Posts Tagged microclimate
Humanity world-wide loses a piece of itself every time we lose more of the natural world that nurtures and protects us. When we destroy the natural world, we lose pieces of our soul, the part of us that thrives on the beauty of a cool mountain breeze kissing our faces, the melodic chatter of a clear-running stream, and the exquisite call of a Wood Thrush echoing through a healthy forest. Our hearts are so much smaller without our connection to the beauty of the natural world.
In the southeastern Piedmont region of NC where I live, the natural world is under assault every hour of every day. The population of my region is soaring, mostly due to the arrival of many new residents from other parts of the US and the world. As people move in, the forests I grew up with are disappearing. The dwindling patches left are degrading rapidly, due in large part to the invasion of an increasing number of non-native invasive exotic species of plants, animals — especially devastatingly damaging insects — and diseases.
One casualty of this urbanizing landscape — throughout the US — is the Monarch butterfly. My generation grew up knowing this beautiful creature — one of the most recognizable species of butterflies in North America. In school, we learned about their life cycle, admired their emerald green chrysalises, and marveled at their annual migrations to Mexico. Every gardener who plants with butterflies in mind knows that species of milkweed are the only plants that Monarch caterpillars will eat, so we tuck them into our yards to ensure Monarch visits.
However, in recent years — and most especially this year — our milkweeds have been uneaten by the colorful Monarch caterpillars. In my yard, I’ve only seen two adult Monarch butterflies during the entire growing season. Wonder Spouse took the photos of the one in this post last week. We were so excited when we spotted it in our front garden that we dropped what we were doing and ran for our cameras.
Many experts believe that Monarch butterflies are in serious trouble. Much of the reason is probably habitat destruction, both in North America and in their winter homes in Mexico. You can read an article about their decline here.
Monarch butterflies are well known and loved, and still they are in trouble. Multiply their peril a thousand-fold for a delicately exquisite, extremely rare wildflower: Oconee Bells.
Oconee Bells live in just a couple of spots along a geographic region known as the Southern Blue Ridge Escarpment. This part of the Blue Ridge Mountains rises abruptly up from the piedmont regions of South and North Carolina, creating a remarkable rise in land elevation over a short distance. The region is also characterized by very narrow gorges; at their bottoms, sunlight never penetrates, and temperature and moisture levels remain remarkably steady.
Such areas possess unique microclimates that an astonishing array of species of plants and animals have exploited. So much so, in fact, that this region holds more than three times the number of plant and animal species than undisturbed rainforests in Central and South America. The diversity of life is astounding, and tightly adapted to the unique geography and microclimates of this region.
The Southern Blue Ridge Escarpment is beginning to be degraded by the intrusion of concrete and asphalt, consequently destroying the delicate ecology of gorge bottoms, where Oconee Bells live. Deforestation on the ridge tops leads to massive erosion down the sides of the steep gorges. In some cases, the Oconee Bells living at the bottom have been scoured from their homes by water cascading down eroded ridge tops.
Oconee Bells were never plentiful, and now their increasing rarity makes them coveted by gardeners who want to possess every rare and beautiful plant they can. Oconee Bells are almost impossible to propagate; growing conditions cannot vary for them at all. Thus, plants sell for very high prices, making them a target of plant poachers.
In North Carolina, we have plant poacher problems at both ends of our state. On the coast, they steal into our preserves at night to dig up Venus Fly Traps. This species, native only to a 75-mile area around Wilmington, NC, is successfully propagated in the horticulture trade. Even so, plant poachers steal thousands, degrading their habitats at the same time.
In our mountains, plant poaching is worse. Folks illegally collect our native ginseng, goldenseal, and other wildflowers known for their medicinal properties. They steal Oconee Bells for covetous gardeners. They do not care that they may eliminate a plant population from a site. They see dollar signs, not irreplaceable beauty.
In North Carolina, we are fortunate to have a group in our government with an important mission:
The Mission of the Plant Conservation Program is to conserve the native plant species of North Carolina in their natural habitats, now and for future generations.
Three individuals comprise this department. They are working to identify and protect the rarest and most threatened plant species in the state. They’ve identified plant populations all over the state. That’s a big job for three people. Fortunately, they have help.
The Friends of Plant Conservation is a non-profit organization founded explicitly to support the work of the NC Plant Conservation Program. Members volunteer to help manage and protect the preserves created by the Plant Conservation Program by participating in activities such as work days devoted to clearing out competing vegetation. They also provide essential financial support, since, like every governmental department in NC, the Plant Conservation Program’s budget does not begin to pay for the work that needs doing.
Right now, the Friends of Plant Conservation are frantically trying to raise enough money to pay for the purchase of land holding the last healthy population of Oconee Bells in North Carolina — the last natural population of Shortia galacifolia var. brevistyla in the world. The owners of this property love and appreciate this unique wildflower, and they’ve agreed to sell it, at cost, to NC to create a preserve. The owner who has protected this population from poachers and who cherished his land recently died after a long illness. His heirs wish to honor his memory by fulfilling his dream of creating this preserve for Oconee Bells. Time is critical. Funds are short.
An anonymous lover of natural beauty has recently stepped forward and is offering to match all donations — four dollars for every dollar donated. Imagine — a donation of $100 will become $500. For once, perhaps beauty can be saved.
To learn more about this wildflower and how to send your donation to save beauty, please go here. Even small donations will make a difference, thanks to the anonymous matching donor.
Of course, saving rare species like Oconee Bells, and suddenly declining species, like the Monarch Butterfly, is about much more than saving beauty. Scientists compare these imperiled species to canaries in coal mines. Before the days of oxygen sensors, miners carried caged canaries. The canaries were more sensitive to drops in oxygen levels than humans. When the canaries keeled over, the miners knew they had only minutes to escape the same fate.
No animal or plant exists in a vacuum. They are parts of ecosystems, intricate groupings of species that evolved together and depend on each other in ways that are still not fully understood. Scientists do know that every time another species disappears from the delicate dance of an ecosystem, remaining species are also imperiled. No one knows how many species can disappear before the dance stops.
The natural world feeds us, body and soul. Please follow the link provided above, and if you can help save this uniquely special place, know that you will become an invaluable contributor to saving Oconee Bells, and a piece of our souls as well.
You know the saying that moss always grows on the north side of trees? That’s because the north-facing side of tree trunks is usually slightly cooler, shadier, and more moist than their other sides. Moss likes cool, shady, moist spots, so it often grows on the north-facing sides of trees — at least in North America.
Such mossy spots exist because of differences in microclimate. A microclimate is the climate of a small area that differs from its surrounding area. It may be hotter, cooler, wetter, windier — but something makes that spot slightly different from its surroundings.
In the southeastern Piedmont, north-facing steep slopes adjacent to creeks and rivers create microclimates that favor some of my favorite plants: Beech trees, spring ephemeral wildflowers like Hepatica and Blood Root, and Pawpaw trees to name a few.
Even the smallest suburban yard has microclimates. The south side of your house differs from the north side. A hilltop will be drier and windier than the bottom of a hill.
If you pay attention, soon you’ll know which parts of your yard get frost soonest, where the snow melts first — or last. These are clues to microclimates in your yard.
One of the most striking microclimates in my yard is the south-facing wall of my garage. Even during a record 20-inch snowfall, less than an inch piled up within two feet of that wall. The birds figured it out, huddling together for warmth on the one spot of remaining bare ground. I think it may be a full zone higher there. I’m mostly 7B, but I’m pretty sure I could safely grow Zone 8 plants behind my garage. I’ll get around to trying eventually.
Last week, two Winterhazel (Corylopsis sp.) shrubs growing within 20 feet of each other reminded me of the importance of microclimate differences. I wrote about these non-native early spring bloomers here. The one in the photo at the top of this entry shows off its lovely yellow autumn color. Probably because it’s not native, it is slower to color up in fall, which makes it more susceptible to early freezes.
The Winterhazel in the above photo grows a bit uphill from an identical shrub that I planted just above a little pond near our creek. Both shrubs are the same size. The one in the top photo often blooms a few days before the other, but I hadn’t realized the significance of that difference until last week when our low hit 24 degrees Fahrenheit.
The shrub above was unaffected by the cold. But its sister shrub by the pond, which had only just begun to show fall color, was zapped hard. The leaves died instantly, turning pale and falling to the ground. Here’s a photo of the zapped shrub shot the same day as the one above. You may need to click on it to see the few dead leaves still clinging to the branches.
Although unsightly, the zapped Winterhazel is not damaged. It will still bloom next spring. But the striking difference between the appearance of these identical shrubs caused me to take a hard look at their microclimates.
The still-beautiful Winterhazel is a bit higher up the hill, which may mean the cold air doesn’t collect on top of it quite as quickly. But I think the big difference is my house. The pretty Winterhazel is completely protected from north winds by my house. The zapped Winterhazel is not only lower down the hill, it is just far enough to be out of the wind shadow of my home. North winds have a direct line from the north side of my yard, past my house, to the south-facing floodplain where the zapped shrub resides.
The difference between the two microclimates was probably just a degree or two, but combined with a biting north wind, the zapped shrub surrendered to the cold.
These two shrubs reminded me of the importance of paying attention to microclimates whenever I’m planting new additions or relocating established plants. As in so much of life, the smallest differences can have the largest impacts.
For an excellent discussion of microclimates, check out this site.