Browsing by Author "Kamppari, Visa"

Many noble hardwood species of boreal and temperate climate zones will experience increased selection pressure for adaptive traits as climate change proceeds. This will cause shifts in the timing of phenological events such as budburst in spring. Shifts in phenology may disrupt interaction between species and their environment as well as interaction within and between species. Changes in the timing of annual life cycle traits may threaten species’ current fitness and potential to adapt to future climates. The rate and magnitude of phenological shifts will increase along with increasing temperatures. To adapt to changing environmental conditions, species need to possess adaptive variation in life cycle traits. In small and isolated populations at northern margins of species distribution, variation in adaptive traits is threatened by low genetic variation, low gene flow and genetic drift. To preserve the adaptive potential of noble hardwood populations in Finland, ex situ gene conservation collections are established where genetic resources are conserved as living trees. To characterize the adaptive potential currently present in Finnish gene conservation collections of European maple (A. platanoides L.), small-leaved linden (T. cordata Mill.) and European white elm (U. laevis Pall.), the amount of current phenological diversity should be evaluated. For this purpose, budburst progress in the collections was tracked by phenotypic observations on budburst phenological phases in relation to accumulating temperature. The data did not allow for analysis of variance between origin populations; therefore, a more conservative approach was chosen where conserved genetic resources were assessed by examining budburst differentiation between groups of origin populations. The level of differentiation in budburst temperatures is used as an indicator of spring phenological diversity to determine if the conserved origins are adapted to the same spring temperature range. No significant differentiation was found in the timing of budburst between groups of origins. Therefore, the conserved origins are presumed to be adapted to the same spring temperature range within their respective species distribution in Finland. However, low phenological diversity may magnify the threats imposed to these species by climate change. Genetic studies are recommended for deeper understanding of underlying genetic diversity and adaptive potential of the stored genetic resources.