Niche dynamics in space and time

Niche conservatism, the tendency of a species niche to remain unchanged over time, is often assumed when discussing, explaining or predicting biogeographical patterns. Unfortunately, there has been no basis for predicting niche dynamics over relevant timescales, from tens to a few hundreds of years. The recent application of species distribution models (SDMs) and phylogenetic methods to analysis of niche characteristics has provided insight to niche dynamics. Niche shifts and conservatism have both occurred within the last 100 years, with recent speciation events, and deep within clades of species. There is increasing evidence that coordinated application of these methods can help to identify species which likely fulfill one key assumption in the predictive application of SDMs: an unchanging niche. This will improve confidence in SDM-based predictions of the impacts of climate change and species invasions on species distributions and biodiversity. *These authors contributed equally. Niche conservatism, the tendency of a species niche to remain unchanged over time, is often assumed when discussing, explaining or predicting biogeographical patterns. Unfortunately, there has been no basis for predicting niche dynamics over relevant timescales, from tens to a few hundreds of years. The recent application of species distribution models (SDMs) and phylogenetic methods to analysis of niche characteristics has provided insight to niche dynamics. Niche shifts and conservatism have both occurred within the last 100 years, with recent speciation events, and deep within clades of species. There is increasing evidence that coordinated application of these methods can help to identify species which likely fulfill one key assumption in the predictive application of SDMs: an unchanging niche. This will improve confidence in SDM-based predictions of the impacts of climate change and species invasions on species distributions and biodiversity. *These authors contributed equally. speciation following the division of a large population into at least two new populations that are separated by a geographic barrier. niche attributes of a species or clade are affected by genetic drift or selection in directions that are random and vary independently over time. an aspect of the environmental niche that is defined by limits in climatic variation. Outside of this niche, a population cannot maintain a positive net rate of population increase (e.g. owing to excessively low minimum winter temperature, insufficient growing season precipitation, etc). occurs when natural selection favors phenotypic values that tend to lie either above or below the mean phenotypic value in a population. all environmental conditions that meet the physiological requirements of a species necessary for positive population growth rates (compare fundamental and realized niches, described below). the tendency for the few individuals that disperse and found a new population to carry only a small, and potentially unrepresentative, portion of the genetic variation that exists in their population(s) of origin. the requirements of a species to maintain a positive population growth rate, disregarding biotic interactions. the requirements of a species to maintain positive population growth rates (see fundamental and realized niche). the tendency for related species to have similar fundamental and/or realized niches; also, the tendency for the niche of a species to be little changed over time (i.e. to exhibit temporal autocorrelation). any change in the position of either the fundamental or realized (Hutchinsonian) niche of a species. lack of any kind of change in the niche. Applies to either the fundamental or realized niche. a model in which purely random processes create observed patterns; it is used in constructing a null hypothesis for statistical testing. the tendency for more closely related species to have more similar characteristics. the portion of the fundamental niche in which a species has positive population growth rates, given the constraining effects of biological interactions, such as competition. a model that describes or predicts the probability of the presence or absence of a species across environmental gradients or in a specified geographical area.