A vigorous belt of chilly rain passed over Sewanee this morning. In its wake, a Canada Warbler feeding on the shrubs in our garden. This is a bird of the boreal forest, found here only during migration. Cool rain, falling temperatures, a forecast for a week of low humidity and clear sunny skies, and the Bird from the North: these all speak of the season’s change.
The plants are ready. Many local species make use of the autumnal surge of birds to complete their pollination and seed dispersal. Cardinal flowers bloom along lake edges, beckoning hummingbirds with their crimson blooms. Dogwood and beautyberry offer brightly colored fruits to the passing thrushes, vireos and warblers. These birds feed on North American insects all summer, then become frugivorous on their tropical wintering grounds. They start the fruity feast right here, gobbling the fruits of our native shrubs and depositing the seeds a few hours later.
One of the most abundant of these fruiting shrubs is spicebush (Lindera benzoin), a species that is particularly common on the mountain slopes. This has been an incredible year for spicebush. I’ve never seen so many fruits. The warm spring must have suited them.
Like Christmas trees loaded with goodies, the plants will be stripped bare when the party gets going. For now, they sit in a quiet forest, waiting for the rambunctious guests to arrive. But unlike the treats on Christmas tree which make up just a small part of the festive food, these berries are the main meal for migrant birds. Now that dogwoods are nearly gone from our forests, killed by an invading fungus, spicebush is a lifeline for the feathered travelers.
I’ve noticed these berries and nuts, too. One of my dogwood trees has more berries than ever before, making me long for spring already. Just yesterday (I think you will appreciate this), I finally identified a tree whose beautiful little green fuzzy things had confused me. How did I identify it? I saw acorns (dead giveaway) on the ground and bursting forth from those razor-like green “flowers.” I discovered that it’s a sawtooth oak. But now that I know what it is, I am worried about it. I read that it’s considered an invasive species.in some areas. Is it in ours?
To my knowledge, sawtooth oak is not considered a problem here in Sewanee — yet. In other parts of TN and surrounding states it is considered a problem (or a potential problem). It tends to breed earlier and more vigorously than natives. I’d pull any youngsters that you see growing nearby. Where is it?
We have had a very odd year. We had November in October and October in November in 2011, and this year, March in April and April in March July in June, when temperatures in Nashville soared above 100 for endless days, and then August and September in July and August, and the weather now feels more like October (at least the Octobers of the last 10-odd years) than it does September, which has become an extension of summer.
I wonder how unpredictable climate change–now inevitable–will make weather patterns worldwide. In the meantime, I’m enjoying the lovely weather–ideal for riding my bicycle to work.
I agree: the months seem to have been jumbled, with an extra ten degrees thrown in all around for good measure. One of the more disruptive things about climate change will be the new combinations of temps — e.g., long warm springs followed by freezes — that will really mess with the viability of a lot of species. It is these new regimes that may do the real damage in terrestrial ecosystems, not just the increased temps. How it will all affect bike-riding weather, no-one knows! But enjoy the fresh air…
Lots of berries on our wild spicebushes in Piedmont Virgina as well. Perhaps wildlife-oriented gardeners can plant more of these great shrubs as ornamentals, taking some of the sting out of the dogwoods’ decline. Other spicebush benefits include good fall color and a pleasing scent when the leaves and twigs are crushed. And it’s the larval host to the spicebush swallowtail. Best of all, the deer ignore ours — the spicy smell must be displeasing to them. I wonder how they would do in Sewanee gardens where the deer pressure is so high?
And speaking of cardinal flowers, I spotted some in bloom yesterday along the Mountain Goat Trail, along with my late summer/early fall favorite, jewelweed. Gotta feed those rubythroats.
The spicebush does get nibbled by deer here, but it seems to avoid getting hammered.
I do think that gardeners have an important role. So much of the land is developed or semi-developed that what we do in our backyards adds up to an important factor in the overall ecology of the world. I know from the research that I’ve done with students here that biodiversity can be quite high in low-density developments — in some cases higher than in the woods. Humans bring water, extra shrubbery, calcium in the form of lime and wood ash, and all sorts of other goodies that can draw in species that were previously rare.
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