Climate-change habitat shifts for the vulnerable endemic oak species(Quercus arkansana Sarg.)

Quercus arkansana(Arkansas oak)is at risk of becoming endangered,as the total known population size is represented by a few isolated populations.The potential impact of climate change on this species in the near future is high,yet knowledge of its predicted effects is limited.Our study utilized the biomod2 R package to develop habi-tat suitability ensemble models based on bioclimatic and topographic environmental variables and the known loca-tions of current distribution of Q.arkansana.We predicted suitable habitats across three climate change scenarios(SSP1-2.6,SSP2-4.5,and SSP5-8.5)for 2050,2070,and 2090.Our findings reveal that the current suitable habitat for Q.arkansana is approximately 127,881 km^(2) across seven states(Texas,Arkansas,Alabama,Louisiana,Mississippi,Georgia,and Florida);approximately 9.5%is encompassed within state and federally managed protected areas.Our models predict that all current suitable habitats will disap-pear by 2050 due to climate change,resulting in a northward shift into new regions such as Tennessee and Kentucky.The large extent of suitable habitat outside protected areas sug-gests that a species-specific action plan incorporating pro-tected areas and other areas may be crucial for its conserva-tion.Moreover,protection of Q.arkansana habitat against climate change may require locally and regionally focused conservation policies,adaptive management strategies,and educational outreach among local people.

Modifications in aroma characteristics of'Merlot'dry red wines aged in American,French and Slovakian oak barrels with different toasting degrees

Aging in oak barrels is widely used in enology which could bring flavor changes and aromatic complexity to wines.In the present study,the aroma compounds were analyzed from the‘Merlot’dry red wines,which were fermented in two types of fermenters(stainless steel tank and rotated oak barrel)and aged in six types of oak barrels(three geographic origins×two toasting degrees)for different time(0,3,6 and 9 months,respectively).Results showed that 30 volatiles were associated with barrels and increased during oak aging.The fermenters could influence the intensities of the toast,leathery,smoky,fruity,floral and caramel aromas.The concentration of whisky lactone,eugenol,cis-isoeugenol,and the intensities of the toast and spicy aromas were highest in the wines aged in American oak and were lowest in the wines aged in French oak barrels.The concentrations of guaiacol,syringol,trans-isoeugenol,furfural alcohol,vanilla,cis-whisky lactone enabled the medium toasting barrels to be distinguished from the light toasting ones.The compounds originating from the barrels could be used to distinguish the types of different barrels,but the other general grape-derived and fermentation-derived volatiles could not.The fermenters,oak species and toasting degrees of the barrels all had significant effects on the aroma profiles of the aged‘Merlot’dry red wines,but the influence of the geographic origin was not obvious.

Leaf traits from stomata to morphology are associated with climatic and edaphic variables for dominant tropical forest evergreen oaks

Aims Understanding variation and coordination of leaf traits at multiscales along elevational gradients can help predict the likely responses of dominant species to climate change.We seek to determine the extent to which variation in leaf stomatal,anatomical and morphological traits is associated with environmental factors,and whether ecological strategies of Cyclobalanopsis species shift with elevations.Methods In a tropical forest landscape in Jianfengling,South China,we determined leaf traits related to stomata,anatomy and morphology of six evergreen oak species(Cyclobalanopsis bambusaefolia,C.hui,C.patelliformis,C.fleuryi,C.tiaoloshanica and C.phanera)along a long elevational gradient(400–1400 m above sea level).Important Findings We found that stomatal density and stomatal pore index increased,whereas spongy mesophyll thickness to leaf thickness ratios decreased,significantly with elevation.The leaf area and leaf dry matter content increased and decreased,respectively,with elevation.Variations in stomatal,anatomical and morphological traits were mainly correlated to the mean annual temperature,mean annual sum precipitation and soil pH.At low and high elevations,the oak species exhibited strong stress tolerance combined with competition strategy,while they shifted toward more clearly the competitive strategy at intermediate elevations.And the changes in soil phosphorus concentration and soil pH along the elevation may drive the shift of ecological strategy.The results showed that the dominant oak species in tropical forests respond to environmental change by modulating traits at multiple levels,from that of the individual cell,through tissue and up to the whole leaf scale.