A nutrient cycle (or ecological recycling) is the movement and exchange of organic and inorganic matter back into the production of living matter. The process is regulated by food web pathways that decompose matter into mineral nutrients. In biology, detritus is non-living particulate organic material (as opposed to dissolved organic material). It typically includes the bodies or fragments of dead organisms, as well as faecal material.

Conservation biology is the scientific study of the nature and status of Earth's biodiversity with the aim of protecting species, their habitats and ecosystems from excessive rates of extinction and the erosion of biotic interactions. The term conservation biology was introduced as the title of a conference held at the University of California, San Diego in La Jolla, California in 1978 organised by biologists Bruce Wilcox and Michael E. Soulé.

World Environment Day (WED) is observed on June 5 every year to promote awareness on the importance of preserving our biodiversity, the need to identify problems related to the environment and ways to take corrective action. April 22^nd is when the Earth Day is observed.

Biomass derived energy holds the promise of reducing carbon dioxide emission, a significant contributor to global warming, as carbon dioxide acts as a “greenhouse” gas by trapping heat absorbed by the earth from the sun. Although the burning of biomass releases as much carbon dioxide as the burning of fossil fuels, biomass burning does not release “new carbon” into the atmosphere, which the burning of fossil fuels does. The estimated biomass production in the world is 146 billion tonnes a year, consisting of mostly wild plant growth. Wood remains the largest biomass energy source today.

Biomes are climatically and geographically defined as similar climatic conditions on the Earth such as communities of plants, animals and soil organisms. Biomes are defined by factors, such as plant structures (such as trees, shrubs and grasses), leaf types (such as broadleaf and needleleaf), plant spacing (forest, woodland and savanna) and climate. Unlike ecozones, biomes are not defined by genetic, taxonomic or historical similarities.

A habitat corridor, wildlife corridor or green corridor is an area of habitat connecting wildlife populations separated by human activities or structures (such as roads, development or logging). This allows an exchange of individuals between populations, which may help to prevent the negative effects of inbreeding and reduced genetic diversity (via. genetic drift) that often occur within isolated populations.

A temperate grassland or shrubland biome is known commonly as steppe in central Asia, prairie in North America, and pampas in South America.

A savanna or savannah, is a grassland ecosystem characterized by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses. Some classifications also recognize savannah as grasslands from which trees are absent. Savannahs are also characterized by seasonal water availability, with the majority of rainfall confined to one season. Savannahs are subject to regular wildfires and the ecosystem appears to be the result of human use of fire.

The Palaearctic Zone comprises of Eurasia and North Africa. North America falls under the Nearctic Zone. These ecozones are established by World Wide Fund for Nature.

The Siju-Rewak Corridor, located in the Garo Hills of India, protects an important population of elephants (thought to be approximately 20% of all the elephants that survive in the country). This corridor project links together the Siju Wildlife Sanctuary and the Rewak Reserve Forest in Meghalaya State, close to the India-Bangladesh border.

Kelp forests are underwater areas with a high density of kelp. They are recognized as one of the most productive and dynamic ecosystems on Earth. Kelps are large seaweeds (algae). Kelp forests occur worldwide throughout temperate and polar coastal oceans.

Urbanisation can split up habitat areas, causing animals to lose both their natural habitat and the ability to move between regions to use all of the resources they need to survive. Habitat fragmentation due to human development is an ever-increasing threat to biodiversity, and habitat corridors are a possible solution. The Emerald network is an ecological network to conserve wild flora and fauna and their natural habitats of Europe, which was launched in 1998 by the Council of Europe as a part of its work under the Convention on the Conservation of European Wildlife and Natural Habitats or Bern Convention that came into force on 1 June, 1982. Interbreeding is one of the aims of building habitat corridors, since it promotes genetic diversity and improves the overall population.

An ecoregion (ecological region) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than an ecozone. All three of these are larger than an ecosystem. Ecoregions cover relatively large areas of land or water, and contain characteristic, geographically distinct assemblages of natural communities and species. The biodiversity of flora, fauna and ecosystems that characterises an ecoregion tends to be distinct from that of other ecoregions.

Ecotopes are the smallest ecologically distinct landscape features in a landscape mapping and classification system. As such, they represent relatively homogeneous, spatially explicit landscape functional units that are useful for stratifying landscapes into ecologically distinct features for the measurement and mapping of landscape structure, function and change. In ecology, a niche is a term describing the way of life of a species. Each species is thought to have a separate, unique niche. The ecological niche describes how an organism or population responds to the distribution of resources and competitors.

Montane ecology is the branch of ecology that studies life systems on mountains or other high elevation regions on the Earth. The ecosystems on mountains are strongly affected by climate, which gets colder as elevation increases. Dense forests are common at moderate elevations. However, as the elevation increases, the climate becomes harsher, and the plant community transitions to grasslands or tundra.