Community action on biodiversity

Biodiversity (or biological diversity) is the variety and variability of life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and phylogenetic diversity. Diversity is not distributed evenly on Earth. It is greater in the tropics as a result of the warm climate and high primary productivity in the region near the equator. Tropical forest ecosystems cover less than one-fifth of Earth's terrestrial area and contain about 50% of the world's species. There are latitudinal gradients in species diversity for both marine and terrestrial taxa.

Rewilding is a form of ecological restoration aimed at increasing biodiversity and restoring natural processes. It differs from other forms of ecological restoration in that rewilding aspires to reduce human influence on ecosystems. It is also distinct from other forms of restoration in that, while it places emphasis on recovering geographically specific sets of ecological interactions and functions that would have maintained ecosystems prior to human influence, rewilding is open to novel or emerging ecosystems which encompass new species and new interactions.

A key feature of rewilding is its focus on replacing human interventions with natural processes. Rewilding enables the return of intact large mammal assemblages. This implies the natural groupings of large mammal species in an area to promote the restoration of trophic networks. The mechanism of rewilding is a process of rebuilding, to restore natural ecosystems by introducing or re-introducing large mammals to promote resilient, self-regulating, and self-sustaining ecosystems. Rewilding projects are usually part of programs for habitat restoration and conservation biology, and ideally they should be based on sound ecological theory and evidence.

While rewilding initiatives can be controversial, the United Nations has listed rewilding as one of several methods needed to achieve massive scale restoration of natural ecosystems, which they say must be accomplished by 2030 as part of the 30x30 campaign.

A wildlife garden (or habitat garden or backyard restoration) is an environment created with the purpose to serve as a sustainable haven for surrounding wildlife. Wildlife gardens contain a variety of habitats that cater to native and local plants, birds, amphibians, reptiles, insects, mammals and so on, and are meant to sustain locally native flora and fauna. Other names this type of gardening goes by can vary, prominent ones being habitat, ecology, and conservation gardening.

Both public and private gardens can be specifically transformed to attract the native wildlife, and in doing so, provide a natural array of support through available shelter and sustenance. This method of gardening can be a form of restoration in private gardens as much as those in public, as they contribute to connectivity due to the variability of their scattered locations, as well as an increased habitat availability.

Establishing a garden that emulates the environment before the residence was built and/or renders the garden similar to intact wild areas nearby (rewilding) will allow natural systems to interact and establish an equilibrium, ultimately minimizing the need for gardener maintenance and intervention. Wildlife gardens can also play an essential role in biological pest control, and also promote biodiversity, native plantings, and generally benefit the wider environment. Some environmental benefits include the reduction in pest populations through the natural mechanism of biological pest control, by helping reduce the need for pesticides. Habitat gardens also provide the environment an ecosystem service by recharging aquifers by intercepting rainfall.

A wildlife corridor, also known as a habitat corridor, or green corridor, is an designated area that connects wildlife populations that have been separated by human activities or structures, such as development, roads, or land clearings. These corridors enable movement of individuals between populations, which helps to prevent negative effects of inbreeding and reduced genetic diversity, often caused by genetic drift, that can occur in isolated populations. Additionally, corridors support the re-establishment of populations that may have been reduced or wiped out due to random events like fires or disease. They can also mitigate some of the severe impacts of habitat fragmentation, a result of urbanization that divides habitat areas and restricts animal movement. Habitat fragmentation from human development poses an increasing threat to biodiversity, and habitat corridors help to reduce its harmful effects.

The Nature Conservancy (TNC) is a global environmental organization headquartered in Arlington, Virginia. As of 2021, it works via affiliates or branches in 79 countries and territories, as well as across every state in the US.

Founded in 1951, The Nature Conservancy has over one million members globally as of 2021 and has protected more than 119,000,000 acres (48,000,000 ha) of land in its history. As of 2014, it is the largest environmental non-profit organization by assets and revenue in the Americas.

At the 9th World Wilderness Congress in Mérida, Mexico, WILD, with the collaboration of a spectrum of international organizations, governments and individuals, introduced Nature Needs Half, which aspires that humans give up use of half of land and water on Earth, in order to support wilderness. Marine biologist Sylvia Earle and Jane Goodall have endorsed Nature Needs Half, with Earle's only criticism being that she "hoped that half would be enough". Since its inception, WILD has begun collecting and conducting case studies of places around the world that have, or are on track to achieve, at least half protection.

Biodiversity in agriculture is the measure of biodiversity found on agricultural land. Biodiversity is the total diversity of species present in an area at all levels of biological organization. It is characterized by heterogeneous habitats that support the diverse ecological structure. In agricultural areas, biodiversity decreases as varying landscapes are lost and native plants are replaced with cultivated crops. Increasing biodiversity in agriculture can increase the sustainability of farms through the restoration of ecosystem services that aid in regulating agricultural lands. Biodiversity in agriculture can be increased through the process of agroecological restoration, as farm biodiversity is an aspect of agroecology.

Biodiversity is the measure of biotic and abiotic diversity in an ecosystem, described by heterogeneity. The loss of biodiversity in agriculture has been an increasing issue since the global increase of food demands and success of popular crops. This loss of heterogeneity declines species biodiversity on agricultural lands. Biodiversity in agriculture is essential in providing ecosystem services, which conserves biodiversity while providing agricultural services.