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Protectors of Pine Oak Woods · Current
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Forest Restoration Forest
Restoration Great
Kills, April 17, 2010
The 166th Forest Restoration Workshop was a bit of a cheat since for this session there were no forests to “restore”. Instead of the usual invasive removal in the Greenbelt, 5 members of Protectors (with 2 arriving later) assembled at Great Kills to help Chuck Perry prepare the wildflower garden at the Environmental Education Center for spring planting. Chuck arrived early so that he could run a weed-wacker around the periphery without throwing dirt and debris in anyone’s face, and we joined him at 10:00 to loosen soil and rake out weeds and roots from a ring around the edge where we planted Joe-Pye Weed (Eupatorium purpureum) and Black-eyed Susan (Rudbeckia hirta) from the Native Plant Center. As is the current practice, all the plants were Staten Island natives that are accustomed to our particular climate and environment.
The Greenbelt Native Plant Center, a project of the Department of Parks and Recreation, takes care to propagate a variety of plants gathered from our region, making sure not to collect just the “nicest” or “fullest” or “tallest” of any one kind. Their intent is to provide varieties of each plant they cultivate in order to increase the likelihood that some of the plants would be accustomed to the different micro-environments in which they might later be planted. In this respect the GNPC is not like a commercial nursery, always looking for the “prettiest” foliage or most shapely plant. This is fitting, I think, because the wild-flower garden isn’t a flower garden in the traditional, pretty landscaped sense; it is a patch from which we hope wild-flowers can seed and spread to the rest of the hillside. Chuck has planted other types of wild-flowers there in the past, and later this spring plans to sow seeds he collected from earlier plantings. We could see a few shoots coming up through the mat of Crown Vetch (Coronilla varia) that grows there, but it was far too early to have any chance of distinguishing the wild-flower sprouts from the “weeds”. (As far as I know, Crown Vetch is not considered an invasive plant in New York State, but is listed as such for many states to the south. This attractively blooming member of the pea family was often planted to control erosion on slopes, but now seems to be getting out of control and can be found almost everywhere in Great Kills Park.) After planting, we stowed our tools in Chuck’s truck and walked down the hill toward the marina.
The hillside there is a grassland studded with sporadic shrubs. Bayberry (Morella pensylvanica) grows naturally, recognizable by the odor of its resin dotted leaves, and Groundsel (Baccharis halimifolia) whose female plants will bear white, bearded seeds come the fall, and several shrubs that look like they might be Beach Plum (Prunis maritima) have been planted lower down toward the boat basin. Overlooking the slope are poles bearing white artificial Purple Martin houses in the shape of hanging gourds, although, unlike at nearby Lemon Creek, I don’t believe that Purple Martins have been attracted to nest. (Purple Martins are our largest swallows, but established colonies here can be a bit chancy. Lemon Creek is further southwest on Prince’s Bay. A few years ago an extended late cold snap retarded the emergence of insects these spring migrants depend upon, and the colony was a casualty. I do not know if these uncommon swallows have yet returned. Www.purplemartin.org is a web site that will probably tell you more than you ever wanted to know about the needs of these birds.)
We don’t have many natural grasslands on Staten Island - or for that matter in New York City or even New York State. Grasslands are a kind of endangered species of landscape, as are the mixed landscapes that are transitional between open fields and forests. New York State seems to have had the greatest amount of grasslands in the last century when small farm agriculture began to be phased out. Small farms that could not effectively be combined into larger, more efficient agribusinesses were abandoned, and as their fields reverted to grasslands some birds such as Bobolinks, Meadowlarks and certain field loving sparrows became more common. Abandoned fields, however, don’t remain grasslands for long. Unless, as in western prairies, the grass is so thick and unbroken that other seeds cannot fight through, pioneer sun-loving plants appear, shrubs eventually become established, fast-growing trees such as Red Cedar (Juniperous virginiana) and Grey Birch (Betula populifolia) find root, and unless some major event intervenes the abandoned fields evolve into woodlands. (It’s quite amazing how fast some trees appear, especially the invasives. Several years ago ground was re-graded adjacent to Mariner’s Marsh and fill laid for the Arlington Rail yards. By the second season the rail-yard-to-be looked like a plantation of Empress Tree saplings (Paulownia tomentosa). Invasive as these trees are, they weren’t a match for the rails and railroad ties to come.) Many old field have gone through this succession and now those grassland birds that benefitted from abandoned fields are in decline, even more so since in still existing fields forage crops are now mowed more frequently by farmers trying to wring out multiple harvests each season, often with great mortality to summer nestlings.
Our areas that remain grasslands are usually those in which the growth of shrubs is suppressed, either by fire or by periodic mowing. Some of these artificial grasslands once were airfields such as Floyd Bennett Field in Brooklyn or Miller Field on Staten Island, where the shrubs were suppressed to insure visibility across the field. When such artificial fields were no longer used, local authorities occasionally recognized the value of maintaining the grassland habitat. The NYSDEC maintains the grasslands at Mt. Loretto by mowing alternate areas in the fall after the nesting season and after small mammals have retired for the winter, and at Floyd Bennett Field in Brooklyn, the National Park Service, at the urging of Brooklyn birders, mows in the fall to constrain the grown of shrubs.
A newer source of grasslands is, of course, our former landfills such as Great Kills and the much vaunted Fresh Kills. I find it somewhat bemusing, however, that we take such pride in renovating former landfills and re-purposing them at great cost compared to what we spend to preserve existing natural areas... but realistically, what else could be done with such landfills other than leaving them fester on the landscape or mining them for discarded raw materials in some kind of a futuristic Sci-Fi scenario? They must be carefully capped to contain buried contaminants and the buried spoil takes generations to settle and stabilize. (This consideration springs to mind whenever I hear about plans to erect windmills at Fresh Kills - how can foundations be installed without disrupting the cap and while the ground is still settling?)
These new grasslands might never become very much like those of old days since many original species of plants have long ago vanished, but if you’ve visited the new grassy mounds at Fresh Kills you must credit that great planning and effort has gone into establishing a large variety of grasses and forbs, and that it has already become an attractive spot to fancy butterflies and to observe insects of the field. It must also be said that there is an advantage afforded by these re-purposed grasslands: they allow us to begin again without - or at least with fewer - invasive species. The 132 acres of the Brookfield landfill, now a scar of denuded soil visible from the LaTourette hillside of the Blue Trail, harbors much illegally dumped toxic waste. Realizing that any attempt to remove the waste would certainly release some of it into Richmond Creek, a decision was made to leave it buried, cap it, and cover it with 2 million tons of clean fill, much as was done at adjoining Fresh Kills. The current schedule is to install shrubs there by 2017, and if all goes well, and if you are a young parent, perhaps your children’s children will be able to enjoy it. These things take a very long view.
There are a few small, unique natural grasslands on Staten Island. On the Protectors’ old brochures there is a picture of a line of hikers going up a grassy trail on a serpentine barrens on Hyerdahl Hill. You’ll recall that the serpentine barrens are open places where Staten Island’s underlying serpentinite rock becomes exposed. That rock is rich in magnesium instead of the calcium that most plants need to prosper. Some few plants, however, can tolerate these conditions, and a somewhat unique assemblage of plants develops on the barrens. The barrens in the photo appear extensive and open, but today they are no longer so extensive. Over the long term, the original plants grow and decay, producing a new layer of soil on which plants less tolerant of the high levels of magnesium can survive, and soon shrubs begin to appear, then Grey Birch, and even Sweetgum (Liquidambar styraciflua). Essentially, the barrens become buried unless erosion occurs to expose new serpentinite and keep the level of magnesium in the upper soil high. Regular fires, the result of occasional lightning or more frequently arson, also helped to keep these barrens open. The fires killed opportunistic shrubs and trees, and returned nutrients locked up in wood back to the soil, enriching it and encouraging new growth. The occasional fires that still occur produce a flush of new plants that take advantage of released minerals and the newly opened space. Danger of property damage or loss of life, coupled with a better fire suppression response, have for the most part made these fires a thing of the past, and the area of serpentine barrens is shrinking.
Fires also occur on the South Shore where a vast extent of invasive Phragmites (Phragmites australis) provides ready-made fuel for brush fires in the dry seasons. On Easter of 2009 such a fire at nearby Oakwood Beach burned for three hours and required a six-alarm response from the Fire Department. Following the fire, Staten Island botanist Richard Lynch reported the flowering of hundreds of Turk’s Cap Lilies (Lilum supurbum) in the burnt area. The Latin name should give you a clue to the appearance of these spectacular flowers. I was eager to see this sight, but read the report much too late; by the time I visited the area they had bloomed long ago and the Phragmites had already grown back chest high. A few Mallows (Hibiscus sps.) were present and blooming, as was Saltmarsh Fleabane (Pluchea odorata), and Climbing Hempweed (Mikania scandens) festooned some of the reeds and shrubs, but nary a Lily blossom was seen.
Just this March a similar fire occurred at Great Kills on the slopes around the model airplane field, but this fire isn’t likely to produce a field of lilies later in this summer. The Turk’s Caps at Oakwood Beach were probably endemic, their seeds surviving in the seed bank of the soil. The soil at Great Kills was trucked in to cover the landfill spoil some 60 years ago, and whatever seeds existed were probably jumbled deep into the dirt where they perished. The soil on these open hills was moist, fertile ground for the giant reeds, and Phragmites became an invasive mono-culture, intolerant of other plants and rapidly spreading by means of underground stems called rhizomes. (Many grasses use underground stems or their above ground counterpart, called stolons, to spread vegetatively. At Northern Mt. Loretto State Forest I encountered a stoloniferous grass growing at the edge of a hard-packed trail. Not having eyes with which to see the shortest way off the rock-hard path, the grass had extended its jointed stolon until it finally grew new roots and sprouted leaves in soft soil at the edge of the path - some seventeen feet further away!) Rhizomes are the Phragmites’ secret ability to survive the fires for which they provide fuel. The shrubs and other grasses above ground burn away, but the nutrient-packed rhizomes below survive and quickly re-sprout new reeds. Scraping the bark on the skeletons of Sumac and other shrubs in the charred area revealed not a sign of green; all was dead but the Phragmites.
Earlier on my way to the restoration site I had stopped close to a baseball backstop to look at an uprooted tree in the midst of the newly sprouted Phragmites. Two items caught my attention: the first were bundles of newspaper entwined in the roots of the tree, still not rotted after all these years of burial, and second were the baseballs. Standing in just that one spot I was able to see 11 burned balls lying on the surface surrounded by spears of bright green reeds. The fact that so many balls hadn’t been recovered by the kids is a testimony to how thick the Phragmites grew there.
Phragmites, the familiar giant reed which grows everywhere around the globe in our latitudes, was not always the invasive plant we see today; in the not too distant past it co-existed here on the edges of wetlands with other large grasses and reeds such as cat-tails. Why it should suddenly begin to grow out of control was a mystery until it was discovered that the run-away reed was a European strain of the same species as our native reed, but with a difference in that its roots produced many times the amount of compounds that suppress competing plants than did our native stock. With this advantage there was no stopping its spread, and it has become a huge problem in our parks and wetlands. The most successful method of control seems to be laborious and expensive dredging, or cutting it and covering the site with a layer of heavy black plastic until all the new shoots die from lack of sunlight and all the rhizomes have exhausted their store of food. Once eliminated, there is the problem of substituting more desirable plants and making sure the Phragmites don’t come right back! There is hope is that eventually some safe biological control can be found: some insect or fungus that feeds only on Phragmites or in some way damages it alone and no other plant. A leaf-eating beetle was introduced - successfully so far - to control the spread of Purple Loosestrife (Lythrum salicaria) in our wetlands, so perhaps a similar biological control can be found for Phragmites. The beetles primarily attack invasive loosestrife, but also occasionally feed on a few native species. After careful study the USDA concluded that the risk to native plants of having their habitat overrun by Purple Loosestrife was greater than the loss the beetles would cause. (A website that will tell you more than you want to know about introducing these beetles is: http://www.extension.umn.edu/distribution/horticulture/dg7080.html). In some spots along the northeast Atlantic coast European insects have been found that damage Phragmites, but no-one seems to know how they were introduced. It is very necessary to introduce such agents with extreme care lest the cure itself become a plague.
The walk following the Restoration was pleasant, though perhaps unremarkable. The threatened rain held off, although the day was cloudy as forecast, and became somewhat chilly as the wind rose toward the late afternoon. We decided to walk toward Crooke’s Point at the end of the peninsula to look at the Osprey nesting platform and perhaps see some of the Eastern Towhees (the bird that calls “drink your TEA”), but were turned back by one of the many blockades erected by the National Parks Service. Some residual traces of radium from medical waste were found in the landfill spoil a few years ago, and contractors removing this contaminant discovered yet more near one of the ballfields and between the ranger’s office and the model airplane field. Although the waste was buried 12 to 18 inches deep, the National Park Service chose to err on the side of caution, and this March closed almost 50% of Great Kills Park. Like Mariner’s marsh in Arlington, it is likely that this part of the park will remain closed for some time for more testing and then for remediation. Not knowing that Crooke’s was still accessible, we decided to turn back and walk along the Blue Trail that parallels Hylan Boulevard. No Towhees there, but everywhere Mockingbirds and on the way we were overflown by several flocks of Glossy Ibises that came to roost in trees close to the boat basin.
The Blue Trail, however, had closures of its own; barely 500 feet from its entrance we came upon a Wild Black Cherry (Prunus serotina) blown down across the trail. Its stump lay well into the gully on the Hylan Boulevard side, and its crown, heavily laden with vine, was firmly tangled in a wall of impassible briar to our right. Standing at the trunk, we could see an additional 4 or 5 trees blocking the trail just a little further on. There was no passage to be had that way, so we retraced our steps and then followed the fire road that skirts the ballfields and runs parallel to the Blue Trail to the park entrance at Buffalo Street. There we paused to examine some of the aliens in the mint family that commonly grow in waste places and disturbed areas: Heal-all (Prunella vulgaris) and Gill-or-the Ground (Glechoma hederacea). Plants of the mint family are recognized by their square stems, opposite leaves and two-lipped flowers. Heal-all, which goes by quite a variety of common names and is widely considered a medicinal plant, quite likely grows in your back-yard or neighboring park. Heal-all can be found in bloom throughout the entire summer, bearing a dense cluster of usually lavender-colored flowers on a stalk that grows a foot or more tall. Its appearance can be varied, especially when it grows on paths where it is trampled down, or on lawns where it is repeatedly mown. In those places it blossoms close to the earth. Because it is opportunistic and commonly found, most folk consider it to be a weed. It is most probably an alien species, and in our latitude is found across the world. Gill-or-the-Ground, which occurs as a kind of short vine with rounded, lobed short-stalked leaves and vivid bluish flowers, also goes by a number of common names such as “Creeping Charlie”. Many, but not all, of the mints have a fragrant aroma derived from the oils they product to deter insect predators. Crushed Gill leaves, we found, were very fragrant. (One of the very similar flowers in the mint family that we didn’t see on this walk was Henbit (Lamium amplexicule), which has clasping, non-stalked leaves close to smaller, more lavender flowers. It’s probably a good thing we didn’t run across it because I often confuse the two, but now I’ll try to remember that Gill leaves are always stalked. Both can appear about the same time of year and in similar places, but Gill-over-the-Ground is a perennial, whereas Henbit is a winter annual and has to reseed itself every year. Winter annuals begin their growth in late summer and fall and winter over so that they can blossom early in spring.)
We crossed Buffalo Road and descended to the beach on the ocean side, where Sandra spotted a pair of American Oystercatchers far off at the water’s edge. These bold patterned black and white birds use their thick, strong bright-orange bills to dig about in the sand for buried mollusks, and tend to keep their distance from people on the beach. Because there is less and less suitable beach available for breeding, their population is declining along the Atlantic coast and we see fewer and fewer of them. It had been several years since I walked that section of the beach, and I found things much changed since then. Walking back toward the Beach Center, we passed sandy banks that were 10 to 12 feet tall when last I was there. Recent storms have eroded them well back toward the roadway where they now stand only 5 to 6 feet above crumbled sand mounded on the beach, and where the corpses of a series of undermined Cottonwood trees (Populus deltoides) lie prostate, their branches extending like boney arms and fingers toward the sea. Residents of old can recall an old beach house that used to exist here, and which they say now would be some 60 feet or more off in the ocean. Storms erode the banks and ocean currents continually carry the sand along the peninsula, depositing it at the western end where it builds up and blocks the channel into the boat basin of the marina. That channel is now shallow and close offshore, and will soon necessitate another dredging if the basin is to remain usable. A consequence of this erosion is likely to be an exodus of the Bank Swallows that were accustomed to nesting in holes in the banks. The swallows need to find banks whose soil is loose enough to excavate yet firm enough to support nesting holes 3 to 5 feet deep, and which are tall and steep to prevent predators from climbing to the nests. The banks here are now so low that they may have to search elsewhere. I doubt that we will any longer see the sight of the birds performing aerial acrobatics here and then flying headlong toward the banks where they fold their wings at the last moment and disappear into the holes. It was a sight worth seeing. I hope that they nest as well in the steep banks of Mt. Loretto Unique Area so that I can see it again.
DfR 4-20-10
P.S. While showing photos at the last Protectors’ Semi-Annual meeting a woman asked me if Bird’s-eye Speedwell was also called Veronica, and I replied that I thought that was another flower. Upon getting home, consulting a field guide confirmed my ignorance when I discovered that the Genus name for all the Speedwells is Veronica. Unfortunately, no one I quizzed was able to recall who had asked the question... So, if you asked and happen to read this screed, you were correct, and I was wrong!
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