Wednesday, February 17, 2010

Winter! (spring?)


It’s the middle of February and we’ve being going so hard I’ve been letting this report on activities fall way behind. Already this winter (it feels like spring) folks in Forest ecology and botany (RRS 163) have been out looking at forest structure and succession in a variety of field sites. One of the problems of assessing these sites in the winter is figuring out which species of shrubs are present – as the majority have shed their leaves for the winter. The RRS 163 folks have been spending time learning to identify these species just from the twigs with their winter buds.

In the lab, my second year university botany class (Biol 210) has been sectioning and studying the meristems of local native plants and set up a germination study for whitebark pine.

This species of high elevation pine is endangered throughout most of its range, due to three main changes in the subalpine environment. The first, white pine blister rust (Cronartium ribicola), has become an epidemic on whitebark pine since its introduction to North America early in this century.

The second change, the implementation of effective fire suppression, has reduced the regeneration of whitebark pine. This pine species depends on the creation of open areas, where competitive canopy and understory cover has been removed in order for seedlings to become established. There is concern that fire suppression is leading to successional replacement of whitebark pine by more shade tolerant species, such as subalpine fir (Abies lasiocarpa) and Engelmann spruce (Picea engelmanni).

Until recently, Canadian whitebark pine populations where not considered to be under great threat from mountain pine beetle. However, a very large increase in beetle activity in British Columbia in the last few years. Oops! I forgot climate change….but that’s another rant. Learn more about the species and issues here.

Why collect and germinate seeds? Well, the trees that are left after an area has been severely infected by blister rust may have some genetic resistances to the disease. So we collect seeds from these ‘plus’ trees to grow out the seedlings and then attempt to determine if they really do have some genetic resistance by exposing the new individuals to blister rust spores. If they are resistant then more seedlings from those trees will be grown for restoration planting.

Now, germinating the seeds in any amount is notoriously difficult. One method to improve germination success in difficult or ‘recalcitrant’ seeds is making a small nick or cut into the seed coat. This allows water to be more easily taken up by the embryo and has been shown to increase germination success. Therefore, our interests in the germination study is to determine how much of an effect hand nicking the tough mature seed coat of whitebark pine has on boosting germination success of this species.

I’ve also inflicted whitebark mania on the ADGIS spatial statistics students. In their statistical refresher month, they have been learning how to use R for data analysis of whitebark prescribed burn data from the Rocky Mountains National Parks.

Well, all this hard work is going to deserve a trip to the subalpine on skis sometime soon to check out the trees...Maybe some fun pictures next week.

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