Nitrogen-fixing in the context of "Fire"

The peanut (Arachis hypogaea), also known as the groundnut, goober (US), goober pea, pindar (US) or monkey nut (UK), is a legume crop grown mainly for its edible seeds, contained in underground pods. It is widely grown in the tropics and subtropics by small and large commercial producers, both as a grain legume and as an oil crop. Geocarpy is atypical among legumes, which led botanist Carl Linnaeus to name the species hypogaea, from Greek 'under the earth'.

The peanut belongs to the botanical family Fabaceae (or Leguminosae), commonly known as the legume, bean, or pea family. Like most other legumes, peanuts harbor symbiotic nitrogen-fixing bacteria in root nodules, which improve soil fertility, making them valuable in crop rotations.

An endosymbiont or endobiont is an organism that lives within the body or cells of another organism. Typically, the two organisms are in a mutualistic relationship. Examples are nitrogen-fixing bacteria (called rhizobia), which live in the root nodules of legumes, single-cell algae inside reef-building corals, and bacterial endosymbionts that provide essential nutrients to insects.

Endosymbiosis played key roles in the development of eukaryotes and plants. Roughly 2.3 billion years ago an archaeon (likely within the Asgard superphylum) absorbed an alphaproteobacterium through phagocytosis, that eventually became the mitochondria that provide energy to almost all living eukaryotic cells. Approximately 1 billion years ago, some of those cells absorbed cyanobacteria that eventually became chloroplasts, organelles that produce energy from sunlight. Approximately 100 million years ago, a lineage of amoeba in the genus Paulinella independently engulfed a cyanobacterium that evolved to be functionally synonymous with traditional chloroplasts, called chromatophores.

Fire is the rapid oxidation of a fuel in the exothermic chemical process of combustion, releasing heat, light, and various reaction products.Flames, the most visible portion of the fire, are produced in the combustion reaction when the fuel reaches its ignition point temperature. Flames from hydrocarbon fuels consist primarily of carbon dioxide, water vapor, oxygen, and nitrogen. If hot enough, the gases may become ionized to produce plasma. The color and intensity of the flame depend on the type of fuel and composition of the surrounding gases.

Fire, in its most common form, has the potential to result in conflagration, which can lead to permanent physical damage. Fire directly impacts land-based ecological systems worldwide. The positive effects of fire include stimulating plant growth and maintaining ecological balance. Its negative effects include hazards to life and property, atmospheric pollution, and water contamination. When fire removes protective vegetation, heavy rainfall can cause soil erosion. The burning of vegetation releases nitrogen into the atmosphere, unlike other plant nutrients such as potassium and phosphorus which remain in the ash and are quickly recycled into the soil. This loss of nitrogen produces a long-term reduction in the fertility of the soil, though it can be recovered by nitrogen-fixing plants such as clover, peas, and beans; by decomposition of animal waste and corpses, and by natural phenomena such as lightning.