Black walnuts are supposed to be classic cases on allelopathy. Yet there is nothing in these “Caddo” black walnuts that really says “allelopathy” very strongly. Many trees had close neighbours, and several of them had Virginia Creeper growing on them. Not exactly what I would expect of an allelopathic tree. I need to find out more about what’s going on.
On Friday I went out to one of the Caddo canyons with T.H. Milby and George Geissler (a state forester) to core black walnut trees that are parent trees in T.H.’s study.
The last time I did any tree-coring it was some of Lissa’s Austrian Pines at Saugatuck Dunes State Park. That was a long time ago. Unlike that time, we had an experienced tree-corer to line up the corer, and a well-maintained core. That really made a lot of difference when it came to extracting the cores. I was really surprised at how wet the heartwood was – it was far wetter than the sapwood. It probably was a consequence of the wet weather. Initially George suggested that the tree was probably hollow at some point, but it seemed a little less certain when every tree was equally wet at the core. They may well all have holes, but it’s always less likely when every tree was like that.