Tag Archives: natural history

Get to know some local pines

This is an article I wrote for the April issue of the Inside/Out. The loblolly pines are done ‘flowering,’ but yellow jasmine is still blooming in pinewoods and there is more to see under the pines.

Parkwood under the pines

I used to discount the pinewoods that are so abundant around here as pretty dull and barren, but pines can grow on you. This month the sky will be hazy with clouds of pollen (winged, like the seeds) for about two weeks, much of it probably wafting from loblolly pines. Their glistening needles seem so green in the intensifying sunlight, before the softer greens of hardwoods emerge. There are three or four pines native to Parkwood and another two that aren’t quite native.

The most abundant pine is the loblolly pine, Pinus taeda (taeda refers to torches). Their seeds sprout wherever there is bare, sunny ground, but loblolly probably refers to temporary puddles. Loblollies have relatively long needles, usually three in a fasicle, a bundle of needles that is actually a tiny branch, and rough dark gray and reddish bark. The cones are large and prickly. Most of Parkwood’s pines are still relatively small, but loblollies can grow 115′ tall, five feet across, and live more than 200 years. There used to be some around three feet across behind Racliff Circle, and there are still some very large pines on low ground by the Ball Field and behind Ace Hardware.

Shortleaf pines are common, but their ranks are much fewer than the loblollies. Shortleaf pines usually grow on hills and have short needles, two or three to a sheath, the smallest cones, and smooth brownish bark furrowed into large rectangles. They have small, but spreading dark green parasol-like crowns, reminding me of a Japanese painting, supported by sturdy, angular branches. Unlike loblollies, shortleaf stumps can re-sprout when young. Shortleaf pines can grow up to 150′ tall and 3-4 feet across, and like loblollies are an important timber tree. Their scientific name is P. echinata, probably referring to the hedgehog-like spines on their cones.

There are a few Virginia pines (P. virginiana) around, but they are more common west and north. They are also called scrub pines and often form thickets of small trees, though they can get 60′ tall. The needles come in twos, and curl. The cones are small and cling to branches years after the seeds have all fallen out. Overall they have a bristlely appearance with weathered and broken old branches and flakey brown bark, but their airy branches arch gracefully. There are a few behind Parkwood Elementary’s ballfield.

Pond pines resemble loblollies, but have slightly shorter needles on easily broken twigs and small, round, and not very prickly cones. There might be some around here, but they are more common east. They are called pond pines because they like moist ground and their scientific name, P. serotina, meaning late, probably refers to how the pinecones are held for years. Virginia pines and pond pines aren’t often cut for wood.

North Carolina’s state tree, the longleaf pine, is typical of the Sandhills and might never have grown in Parkwood naturally. They have needles so long they are woven into baskets and saplings have a strange, grasslike form. Longleaf pines are adapted to survive fires, so they form pine savannas when periodic fires are allowed to burn, killing the hardwoods. These majestic pines aren’t limited to wet soil, but P. palustris refers to marshes.

Eastern white pines are common Christmas trees and can last at least several years if planted here, though they are native to the Appalachians and north, where old growth trees grew over 200′ tall. They do grow naturally in one spot nearby, the White Pines Preserve in Chatham County ( triangleland.org/what-we-do/nature-preserves/white-pines-nature-preserve ), where they found shelter on a north-facing slope along the Deep River after the ice ages. White pines have soft bluish needles coming in fives and unusual long thornless cones (and they are called P. strobus, strobus meaning pinecone). The branches form whorls around the trunk. White pines are cut for timber, but are softer than southern yellow pines like loblolly.

Pines are a prominent feature of the landscape because they are among the first trees to grow. Loblollies are the main pioneering pine around here, sometimes with shortleafs, and Virginia pines are first in other places, often on bare clay. These pines can’t stand shade, so if not disturbed by logging or fire, hardwoods eventually take over. Some flowers are common under the sighing and creaking pines. The flowers of yellow jasmine vines bedeck pine forests now. I have often found rare pink ladyslipper orchids shaded by pines [these flower in May], as well as downy rattlesnake plaintain (another orchid), yellow-eyed grass, Pipsissewa, pencil flower, and wild roses. Brown-headed nuthatches, talkative little birds that sound like squeak toys live in pines, as do pine warblers, and birds of prey nest there. On hot, dry days of late summer, the raspy, treefrog like calls of Robinson’s cicadas often resonate out of pines. Around the same time, it becomes hard to walk barefoot under the pines, because squirrels sit in favorite branches to eat green cones like corncobs and rain down thorny scales.

Notices: We met April 13th and our May meeting will be next Monday, the 5th, at the Mediterranean restaurant in the Parkwood Shopping Center, time TBA.

This week we are looking at the umbrella magnolias and pinxterflower azaleas, but see the listserve for those announcements.

The life and death of an ash tree

Our next meeting will be Sunday, January 26th at 4pm, to plan for Creek Week 2014 (March 15-22) and discuss some development issues, etc. Contact us for the address of the residence where we are meeting.

Below is an expanded version of an article I wrote for the January issue of the Parkwood Inside/Out. This giant ash tree grows beside the stream that flows from the corner of Barbee and 54, through Parkwood to NE Creek at the bridge on Grandale Road.

The life and death of an ash tree

An ash tree in Parkwood is one the largest I have come across. There are taller trees, but this ash is nearly four feet across, beating large ash in the wild bottomlands around NE Creek and the big ash in downtown Chapel Hill. Parkwood’s ash is a little south of McCormick Road, near the intersection with Auburndale, beside the stream in the common green area, and can be seen from the road. Ash trees usually have very straight trunks, but this giant leans southwest and has lost huge limbs to the force of wind or ice over its long life. It is hard to say why it leans. That section of woods is relatively young and this ash is the biggest tree there. It has pale bark, and as a reaction to tilting, it grows more on the leaning side, producing unusually deep 4” furrows, resembling a baleen whale’s throat or treads. In one place the bark is brown, probably from deer rubbing the velvet off their antlers. There are rows of holes created by yellow-bellied sapsuckers, woodpeckers that winter here and tap trees for sap.

During the growing season, the ash’s massive trunk is obscured by understory oaks, dogwoods, and black cherries. American beech, increasingly common in Parkwood, and Northern red oak saplings wait for the ash to fall. This is the only spot I know of where pawpaws grow inside Parkwood, though they are quite common as small riparian trees along NE Creek. The pawpaws probably would benefit from more light, though the site might still be a bit dry for them to produce their sweet bananalike fruit. There is a seemingly innocent sprig of English ivy, a plant which is taking over in nearby sections of the woods, and a Nandina bush with purple foliage, another non-native, but much less invasive. Partridgeberry, ‘wild onions,’ and grape ferns form the herb layer under the ash.

Each ash produces only male or female flowers, and this must be a male tree. Perhaps it is a parent of large ash on nearby Timmons Drive, or even throughout the area.

Our ash is probably a white ash. Green, pumpkin, and Carolina ash also grow in Durham. They look similar, all living up to their scientific name, Fraxinus, the Latin name for ash, which also means spear, and describes their typical soaring shape. Ash have leaves and twigs growing in pairs along a stem, and their pinnately compound leaves are made up of oval leaflets, resembling the leaves of walnuts, hickories, and locusts. In fall ash turn gold, orange, and purple. Ash saplings have smooth gray bark and mature trees have somewhat furrowed or rough bark, depending on the species.

White ash is the most economically valuable ash. High-quality baseball bats are made from white ash, as well as other objects requiring lightweight, strong wood with a spring, like oars, lacrosse sticks, musical instruments, furniture, and bowling lanes. It is also an easy to split, hot burning firewood. White ash has been used to relieve fevers, sores, and snake bites, as a laxative, and as an aphrodisiac, among other medicinal uses. Ash have a long history in mythology, for example the Norse axis mundi/world tree Yggdrasil is supposed to have been an ash, and according to folklore snakes don’t like ash trees. White ash likes well-drained, but not very dry soil and is one of the first trees to sprout in abandoned fields. White and green ash can tolerate shade as seedlings, waiting for their chance to shoot into the canopy when an old tree dies. The big snowstorm that left two feet of snow and ice and other bouts of freezing rain have knocked down most of the young pines behind the Parkwood Volunteer Fire Station, leaving a woods of only ash and winged elm in places. Pumpkin and Carolina ash like wet habitats, and ash are one of the main trees in swamps and bottomlands. Ash trees can be seen next to the Parkwood Association office, where there used to be a trailer, and at the Parkwood Convenience Store, at the corner of Seaton and Revere. Ash of some kind can be found on most streets in Parkwood and are common throughout the Triangle.

Late last summer I watched big pale green, red, and yellow hornworms on an ash sapling at Falls Lake. These were waved sphinx moth caterpillars, but the red markings were unusual. Usually their larvae don’t have any red coloration, but these were mostly red with yellow markings when small and then mostly green, but with red heads, horns, and markings. A few other sphinxes feed on ash, as do caterpillars of black and yellow Eastern tiger swallowtails. These green caterpillars have fake eyes complete with angry eyebrows, to mimic snakes, and if that fails, they can send out bright orange ‘horns’ that emit a smelly fluid. The big, shiny black rhinoceros or unicorn beetles sometimes found under streetlights at the Parkwood Shopping Center also eat ash. Ash have wind-pollinated flowers in early spring, but honeybees and other insects sometimes harvest pollen from male flowers. The winged seeds, or keys, of ash trees are eaten by weevils, mice, and birds such as wood ducks, turkeys, and purple finches. Large ash often have hollows where birds and squirrels can nest. Our ash seems to house a colony of big black ants, judging from the seemingly arboreal ants walking along its trunk last summer. Deer and rabbits eat the leaves while beavers like ash bark. Ash growing around the beaver impoundments on Grandale or elsewhere could host mistletoe.

Native beetles and two species of dayflying moth that mimic wasps bore into living or dead ash trees, but a new ash-boring beetle from East Asia is on its way to killing virtually all ash. Emerald ash borer or EAB reached Michigan in the 90’s, probably in shipping materials. It wasn’t noticed until 2002 and has since spread throughout the Eastern US and Canada, in part because people violated quarantines on firewood and other products. Their grubs tunnel under the bark of trees as small as 1” across, and since these are non-native animals, they come in out of control numbers that girdle our naïve ash, killing them within a few years of colonization. A good online resource to check out is www.emeraldashborer.info .

Earlier this summer emerald ash borers crossed into Granville County from a pocket across the border in Virginia and a quarantine was imposed (see http://www.ncforestservice.gov/forest_health/fh_eabfaq.htm ). This is likely to be the end for Parkwood’s great ash in the near future, when the emerald ash borer gets to Durham, on its own power or by hitching a ride, and a great many beetles could come from it. There is cause for hope – some ash seem to have survived the borer up north, introduced Asian and native parasitoid wasps could help control the beetle, and individual trees can be protected with insecticides that are relatively safe for the environment. Emerald ash borer has a big ecological and economic impact, and even harms human health, so communities in the Triangle should prepare.

You can read more about emerald ash borer in my article in the February issue of Carolina Gardener magazine (www.carolinagardener.com).