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 interruption and action. Effective restoration requires
an explicit goal or policy, preferably an unambiguous one that is
articulated, accepted, and codified. Restoration goals reflect societal
choices from among competing policy priorities, but extracting such
goals is typically contentious and politically challenging.
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 Earth's biota are 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. In 2019, the United Nations General Assembly 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, the reintroduction of native species (preferably native species that have local adaptation),
and habitat and range improvement for targeted species. For many
researchers, the ecological restoration must include the local
communities: they call this process the "social-ecological restoration".
E. O. Wilson, a biologist, stated, "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.
US
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, which 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
Australia
has also been the site of historically significant ecological
restoration projects. They commenced in the 1930s. These projects were
responses to the extensive environmental damage inflicted by colonising
settlers, following the forced dispossession of the First Nations
communities of Australia. The substantial Traditional Ecological
Knowledge of First Nations communities was not utilised in the
historical restoration projects.
Interestingly, many of the first Australian settler restoration
projects were initiated by volunteers, often in the form of community
groups. Many of these volunteers appreciated and utilised science
resources, such as botanical and ecological knowledge. Local and state
government agencies participated, and also industry. Australian
scientists came to play an increasingly important role. A prominent
scientist who took an interest in the reversal of vegetation degradation
was botanist and plant ecologist Professor T G Osborn, University of
Adelaide, who, in the 1920s, conducted pioneering research into the
causes of arid-zone indigenous vegetation degradation. From this time,
Australian botanists, plant ecologists and soil erosion researchers have
increasingly developed interests in the recovery of ecological
functioning on degraded sites.
The earliest known attempt by Australian settlers to restore a
degraded natural ecosystem commenced in 1896, at Nairm (as it is known
to people of the Kulin nation), or Port Phillip Bay, Melbourne.
Local government and community groups replanted degraded areas of the
foreshore reserves with the indigenous plant species, Coastal Teatree (Leptospermum laevigatum).
Possibly the ecological aspirations were limited, as essentially, the
projects were motivated by utilitarian considerations: to conserve
recreation sites, and promote tourism. However, some local residents,
such as distinguished Australian journalist, nature writer and amateur
ornithologist Donald Macdonald, were distressed at the loss of valued
biological qualities, and campaigned to fully restore the Teatree
ecosystems and conserve them and their indigenous fauna. Indeed,
Macdonald espoused many of the principles and practices of ecological
restoration, but he lacked opportunities to actually implement such a
project.
The degraded arid-zone regions of Australia attracted historical
ecological restoration projects. Following the forced dispossession of
First Nations communities between ca.1830 and ca.1880, a pastoral
industry was established in the arid-zone regions of South Australia and
New South Wales. By ca.1900 these regions had become substantially
degraded, due to a combination of overstocking, the ravages of rabbits
and other feral animals, and the harsh arid conditions that inhibited
recovery of the indigenous vegetation. Severe wind erosion resulted.
From approximately 1930 Australian pastoralists implemented revegetation
projects that had as their aim the substantial to full restoration of
indigenous flora to degraded, wind eroded areas.
At his arid-zone Koonamore research station in South Australia,
established in 1925, Professor T G Osborn studied the loss of indigenous
vegetation caused by overstocking and the resultant wind erosion and
degradation, concluding that restoration of the indigenous saltbushes (Atriplex spp. ), bluebushes (Maireana spp.) and Mulga (Acacia aneura)
vegetation communities was possible, if a stock exclosure and natural
regeneration revegetation technique was applied to degraded paddocks (or
fields).
Most likely influenced by Osborn's research, throughout the 1930s South
Australian pastoralists adopted this revegetation technique. At
Wirraminna station (or property, ranch), for example, following fencing
to exclude stock, severe
soil-drifts were fully revegetated and stabilised by means of natural
regeneration of the indigenous vegetation. Also, it was found that
furrowing (or ploughing) of eroded areas resulted in the natural
regeneration of indigenous vegetation. So successful were these programs
that the South Australian government adopted them as approved state
soil conservation policies in 1936. Legislation introduced in 1939
codified these policies.
In 1936 mining assayer Albert Morris
and his restoration colleagues initiated the Broken Hill regeneration
area project. This project involved the natural regeneration of
indigenous flora on a severely wind eroded site of hundreds of hectares,
located in arid western New South Wales.
Morris was responding to the widespread wind erosion that had arisen
from pastoral industry overstocking practices. It is quite likely that
he was influenced by the South Australian research work of Professor
Osborn. Completed in 1958, the successful project still maintains
substantial ecological functioning today as the Broken Hill Regeneration
Area (1700 hectares).
Morris was a pioneering and highly skilled arid-zone botanist, and was
also familiar with some basic principles of ecology. Local and state
governments, and the Broken Hill mining industry, supported and funded
the project.
The Broken Hill regeneration area project has been described as
an irrigation and tree planting project, and as a USA "dust bowl"
shelterbelt planting project. However, to revegetate 1700 hectares by
planting, hundreds of thousands of plants would have been required, but
there is no historical documentation that reveals planting programs of
this scale, or near it. Furthermore, although Morris did design some
small tree planting and irrigation projects for the local community and a
mining company, it is well documented that his main revegetation
interest was in a stock exclosure and natural regeneration technique.
As the historical documentation reveals, the regeneration area project
relied almost entirely on the germination of the naturally distributed
seed of the local indigenous flora species (natural regeneration), and
the exclusion of damaging grazing animals (stock exclosure).
In fact, as the regeneration area project was so well adapted to the
harsh arid-zone conditions, the New South Wales state government adopted
it as a model for the proposed restoration of the twenty million
hectares of the arid western portion of the state that had been reduced
to a severely eroded condition. Legislation to this effect was passed in
1949.
Another very significant, early Australian settler ecological
restoration project occurred on the north coast of New South Wales. From
approximately 1840 settlers forcibly occupied the coastal hinterlands,
dispossessed First Nations communities, destroyed extensive areas of
biologically diverse rainforest and converted the land to farms. Only
smalll patches of rainforest survived. In 1935 dairy farmer Ambrose
Crawford, alarmed by the possible loss of all of the rainforest,
commenced restoring a degraded four acres (1.7 hectares) patch of local
rainforest, or "Big Scrub" (Lowland Tropical Rainforest), as it was
referred to, at Lumley Park reserve, Alstonville.
Clearing of the weeds that were smothering the rainforest plants, and
planting of suitable indigenous rainforest species, were his two main
restoration techniques. Crawford utilised professional government
botanists as advisors, and received support from his local government
council. The restored rainforest reserve still exists today, a vital
home to threatened plant and animal species.
Two attempted but ultimately unsuccessful projects that displayed
many of the hallmarks of ecological restoration commenced in New South
Wales in the early 1930s. Entomologist Walter Froggatt set out to
restore Sydney Hawkesbury Sandstone flora to degraded Balls Head
Reserve, Sydney Harbour, Sydney. Unfortunately, following Froggatt's
death in 1937, the project lapsed into landscaping. About the same time, marine biologist David Stead commenced a project to restore the Australian Koala (Phascolarctos cinereus)
to New South Wales, where it had been much slaughtered by hunters
engaged in fur trading. Unfortunately, Stead's project ran into
financial difficulties.
Traditional ecological knowledge and restoration ecology
Traditional ecological knowledge (TEK) from Indigenous Peoples demonstrates how restoration ecology is a historical field, lived out by humans for thousands of years.
Indigenous people have acquired ecological knowledge through
observation, experience, and management of the natural resources and the
environment around them. In the past, they used to manage their
environment and changed the structure of the vegetation in a way not
only to meet their basic needs (food, water, shelter, medicines) but
also to improve desired characteristics and even increasing the
populations and biodiversity. In that way, they were able to achieve a
close relationship with the environment and learned lessons that
indigenous people keep in their culture.
This means there are many things that could be learned from people locally indigenous to the ecosystem being restored because of the deep connection and biocultural and linguistic diversity of place.
The dynamic of the use of natural resources by indigenous people
contemplate many cultural, social, and environmental aspects, since they
have always had an intimate connection with the animals and plants
around them over centuries since they obtained their livelihood from the
environment around them.
However, restoration ecologists must consider that TEK is place dependent due to intimate connection
and thus when engaging Indigenous Peoples to include knowledge for
restoration purposes, respect and care must be taken to avoid
appropriation of the TEK. Successful ecological restoration which includes Indigenous Peoples must be led by Indigenous Peoples to ensure non-indigenous people acknowledge the unequal relationship of power.
Traditional Ecological Knowledge and Restoration Ecology in Practice
Kat Anderson wrote a descriptive, historically based background book, A Tended Wilderness,
about the indigenous peoples of the California coast and their intimate
interactions with the environment. California Indians have a rigid and
complex harvesting, management and production practice. The practices
observed leaned heavily into typical horticultural techniques as well as
concentrated forest burning. The applications of preservation and
conservation based on the California Indians' practices, she hopes will
assist in shattering the hunter-gatherer stereotype so long perpetuated
in western literature. In "A Tended Wilderness", Anderson breaks down
the concept that California was an untouched civilization that was built
into a fertile environment by European explorers. However this is not
an accurate depiction; though to Westerners it may not seem modernized,
the native peoples have since defined what the population ecology was in
that land. For them, Wilderness was land not tended to by humans at
all. In "Indigenous Resource Management" Anderson sheds light on the
diverse ways native peoples of California purposely harvested and
managed the wild. The California Indians had a rich knowledge of ecology
and natural techniques to understand burn patterns, plant material,
cultivation, pruning, digging; what was edible vs. what was not. This
did not just extend to plants but also into wildlife management – how
abundant, where the distribution was, and how diverse the large mammal
population was. "Restoration" covers how contemporary land uses caused
degradation, fragmentation and loss of habitat. The way the United
States has counteracted that is through land set aside from all human
influence. As for the future, Anderson highly suggests looking to
indigenous practices for ecosystem restoration and wildlife management.
Theoretical foundations
Restoration ecology draws on a wide range of ecological concepts.
Disturbance
Disturbance
is a change in environmental conditions that disrupt 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 population
and increases the degree of isolation. These smaller and isolated
populations are more vulnerable to extinction. Fragmenting ecosystems
decreases the 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 completely
self-perpetuating and fully functional ecosystem 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 "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
Leaf litter accumulation
Leaf
litter accumulation plays an important role in the restoration process.
Higher quantities of leaf litter hold higher humidity levels, a key
factor for the establishment of plants. The process of accumulation
depends on factors like wind and species composition of the forest. The
leaf litter found in primary forests is more abundant, deeper, and holds
more humidity than in secondary forests. These technical considerations
are important to take into account when planning a restoration project.
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 ensure 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
many 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 the 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 the 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. The 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 a 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 the desired
outcome.
Sourcing land for restoration
A study quantified climate change mitigation potentials of 'high-income' nations shifting diets – away from meat-consumption
– and restoration of the spared land. They find that the hypothetical
dietary change "could reduce annual agricultural production emissions of
high-income nations' diets by 61% while sequestering as much as 98.3
(55.6–143.7) GtCO2
equivalent, equal to approximately 14 years of current global
agricultural emissions until natural vegetation matures", outcomes they
call 'double climate dividend'.
Sourcing material for restoration
For
most restoration projects it is generally recommended to source
material from local populations, to increase the 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 that
the species is exposed to, either now, or under projected climate
change. 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. Similarly, a suite of new methods are surveying gene-environment interactions in order to identify the optimum source populations based on genetic adaptation to environmental conditions.
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
- The environmental health of nearby populations
There exist considerable differences of opinion on how to set
restoration goals and how to define their success. Ultimately specifying
the restoration target or desired state of an ecosystem is a societal
choice, informed by scientists and technocrats, but ultimately it is a
policy choice. Selecting the desired goal can be politically
contentious.
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.
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.
One approach to addressing this gap has been the development of
International Principles & Standards for the Practice of Ecological
Restoration by the Society for Ecological restoration (see below) –
however this approach is contended, with scientists active in the field
suggesting that this is restrictive, and instead principles and
guidelines offer flexibility.
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.
Food security and nature degradation
A
range of activities in the name of "nature restoration", such as
monoculture tree plantations, "degrade nature—destroying biodiversity,
increasing pollution, and removing land from food production".
Consideration as a substitute for steep emission reductions
Climate benefits from nature restoration are "dwarfed by the scale of ongoing fossil fuel emissions".
It risks "over-relying on land for mitigation at the expense of phasing
out fossil fuels". Despite of these issues, nature restoration is
receiving increasing attention, with a study concluding that "Land
restoration is an important option for tackling climate change but
cannot compensate for delays in reducing fossil fuel emissions" as it's
"unlikely to be done quickly enough to notably reduce the global peak
temperatures expected in the next few decades".
For instance, researchers have compared reforestation and prevention of (mainly tropical) deforestation in specific:
Timelapse of recent deforestation of the Amazon rainforest
Researchers, including from the
European Commission,
found that, in terms of environmental services, it is better to avoid
deforestation than to allow for deforestation to subsequently reforest,
as the former leads to i.a. irreversible effects in terms of
biodiversity loss and
soil degradation. Furthermore, the probability that legacy carbon will be released from soil is higher in younger boreal forest.
Global greenhouse gas emissions caused by damage to tropical
rainforests may be have been substantially underestimated until around
2019. Additionally, the effects of af- or reforestation will be farther in the future than keeping existing forests intact. It takes much longer − several decades − for the benefits for global warming to manifest to the same
carbon sequestration benefits from mature trees in tropical forests and hence from limiting deforestation.
Mackey and Dooley consider "the protection and recovery of carbon-rich
and long-lived ecosystems, especially natural forests" "the major
climate
solution".
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".
International Principles & Standards for the Practice of Ecological Restoration
The Society for Ecological Restoration
(SER) released the second edition of the International Standards for
the Practice of Ecological Restoration on September 27, 2019, in Cape
Town, South Africa, at SER's 8th World Conference on Ecological
Restoration.
This groundbreaking publication provides updated and expanded guidance
on the practice of ecological restoration, clarifies the breadth of
ecological restoration and allied environmental repair activities, and
includes ideas and input from a diverse international group of
restoration scientists and practitioners.
The second edition builds on the first edition of the Standards,
which was released December 12, 2016, at the Convention on Biological
Diversity's 13th Conference of the Parties in Cancun, Mexico. The
development of these Standards has been broadly consultative. The first
edition was circulated to dozens of practitioners and experts for
feedback and review. After release of the first edition, SER held
workshops and listening sessions, sought feedback from key international
partners and stakeholders, opened a survey to members, affiliates and
supporters, and considered and responded to published critiques.
The International Principles and Standards for the Practice of Ecological Restoration:
- Present a robust framework to guide restoration projects toward achieving intended goals
- Address restoration challenges including: effective design and
implementation, accounting for complex ecosystem dynamics (especially in
the context of climate change), and navigating trade-offs associated
with land management priorities and decisions
- Highlight the role of ecological restoration in connecting social, community, productivity, and sustainability goals
- Recommend performance measures for restorative activities for industries, communities, and governments to consider
- Enhance the list of practices and actions that guide practitioners
in planning, implementation, and monitoring activities, including:
appropriate approaches to site assessment and identification of
reference ecosystems, different restoration approaches including natural
regeneration, and the role of ecological restoration in global
restoration initiatives
- Include an expanded glossary of restoration terminology
- Provide a technical appendix on sourcing of seeds and other propagules for restoration.
The Standards are available for free at www.ser.org/standards.
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