Information

From Wikipedia, the free encyclopedia

The ASCII codes for the word "Wikipedia" represented in binary, the numeral system most commonly used for encoding textual computer information

 

Information can be thought of as the resolution of uncertainty; it is that which answers the question of "what an entity is" and thus defines both its essence and nature of its characteristics. It is associated with data, as data represents values attributed to parameters, and information is data in context and with meaning attached. Information relates also to knowledge, as knowledge signifies understanding of an abstract or concrete concept.

In terms of communication, information is expressed either as the content of a message or through direct or indirect observation. That which is perceived can be construed as a message in its own right, and in that sense, information is always conveyed as the content of a message.

Information can be encoded into various forms for transmission and interpretation (for example, information may be encoded into a sequence of signs, or transmitted via a signal). It can also be encrypted for safe storage and communication.

The uncertainty of an event is measured by its probability of occurrence and is inversely proportional to that. The more uncertain an event, the more information is required to resolve uncertainty of that event. The bit is a typical unit of information, but other units such as the nat may be used. For example, the information encoded in one "fair" coin flip is log₂(2/1) = 1 bit, and in two fair coin flips is log₂(4/1) = 2 bits.

The concept of information has different meanings in different contexts. Thus the concept becomes related to notions of constraint, communication, control, data, form, education, knowledge, meaning, understanding, mental stimuli, pattern, perception, representation, and entropy.

Etymology

The English word apparently derives from the Latin stem (information-) of the nominative (informatio): this noun derives from the verb informare (to inform) in the sense of "to give form to the mind", "to discipline", "instruct", "teach". Inform itself comes (via French informer) from the Latin verb informare, which means to give form, or to form an idea of. Furthermore, Latin itself already contained the word informatio meaning concept or idea, but the extent to which this may have influenced the development of the word information in English is not clear. 

The ancient Greek word for form was μορφή (morphe; cf. morph) and also εἶδος (eidos) "kind, idea, shape, set", the latter word was famously used in a technical philosophical sense by Plato (and later Aristotle) to denote the ideal identity or essence of something (see Theory of Forms). 'Eidos' can also be associated with thought, proposition, or even concept. 

The ancient Greek word for information is πληροφορία, which transliterates (plērophoria) from πλήρης (plērēs) "fully" and φέρω (phorein) frequentative of (pherein) to carry through. It literally means "bears fully" or "conveys fully". In modern Greek the word Πληροφορία is still in daily use and has the same meaning as the word information in English. In addition to its primary meaning, the word Πληροφορία as a symbol has deep roots in Aristotle's semiotic triangle. In this regard it can be interpreted to communicate information to the one decoding that specific type of sign. This is something that occurs frequently with the etymology of many words in ancient and modern Greek where there is a very strong denotative relationship between the signifier, e.g. the word symbol that conveys a specific encoded interpretation, and the signified, e.g. a concept whose meaning the interpreter attempts to decode. 

In English, “information” is an uncountable mass noun.

Information theory approach

In information theory, information is taken as an ordered sequence of symbols from an alphabet, say an input alphabet χ, and an output alphabet ϒ. Information processing consists of an input-output function that maps any input sequence from χ into an output sequence from ϒ. The mapping may be probabilistic or deterministic. It may have memory or be memoryless.

As sensory input

Often information can be viewed as a type of input to an organism or system. Inputs are of two kinds; some inputs are important to the function of the organism (for example, food) or system (energy) by themselves. In his book Sensory Ecology Dusenbery called these causal inputs. Other inputs (information) are important only because they are associated with causal inputs and can be used to predict the occurrence of a causal input at a later time (and perhaps another place). Some information is important because of association with other information but eventually there must be a connection to a causal input. In practice, information is usually carried by weak stimuli that must be detected by specialized sensory systems and amplified by energy inputs before they can be functional to the organism or system. For example, light is mainly (but not only, e.g. plants can grow in the direction of the lightsource) a causal input to plants but for animals it only provides information. The colored light reflected from a flower is too weak to do much photosynthetic work but the visual system of the bee detects it and the bee's nervous system uses the information to guide the bee to the flower, where the bee often finds nectar or pollen, which are causal inputs, serving a nutritional function.

As representation and complexity

The cognitive scientist and applied mathematician Ronaldo Vigo argues that information is a concept that requires at least two related entities to make quantitative sense. These are, any dimensionally defined category of objects S, and any of its subsets R. R, in essence, is a representation of S, or, in other words, conveys representational (and hence, conceptual) information about S. Vigo then defines the amount of information that R conveys about S as the rate of change in the complexity of S whenever the objects in R are removed from S. Under "Vigo information", pattern, invariance, complexity, representation, and information—five fundamental constructs of universal science—are unified under a novel mathematical framework. Among other things, the framework aims to overcome the limitations of Shannon-Weaver information when attempting to characterize and measure subjective information.

As an influence that leads to transformation

Information is any type of pattern that influences the formation or transformation of other patterns. In this sense, there is no need for a conscious mind to perceive, much less appreciate, the pattern. Consider, for example, DNA. The sequence of nucleotides is a pattern that influences the formation and development of an organism without any need for a conscious mind. One might argue though that for a human to consciously define a pattern, for example a nucleotide, naturally involves conscious information processing. 

Systems theory at times seems to refer to information in this sense, assuming information does not necessarily involve any conscious mind, and patterns circulating (due to feedback) in the system can be called information. In other words, it can be said that information in this sense is something potentially perceived as representation, though not created or presented for that purpose. For example, Gregory Bateson defines "information" as a "difference that makes a difference".

If, however, the premise of "influence" implies that information has been perceived by a conscious mind and also interpreted by it, the specific context associated with this interpretation may cause the transformation of the information into knowledge. Complex definitions of both "information" and "knowledge" make such semantic and logical analysis difficult, but the condition of "transformation" is an important point in the study of information as it relates to knowledge, especially in the business discipline of knowledge management. In this practice, tools and processes are used to assist a knowledge worker in performing research and making decisions, including steps such as:

• Review information to effectively derive value and meaning
• Reference metadata if available
• Establish relevant context, often from many possible contexts
• Derive new knowledge from the information
• Make decisions or recommendations from the resulting knowledge

Stewart (2001) argues that transformation of information into knowledge is critical, lying at the core of value creation and competitive advantage for the modern enterprise. 

The Danish Dictionary of Information Terms argues that information only provides an answer to a posed question. Whether the answer provides knowledge depends on the informed person. So a generalized definition of the concept should be: "Information" = An answer to a specific question".

When Marshall McLuhan speaks of media and their effects on human cultures, he refers to the structure of artifacts that in turn shape our behaviors and mindsets. Also, pheromones are often said to be "information" in this sense.

As a property in physics

Information has a well-defined meaning in physics. In 2003 J. D. Bekenstein claimed that a growing trend in physics was to define the physical world as being made up of information itself (and thus information is defined in this way) (see Digital physics). Examples of this include the phenomenon of quantum entanglement, where particles can interact without reference to their separation or the speed of light. Material information itself cannot travel faster than light even if that information is transmitted indirectly. This could lead to all attempts at physically observing a particle with an "entangled" relationship to another being slowed down, even though the particles are not connected in any other way other than by the information they carry.

The mathematical universe hypothesis suggests a new paradigm, in which virtually everything, from particles and fields, through biological entities and consciousness, to the multiverse itself, could be described by mathematical patterns of information. By the same token, the cosmic void can be conceived of as the absence of material information in space (setting aside the virtual particles that pop in and out of existence due to quantum fluctuations, as well as the gravitational field and the dark energy). Nothingness can be understood then as that within which no matter, energy, space, time, or any other type of information could exist, which would be possible if symmetry and structure break within the manifold of the multiverse (i.e. the manifold would have tears or holes). Physical information exists beyond event horizons, since astronomical observations show that, due to the expansion of the universe, distant objects continue to pass the cosmological horizon, as seen from a present time, local observer point of view.

Another link is demonstrated by the Maxwell's demon thought experiment. In this experiment, a direct relationship between information and another physical property, entropy, is demonstrated. A consequence is that it is impossible to destroy information without increasing the entropy of a system; in practical terms this often means generating heat. Another more philosophical outcome is that information could be thought of as interchangeable with energy. Toyabe et al. experimentally showed in nature that information can be converted into work. Thus, in the study of logic gates, the theoretical lower bound of thermal energy released by an AND gate is higher than for the NOT gate (because information is destroyed in an AND gate and simply converted in a NOT gate). Physical information is of particular importance in the theory of quantum computers. 

In thermodynamics, information is any kind of event that affects the state of a dynamic system that can interpret the information.

The application of information study

The information cycle (addressed as a whole or in its distinct components) is of great concern to information technology, information systems, as well as information science. These fields deal with those processes and techniques pertaining to information capture (through sensors) and generation (through computation, formulation or composition), processing (including encoding, encryption, compression, packaging), transmission (including all telecommunication methods), presentation (including visualization / display methods), storage (such as magnetic or optical, including holographic methods), etc. 

Information visualization (shortened as InfoVis) depends on the computation and digital representation of data, and assists users in pattern recognition and anomaly detection.

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  Partial map of the Internet, with nodes representing IP addresses
  
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  Galactic (including dark) matter distribution in a cubic section of the Universe
  
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  Information embedded in an abstract mathematical object with symmetry breaking nucleus
  
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  Visual representation of a strange attractor, with converted data of its fractal structure
  

Information security (shortened as InfoSec) is the ongoing process of exercising due diligence to protect information, and information systems, from unauthorized access, use, disclosure, destruction, modification, disruption or distribution, through algorithms and procedures focused on monitoring and detection, as well as incident response and repair. 

Information analysis is the process of inspecting, transforming, and modelling information, by converting raw data into actionable knowledge, in support of the decision-making process. 

Information quality (shortened as InfoQ) is the potential of a dataset to achieve a specific (scientific or practical) goal using a given empirical analysis method.

Information communication represents the convergence of informatics, telecommunication and audio-visual media & content.

Technologically mediated information

It is estimated that the world's technological capacity to store information grew from 2.6 (optimally compressed) exabytes in 1986 – which is the informational equivalent to less than one 730-MB CD-ROM per person (539 MB per person) – to 295 (optimally compressed) exabytes in 2007. This is the informational equivalent of almost 61 CD-ROM per person in 2007.

The world’s combined technological capacity to receive information through one-way broadcast networks was the informational equivalent of 174 newspapers per person per day in 2007.

The world's combined effective capacity to exchange information through two-way telecommunication networks was the informational equivalent of 6 newspapers per person per day in 2007.

As of 2007, an estimated 90% of all new information is digital, mostly stored on hard drives.

As records

Records are specialized forms of information. Essentially, records are information produced consciously or as by-products of business activities or transactions and retained because of their value. Primarily, their value is as evidence of the activities of the organization but they may also be retained for their informational value. Sound records management ensures that the integrity of records is preserved for as long as they are required.

The international standard on records management, ISO 15489, defines records as "information created, received, and maintained as evidence and information by an organization or person, in pursuance of legal obligations or in the transaction of business". The International Committee on Archives (ICA) Committee on electronic records defined a record as, "recorded information produced or received in the initiation, conduct or completion of an institutional or individual activity and that comprises content, context and structure sufficient to provide evidence of the activity".

Records may be maintained to retain corporate memory of the organization or to meet legal, fiscal or accountability requirements imposed on the organization. Willis expressed the view that sound management of business records and information delivered "...six key requirements for good corporate governance...transparency; accountability; due process; compliance; meeting statutory and common law requirements; and security of personal and corporate information."

Semiotics

Michael Buckland has classified "information" in terms of its uses: "information as process", "information as knowledge", and "information as thing".

Beynon-Davies explains the multi-faceted concept of information in terms of signs and signal-sign systems. Signs themselves can be considered in terms of four inter-dependent levels, layers or branches of semiotics: pragmatics, semantics, syntax, and empirics. These four layers serve to connect the social world on the one hand with the physical or technical world on the other.

Pragmatics is concerned with the purpose of communication. Pragmatics links the issue of signs with the context within which signs are used. The focus of pragmatics is on the intentions of living agents underlying communicative behaviour. In other words, pragmatics link language to action.

Semantics is concerned with the meaning of a message conveyed in a communicative act. Semantics considers the content of communication. Semantics is the study of the meaning of signs - the association between signs and behaviour. Semantics can be considered as the study of the link between symbols and their referents or concepts – particularly the way that signs relate to human behavior. 

Syntax is concerned with the formalism used to represent a message. Syntax as an area studies the form of communication in terms of the logic and grammar of sign systems. Syntax is devoted to the study of the form rather than the content of signs and sign-systems. 

Nielsen (2008) discusses the relationship between semiotics and information in relation to dictionaries. He introduces the concept of lexicographic information costs and refers to the effort a user of a dictionary must make to first find, and then understand data so that they can generate information. 

Communication normally exists within the context of some social situation. The social situation sets the context for the intentions conveyed (pragmatics) and the form of communication. In a communicative situation intentions are expressed through messages that comprise collections of inter-related signs taken from a language mutually understood by the agents involved in the communication. Mutual understanding implies that agents involved understand the chosen language in terms of its agreed syntax (syntactics) and semantics. The sender codes the message in the language and sends the message as signals along some communication channel (empirics). The chosen communication channel has inherent properties that determine outcomes such as the speed at which communication can take place, and over what distance.

Forest restoration

From Wikipedia, the free encyclopedia

 

In the 1980s, conservation organizations warned that, once destroyed, tropical forests could never be restored. Thirty years of restoration research now challenge this: a) This site in Doi Suthep-Pui National Park, N. Thailand was deforested, over-cultivated and then burnt. The black tree stump was one of the original forest trees. Local people teamed up with scientists to repair their watershed.

 

Fire prevention, nurturing natural regeneration and planting framework tree species resulted in trees growing above the weed canopy within a year.

 

After 12 years, the restored forest overwhelmed the black tree stump.

Forest restoration is defined as “actions to re-instate ecological processes, which accelerate recovery of forest structure, ecological functioning and biodiversity levels towards those typical of climax forest” i.e. the end-stage of natural forest succession. Climax forests are relatively stable ecosystems that have developed the maximum biomass, structural complexity and species diversity that are possible within the limits imposed by climate and soil and without continued disturbance from humans. Climax forest is therefore the target ecosystem, which defines the ultimate aim of forest restoration. Since climate is a major factor that determines climax forest composition, global climate change may result in changing restoration aims.

Forest restoration is a specialized form of reforestation, but it differs from conventional tree plantations in that its primary goals are biodiversity recovery and environmental protection.

Scope

Forest restoration may include simply protecting remnant vegetation (fire prevention, cattle exclusion etc.) or more active interventions to accelerate natural regeneration, as well as tree planting and/or sowing seeds (direct seeding) of species characteristic of the target ecosystem. Tree species planted (or encouraged to establish) are those that are typical of, or provide a critical ecological function in, the target ecosystem. However, wherever people live in or near restoration sites, restoration projects often include economic species amongst the planted trees, to yield subsistence or cash-generating products. 

Forest restoration is an inclusive process, which depends on collaboration among a wide range of stakeholders including local communities, government officials, non-government organizations, scientists and funding agencies. Its ecological success is measured in terms of increased biological diversity, biomass, primary productivity, soil organic matter and water-holding capacity, as well as the return of rare and keystone species, characteristic of the target ecosystem. Economic indices of success include the value of forest products and ecological services generated (e.g. watershed protection, carbon storage etc.), which ultimately contribute towards poverty reduction. Payments for such ecological services (PES) and forest products can provide strong incentives for local people to implement restoration projects.

Opportunities for forest restoration

Demonstration forest restoration plot, SUNY-ESF, Syracuse, NY

 

Forest restoration is appropriate wherever biodiversity recovery is one of the main goals of reforestation, such as for wildlife conservation, environmental protection, eco-tourism or to supply a wide variety of forest products to local communities. Forests can be restored in a wide range of circumstances, but degraded sites within protected areas are a high priority, especially where some climax forest remains as a seed source within the landscape. Even in protected areas, there are often large deforested sites: logged over areas or sites formerly cleared for agriculture. If protected areas are to act as Earth’s last wildlife refuges, restoration of such areas will be needed.

Many restoration projects are now being implemented under the umbrella of “forest landscape restoration” (FLR), defined as a “planned process to regain ecological integrity and enhance human well-being in deforested or degraded landscapes”. FLR recognizes that forest restoration has social and economic functions. It aims to achieve the best possible compromise between meeting both conservation goals and the needs of rural communities. As human pressure on landscapes increases, forest restoration will most commonly be practiced within a mosaic of other forms of forest management, to meet the economic needs of local people. 

A recent focal area for forest restoration efforts is within the urban context, where both people and biodiversity will benefit, however this context presents unique challenges.

Natural regeneration

Tree planting is not always essential to restore forest ecosystems. A lot can be achieved by studying how forests regenerate naturally, identifying the factors that limit regeneration and devising methods to overcome them. These can include weeding and adding fertilizer around natural tree seedlings, preventing fire, removing cattle and so on. This is "accelerated" or "assisted" natural regeneration. It is simple and cost-effective, but it can only operate on trees that are already present, mostly light-loving pioneer species. Such tree species are not usually those that comprise climax forests, but they can foster recolonization of the site by shade-tolerant climax forest tree species, via natural seed dispersal from remnant forest. Because this is a slow process, biodiversity recovery can usually be accelerated by planting some climax forest tree species, especially large-seeded, poorly dispersed species. It is not feasible to plant all the tree species that may have formerly grown in the original primary forest and it is usually unnecessary to do so, if the framework species method can be used.

Post-fire regeneration

In large parts of the world, forest fires cover a heavy toll on forests. That can be because of provoked deforestation in order to substitute forests by crop areas, or in dry areas, because of wild fires occurring naturally or intentionally. A whole section of forest landscape restoration in linked to this particular problem, as in many cases, the net loss of ecosystem value is very high and can open the drop to an accelerated further degradation of the soil conditions through erosion and desertification. This indeed has dire consequences on both the quality of the habitats and their related fauna. Nevertheless, in some specific cases, wild fires do actually allow to increase the biodiversity index of the burnt area, in which case the Forest Restoration Strategies tend to look for a different land-use.

Forest restoration projects

Ashland Forest Resiliency Stewardship Project

The Ashland Forest Resiliency Stewardship Project (AFR) is a decade long, science-based project launched in 2010 with the intent of reducing severe wildfire risk, but also protecting water quality, old-growth forest, wildlife, people, property, and the overall quality of life within the Ashland watershed. The primary stakeholders in this cooperative restoration effort are the U.S. Forest Service, the City of Ashland, Lomaktsi Restoration Project, and the Nature Conservancy. The project was launched with initial funding from the Economic Recovery stimulus, and has more recently received funding from the Forest Service Hazardous Fuels program and the Joint Chiefs Landscape Restoration Partnerships program to back the project through 2016.

Located in the dry forests of southern Oregon, the threat of wildfire is a reality for land managers and property owners alike. The boundaries of the city of Ashland intersect with the surrounding forest in what is referred to as the wildland-urban interface (WUI). Historically, the forests of this region experienced a relatively frequent fire return interval, which prevented buildup of heavy fuel loads. A century of fire exclusion and suppression on federal lands in the Pacific Northwest has led to increased forest density and fuel loads, and thus a more persistent threat of devastating wildfire.

The AFR project has implemented restoration techniques and prescriptions that aim to replicate the process of ecological succession in dry, mixed-conifer forests of the Pacific Northwest. The approach involves a combination of fuels reduction, thinning small-diameter trees, and carrying out prescribed burns. Priority is given to maintaining ecological function and complexity by retaining the largest and oldest trees, preserving wildlife habitat and riparian areas, and protecting erodible soils and maintaining slope stability. 

Since its inception in 2010, the AFR project has completed restoration work on 4,000 of the 7,600 acres slated for the project. The project has provided educational experience to over 2,000 students and has benefitted the local community by creating jobs and providing workforce training. Currently, helicopter logging operations are thinning 1,100 acres of the watershed while controlled burning operations take place as air quality conditions allow.

Forest landscape restoration

Forest landscape restoration (FLR) is defined as “a planned process to regain ecological integrity and enhance human well-being in deforested or degraded landscapes”. It comprises tools and procedures to integrate site-level forest restoration actions with desirable landscape-level objectives, which are decided upon via various participatory mechanisms among stakeholders. The concept has grown out of collaboration among some of the world's major international conservation organizations including the International Union for Conservation of Nature (IUCN), the World Wide Fund for Nature (WWF), the World Resources Institute and the International Tropical Timber Organization (ITTO).

Aims

The concept of FLR was conceived to bring about compromises between meeting the needs of both humans and wildlife, by restoring a range of forest functions at the landscape level. It includes actions to strengthen the resilience and ecological integrity of landscapes and thereby keep future management options open. The participation of local communities is central to the concept, because they play a critical role in shaping the landscape and gain significant benefits from restored forest resources. Therefore, FLR activities are inclusive and participatory.

Desirable outcomes

The desirable outcomes of an FLR program usually comprise a combination of the following, depending on local needs and aspirations:

• identification of the root causes of forest degradation and prevention of further deforestation,
• positive engagement of people in the planning of forest restoration, resolution of land-use conflicts and agreement on benefit-sharing systems,
• compromises over land-use trade-offs that are acceptable to the majority of stakeholders,
• a repository of biological diversity of both local and global value,
• delivery of a range of utilitarian benefits to local communities including:
  • a reliable supply of clean water,
  • environmental protection particularly watershed services (e.g. reduced soil erosion, lower landslide risk, flood/drought mitigation etc.),
  • a sustainable supply of a diverse range of forest products including foods, medicines, firewood etc.,
  • monetary income from various sources e.g. ecotourism, carbon trading via the REDD+ mechanism and from payments for other environmental services (PES)

Activities

FLR combines several existing principles and techniques of development, conservation and natural resource management, such as landscape character assessment, participatory rural appraisal, adaptive management etc. within a clear and consistent evaluation and learning framework. An FLR program may comprise various forestry practices on different sites within the landscape, depending on local environmental and socioeconomic factors. These may include protection and management of secondary and degraded primary forests, standard forest restoration techniques such as "assisted" or "accelerated" natural regeneration (ANR) and the planting of framework tree species to restore degraded areas, as well as conventional tree plantations and agroforestry systems to meet more immediate monetary needs.

 

The IUCN hosts the Global Partnership on Forest Landscape Restoration, which co-ordinates development of the concept around the world. 

In 2014, the Food and Agricultural Organization of the United Nations established the Forest and Landscape Restoration Mechanism. The Mechanism supports countries to implement FLR as a contribution to achieving the Bonn Challenge - the restoration of 150 million hectare of deforested and degraded lands by 2020 - and the Convention on Biological Diversity Aichi Biodiversity Targets - related to ecosystem conservation and restoration. 

In partnership with the Global Mechanism of the United Nations Convention to Combat Desertification, FAO released two discussion papers on sustainable financing for FLR in 2015. Sustainable Financing for Forest and Landscape Restoration: The Role of Public Policy Makers provides recommendations and examples of FLR financing for countrues. Sustainable Financing for Forest and Landscape Restoration - Opportunities, challenges and the way forward provides an overview of funding sources and financial instruments available for FLR activities.

Restoration ecology

From Wikipedia, the free encyclopedia

 

Recently constructed wetland regeneration in Australia, on a site previously used for agriculture

 

Rehabilitation of a portion of Johnson Creek, to restore bioswale and flood control functions of the land which had long been converted to pasture for cow grazing. The horizontal logs can float, but are anchored by the posts. Just-planted trees will eventually stabilize the soil. The fallen trees with roots jutting into the stream are intended to enhance wildlife habitat. The meandering of the stream is enhanced here by a factor of about three times, perhaps to its original course.

 

Restoration ecology is the scientific study supporting the practice of ecological restoration, which is the practice of renewing and restoring degraded, damaged, or destroyed ecosystems and habitats in the environment by active human intervention and action. 

Natural ecosystems provide ecosystem services in the form of resources such as food, fuel, and timber; the purification of air and water; the detoxification and decomposition of wastes; the regulation of climate; the regeneration of soil fertility; and the pollination of crops. These ecosystem processes have been estimated to be worth trillions of dollars annually. There is consensus in the scientific community that the current environmental degradation and destruction of many of the Earth's biota is taking place on a "catastrophically short timescale". Scientists estimate that the current species extinction rate, or the rate of the Holocene extinction, is 1,000 to 10,000 times higher than the normal, background rate. Habitat loss is the leading cause of both species extinctions and ecosystem service decline. Two methods have been identified to slow the rate of species extinction and ecosystem service decline, they are the conservation of currently viable habitat, and the restoration of degraded habitat. The commercial applications of ecological restoration have increased exponentially in recent years. The United Nations General Assembly (01.03.2019) declared 2021 – 2030 the UN Decade on Ecosystem Restoration 

Definition

Restoration ecology is the academic study of the process, whereas ecological restoration is the actual project or process by restoration practitioners. 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". Ecological restoration includes a wide scope of projects including erosion control, reforestation, removal of non-native species and weeds, revegetation of disturbed areas, daylighting streams, reintroduction of native species (preferably native species that have local adaptation), and habitat and range improvement for targeted species.

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

History

Restoration ecology emerged as a separate field in ecology in the late twentieth century. The term was coined by John Aber and William Jordan III when they were at the University of Wisconsin–Madison. However, indigenous peoples, land managers, stewards, and laypeople have been practicing ecological restoration or ecological management for thousands of years.

Considered the birthplace of modern ecological restoration, the first tallgrass prairie restoration was the 1936 Curtis Prairie at the University of Wisconsin–Madison Arboretum. Civilian Conservation Corps workers replanted nearby prairie species onto a former horse pasture, overseen by university faculty including renowned ecologist Aldo Leopold, botanist Theodore Sperry, mycologist Henry C. Greene, and plant ecologist John T. Curtis. Curtis and his graduate students surveyed the whole of Wisconsin, documenting native species communities and creating the first species lists for tallgrass restorations. Existing prairie remnants, such as locations within pioneer cemeteries and railroad rights-of-way, were located and inventoried by Curtis and his team. The UW Arboretum was the center of tallgrass prairie research through the first half of the 20th century, with the development of the nearby Greene Prairie, Aldo Leopold Shack and Farm, and pioneering techniques like prescribed burning.

The latter-half of the 20th century saw the growth of ecological restoration beyond Wisconsin borders. The 285-hectare Green Oaks Biological Field Station at Knox College began in 1955 under the guidance of zoologist Paul Shepard. It was followed by the 40-hectare Schulenberg Prairie at the Morton Arboretum, started in 1962 by Ray Schulenberg and Bob Betz. Betz then worked with The Nature Conservancy to establish the 260-hectare Fermi National Laboratory tallgrass prairie in 1974. These major tallgrass restoration projects marked the growth of ecological restoration from isolated studies to widespread practice.

Australia has also been the site of historically significant ecological restoration projects. In 1935 Ambrose Crawford commenced restoring a degraded four acres (1.7 hectares) patch of the Big Scrub (Lowland Tropical Rainforest) at Lumley Park reserve, Alstonville, in northern New South Wales. Clearing of weeds and planting of suitable indigenous flora species were his main restoration techniques. The restored rainforest reserve still exists today and is home to threatened plant and animal species. In 1936 Albert Morris and his restoration colleagues initiated the Broken Hill regeneration area project, which involved the natural regeneration of indigenous flora on a severely degraded site of hundreds of hectares in arid western New South Wales. Completed in 1958, the successful project still maintains ecological function today as the Broken Hill Regeneration Area.

Theoretical foundations

Restoration ecology draws on a wide range of ecological concepts.

Disturbance

Disturbance is a change in environmental conditions that disrupts the functioning of an ecosystem. Disturbance can occur at a variety of spatial and temporal scales, and is a natural component of many communities. For example, many forest and grassland restorations implement fire as a natural disturbance regime. However the severity and scope of anthropogenic impact has grown in the last few centuries. Differentiating between human-caused and naturally occurring disturbances is important if we are to understand how to restore natural processes and minimize anthropogenic impacts on the ecosystems.

Succession

Ecological succession is the process by which a community changes over time, especially following a disturbance. In many instances, an ecosystem will change from a simple level of organization with a few dominant pioneer species to an increasingly complex community with many interdependent species. Restoration often consists of initiating, assisting, or accelerating ecological successional processes, depending on the severity of the disturbance. Following mild to moderate natural and anthropogenic disturbances, restoration in these systems involves hastening natural successional trajectories through careful management. However, in a system that has experienced a more severe disturbance (such as in urban ecosystems), restoration may require intensive efforts to recreate environmental conditions that favor natural successional processes.

Fragmentation

Habitat fragmentation describes spatial discontinuities in a biological system, where ecosystems are broken up into smaller parts through land use changes (e.g. agriculture) and natural disturbance. This both reduces the size of the populations and increases the degree of isolation. These smaller and isolated populations are more vulnerable to extinction. Fragmenting ecosystems decreases quality of the habitat. The edge of a fragment has a different range of environmental conditions and therefore supports different species than the interior. Restorative projects can increase the effective size of a population by adding suitable habitat and decrease isolation by creating habitat corridors that link isolated fragments. Reversing the effects of fragmentation is an important component of restoration ecology.

Ecosystem function

Ecosystem function describes the most basic and essential foundational processes of any natural systems, including nutrient cycles and energy fluxes. An understanding of the complexity of these ecosystem functions is necessary to address any ecological processes that may be degraded. Ecosystem functions are emergent properties of the system as a whole, thus monitoring and management are crucial for the long-term stability of ecosystems. A fully functional ecosystem that is completely self-perpetuating is the ultimate goal of restorative efforts. We must understand what ecosystem properties influence others to restore desired functions and reach this goal.

Community assembly

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 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, and migration and extinction rates between species, drive differences in species composition between sites with comparable environmental conditions.

Population genetics

Genetic diversity has shown to be as important as species diversity for restoring ecosystem processes. Hence ecological restorations are increasingly factoring genetic processes into management practices. Population genetic processes that are important to consider in restored populations include founder effects, inbreeding depression, outbreeding depression, genetic drift, and gene flow. Such processes can predict whether or not a species successfully establishes at a restoration site.

Applications

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 resource heterogeneity in a tallgrass prairie restoration project. They found increasing resource heterogeneity, which on its own was insufficient to insure species diversity in situations where one species may dominate across the range of resource levels. Their findings were consistent with the 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 the community structure.

Invasion and restoration

Restoration is used as a tool for reducing the spread of invasive plant species in a number of ways. The first method views restoration primarily as a means to reduce the presence of invasive species and limit their spread. As this approach emphasizes control of invaders, the restoration techniques can differ from typical restoration projects. The goal of such projects is not necessarily to restore an entire ecosystem or habitat. These projects frequently use lower diversity mixes of aggressive native species seeded at high density. They are not always actively managed following seeding. The target areas for this type of restoration are those which are heavily dominated by invasive species. The goals are to first remove the species and then in so doing, reduce the number of invasive seeds being spread to surrounding areas. An example of this is through use of biological control agents (such as herbivorous insects) which suppress invasive weed species while restoration practitioners concurrently seed in native plant species that take advantage of the freed resources. These approaches have been shown to be effective in reducing weeds, although it is not always a sustainable solution long term without additional weed control, such as mowing, or re-seeding.

Restoration projects are also used as a way to better understand what makes an ecological community resistant to invasion. As restoration projects have a broad range of implementation strategies and methods used to control invasive species, they can be used by ecologists to test theories about invasion. Restoration projects have been used to understand how the diversity of the species introduced in the restoration affects invasion. We know that generally higher diversity prairies have lower levels of invasion. Incorporation of functional ecology has shown that more functionally diverse restorations have lower levels of invasion. Furthermore, studies have shown that using native species functionally similar to invasive species are better able to compete with invasive species. Restoration ecologists have also used the variety of strategies employed at different restoration sites to better understand the most successful management techniques to control invasion.

Successional trajectories

Progress along a desired successional pathway may be difficult if multiple stable states exist. Looking over 40 years of wetland restoration data, Klötzli and Gootjans (2001) argue that unexpected and undesired vegetation assemblies "may indicate that 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.

Sourcing material for restoration

For most restoration projects it is generally recommend to source material from local populations, to increase chance of restoration success and minimize the effects of maladaptation. However the definition of local can vary based on species. habitat and region. US Forest Service recently developed provisional seed zones based on a combination of minimum winter temperature zones, aridity, and the Level III ecoregions. Rather than putting strict distance recommendations, other guidelines recommend sourcing seeds to match similar environmental conditions. For example, sourcing for Castilleja levisecta found that farther source populations that matched similar environmental variables were better suited for the restoration project than closer source populations.

Principles

Ecosystem restoration for the superb parrot on an abandoned railway line in Australia

Rationale

There are many reasons to restore ecosystems. Some include:

• Restoring natural capital such as drinkable water or wildlife populations
• Helping human communities and the ecosystems upon which they depend adapt to the impacts of climate change (through ecosystem-based adaptation)
• Mitigating climate change (e.g. through carbon sequestration)
• Helping threatened or endangered species
• Aesthetic reasons 
• Moral reasons: human intervention has unnaturally destroyed many habitats, and there exists an innate obligation to restore these destroyed habitats
• Regulated use/harvest, particularly for subsistence
• Cultural relevance of native ecosystems to Native people
• Environmental health of nearby populations 

Forest restoration in action at the Buffelsdraai Landfill Site Community Reforestation Project in South Africa

 

There exist considerable differences of opinion in how to set restoration goals and how to define their success among conservation groups. Some urge active restoration (e.g. eradicating invasive animals to allow the native ones to survive) and others who believe that protected areas should have the bare minimum of human interference, such as rewilding. Ecosystem restoration has generated controversy. Skeptics doubt that the benefits justify the economic investment or who point to failed restoration projects and question the feasibility of restoration altogether. It can be difficult to set restoration goals, in part because, as Anthony Bradshaw claims, "ecosystems are not static, but in a state of dynamic equilibrium…. [with restoration] we aim [for a] moving target." 

Some conservationists argue that, though an ecosystem may not be returned to its original state, the functions of the ecosystem (especially ones that provide services to us) may be more valuable in its current configuration (Bradshaw 1987). This is especially true in cases where the ecosystem services are central to the physical and cultural survival of human populations, as is the case with many Native groups in the United States and other communities around the world who subsist using ecological services and environmental resources. One reason to consider ecosystem restoration is to mitigate climate change through activities such as afforestation. Afforestation involves replanting forests, which remove carbon dioxide from the air. Carbon dioxide is a leading cause of global warming (Speth, 2005) and capturing it would help alleviate climate change. Another example of a common driver of restoration projects in the United States is the legal framework of the Clean Water Act, which often requires mitigation for damage inflicted on aquatic systems by development or other activities.

Restored prairie at the West Eugene Wetlands in Eugene, Oregon.

Challenges

Some view ecosystem restoration as impractical, partially because restorations often fall short of their goals. Hilderbrand et al. point out that many times uncertainty (about ecosystem functions, species relationships, and such) is not addressed, and that the time-scales set out for 'complete' restoration are unreasonably short, while other critical markers for full-scale restoration are either ignored or abridged due to feasibility concerns. In other instances an ecosystem may be so degraded that abandonment (allowing a severely degraded ecosystem to recover on its own) may be the wisest option. Local communities sometimes object to restorations that include the introduction of large predators or plants that require disturbance regimes such as regular fires, citing threat to human habitation in the area. High economic costs can also be perceived as a negative impact of the restoration process. 

Public opinion is very important in the feasibility of a restoration; if the public believes that the costs of restoration outweigh the benefits they will not support it.

Many failures have occurred in past restoration projects, many times because clear goals were not set out as the aim of the restoration, or an incomplete understanding of the underlying ecological framework lead to insufficient measures. This may be because, as Peter Alpert says, "people may not [always] know how to manage natural systems effectively". Furthermore, many assumptions are made about myths of restoration such as carbon copy, where a restoration plan, which worked in one area, is applied to another with the same results expected, but not realized.

Science-practice gap

One of the struggles for both fields is a divide between restoration ecology and ecological restoration in practice. Many restoration practitioners as well as scientists feel that science is not being adequately incorporated into ecological restoration projects. In a 2009 survey of practitioners and scientists, the "science-practice gap" was listed as the second most commonly cited reason limiting the growth of both science and practice of restoration.

There are a variety of theories about the cause of this gap. However, it has been well established that one of the main issues is that the questions studied by restoration ecologists are frequently not found useful or easily applicable by land managers. For instance, many publications in restoration ecology characterize the scope of a problem in depth, without providing concrete solutions. Additionally many restoration ecology studies are carried out under controlled conditions and frequently at scales much smaller than actual restorations. Whether or not these patterns hold true in an applied context is often unknown. There is evidence that these small-scale experiments inflate type II error rates and differ from ecological patterns in actual restorations.

There is further complication in that restoration ecologists who want to collect large-scale data on restoration projects can face enormous hurdles in obtaining the data. Managers vary in how much data they collect, and how many records they keep. Some agencies keep only a handful of physical copies of data that make it difficult for the researcher to access. Many restoration projects are limited by time and money, so data collection and record keeping are not always feasible. However, this limits the ability of scientists to analyze restoration projects and give recommendations based on empirical data.

Contrasting restoration ecology and conservation biology

Restoration ecology may be viewed as a sub-discipline of conservation biology, the scientific study of how to protect and restore biodiversity. Ecological restoration is then a part of the resulting conservation movement.

Both restoration ecologists and conservation biologists agree that protecting and restoring habitat is important for protecting biodiversity. However, conservation biology is primarily rooted in population biology. Because of that, it is generally organized at the population genetic level and assesses specific species populations (i.e. endangered species). Restoration ecology is organized at the community level, which focuses on broader groups within ecosystems.

In addition, conservation biology often concentrates on vertebrate animals because of their salience and popularity, whereas restoration ecology concentrates on plants. Restoration ecology focuses on plants because restoration projects typically begin by establishing plant communities. Ecological restoration, despite being focused on plants, may also have "poster species" for individual ecosystems and restoration projects. For example, the Monarch butterfly is a poster species for conserving and restoring milkweed plant habitat, because Monarch butterflies require milkweed plants to reproduce. Finally, restoration ecology has a stronger focus on soils, soil structure, fungi, and microorganisms because soils provide the foundation of functional terrestrial ecosystems.

Natural Capital Committee's recommendation for a 25-year plan

The UK Natural Capital Committee (NCC) made a recommendation in its second State of Natural Capital report published in March 2014 that in order to meet the Government's goal of being the first generation to leave the environment in a better state than it was inherited, a long-term 25-year plan was needed to maintain and improve England's natural capital. The UK Government has not yet responded to this recommendation. 

The Secretary of State for the UK's Department for Environment, Food and Rural Affairs, Owen Paterson, described his ambition for the natural environment and how the work of the Committee fits into this at an NCC event in November 2012: "I do not, however, just want to maintain our natural assets; I want to improve them. I want us to derive the greatest possible benefit from them, while ensuring that they are available for generations to come. This is what the NCC's innovative work is geared towards".