Converse relationIn mathematics, the converse relation, or transpose, of a binary relation is the relation that occurs when the order of the elements is switched in the relation. For example, the converse of the relation 'child of' is the relation 'parent of'. In formal terms, if and are sets and is a relation from to then is the relation defined so that if and only if In set-builder notation, The notation is analogous with that for an inverse function. Although many functions do not have an inverse, every relation does have a unique converse.
MinerotrophicMinerotrophic refers to environments that receive nutrients primarily through groundwater that flows through mineral-rich soils or rock, or surface water flowing over land. Minerotrophic, “minerogenous”, and “geogenous” are now often used interchangeably, although the latter two terms refer primarily to hydrological systems, while the former refers to nutrient dynamics. The hydrologic process behind minerotrophic wetlands results in water that has acquired dissolved chemicals which raise the nutrient levels and reduce the acidity.
Cultivated plant taxonomyCultivated plant taxonomy is the study of the theory and practice of the science that identifies, describes, classifies, and names cultigens—those plants whose origin or selection is primarily due to intentional human activity. Cultivated plant taxonomists do, however, work with all kinds of plants in cultivation. Cultivated plant taxonomy is one part of the study of horticultural botany which is mostly carried out in botanical gardens, large nurseries, universities, or government departments.
CultigenA cultigen () or cultivated plant is a plant that has been deliberately altered or selected by humans. Cultigens result from artificial selection. These plants have commercial value in horticulture, agriculture or forestry. Because cultigens are defined by their mode of origin and not by where they grow, plants meeting this definition remain cultigens whether they are naturalised, deliberately planted in the wild, or grown in cultivation.
CultivarA cultivar is a kind of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include division, root and stem cuttings, offsets, grafting, tissue culture, or carefully controlled seed production. Most cultivars arise from purposeful human manipulation, but some originate from wild plants that have distinctive characteristics. Cultivar names are chosen according to rules of the International Code of Nomenclature for Cultivated Plants (ICNCP), and not all cultivated plants qualify as cultivars.
Quaternary extinction eventThe latter half of the Late Pleistocene to the beginning of the Holocene (~50,000-10,000 years Before Present) saw extinctions of numerous predominantly megafaunal species, which resulted in a collapse in faunal density and diversity across the globe. The extinctions during the Late Pleistocene are differentiated from previous extinctions by the widespread absence of ecological succession to replace these extinct megafaunal species, and the regime shift of previously established faunal relationships and habitats as a consequence.
MossMosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (braɪˈɒfətə, ˌbraɪ.əˈfaɪtə) sensu stricto. Bryophyta (sensu lato, Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hornworts. Mosses typically form dense green clumps or mats, often in damp or shady locations. The individual plants are usually composed of simple leaves that are generally only one cell thick, attached to a stem that may be branched or unbranched and has only a limited role in conducting water and nutrients.
