Assisted natural regeneration (ANR) (also termed managed regrowth) is the human protection and preservation of natural tree seedlings in forested areas. Seedlings are, in particular, protected from undergrowth and extremely flammable plants such as Imperata grass. Though there is no formal definition or methodology, the overall goal of ANR is to create and improve forest productivity. It typically involves the reduction or removal of barriers to natural regeneration such as soil degradation, competition with weeds, grasses or other vegetation, and protection against disturbances, which can all interfere with growth. [1] In addition to protection efforts, new trees are planted when needed or wanted (enrichment planting). With ANR, forests grow faster than they would naturally, resulting in a significant contribution to carbon sequestration efforts. It also serves as a cheaper alternative to reforestation due to decreased nursery needs.
The most effective way to implement ANR is very site-specific, and many nations provide guidebooks on how to select and maintain an ANR project. [2] [3]
ANR is a common practice in many Asian countries. This method of protection has been used on Imperata grasslands in the Philippines for over three decades, as well as in China for more than five decades. [4]
According to the Food and Agriculture Organization of the United Nations (FAO), China has since 1999 funded extensive ANR in an effort to prevent soil corrosion in particular. [5] Also the FAO reports that ANR is a common practice in Thailand.
ANR is gaining popularity as global climate change becomes a growing concern.
ANR has typically been used most often in tropical forests, however, it is now being used to help restore forested areas across all ecosystem types. [6]
A wide variety of conditions are required to optimally implement ANR and ensure successful regeneration. One involves a sufficient density of naturally regenerated seedlings, though the specific density required is dependent on specific factors, such as, distribution, species composition, growth rates, soil fertility, etc. A density range of 200 to 800 seedlings per hectare has been suggested to ensure optimal regeneration. [7] The availability of seed sources from nearby remnant forests is necessary to serve as seed inputs for colonization of vegetation. The control or removal of all disturbances (such as, grazing, fires, and logging) is also crucial. [7]
The practice of ANR has a wide range of benefits. ANR focuses on reducing ecological barriers in order to accelerate natural regeneration and growth, rather than the planting of seedlings. [7] This allows for a low-cost method that removes the expenses associated with site preparation and planting/raising seedlings themselves, which can be appealing in large-scale restoration projects. Another benefit involves job opportunities. ANR requires high maintenance and can be labor-intensive, and involve methods of weeding, grass pressing, establishing and maintaining firebreaks, etc. This can ultimately help to create jobs and improve livelihoods in local and/or impoverished communities. [7] However, if the forestation is not a positive change, for example, if the land is needed for food, the people of the community will be unlikely to get involved and produce successful ANR.[ citation needed ]
Carbon sequestration, biodiversity enrichment and recovery are just a few environmental benefits ANR provides, which can help improve ecosystems and mitigate climate change. ANR focuses on native species and natural succession of existing vegetation, which ensures that plant communities and inhabiting wildlife are maintained and are not disturbed. [6]
A carbon sink is anything, natural or otherwise, that accumulates and stores some carbon-containing chemical compound for an indefinite period and thereby removes carbon dioxide from the atmosphere. These sinks form an important part of the natural carbon cycle. An overarching term is carbon pool, which is all the places where carbon can be. A carbon sink is a type of carbon pool that has the capability to take up more carbon from the atmosphere than it releases.
Reforestation is the natural or intentional restocking of existing forests and woodlands (forestation) that have been depleted, usually through deforestation but also after clearcutting. Two important purposes of reforestation programs are for harvesting of wood or for climate change mitigation purposes.
Groundcover or ground cover is any plant that grows over an area of ground. Groundcover provides protection of the topsoil from erosion and drought.
A grassland is an area where the vegetation is dominated by grasses (Poaceae). However, sedge (Cyperaceae) and rush (Juncaceae) can also be found along with variable proportions of legumes, like clover, and other herbs. Grasslands occur naturally on all continents except Antarctica and are found in most ecoregions of the Earth. Furthermore, grasslands are one of the largest biomes on earth and dominate the landscape worldwide. There are different types of grasslands: natural grasslands, semi-natural grasslands, and agricultural grasslands. They cover 31–69% of the Earth's land area.
Silviculture is the practice of controlling the growth, composition/structure, as well as quality of forests to meet values and needs, specifically timber production.
An old-growth forest is a forest that has developed over a long period of time without disturbance. Due to this, old-growth forests exhibit unique ecological features. The Food and Agriculture Organization of the United Nations defines primary forests as naturally regenerated forests of native tree species where there are no clearly visible indications of human activity and the ecological processes are not significantly disturbed. One-third of the world's forests are primary forests. Old-growth features include diverse tree-related structures that provide diverse wildlife habitats that increases the biodiversity of the forested ecosystem. Virgin or first-growth forests are old-growth forests that have never been logged. The concept of diverse tree structure includes multi-layered canopies and canopy gaps, greatly varying tree heights and diameters, and diverse tree species and classes and sizes of woody debris.
Agroforestry is a land use management system in which combinations of trees or shrubs are grown around or among crops or pastureland. Agroforestry combines agricultural and forestry technologies to create more diverse, productive, profitable, healthy, and sustainable land-use systems. There are many benefits to agroforestry such as increasing farm profitability. In addition, agroforestry helps to preserve and protect natural resources such as controlling soil erosions, creating habitat for the wildlife, and managing animal waste. Benefits also include increased biodiversity, improved soil structure and health, reduced erosion, and carbon sequestration.
A secondary forest is a forest or woodland area which has regenerated through largely natural processes after human-caused disturbances, such as timber harvest or agriculture clearing, or equivalently disruptive natural phenomena. It is distinguished from an old-growth forest, which has not recently undergone such disruption, and complex early seral forest, as well as third-growth forests that result from harvest in second growth forests. Secondary forest regrowing after timber harvest differs from forest regrowing after natural disturbances such as fire, insect infestation, or windthrow because the dead trees remain to provide nutrients, structure, and water retention after natural disturbances. Secondary forests are notably different from primary forests in their composition and biodiversity; however, they may still be helpful in providing habitat for native species, preserving watersheds, and restoring connectivity between ecosystems.
Ecological restoration is the process of assisting the recovery of an ecosystem that has been degraded, damaged, or destroyed. It is distinct from conservation and preservation in that it is an "attempt to co-design nature with nonhuman collaborators." Ecological restoration can reverse biodiversity loss, combat climate change, and support local economies. The United Nations named 2021-2030 the Decade on Ecosystem Restoration.
Fire ecology is a scientific discipline concerned with the effects of fire on natural ecosystems. Many ecosystems, particularly prairie, savanna, chaparral and coniferous forests, have evolved with fire as an essential contributor to habitat vitality and renewal. Many plant species in fire-affected environments use fire to germinate, establish, or to reproduce. Wildfire suppression not only endangers these species, but also the animals that depend upon them.
Afforestation is the establishment of a forest or stand of trees (forestation) in an area where there was no recent tree cover. There are 3 types of afforestation:
Forest ecology is the scientific study of the interrelated patterns, processes, flora, fauna and ecosystems in forests. The management of forests is known as forestry, silviculture, and forest management. A forest ecosystem is a natural woodland unit consisting of all plants, animals, and micro-organisms in that area functioning together with all of the non-living physical (abiotic) factors of the environment.
Secondary succession is the secondary ecological succession of a plant's life. As opposed to the first, primary succession, secondary succession is a process started by an event that reduces an already established ecosystem to a smaller population of species, and as such secondary succession occurs on preexisting soil whereas primary succession usually occurs in a place lacking soil. Many factors can affect secondary succession, such as trophic interaction, initial composition, and competition-colonization trade-offs. The factors that control the increase in abundance of a species during succession may be determined mainly by seed production and dispersal, micro climate; landscape structure ; bulk density, pH, and soil texture.
Riparian-zone restoration is the ecological restoration of riparian-zonehabitats of streams, rivers, springs, lakes, floodplains, and other hydrologic ecologies. A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the fifteen terrestrial biomes of the earth; the habitats of plant and animal communities along the margins and river banks are called riparian vegetation, characterized by aquatic plants and animals that favor them. Riparian zones are significant in ecology, environmental management, and civil engineering because of their role in soil conservation, their habitat biodiversity, and the influence they have on fauna and aquatic ecosystems, including grassland, woodland, wetland or sub-surface features such as water tables. In some regions the terms riparian woodland, riparian forest, riparian buffer zone, or riparian strip are used to characterize a riparian zone.
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. Additionally, the potential impacts of climate change on restoration goals must be taken into account, as changes in temperature and precipitation patterns may alter the composition and distribution of climax forests.
Gap dynamics refers to the pattern of plant growth that occurs following the creation of a forest gap, a local area of natural disturbance that results in an opening in the canopy of a forest. Gap dynamics are a typical characteristic of both temperate and tropical forests and have a wide variety of causes and effects on forest life.
The Buffelsdraai Landfill Site Community Reforestation Project (BLSCRP) was initiated in 2008 to alleviate climate change impacts associated with hosting elements of the 2010 FIFA World Cup in Durban. The proposed carbon offset was to be achieved through the planting of more than 500 000 indigenous trees within the buffer zone of the Buffelsdraai Landfill Site. Restoring the forest ecosystem was identified as a way of "absorbing event-related greenhouse gas emissions while enhancing the capacity of people and biodiversity to adapt to the inevitable effects of climate change".
Carbon farming is a name for a variety of agricultural methods aimed at sequestering atmospheric carbon into the soil and in crop roots, wood and leaves. The aim of carbon farming is to increase the rate at which carbon is sequestered into soil and plant material with the goal of creating a net loss of carbon from the atmosphere. Increasing a soil's organic matter content can aid plant growth, increase total carbon content, improve soil water retention capacity and reduce fertilizer use. Carbon farming is one component of climate-smart agriculture.
May Be’ati is an exclosure located in the Dogu'a Tembien woreda of the Tigray Region in Ethiopia. The area has been protected since 1968 by the local community.
Khunale is an exclosure located in the Dogu'a Tembien woreda of the Tigray Region in Ethiopia. The area has been protected since 1990 by the local community.
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