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“Broomsedge bluestem’s primary mode of reproduction is sexual” (see here). That’s one thing I like about plants: they’re not completely dependent on sex to make more of themselves. Which is good, because sex for plants usually involves the intercession of a third party — a moth, a hummingbird, an extinct ground sloth, you name it. Sounds chancy.
In any case, botany geek-talk is cool. “Sessile spikelet 3-4 mm long, twice to half again as long as the internode, the awn straight, 10-15 mm long; pedicellate spikelet wanting or rarely present as a minute scale, pedicel exceeding the sessile spikelet. Flowers: Either sessile and hermaphrodite, or stalked and staminate, sterile or not developed.”
Broomsedge bluestem (Andropogon virginicus L.), also known as whisky grass or yellow bluestem, is slowly spreading through our old fields. The photo above was taken at what we call the Far Field, which was never planted to non-native brome and orchard grass the way the First Field was. I love the stuff, especially at this time of year when its far-from-blue stems and leaves stand out against the snow. Its flame-colored foliage seems appropriate for a plant that flourishes after fires, and thus has evolved to provide a nice, dry tinder. Absent fires, it’s also an early colonizer of overgrazed pastures, old strip mines, and old fields like ours, especially on acidic soils. It’s slowly infiltrating the non-native grasses in First Field, relying on chemical warfare (allelopathogens), but has a harder time competing with the native goldenrod. At the Far Field, it’s restricted almost entirely to the mowed paths; the rest of the five-acre field is dominated by goldenrod…
which looks like this right now (speaking of blue stems). We may have as many as eight different species of goldenrod on the mountain.
This kind of old field habitat is becoming increasingly scarce, so we think it’s important to keep it open. Dad used to use a tractor and mower, but in recent years he’s switched to using hand pruners on the encroaching black locust sprouts. It’s good winter exercise, he says.
The goldenrod provides, among other things, a valuable nectar source for migrating monarch butterflies, which come south along the ridge in great numbers each fall. Plus, this is a northeast-facing hollow. For our own psychological health, especially in the cold, dark months of the year, we appreciate all the extra light a field provides.
To tell the truth, though, it’s very difficult to say whether the value to conservation of maintaining old field habitat is greater than the value of forest interior habitat, which is becoming just as scarce here in the crowded northeast. If we were to let our 45-acre First Field grow in, and/or plant native trees to accelerate the succession, we’d create a parcel of virtually uninterrupted forest close to a mile wide. Numerous studies document how the nesting success of forest interior-dependent songbirds, for example, improves dramatically with distance from the nearest forest edge. But are wood thrushes more important than monarch butterflies? Probably if you’d ask ten different ecologists, you’d get ten different answers. I hate that we even have to make these kinds of choices, playing God.
All over the planet, we are rapidly approaching a point of no return, and not just where climate change is concerned. The loss of biodiversity and the radical simplification of ecosytems are epiphenomena of equal importance to our long-term survival. A world of simplied ecosystems is one with far fewer feedback loops, fewer checks and balances, and therefore greater extremes. Extremes of heat and cold. More catastrophic floods and droughts. Plagues and outbreaks of all kinds. More frequent and hotter fires, many of them fueled by invasive species — as broomsedge bluestem has become in fire-prone Australia. Forests giving way to savannas, and savannas to desert.
But there will be a lot more light. Our descendents will learn to love this shining, depauperate world. They will see God’s stark handiwork at every turn.