Revegetation is the process of replanting and rebuilding the

soil Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

of disturbed land. This may be a natural process produced by

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

colonization and succession, manmade rewilding projects, accelerated process designed to repair damage to a

landscape A landscape is the visible features of an area of land, its landforms, and how they integrate with natural or human-made features, often considered in terms of their aesthetic appeal.''New Oxford American Dictionary''. A landscape includes th ...

due to

wildfire A wildfire, forest fire, or a bushfire is an unplanned and uncontrolled fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire may be more specifically identified as a ...

mining Mining is the Resource extraction, extraction of valuable geological materials and minerals from the surface of the Earth. Mining is required to obtain most materials that cannot be grown through agriculture, agricultural processes, or feasib ...

flood A flood is an overflow of water (list of non-water floods, or rarely other fluids) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are of significant con ...

, or other cause. Originally the process was simply one of applying

seed In botany, a seed is a plant structure containing an embryo and stored nutrients in a protective coat called a ''testa''. More generally, the term "seed" means anything that can be Sowing, sown, which may include seed and husk or tuber. Seeds ...

and fertilizer to disturbed lands, usually

grass Poaceae ( ), also called Gramineae ( ), is a large and nearly ubiquitous family (biology), family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos, the grasses of natural grassland and spe ...

es or

clover Clovers, also called trefoils, are plants of the genus ''Trifolium'' (), consisting of about 300 species of flowering plants in the legume family Fabaceae originating in Europe. The genus has a cosmopolitan distribution with the highest diversit ...

. The fibrous

root In vascular plants, the roots are the plant organ, organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often bel ...

network of grasses is useful for short-term erosion control, particularly on sloping ground. Establishing long-term plant communities requires forethought as to appropriate species for the climate, size of stock required, and impact of replanted vegetation on local fauna. The motivations behind revegetation are diverse, answering needs that are both technical and aesthetic, but it is usually

erosion Erosion is the action of surface processes (such as Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

prevention that is the primary reason. Revegetation helps prevent

soil erosion Soil erosion is the denudation or wearing away of the Topsoil, upper layer of soil. It is a form of soil degradation. This natural process is caused by the dynamic activity of erosive agents, that is, water, ice (glaciers), snow, Atmosphere of Ea ...

, enhances the ability of the soil to absorb more water in significant rain events, and in conjunction reduces turbidity dramatically in adjoining bodies of water. Revegetation also aids protection of engineered grades and other earthworks. Organisations like Trees For Life ( Brooklyn Park) provide good examples.

For conservation

Revegetation is often used to join up patches of natural habitat that have been lost and can be a very important tool in places where much of the natural vegetation has been cleared. It is therefore particularly important in urban environments, and research in

Brisbane Brisbane ( ; ) is the List of Australian capital cities, capital and largest city of the States and territories of Australia, state of Queensland and the list of cities in Australia by population, third-most populous city in Australia, with a ...

has shown that revegetation projects can significantly improve urban bird populations. The Brisbane study showed that connecting a revegetation patch with existing habitat improved bird species richness, while simply concentrating on making large patches of habitat was the best way to increase bird abundance. Revegetation plans, therefore, need to consider how the revegetated sites are connected with existing habitat patches. Revegetation in agricultural areas can support breeding bird populations, but often it supports more common species, rather than those that are in decline.

Spatial arrangement

The spatial arrangement of the selected plant species influences the vegetation system and the greater habitat system. Spatial planning determines interactions between plant species. These interactions can be facilitative or

competitive Competition is a rivalry where two or more parties strive for a common goal which cannot be shared: where one's gain is the other's loss (an example of which is a zero-sum game). Competition can arise between entities such as organisms, indi ...

. Planting certain species together can protect one or both from extreme temperature fluctuations, drying out in the sun, harsh winds, and predators, in addition to improving soil composition. Competition can occur within or between species, and generally weaker individuals and weaker species die out, resulting in increased plant spacing. Spatial arrangement of revegetation species also influences

pollination Pollination is the transfer of pollen from an anther of a plant to the stigma (botany), stigma of a plant, later enabling fertilisation and the production of seeds. Pollinating agents can be animals such as insects, for example bees, beetles or bu ...

and seed dispersal. For species whose seeds are wind-dispersed and animal-dispersed, plant diversity in seed dispersal range is important for genetic fitness. However, too much competition within the seed dispersal range can cause reproduction to be suppressed, so it is important to balance. On the ecosystem level, the spatial planning of revegetation species influences animal species. A more varied plant species composition is more likely to be used by a wider variety of animal species. High-density edible plants mean animals do not have to forage as far to eat, and a plant species even being in the presence of palatable species could lead to it having more interaction with animals. Abiotic aspects of the ecosystem are also altered. Higher density revegetation can reduce

, protect against extreme temperatures, decrease evaporative losses of water, and increase water filtration and reinfiltration. However, higher density revegetation requires the use of more soil nutrients and water, which can potentially dry out and deplete the soil. For riparian revegetation, plant roots help to increase the shear strength of bank soil, and if tree roots begin to lose their strength, the bank is susceptible to land slips. Fibrous or matted roots in particular help to prevent against

, and are typically found in reed and sedge species.

Soil replacement

Mine reclamation may involve soil amendment, replacement, or creation, particularly for areas that have been strip mined or suffered severe

or soil compaction. In some cases, the native soil may be removed before construction and replaced with fill for the duration of the work. After construction is completed, the fill is again removed and replaced with the reserved native soil for revegetation.

Mycorrhizal communities

Mycorrhizae, symbiotic

fungal A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as one of the tradit ...

-plant communities, are important to the success of revegetation efforts. Most woody plant species need these root-fungi communities to thrive, and nursery or greenhouse transplants may not have sufficient or correct mycorrhizae for good survival. Mycorhizal communities are particularly beneficial to nitrogen-fixing woody plants, C4-grasses, and soil environments low in phosphorus. Two types of mycorrhizal fungi aid in restoration: ectomycorrhizal fungi and arbuscular mycorrhizal fungi.

For conservation

Spatial arrangement

Soil replacement

Mycorrhizal communities

See also

References

Further reading