, and to restore the ecosystem to a self-sustainable state, within a certain amount of time.

The aspect of time and performance standards as part of the definition of ecological restoration, has been controversial since the invention of this new profession-- that projects should be completed within a short amount of time, and that the percentage cover of the local native vegetation should be as close to 100% as possible, with less than 1% weed cover.

In the view of biologist E. O. Wilson
E. O. Wilson
Edward Osborne Wilson is an American biologist, researcher , theorist , naturalist and author. His biological specialty is myrmecology, the study of ants....

, "Here is the means to end the great extinction spasm. The next century will, I believe, be the era of restoration in ecology"


Land managers, laypeople, and stewards have been practicing ecological restoration or ecological management for many hundreds, if not thousands of years, yet the scientific field of "restoration ecology" was first identified and coined in the late 1980s by John Aber and William Jordan. The study of restoration ecology has only become a robust and independent scientific discipline over the last two decades, and the commercial applications of ecological restoration are still in the process of developing.

Restoration needs

There is consensus in the scientific community that the current environmental degradation and destruction of many of the Earth's biota is considerable, and is taking place on a "catastrophically short timescale". In fact, estimates of the current extinction rate are 1000 to 10,000 times the normal rate. For many people biological diversity (biodiversity
Biodiversity is the degree of variation of life forms within a given ecosystem, biome, or an entire planet. Biodiversity is a measure of the health of ecosystems. Biodiversity is in part a function of climate. In terrestrial habitats, tropical regions are typically rich whereas polar regions...

) has an intrinsic value; humans have a responsibility toward other living things, and obligations to future generations.

On a more anthropocentric level, natural ecosystems provide human society with food, fuel and timber. More fundamentally, ecosystem services
Ecosystem services
Humankind benefits from a multitude of resources and processes that are supplied by natural ecosystems. Collectively, these benefits are known as ecosystem services and include products like clean drinking water and processes such as the decomposition of wastes...

 involve the purification of air and water, detoxification and decomposition of wastes, regulation of climate, regeneration of soil fertility, and pollination of crops. Such processes have been estimated to be worth trillions of dollars annually.

Habitat (ecology)
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...

 loss is the leading cause of both species extinctions and ecosystem service decline. There are two ways to reverse this trend of habitat loss: conservation of currently viable habitat and restoration of degraded habitats.

Conservation biology and restoration ecology

With regard to biodiversity preservation, it should be noted that restoration activities are complementary to, not a substitute for, conservation efforts. Many conservation programmes, however, are predicated on historical bio-physical conditions - i.e. they are incapable of responding to global climate change, and the assemblages "locked in" that become increasingly fragile and liable to catastrophic collapse. In this sense, restoration is essential to provide new spaces for migration of habitats and their associated flora and fauna. Also, conservation biology often has organisms, and not entire ecosystems and their functions, as its focus, and therefore has limited goals and aims.

Restoration ecology, as a scientific discipline, is theoretically rooted in conservation biology
Conservation biology
Conservation biology is the scientific study of the nature and status of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction...

. While restoration ecology may be viewed as a sub-discipline of conservation biology, foundational differences exist between the disciplines' approaches, focuses and modes of inquiry.


The fundamental difference between conservation biology and restoration ecology lies in their philosophical approaches to the same problem. Conservation biology attempts to preserve and maintain existing habitat and biodiversity. In contrast, restoration ecology assumes that environmental degradation
Environmental degradation
Environmental degradation is the deterioration of the environment through depletion of resources such as air, water and soil; the destruction of ecosystems and the extinction of wildlife...

 and population declines are somewhat reversible processes. Therefore, targeted human intervention can lead to habitat and biodiversity recovery and eventual gains. This does not provide, however, an excuse for converting extremely valuable "pristine" habitat into other uses.


First, both conservation biology and restoration ecology have an unfortunate temperate terrestrial bioregion bias. This issue is probably the result of these fields developing in the geopolitical north, and both fields should attempt to reconcile this bias.

Second, perhaps because plants tend to dominate most (terrestrial) ecosystems, restoration ecology has developed a strong botanical bias, while conservation biology is more strongly zoological.

Similarly, the principal systemic levels of interest differ between the disciplines. Conservation biology has historically focused on target individuals (i.e. endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...

), and has thus concentrated on genetic and population level dynamics. Since restoration ecology is aimed at rebuilding a functioning ecosystem, a broader (i.e. community or ecosystem) perspective is necessary.

Finally, since soils define the foundation of any functional terrestrial system, restoration ecology's ecosystem-level bias has placed more emphasis on the role of soil physical and microbial processes.

Modes of inquiry

Conservation biology's focus on rare or endangered species limits the number of manipulative studies that can be performed. As a consequence, conservation studies tend to be descriptive, comparative and unreplicated. However, the highly manipulative nature of restoration ecology allows the researcher to more rigorously test hypotheses. In fact, every restorative activity is, in essence, an experimental test of what limits populations.


Disturbance is a change of environmental conditions, which interferes with the functioning of a biological system. Disturbance at a variety of spatial and temporal scales is a natural, and even essential, component of many communities.

Humans have had limited "natural" impacts on ecosystems for as long as humans have existed, however the severity and scope of our modern influences has accelerated in the last few centuries. Understanding and minimizing the differences between modern anthropogenic and "natural" disturbances is crucial to restoration ecology. For example, new forestry techniques that better imitate historical disturbances are now being implemented.

In addition, restoring a fully sustainable ecosystem often involves studying and attempting to restore a natural disturbance regime (e.g., fire ecology
Fire ecology
Fire ecology is concerned with the processes linking the natural incidence of fire in an ecosystem and the ecological effects of this fire. Many ecosystems, such as the North American prairie and chaparral ecosystems, and the South African savanna, have evolved with fire as a natural and necessary...



Ecological succession is the process by which the component species of a community changes over time. Following a disturbance, an ecosystem generally progresses from a simple level of organization (i.e. few dominant species) to a more complex community (i.e. many interdependent species) over a few generations. Depending on the severity of the disturbance, restoration often consists of initiating, assisting or accelerating ecological succession
Ecological succession
Ecological succession, is the phenomenon or process by which a community progressively transforms itself until a stable community is formed. It is a fundamental concept in ecology, and refers to more or less predictable and orderly changes in the composition or structure of an ecological community...

al processes.

In many ecosystems, communities tend to recover following mild to moderate natural and anthropogenic disturbances. Restoration in these systems involves hastening natural successional trajectories. However, a system that has experienced a more severe disturbance (i.e. physical or chemical alteration of the environment) may require intensive restorative efforts to recreate environmental conditions that favor natural successional processes.


Habitat fragmentation
Habitat fragmentation
Habitat fragmentation as the name implies, describes the emergence of discontinuities in an organism's preferred environment , causing population fragmentation...

 is the emergence of spatial discontinuities in a biological system. Through land use changes (e.g. agriculture) and "natural" disturbance, ecosystems are broken up into smaller parts. Small fragments of habitat can support only small populations and small populations are more vulnerable to extinction. Further, fragmenting ecosystems decreases interior habitat. Habitat along the edge of a fragment has a different range of environmental conditions and therefore supports different species than the interior. Fragmentation effectively reduces interior habitat and may lead to the extinction of those species which require interior habitat. Restorative projects can increase the effective size of a habitat by simply adding area or by planting habitat corridor
Wildlife corridor
A wildlife corridor or green corridor is an area of habitat connecting wildlife populations separated by human activities . This allows an exchange of individuals between populations, which may help prevent the negative effects of inbreeding and reduced genetic diversity that often occur within...

s that link and fill in the gap between two isolated fragments. Reversing the effects of fragmentation and increasing habitat connectivity are central goals of restoration ecology.

Ecosystem function

An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....

 function describes the foundational processes of natural systems, including nutrient cycles and energy fluxes. These processes are the most basic and essential components of ecosystems. An understanding of the full complexity and intricacies of these cycles is necessary to address any ecological processes that may be degraded. A functional ecosystem, that is completely self-perpetuating (i.e. no management required), is the ultimate goal of restorative efforts. Because these ecosystem
An ecosystem is a biological environment consisting of all the organisms living in a particular area, as well as all the nonliving , physical components of the environment with which the organisms interact, such as air, soil, water and sunlight....

 functions are emergent properties of the system as a whole, monitoring and management are crucial for the long-term stability of an ecosystem.

Evolving concepts

Restoration ecology, because of its highly physical nature, is an ideal testing ground for emerging community ecological principles (Bradshaw 1987). There are also the emerging concepts of inventing new and successful restoration technologies, performance standards, time frames, local genetics, and society's relationship to restoration ecology, and new ethical and religious possibilities, as future topics of discussion and debate.


Community assembly "is a framework that can unify virtually all of (community) ecology under a single conceptual umbrella". Community assembly theory attempts to explain the existence of environmentally similar sites with differing assemblages of species. It assumes that species have similar niche
Ecological niche
In ecology, a niche is a term describing the relational position of a species or population in its ecosystem to each other; e.g. a dolphin could potentially be in another ecological niche from one that travels in a different pod if the members of these pods utilize significantly different food...

 requirements, so that community formation is a product of random fluctuations from a common species pool. Essentially, if all species are fairly ecologically equivalent then random variation in colonization, migration and extinction rates, between species, drive differences in species composition between sites with comparable environmental conditions.

Stable states

Alternative stable states are discrete species compositional possibilities that may exist within a community. According to assembly theory, differences in species colonization, interspecific interactions and community establishment may result in distinct community species equilibria. A community has numerous possible compositional equilibria that are dependent on the initial assembly. That is, random fluctuations lead to a particular initial community assembly, which affects successional trajectories and the eventual species composition equilibrium.

Multiple stable states is a specific theoretical concept, where all species have equal access to a community (i.e., equal dispersal
Biological dispersal
Biological dispersal refers to species movement away from an existing population or away from the parent organism. Through simply moving from one habitat patch to another, the dispersal of an individual has consequences not only for individual fitness, but also for population dynamics, population...

 potential) and differences between communities arise simply because of the timing of each species' colonization.

These concepts are central to restoration ecology; restoring a community involves not only manipulating the timing and structure of the initial species composition, but also working toward a single desired stable state. In fact, a degraded ecosystem may be viewed as an alternative stable state under the altered environmental conditions.


The ecology of ontogeny is the study of how ecological relationships change over the lifetime of an individual. Organisms require different environmental conditions during different stages of their life-cycle. For immobile organisms (e.g. plants) the conditions necessary for germination
Germination is the process in which a plant or fungus emerges from a seed or spore, respectively, and begins growth. The most common example of germination is the sprouting of a seedling from a seed of an angiosperm or gymnosperm. However the growth of a sporeling from a spore, for example the...

 and establishment may be different from those of the adult stage. As an ecosystem is altered by anthropogenic processes the range of environmental variables may also be altered. A degraded ecosystem may not include the environmental conditions necessary for a particular stage of an organism's development. If a self-sustaining, functional ecosystem must contain environmental conditions for the perpetual reproduction of its species, restorative efforts must address the needs of organisms throughout their development.

Application of theory

Restoration is defined as the application of ecological theory to ecological restoration. However, for many reasons, this can be a challenging prospect. Here are a few examples of theory informing practice.

Soil heterogeneity effects on community heterogeneity

Spatial heterogeneity of resources can influence plant community composition, diversity and assembly trajectory. Baer et al. (2005) manipulated soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

 resource heterogeneity in a tallgrass prairie restoration
Prairie Restoration
Prairie restoration is an ecologically friendly way to restore some of the prairie land that was lost to industry, farming and commerce. For example, the U.S...

 project. They found increasing resource heterogeneity alone was insufficient to insure species diversity in situations where one species may dominate across the range of resource levels. Their findings were consistent with theory regarding the role of ecological filters on community assembly. The establishment of a single species best adapted to the physical and biological conditions can play an inordinately important role in determining community structure.

Invasion, competitive dominance and resource use

"The dynamics of invasive species may depend on their abilities to compete for resources and exploit disturbances relative to the abilities of native species". Seabloom et al. (2003) tested this concept and its implications in a California grassland restoration context. They found native grass species were able to successfully compete with invasive exotics, therefore the possibility exists of restoring an original native grassland ecosystem.

Successional trajectories

Progress along a desired successional pathway may be difficult if multiple stable states exist. Looking at over 40 years of wetland restoration data Klotzi and Gootjans (2001) argue that unexpected and undesired vegetation assemblies "may indicate environmental conditions are not suitable for target communities". Succession may move in unpredicted directions, but constricting environmental conditions within a narrow range may rein in the possible successional trajectories and increase the likelihood of a desired outcome.

See also

  • Applied ecology
    Applied ecology
    Applied ecology is a subfield within ecology, which considers the application of the science of ecology to real-world questions. It is an integrated treatment of the ecological, social, and biotechnological aspects of natural resource conservation and management. It is also called ecological or...

  • Bioremediation
    Bioremediation is the use of microorganism metabolism to remove pollutants. Technologies can be generally classified as in situ or ex situ. In situ bioremediation involves treating the contaminated material at the site, while ex situ involves the removal of the contaminated material to be treated...

  • Bush regeneration
    Bush regeneration
    Bush regeneration, a form of natural area restoration is the term used in Australia for the ecological restoration of remnant vegetation areas, such as through the minimisation of negative disturbances, both exogenous such as exotic weeds and endogenous such as erosion...

  • Conservation Effects Assessment Project
    Conservation Effects Assessment Project
    The Conservation Effects Assessment Project was established in 2002 to quantify the environmental impact of the United States Department of Agriculture's conservation program. The project focuses on how watersheds are affected. CEAP monitored fourteen benchmark watershed sites...

  • Ecological design
    Ecological design
    Ecological design was defined by Sim Van der Ryn and Stuart Cowan as "any form of design that minimizes environmentally destructive impacts by integrating itself with living processes." Ecological design is an integrative, ecologically responsible design discipline...

  • Ecological engineering
    Ecological engineering
    Ecological engineering is an emerging study of integrating ecology and engineering, concerned with the design, monitoring and construction of ecosystems...

  • Ecological triage
    Ecological triage
    Ecological triage is an approach to decision making and prioritization of ecological restoration using the concepts of triage in medical situations.-Basic principles:...

  • Environmental impact of mining: Mitigation
  • Floodplain restoration
    Floodplain restoration
    Floodplain restoration is the process of fully or partially restoring a river's floodplain to its original conditions before having been affected by the construction of levees and the draining of wetlands and marshes....

  • Groundwater remediation
    Groundwater remediation
    Groundwater remediation is the process that is used to remove pollution from groundwater. Groundwater is water present below the ground surface that saturates the pore space in the subsurface. At least one half of the population of the United States depends upon groundwater as a source of...

  • Island restoration
    Island restoration
    The ecological restoration of islands, or island restoration, is the application of the principles of ecological restoration to islands and island groups. Islands, due to their isolation, are home to many of the world's endemic species, as well as important breeding grounds for seabirds and some...

  • Land rehabilitation
    Land rehabilitation
    Land rehabilitation is the process of returning the land in a given area to some degree of its former state, after some process has resulted in its damage...

  • Reconciliation ecology
    Reconciliation ecology
    Reconciliation ecology is the branch of ecology which studies ways to encourage biodiversity in human-dominated ecosystems. Michael Rosenzweig first articulated the concept in his book Win-Win Ecology, based on the theory that there is not enough area for all of Earth’s biodiversity to be saved...

  • Riparian zone restoration
    Riparian zone restoration
    Riparian zone restoration is the ecological restoration of riparian zone habitats of streams, rivers, springs, lakes, floodplains, and other hydrologic ecologies.Riparian zones have been degraded throughout much of the world...

  • Stream restoration
    Stream restoration
    Stream restoration or river restoration, sometimes called river reclamation in the UK, describes a set of activities that help improve the environmental health of a river or stream. Improved health may be indicated by expanded habitat for diverse species and reduced stream bank erosion...

External links

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