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Climate change’s huge impact on Mediterranean species’ habitat suitability and spatial and temporal distribution in the coming decades is expected. The present work aimed to reconstruct rockrose (Cistus ladanifer L.) historical and future spatial distribution, a typically Mediterranean species with abundant occurrence in North Africa, Iberian Peninsula, and Southern France. The R ensemble modeling approach was made using the biomod2 package to assess changes in the spatial distribution of the species in the Last Interglacial (LIG), the Last Glacial Maximum (LGM), and the Middle Holocene (MH), in the present, and in the future (for the years 2050 and 2070), considering two Representative Concentration Pathways (RCP 4.5 and RCP 8.5). The current species potential distribution was modeled using 2,833 occurrences, six bioclimatic variables, and four algorithms, Generalized Linear Model (GLM), MaxEnt, Multivariate Adaptive Regression Splines (MARS), and Artificial Neural Networks (ANN). Two global climate models (GCMs), CCSM4 and MRI-CGCM3, were used to forecast past and future suitability. The potential area of occurrence of the species is equal to 15.8 and 14.1% of the study area for current and LIG conditions, while it decreased to 3.8% in the LGM. The species’ presence diaminished more than half in the RCP 4.5 (to 6.8% in 2050 and 7% in 2070), and a too low figure (2.2%) in the worst-case scenario (RCP 8.5) for 2070. The results suggested that the current climatic conditions are the most suitable for the species’ occurrence and that future changes in environmental conditions may lead to the loss of suitable habitats, especially in the worst-case scenario. The information unfolded by this study will help to understand future predictable desertification in the Mediterranean region and to help policymakers to implement possible measures for biodiversity maintenance and desertification avoidance.

Growing forests wildfires in Portugal are an increasing concern since forests in the Mediterranean region are vulnerable to recent global warming. Long-term negative effects are expected on the vegetation with the coming increasing drought. The strawberry tree (Arbutus unedo L.) displays potential to be a successfully business-like cultured in several regions of Portugal and southern Europe, as it is well adapted to climate and soils. In Portugal, this species has been used by local populations particularly for spirit production and for fruit consumption, although it has different possible commercial uses, from processed and fresh fruit production to ornamental, pharmaceutical and chemical applications. In addition, due to its pioneer status, it is valuable for land recovery and desertification avoidance, besides being fire resistant. The available strawberry tree’s data is presence-only. For modelling purposes, a set of placements within the landscape of interest (Portugal) was applied. The species, observed in 318 plots, together with a vector of environmental covariates (7 bioclimatic attributes, slope and altitude) and a defined background were used for modeling purposes. Maxent 3.4.1 was the used software, where the estimated quantity is the probability of the presence of the species, conditioned on the environment. Maxent uses the environmental covariate data from the occurrence records and the background sample, to estimate the ratio between the conditional density of the covariates at the presence sites and the marginal (i.e., unconditional) density of covariates across the study area and so, estimating the relative suitability of one place vs. another. Three different climate scenarios (control run; 2050 and 2070) were tested for two emission scenarios (RCP 4.5 and RCP 8.5, WorldClim), besides the past, 6,000 BP (Mid-Holocene). The reduction of habitat suitable for this species is very significant in the southern regions, even for the best warming scenario (RCP 4.5) in 2050. Central and Northern mountain regions are predicted refuge for this species. Forest policies and management should consider the impact of climate change on the usable areas for forestry, seeing a case-study species particularly adapted to the Mediterranean regions and wildfires, such as strawberry tree. The distribution of the species in the Middle Holocene agrees with previous genetic and fossils studies in the region, which supported two putative refuges for the species since the Last Glacial Maximum and a cryptic refugia in the East-Central mountain region.

A região do Mediterrâneo sofrerá um elevado aumento de temperatura, cerca de 1,5 vezes superior ao período 1880-1920, por comparação com as outras regiões do mundo. Os impactos na floresta em Portugal, devido às alterações climáticas, sugerem uma tendência na migração de espécies, do sul para o norte e do interior para as áreas costeiras. Além disso, sob este cenário, as florestas podem desaparecer das áreas mais secas (a região interior do sul). O risco de incêndios florestais aumentará num clima mais quente e seco e pode ainda ser aumentado pela acumulação de biomassa de alta inflamabilidade no Verão. O impacto na economia florestal pode ser extremamente severo, a diminuição da produtividade, o aumento do risco de incêndio e o risco de pragas e doenças, e podem tornar o investimento florestal pouco atraente, resultando no aumento do abandono florestal. Neste estudo, o nosso objetivo foi modelar do ponto de vista ecológico uma espécie tipicamente mediterrânea amplamente distribuída no país e na região do Mediterrâneo, o medronheiro (Arbutus unedo L.). Através da modelação, é possível revelar o impacto dos fatores ambientais na distribuição dos habitats do medronheiro e avaliar a alteração do nicho ecológico usando cenários contrastantes de aquecimento global. Para aumentar o nosso conhecimento sobre a distribuição espacial da espécie, 318 pontos de presença da espécie, juntamente com um vetor de covariáveis ambientais (7 atributos bioclimáticos, declive e altitude) e pontos de não presença, foram utilizados para modelação. Os dados climáticos atuais e futuros foram obtidos através do WorldClim. Finalmente, a vulnerabilidade do medronheiro aos efeitos da mudança climática global foi examinada usando dois cenários de emissões (RCP 4.5 e 8.5), para prever mudanças de distribuição nos anos 2050 e 2070, utilizando um software de modelação ecológica (MaxEnt). A redução do habitat adequado para esta espécie é significativa nas regiões do sul, considerando os futuros cenários de aquecimento global. As regiões montanhosas do centro e do norte são presumíveis refúgios previstos para esta espécie. A política de gestão florestal deve refletir o impacto da mudança climática nas áreas utilizáveis para a silvicultura, considerando em particular as espécies adaptadas às regiões do Mediterrâneo e aos incêndios florestais, como o medronheiro.