Despite the prolonged miserable weather during the so-called “spring”, the deciduous trees leafed out nicely, birds sing, and woodland flowers begin to bloom. On my home pond I’ve seen several broods of mallards at different times: one of three fuzzy ducklings, one of five, and one of eight. The small broods only stayed a couple of days before moving on. But the brood of eight stayed for over a week, losing one duckling, perhaps to a predator, until they began to get real feathers. In early June, a sleek, well-grown young junco appeared on the deck railing, fully capable of flying and feeding itself but an attentive parent also fed it. Several younger junco fledglings, sporting fine brown streaks, came to feed on seeds too. A pair of red-breasted nuthatches brought their brood of four fledglings to feed on suet and, later, some peanut butter.
A friend and I chose to stroll to Nugget Falls on a morning when — Hallelujah!! — no cruise ships were in and the parking lot and trail would not be jammed with excessively numerous visitors from the monster ships. And no thundering helicopters headed up the Valley toward the glacier. There were a few friendly folks on the trail, presumably locals and independent travelers.
So the stroll was peaceful and the birds were singing. Some robins already were feeding chicks but their songs continued. Wilson’s warblers sang their punctuated song from deep in the understory brush. Orange-crowned warblers, also invisible, added their high-pitched trill. And we heard what was possibly a warbling vireo. Down at ground level, fringe-cup was blooming, many flowers draped on a fairly tall stem, and pink pyrolas had big buds.
My curiosity may get me into trouble sometimes and it certainly gets me into things that are over my head. In this case, it’s plant physiology. And so I must content myself with reporting the basic observations.
In late May, a friend and I were out for a stroll and happened to notice some Sitka spruce cones. Spruces, like most conifers, have both male and female sex organs on the same tree. We remembered reading that the female cones are usually borne near the top of a tree, while male cones are produced on lateral branches below that. That is not a firm rule, however.
We found some spruces with new female cones down at our eye-level and some with old cones just a few feet above the ground. There were two big spruces with exuberant crops of new male cones reaching as far up as we could see, covering every visible branch (except one at the bottom with an old female cone). Those male cones were loaded with pollen that shook loose when the wind stirred the branch. Both of those trees had little or no new needle growth at the tips of the branches.
We then began to look more closely at the branch tips, where new growth (called “spruce tips”) and cones commonly are produced. New growth usually appears at the very end of the branch, sometimes with one or two (or three or even five) sub-terminal bunches of new needles. But sometimes at least one of those sites was occupied by a male cone. We observe that new growth and cones are usually best developed on the best-lit sides of a tree, suggesting that the resources for producing those structures are most available there. But what determines the allocation of resources among the cones and new growth? And what regulates the location of the cones? Plant hormones are probably activated in different ways in different places. But what governs that activity?
Mary F. Willson is a retired professor of ecology.“On The Trails” appears every Wednesday in the Juneau Empire.
Photo by Mary Willson / courtesy Young female spruce cones grow upright and bend down to open when the seeds are ripe and ready to disperse.
Photo by Mary Willson / courtesy A few “macho” spruce trees bore male cones as far up as we could see and very little new growth.
