Disturbance (ecology) in the context of "Wildlife management"

An old-growth forest or primary 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 (34 percent) 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.

As of 2020, the world has 1.11 billion ha (2.7 billion acres) of primary forest remaining. Combined, three countries (Brazil, Canada, and Russia) host more than half (61 percent) of the world's primary forest. The area of primary forest has decreased by 81 million ha (200 million acres) since 1990, but the rate of loss more than halved in 2010–2020 compared with the previous decade.

In the context of ecological stability, resistance is the property of communities or populations to remain "essentially unchanged" when subject to disturbance. The inverse of resistance is sensitivity.

In ecology, resilience is the capacity of an ecosystem to respond to a perturbation or disturbance by resisting damage and subsequently recovering. Such perturbations and disturbances can include stochastic events such as fires, flooding, windstorms, insect population explosions, and human activities such as deforestation, fracking of the ground for oil extraction, pesticide sprayed in soil, and the introduction of exotic plant or animal species. Disturbances of sufficient magnitude or duration can profoundly affect an ecosystem and may force an ecosystem to reach a threshold beyond which a different regime of processes and structures predominates. When such thresholds are associated with a critical or bifurcation point, these regime shifts may also be referred to as critical transitions.

Human activities that adversely affect ecological resilience such as reduction of biodiversity, exploitation of natural resources, pollution, land use, and anthropogenic climate change are increasingly causing regime shifts in ecosystems, often to less desirable and degraded conditions. Interdisciplinary discourse on resilience now includes consideration of the interactions of humans and ecosystems via socio-ecological systems, and the need for shift from the maximum sustainable yield paradigm to environmental resource management and ecosystem management, which aim to build ecological resilience through "resilience analysis, adaptive resource management, and adaptive governance". Ecological resilience has inspired other fields and continues to challenge the way they interpret resilience, e.g. supply chain resilience.

Ecological succession is the process of how species compositions change in an ecological community over time.

The two main categories of ecological succession are primary succession and secondary succession. Primary succession occurs after the initial colonization of a newly created habitat with no living organisms. Secondary succession occurs after a disturbance such as fire, habitat destruction, or a natural disaster destroys a pre-existing community.

Temperate deciduous or temperate broadleaf forests are a variety of temperate forest 'dominated' by deciduous trees that lose their leaves each winter. They represent one of Earth's major biomes, making up 9.69% of global land area. These forests are found in areas with distinct seasonal variation that cycle through warm, moist summers, cold winters, and moderate fall and spring seasons. They are most commonly found in the Northern Hemisphere, with particularly large regions in eastern North America, East Asia, and a large portion of Europe, though smaller regions of temperate deciduous forests are also located in South America. Examples of trees typically growing in the Northern Hemisphere's deciduous forests include oak, maple, basswood, beech and elm, while in the Southern Hemisphere, trees of the genus Nothofagus dominate this type of forest. Temperate deciduous forests provide several unique ecosystem services, including habitats for diverse wildlife, and they face a set of natural and human-induced disturbances that regularly alter their structure.

A secondary forest (or second-growth 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 (primary or primeval 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.

The legal definition of what constitutes a secondary forest vary between countries. Some legal systems allows certain degree of subjectivity in assigning a forest as secondary.