Please bear with me as I'm new to the forum and sketchy on my posting ability. I'm interesting in learning more about the mast years of white spruce. How often do they naturally occur and what factors play a part in their frequency? Both my neighbour and I have mature trees but we have different mast years. I had one in 2002 and she is having one this year. I'm in Calgary. Thanks and I hope I can find this again.
Unusual for two trees that close together to have heavy crops in different years. Usually all the trees of a particular species will have their heavy crops in the same years. Determination of when crops occur is partly periodicity - it takes the trees a few years (anything from 2 to 7 or more) to build up sufficient energy reserves; and partly weather - a spell of hot weather when the following year's buds are being developed is the usual trigger to set off a crop. Typically this is in late spring or early summer, so a hot sunny June 2007 will trigger a large crop in 2008. Different species (and perhaps also different populations of one species) have slightly different optimum trigger periods for a crop; thus one species might be adapted to respond to a hot early June, while another might respond to a hot late June. This could possibly explain what you saw with your tree and the neighbour's tree, if they were of different seed origin (e.g. one from local seed, one imported from Quebec or somewhere else). But that's just unproven speculation!
Thanks Michael F. I found this unusual as both trees experience the same environmental conditions including supplemental watering and fertalizing. The seed origin could be a factor as her's was grown from local seed by her son and mine was purchased from a local nursery so may not be from local seed.