The Potential for Future Shifts in Tree Species Distribution Provided by Dispersal and Ecological Niches: A Comparison between Beech and Oak in Europe

Abstract

(1) Due to global warming, distribution ranges of temperate tree species are shifting northwards and upslope to cooler areas. Shifts in distribution first become visible through changes in regeneration dynamics. However, the future distribution of tree species in the face of rapid climate change depends not only on the climatic suitability of the tree species, but also on its ability to disperse into new habitats. The aim of the study was therefore to examine how the distribution of European beech and European oak shifts and how species can spread from fragmented seed trees. (2) In order to investigate the shift in distribution of beech and oak, the bioclimatic envelopes of the old trees and different size classes of the natural regeneration were compared. Subsequently, a simulation of the potential distribution for the present climate, as well as for the climate for the reference period 2091–2100, for three different representative concentration pathways (RCP) scenarios was determined. In order to determine which of these areas can actually be colonised, a dispersal potential for the species was determined using a quantile regression, taking habitat fragmentation into account. (3) The results of the present study demonstrate range shifts of the tree species regeneration distribution (B0, B1 and B2) compared to the overstorey distribution (OST). While oak regeneration shows an expansion of its distribution in the cold-wet range, beech regeneration shows a reduction of its distribution in the dry-warm range. As the dispersal potential of oak exceeds that of beech, it is expected that oak will be better able to spread from fragmented seed trees. However, the results also indicate that many areas, despite climatic suitability, cannot be colonised due to too large dispersal distances. (4) For the forest management, this results in an important planning tool for future tree species composition, as climatic suitability, habitat connectivity and dispersal ability are taken into account.

Veteran trees in decline: Stratified national monitoring of oaks in Norway

“…While oak in Norway is at the northernmost border of its distribution in Europe, the ongoing climate change might shift oak distribution northward (Dyderski et al, 2018, Axer et al, 2021, thereby increasing the importance of populations of oak and associated species in Norway. Veteran oaks and other very old trees can be especially important in light of climate change, as they represent an evolutionary resource with genotypes stemming from establishment under a range of different environmental conditions (Cannon et al, 2022).…”

Tendencias mundiales en el modelado de la distribución de especies arbóreas

“…Frecuencia y porcentaje de uso de variables incluidas en modelos complejos de 250 publicaciones de distribución de especies arbóreas en el periodo 1990-2022. (physiological, climatic, edaphological variables, solar radiation, species genetics, area disturbance and habitat suitability variables of the species studied) (Axer et al, 2021;Manzanilla-Quijada et al, 2020;Ramírez-Magil et al, 2020), and even have sufficient data on species abundance to allow their inclusion in the model (Bañuelos-Revilla et al, 2019).…”

“…(3) elevación y variables derivadas, tales como topografía de pendiente, curvatura o rugosidad y microclimáticas; (4) variables obtenidas mediante teledetección, como índices de vegetación, temperatura en superficie o clasificaciones de la cubierta del suelo, que han sido poco empleadas aunque tienen potencial importante (Chen et al, 2022). No obstante, 21.6 % de las publicaciones poseen información suficiente para hacer análisis complejos (variables fisiológicas, climáticas, edafológicas, radiación solar, genética de la especie, perturbación del área y variables de idoneidad de hábitat de las especies estudiadas) (Axer et al, 2021;Manzanilla-Quijada et al, 2020;Ramírez-Magil et al, 2020), incluso, cuentan con datos suficientes de abundancia de las especies que permiten su inclusión en el modelo (Bañuelos-Revilla et al, 2019).…”

More losses than gains? Distribution models predict species-specific shifts in climatic suitability for European beech forest herbs under climate change

“…In the study coming from Romanian Carpathians (García-Duro et al, 2021), forests dominated by Fagus sylvatica were most vulnerable to climate change, with drought periods associated with large mortality events. Moreover, beech regeneration showed a reduction of its distribution in the dry-warm range (Axer et al, 2021). Increasing dieback of beech and other co-occurring tree species induced by heatwaves and drought stress (Margalef-Marrase et al, 2020;Lloret et al, 2022) is assumed to have strong effect on plant species assemblages because these communities show high degree of association with Fagus sylvatica and forest stand properties in beech-dominated ecosystems.…”