Naturalized distributions show that climatic disequilibrium is structured by niche size in pines (PinusL.)

Abstract

Aim The assumption that the native distributions of species are in equilibrium with climate has been shown to be frequently violated, despite its centrality to many niche model applications. We currently lack a framework that predicts these violations. Here, we examine whether variation in climatic disequilibrium is structured by properties of species’ native distributions and climatic niches. Location Global. Methods We built climatic niche models for 106 pine (Pinus L.) species, including 25 that have naturalized outside their native range. We measured the extent of climate space occupied exclusively by naturalized populations and considered what fraction of this space was available within the native continent and near the native range. We examined the consequences of disequilibrium for estimates of potential range filling and sister species niche conservatism. Results Most species (23 of 25) have naturalized in climate conditions outside the native niche, leading to increases in the total known suitable climate space. Increases in niche size were negatively related to native niche size. Increases were often large; one species expanded its niche by almost 10% of the global climate space. These increases were associated primarily with cooler, wetter and less seasonal climates. Increases in known niche size lowered potential range filling estimates within species’ native continent and ecoregion. Naturalized data did not strengthen support for niche conservatism among sister species. Main conclusions Among pines, climatic disequilibrium is the norm and not the exception. The magnitude of this disequilibrium can be vast, such that the native range greatly under‐represents the true climatic tolerances of some species. Fortunately, this disequilibrium can be predicted largely by the size of a species’ native niche. Accounting for this disequilibrium can improve our ability to characterize ecological phenomena, including potential range filling. This is an essential step towards improving the conservation value of ecological niche models.

Highly invasive tree species are more dependent on mutualisms

“…Also, the higher the value of positive Z scores, the more invasive a species would be (Rejmánek et al ). In this regard, based on a recently compiled database of worldwide occurrences of naturalized Pinus species (Perret et al ) the Z score is positively and highly correlated with the number of naturalized occurrences for the 34 species included in our database ( P < 0.0001; R 2 = 0.38). On the other hand, lower values of seed mass correspond to a higher invasive capacity for Pinus species (Richardson et al , , Rejmánek , Rejmánek and Richardson , Grotkopp et al , Grotkopp et al , Rejmánek et al ).…”

“…Further, according to a global database of invasive trees and shrubs, 90% of Pinus species that have become invasive around the world have been classified as invasive according to the Z score (Rejmánek and Richardson ). In addition, according to a recently compiled database of Pinus species naturalized occurrences, the Z score is highly and positively correlated with the number of sites where each species has become naturalized ( P < 0.0001; R 2 = 0.38) (Perret et al ). However, some of the Pinus species regarded as noninvasive have not been widely introduced outside their native range (Essl et al , McGregor et al ), which results in reduced number of opportunities for invasion (Lockwood et al ).…”

Closely related species show species-specific environmental responses and different spatial conservation needs: Prionailurus cats in the Indian subcontinent

“…However, evidence for species-specific ecological requirements among closely related species has also been widely reported in the literature 13 , and hence assuming conservatism in environmental responses can lead to erroneous conclusions. For example, closely related species of pines 14 , 15 , tropical amphibians 16 , 17 , tropical lizards 18 – 20 and small mammals 21 have shown unique niche properties. Evidence is considerably sparser for small endothermic species in the tropics, though not completely absent 22 , 23 .…”

Seed release by a serotinous pine in the absence of fire: implications for invasion into temperate regions

“…However, pines have also been introduced to regions outside their native climate niche, particularly to regions with cooler, wetter and less seasonal climates (Essl et al 2011; Perret et al 2019). Such environments are often described as non-fire-prone ( sensu Lamont and He 2017) and are typically characterized by plant species without unambiguous adaptations to fire (i.e.…”