Air flows depend on global temperatures. The higher the latter, the stronger the winds. A 2-degree centigrades increase might spur the dispersal of pollens and seeds over much larger areas than usual. As a result of stronger winds caused by global warming, seeds and pollen of Northern forests are being carried over longer distances, spreading them over previously unreached areas. Northern forests, then, could somehow benefit from global warming.
A research carried on by the University fof Helsinki found that a temperature only three degrees Celsius warmer increased the dispersal of seeds and the speed at which populations spread throughout the growth season. Particularly for those plants which have light seeds, the annual spreading speed increased dramatically, by approximately 30–40 meters.
Seed and pollen dispersal profoundly affects the dynamics and genetic variation of plant populations. Spreading into more favourable areas will help them survive in the warming climate. Wind conditions play a key role, as turbulent vertical streams, in particular, spread seeds very efficiently, even over long distances.
On the basis of these results, it seems that global warming accelerates the spread of plants, but it will not alone be sufficient to help plant populations to relocate to new vegetation zones. However, on a more local level, global warming may have a significant impact, as original and newly introduced species spread faster from one place to another and take over new patches of habitat. The combined effects of global warming are difficult to predict, and the research carried out by Kuparinen’s team illustrates the complexity of ways in which increased temperatures may affect the flora in Northern forest habitats.