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Protectors of Pine Oak Woods · Current
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Sharrots Beach Cleanup October 16, 2010 Protectors’ 172nd Forest Restoration could have been a washout with all but two regulars otherwise engaged and no other volunteers responding, but none-the-less Elaine and I came to High Rock to yank out a little more Aralia elata (otherwise known as Japanese Angelica or the “alien” Devil’s Walking Stick). Saturday morning was cool and breezy, and the clouds scudding across the sun made us alternately warm then chilly. There had been a wind advisory earlier that day that was forecast end at 6 a.m., but later was revised to extend through the afternoon. On occasion, treetops above us swayed dramatically, but strangely only a few leaves fell; acorns did, however, one of which tried its best to brain me - a poor reward, I thought, for trying to help its saplings! At ground level we felt little of those breezes visible up above, although now and then even low lying shrubs would be stirred, and I wondered what these gusts were like out in the open. Many local oaks of the black oak group seemed to be having a mast year and their acorns thickly carpeted the ground, so I guess I was lucky to have been struck only once.
We shouldered our two weed wrenches and set out for the north side of Loosestrife Swamp where Aralia has been seeding from mature trees in the Moravian Cemetery. I missed our turn, however, and instead of arriving at the extensive patch we were looking for, we ended up overlooking Lake Orbach at Pouch Camp. We could hear campers chattering on an adjacent hill, and across the lake saw patches of Red Maple and Sweet Gum showing their fall hues. Here close to the lake was a nice picture of fall color: patches of reds, browns and yellows. These trees at least hadn’t suffered during the summer dry season, and were cause for optimism that their color would hang on for “leaf peeping” on the 10 mile hike at the end of October. We turned back down the hill toward the cemetery, yanking out the occasional Aralia as we went, until we came upon a clearing created by the fall of several trees during this summer’s storms. Here we found a patch of numerous Aralia sprouts and a few saplings taking advantage of the sudden abundance of light and the soft soil churned up by the roots of the fallen trees. The size of this patch was just right for a pair of restorers to tackle in a under a few hours, so we set to it. Paradoxically we found it much easier to uproot the larger saplings, either by tool or by hand, than to uproot the tinier seedlings. As often as not, the small ones would break leaving roots in the soil, whereas the more robust plants tended to come out whole. These root remnants may sprout again next year and require another pull. Small clearings like the one we worked at are more numerous in the Greenbelt this year thanks to the severity of early summer storms that have brought downs numerous trees. On inspection, many of these fallen trees are found to be at least partially hollow. Hollow trees in the woods are probably more frequent than we realize; fungi often invade and rot out the heartwood leaving the growing shell of the tree standing somewhat as if the tree was a giant hollow straw. This heartwood rot must become very extensive before the resistance of the trunk to buckling is so reduced that the tree splinters and falls. Often the rot is all internal and does not show, but much of the time small openings to the interior may be found close to the root collar of the tree. These hollows serve as animal shelters or nesting places for birds such as wrens and are an important resource in a living forest, and I was disappointed to see that the DEC removed many of the hollow trees and snags close to the trails at Northern Mount Loretto, but I suppose the DEC is acting in the best interest of those people who frequent the trails. These standing hollow trees with mysterious interiors invite curiosity; one such is a large hollow oak standing on the north side of the White Trail between Buttonbush Swamp and the turn of the trail to the Hyerdahl ruins. Almost every-time I passed by that oak I stopped to look inside. Usually there was nothing to see but an occasional mushroom and a pile of rotted wood fragments, but in winter after storms I sometimes found a picturesque arrangement of ice “stalagmites” in shades of brown and tan formed by stained, freezing water dripping from high above inside the trunk. That deeply hollowed tree still stands along the trail, but has lost several branches during the spring storms, and shows another opening at the base of the trunk. Water no longer drips down the interior in the same way, and it’s likely the spring winds have put an end to those eye-catching ice formations.
Hikers enjoy the fallen tree clearings, welcoming their contrasts of light and shade, and the treefalls that create them are one of the ways a forest perpetuates itself. When a forest matures on its way to becoming what is called an old-growth forest, it begins to consist of expanses of widely separated, tall trees whose canopy casts a dense shade on the floor beneath. Some few low forbs such as sarsaparilla and shrubs such as our forest viburnums tolerate the shade, if it is not too dense, and there are usually a few tall, slow-growing, thin-trunked trees forming an understory layer. The forest floor is usually easy to traverse because so few plants grow in the shade below. When one of the large trees fall, there are a few seasons in which what used to be shadow is now light or partial shade, and whatever lesser trees grew close beside the casualty are able to utilize the now available sunlight to shoot for the sky. On the floor below, soft low plants spring up from seeds banked in the soil, followed by woody vines such as Virginia Creeper (Parthenocissus quinquefolia), Greenbriars (Smilax sps.), and Poison Ivy (Toxicodendron radicans) - and all too often our enemies Oriental Bittersweet (Celastrus orbiculatus) and Japanese Honeysuckle (Lonicera japonica). The woody vines are slower to move in than the forbs - the soft, non-grass flowering plants - because much of their energy must be dedicated to producing their woody structure, but once established they can form an impenetrable tangle for a number of years until the tree cover becomes dense enough to shade them out. Shrubs and trees are even slower to grow since even more of their resources must be dedicated to making wood; that wood, however, will eventually enable them to overtop and shade out their non-woody competitors. The temporary gap in the canopy soon closes, and the floor becomes dark and cool again. The fallen tree itself slowly rots, returning the minerals and organic compounds that were sequestered in its wood to the soil. The area immediately around the rotting tree becomes fertile and encourages the growth of new seedlings, and those plants growing close are sheltered from being trampled. These rotting toppled trees we call nurse trees, and sometimes after a long trunk has rotted away we can still detect its presence by a line of saplings that have sprung up in its place. Most of our Greenbelt is still in the process of becoming mature forest with a few scattered nurse trees, but it hasn’t yet gotten to the old-growth stage. It’s coming along, however - just give it another one hundred years or so - and even now there are many areas where the shade on the forest floor is impressively dense. We read in books about forest ecology that large, disturbed, cleared areas undergo a predictable natural succession from field to forest: soft flowering forbs are succeeded by grasses and vines, then shrubs and pioneer trees such as aspens and grey birch. Eventually these are followed by tall, longer-lived, slow growing trees such as oak, hickory and tulip whose seedlings need the shelter of the pioneer trees, but will later overtop them and shade them out. As time passes the mix of trees and other plants in the forest changes until an equilibrium is reached and the composition of plants, both the mix of types and their percentages, becomes set until some large-scale disturbance forces another change. This end product is called a climax forest, and on Staten Island we haven’t yet gotten there. Historically most of our woodlands have been cleared and developed several times over, and are only now again reaching a mature state. Where the trees have fallen, however, we can see succession occurring, although on a very small scale. Because the woods are shady and moist, grasses play a relatively small role in this succession. (In large cleared areas, there is little shade; consequently the soil sometimes becomes dry. Grasses with their resistant roots are able to survive such periods so they often persist for some time, shading and stabilizing the soil so that shrubs can move in later and the usual, predictable succession can proceed.) Because the openings created by a treefall are usually small and quick to close plants that require sun don’t last long. Sometimes, however, a treefall is substantial, as when a large tree brings down several others in a domino effect. In this case forbs and grasses may have several seasons in the sun. These larger openings welcome creatures and plants of the forest as well as those that inhabit edges, and become a richer environment than either the forest or field alone. Many birds such as towhees prefer to nest in these edge habitats, and frequently flycatchers may be seen hawking insects that stray into the sun (& cowbirds as well lurk there to be able to sneak easily into the nests of other birds to lay eggs to be brought up by foster parents). Vines and shrubs fruit abundantly in these edge habitats providing food for fall migration and winter sustenance. Unfortunately those fruits are all too often multiflora rose hips and the berries of oriental bittersweet. Around our work area both Mapleleaf Viburnum and Lowbush Blueberry displayed their muted fall pink and lavender colors, and everywhere in the leaf litter the caps of large, gilled mushrooms were appearing. Now aware of the shot-ridden appearance of leaves eaten by the Viburnum Leaf Beetle, we saw at least a few signs of beetle feeding on Arrowwood Viburnum almost everywhere we went. Since this is the season in which the adults lay their eggs, we examined the upper twigs of predated plants searching the undersides of the stems for egg tracts, and found them on about one of five plants. Given that we hadn’t seen the beetles here prior to this year, this seems to be a disturbingly large number of infested shrubs, and suggests a greater outbreak to come. If our native predators such as the voracious ladybug larvae can’t keep the number of these beetles down, there will be a large adjustment in the distribution of understory plants in our forests (by chance there was a ladybug on the very first infested viburnum we examined - let’s hope she laid a lot of eggs!). Since both the beetle larvae in spring and the adults in late summer feed upon the viburnum of their choice - and that is Arrowwood (Viburnum dentatum), followed by Highbush Cranberry (Viburnum opulus var. americana) and Mapleleaf Viburnum (Viburnum acerifolium) - viburnum suffers twice in the same growing season, and I have read that if a viburnum is heavily fed upon for three years running it is not likely to survive. Eventually reserves in the shrub’s roots are exhausted, and with their leaves in tatters they cannot photosynthesize enough during the growing season to recover; the problem is greater for very young plants that have not been able to establish an extensive root system. A recent study published in The Entomologist examined the ecology of a site in which Arrowwood Viburnum had been decimated by beetles. The investigators had feared that as the Arrowwood disappeared from that plant community, it would be replaced by undesirable alien invasive species, but they found that at least in this particular study such replacement did not occur. However, one should not come away from this study thinking that all will be well here. One cannot draw firm conclusions from just one small study; this study site, for example, was in an old field dominated by Goldenrod and other open area flora, an environment considerably different from our shady woods. What happened there will be unlike what happens in our moister, shady environment. Moreover, the loss of any single strand in the living web of a plant and animal community puts a stress on the survivors, and we are not likely to be aware of just whose existence depends greatly upon Arrowwood until those other creatures begin to disappear as well. In fact, given out relatively little knowledge of woodland micro-fauna, we may not even recognize that some small invertebrates have disappeared along with the Arrowwood unless their absence cascades up the food chain to affect larger, more visible organisms. Alien species may disrupt the ecology of the forest in many ways. The white, four-petaled Garlic Mustard (Allaria petiolata), for instance, has obviously altered the visible composition of plants along our forest trails, crowding out native species and depositing chemical inhibitors in the soil that disrupt the growth of saplings, but we might not recognize that the change is occurring since it takes place over a number of years. Few other than entomologists are probably aware that Garlic Mustard jeopardizes the survival of a butterfly, the West Virginia White (Pieris virginiensis). The caterpillars of this butterfly - which range charts show appears in our region - feed exclusively on toothworts such as the Cut-leaved Toothwort (Cardamine concatenata), a flowering plant in the same family as the mustards and which can be found along the trails in Willoughbrook Park. Where the Garlic-Mustard alien crowds out the native toothwort, the butterflies lay eggs on the similar appearing Garlic-Mustard, but the chemistry of these plants are different enough that the butterflies’ eggs do not hatch. Thanks in great part to the spread of Garlic-Mustard this butterfly is now slowly disappearing.... When others had joined us after the work session we took our customary walk on nearby trails. Unlike earlier in the season large capped mushrooms were plentiful, although most were concealed by fallen leaves. Around loosestrife swamp the majority seem to be Citron Amanitas (Amanita citrina), a pale yellow, green tinged mushrooms with a raw potato odor, although there were also the occasional brittle russulas and milk-caps. The amanitas are an interesting group of gilled mushrooms; they can be conspicuously large and visible from the trail, and are notorious for harboring several very poisonous species. (The white-spotted, red-capped mushroom so favored by greeting card and children’s book illustrators is another amanita, the European version of the Fly Agaric (Amanita muscaria). Indeed, although some species are edible, some also have the distinction of causing almost 90% of the fatal mushroom poisonings in our country. (Responsible mycophagists usually have a simple rule - simply don’t collect amanitas!) In our region just two years ago an employee working at a highway rest stop harvested and ate several seemly delectable mushrooms that later were determined to be amanitas and unfortunately did not survive the experience. Out of the several thousand species of mushrooms in the US - the exact number is a matter of speculation - only about 200 are deemed poisonous, and of that number most are not deadly, but are what we would call “sickeners”. The mushroomer’s joke is that those won’t kill you; “they’ll just make you wish that you were dead.” The moral is that if you’re going to eat wild stuff, be it mushrooms, berries, leaves or stems, you have to be absolutely sure that you’ve identified your food correctly. Poison centers divide the types of mushroom toxins into eight groups in order to facilitate diagnosis and treatment. Unfortunately choosing an appropriate treatment depends on identifying the fungal culprit, and in many cases the sufferers can give only a vague description. If the poisoning is recognized early enough, specimens might be retrieved from the collecting spot and taken to a mycologist associated with the poison center, and occasionally victims might have saved a few mushrooms for later consumption, but more often the mycologist must make a guess based on verbal descriptions and the knowledge of what particular mushrooms would likely be found in that season and place. Poisonous Amanitas are in a group that have amanatoxins, enzymatic toxins rather logically named after their source. These enzymes act to kill the cells of the liver and kidneys and prevent the liver from regenerating. Unless the treatment is prompt the result can be death or the need of an organ transplant, and even if treatment is successful, damage to the liver and kidneys may be permanent and debilitating. Unfortunately for those who mistake the identity of these mushrooms, symptoms of nausea and gastric upset which would alert one to trouble are delayed and temporary. After a short period of sickness, the diner recovers and all seems well, but during this quiescent period the toxic enzymes are at work destroying the liver’s ability to detoxify, and eventually the kidneys become overloaded by the products of the dying liver and begin to fail. When symptoms of liver dysfunction emerge, it is often too late to begin effective treatment. Mushrooms poisonings are fortunately a rare occurrence, probably because there are relatively few people in this country that collect wild mushrooms for the table and because most of those collectors are very cautious. The trend for foraging for wild food is growing, however, and many newcomers to our area, especially those from Russia and the eastern European nations are accustomed to going to the countryside to harvest mushrooms. These harvesters are especially at risk since it is a common assumption that the familiar appearing mushrooms they see are identical to those of their native lands - a assumption that is often just plain wrong. For the same reasons on the west coast of the US mushroom poisonings are frequently reported among Mexican and South American emigrants. Luckily for them, however, prompt access to competent medical help is usually available, and fatalities are rare. The season for collecting wild mushrooms is coming to an end, thus lessening the danger of poisoning except for those who have preserved their harvest, but poisonous amanitas are still appearing, and a small, brown mushroom that fruits in fall on wood called the Deadly Galarina (Galerina autumnalis) is coming into season. On almost every mushroom foray I’ve attended newcomers are warned about the necessity of positively identifying - without the shadow of a doubt - the mushrooms they might consume, and are told the only way to do so is to learn the characteristics of each edible one by one, and especially to learn the characteristics of the poisonous ones. There was always someone, however, who wanted a simple rule to follow. Unfortunately there isn’t such a rule; there is a lot of folk-lore such as “poisonous mushrooms turn silver coins black,” and “if they’re growing on grass they’re OK (and vise-versa, “they’re OK if they grow on wood!”).” Another is that if animals can eat a mushrooms it must be OK, but that one is really wrong! - the digestive systems of humans and other animals are not identical, and animals regularly consume fare that can sicken us. I have seen squirrels running up trees carrying what seemed to be Death Angels (Amanita bisporigera) in their mouths - although admittedly I haven’t been there to see if they survived the feast! And just a few Sundays ago I encountered a 94 year-old mushroom collector who very seriously advised “look for the worm,” explaining that the edible mushrooms would always have a larvae or two in them and that if they weren’t bug eaten they should be avoided. Well, I’ve encountered a number of bug-eaten amanitas, and certainly wouldn’t consider eating any of them, bugs present or not, but the old fellow’s still alive and claimed to have collected mushrooms for over 74 years! Maybe he was just especially lucky! Next month Protector’s Forest Restoration will be at Clove Lakes Park. This summer several of us attended a short series of classes sponsored by the NYCDPR Natural Resources Group designed to help us identify invasive plants of special concern in New York City parks. Those who completed the course were given heavy leather gloves, a trowel, a good pair of hand pruners, and a USDA field guide to invasive species. The classes were held at Clove Lakes Park close to Martling Avenue where there has been a large effort to restore the degraded forest by first applying herbicide to an area and then, after the unwanted plants have died, to replant with native species. This restoration is in its third year, and several of the areas are being used as test plots to evaluate which restoration techniques are going to work best. The purpose of the NRG classes was to train and encourage volunteers to recognize and remove invasive plants from these restored areas until the newly planted shrubs and trees had grown to such a size that they couldn’t be overwhelmed by invasive vines and eventually would be able to shade them out. I’m told that there were major efforts to plant trees in this park in the past, especially planting of groves of pines, but consistent weeding was not pursued, and many of these trees succumbed to invasive vines. Now a new effort is being made to restore the degraded areas, and thanks to the Million Tree Initiative this new effort is substantial; several Saturdays ago on It’s My Park Day I happened to be at Clove Lakes Park and came upon one of the planting sessions. A large crowd of volunteers had assembled to replant a recent herbicide treated area, and I joined them for a few hours. In that afternoon and in that one small area some 3125 trees were planted (according to the two city employees I asked - although a recent NYCDPR web account says 2500); all of them needing periodic tending lest they be overwhelmed. Although our effort is primarily in the Greenbelt, we have scheduled our 173rd restoration at Clove Lakes. Over a decade ago when the city did not have the finances to continue caring for trees that had been planted with funding from a Lila Wallace Foundation grant in the Greenbelt, Dick Buegler set out to continue the removal of invasive vines from those trees, and that’s when the numbering of our “Forest Restoration Workshops” begins. All those thousands of recently planted “Million Trees” will need some tender care lest they succumb to vines like many of the earlier planted pines, so we’ll dirty our gloves a little to help them along. DfR 11-13-2010 |
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