Final Report Summary - ALT-LAT-RANGE (Can altitudinal data predict latitudinal responses of plants to climate change?)
Rapid changes in climate are predicted to disrupt the conditions which determine the distribution of species, with the most dramatic effects predicted to occur at species range edges. At the population level, such changes induce range shifts, both at altitudinal and latitudinal level. With this study, we aimed: i) to determine the capacity for population expansion in altitude and latitude as a consequence of climatic change, ii) to evaluate the likely range contraction at species lowermost/southernmost distribution limits due to changes in growth and reproduction, and iii) to analyse local adaptations able to alter plant responses to climatic alterations. We reached these objectives selecting two widely distributed species across Europe (Pinus sylvestris and Juniperus communis) as focal species and following two main approaches: a) a field study explicitly comparing the demographical structure, growth and reproduction investment of populations across both latitudinal and altitudinal gradients covering the complete distribution range of the focal species, from Mediterranean to the Arctic; and b) controlled conditions experiments to determine geographical variations in the response to foreseen climatic conditions as well as morphological and physiological local adaptations. We found evidence for altitudinal range displacement for both focal species at the southern edge of the distribution, by a health decline at the lower populations and vigour increase on populations at higher altitudes. In addition, we detected a consistent advance of treeline across the complete latitudinal distribution in response to the detected rise in temperature in the northern hemisphere during the last decades. By means of different experiments strictly under controlled environment, we analysed the physiological response of P. sylvestris seedlings from the two latitudinal extremes to the predicted climate for the coming decades. Increased temperatures reduced germination time and enhanced biomass gain at both ranges, but improved survival only at northern limit while decreasing it at the southern range edge. Higher precipitation also increased survival and biomass, but only under a southern climate. Seeds from the southern origin emerged faster, produced bigger seedlings, and allocated higher biomass to roots and survived better than northern ones, which conferred on them higher survival probabilities, better nutritional status and lower drought stress. Our results indicate that recruitment will be reduced at the southernmost range of the species, whereas it will be enhanced at the northern limit, and that the southern seed sources are better adapted to survive under drier conditions. Thus, recruitment at the latitudinal range limits of P. sylvestris is likely to be heavily impacted by predicted changes in climate for the coming decades. These results also help us to understand the mechanisms of local adaptation at the southern range edge and indicate southern populations as a valuable genetic resource to buffer the response of Scots pine against such extreme climatic events.
The objectives and main findings of the project ALT-LAT-RANGE are publicly accessible through the following websites:
https://sites.google.com/site/lmatiasecology/home/projects
http://www.biogeo.org/ASJ/Pine_AltLat.html
The objectives and main findings of the project ALT-LAT-RANGE are publicly accessible through the following websites:
https://sites.google.com/site/lmatiasecology/home/projects
http://www.biogeo.org/ASJ/Pine_AltLat.html