In ecological land management, as in many other things, less is sometimes more. Doing little or nothing is a management decision, even if it’s one made from laziness or lack of resources. Sometimes it’s the best choice to make.
This is a principle that needs to be invoked with caution. For example, if a habitat depends on periodic disturbance to retain its characteristics, doing nothing can be disastrous. This circumstance pertains to the Vineyard’s grassland and barren habitats, which rely on grazing, salt spray, fire, or other interventions to keep taller, woody vegetation from taking over. Without periodic management of some kind, these habitats slowly but relentlessly evolve into oak woodland.
But in some other circumstances, reducing management or suspending it altogether can produce a gratifying ecological response. A fine illustration exists near my home in Oak Bluffs, where O.B. parks and recreation has designated a “no-mow” zone on the sandy hillside overlooking Sunset Lake. The affected area is not large, occupying perhaps a fifth of the total area of the hillside. But I’ve watched with interest as native plants and animals respond to this reduction in management frequency.
This park was, to be sure, interesting to start with. Historical photographs of the area show a remarkably similar hillside a century or more ago. The habitat here, that is to say, has remained relatively unchanged for a very long time, making the site a sort of ecological time capsule from when Martha’s Vineyard was a very different, much less developed, much less forested place. Often in such circumstances, plant and animal populations can persist long after they’ve been eradicated in surrounding areas where conditions have changed.
With lean soil, regular exposure to salt spray during northeast gales, and unrelenting sun during the summer, the hillside as a whole has retained a largely native mix of plant species that are well-adapted to these harsh conditions. Several of our tough native grass species flourish there, notably little bluestem, which is a key component of the Vineyard’s arid grasslands. Sickle-leaved golden aster, a delightful, yellow-bloomed wildflower with thin, needle-like leaves, also does well here. It’s a familiar, even characteristic species of Vineyard grassland, which hides the fact that from a regional perspective, it’s a highly specialized and generally rare plant.
Suspending growing-season mowing on part of the hillside doesn’t seem to have changed the mix of species very much; I find roughly the same plants in the no-mow zone as I do on the broader hillside. But the effect is quite different. The suspension of mowing during the growing season allows more plants to mature and drop seeds, allowing some species to persist at much greater density than they exhibit in the regularly mowed area. And the taller, more fully developed vegetation translates into greater structural complexity, affording more opportunities for insects to shelter and forage.
The no-mow zone is now the epicenter of a huge population of the grasshopper Orphulella pelidna. Rather local on the Vineyard, though often abundant where it does occur, this inch-long insect occurred on this hillside even when the entire area was being frequently mowed; the population may well have persisted here for a century or more, even as development and reforestation reduced its options elsewhere on the Island. But the no-mow zone has converted Orphulella from something I encounter occasionally on the hillside into a species that is truly abundant here.
Likewise, the no-mow zone is one of only three places on Martha’s Vineyard where I’ve found the ground-nesting bee Colletes thoracicus. Digging nest burrows in exposed, sandy soil, the females of this species seem to prefer to nest in settings where their burrows can be partially concealed under clumps of grass or other vegetation. The no-mow zone apparently offers ideal conditions, with small patches of open sand tucked in among the maturing grasses and wildflowers.
In a typical year, several hundred female bees make this their home, and while the colony occasionally spills out in the frequently mowed area, it is clearly the no-mow zone that most interests these insects. I wish I knew how long the colony has been here; I didn’t discover it until a couple of years ago, and I wonder if the no-mow policy attracted a new colony or merely allowed an existing colony, perhaps one that has been here for decades, to become more successful. But in any case, a locally uncommon bee is breeding happily and prolifically among the dog-walkers and runners who frequent this little park.
I don’t wish to overstate the case: its modest size limits the ecological benefits of the no-mow zone, and the heavy human use and densely developed surroundings of the hillside as a whole inevitably limit the site’s potential for supporting rarities or extremely high diversity. But by simply doing less instead of more, the town Parks and Recreation department has substantially increased the ecological value of this interesting park, allowing a longstanding mix of well-adapted native species to flourish alongside a popular recreational resource. This is what thoughtful land management looks like.
