Upland Shores

Rivershores

ctober, 1927, was a wet month in Vermont. Rainfall had been higher than usual. The ground was saturated, and rivers and streams were full. On the first Oday of November, an unusual series of meteorological events began to converge on Vermont. By November 3, rain was falling in unprecedented amounts, and by the end of the day on the 4th, nine inches had fallen in some parts of the state. The already full streams and wet ground could not handle all this water, and the result was the greatest natural disaster in Vermont’s written history: the Great Flood of 1927. Curiously, New Englanders from outside Vermont’s borders do not count the 1927 flood as a major event. There was some damage in neighboring states, but the bulk of the rainfall, and most of the damage, occurred in Vermont. Eighty-four Vermonters lost their lives, 55 of them in the Winooski Valley alone. River towns throughout Vermont keep the history of the Great Flood alive. City Hall in Montpelier, on the Winooski River, is decorated with photographs of water lapping the steps of the Capitol. A marker in Cambridge, on the Lamoille River, shows that the floodwaters reached the second stories of buildings in the village. Gaysville, on the White River, was washed away completely and is remembered only in pictures. The loss of human life and property caused by the flood of 1927 and lesser floods is well documented. Changes to the natural communities of rivershores and floodplains are not as well understood, however. How did the plants and animals of the rivershores respond to so much water? Local lore in the town of Sharon, on the White River, tells us that a huge amount of floodplain land was lost in the 1927 flood. Large areas of open ledge on the riverbank are said to have been laid bare. A 60 acre field became a 40 acre field in two dramatic days. Rivershores, perhaps more than any other natural system, reflect the impacts of short- term events. A flood may, in a few short hours, remove tons of soil that took thousands of years to accumulate. An ice jam in the winter may kill trees and shrubs. Spring floods may leave silt carried from far upstream, covering plants and rock. The natural tendency of a river is to clear anything in its path, either by the sheer force of moving water or, in cold climates, by the more abrasive force of ice. When the waters recede and the ice disappears – that is, for most of the growing season – rivershores are calm, sunny, open places, naturally stripped of trees and shrubs. The only perennial plants that survive the regular abrasion and flooding are the ones with firm roots or rhizomes that hold them tenaciously in place. Annuals survive by sending their progeny out to unknown seed beds downstream.

190 / Wetland, Woodland, Wildland Rivershore plants may deceive the naturalist in summer: long, lacy grasses wave in the breeze, delicate harebell flowers hang from slender stalks, and translu- cent touch-me-not leaves grace waist-high plants. But visit the same riverbank in flood time, and you’ll find the grasses flattened to the ground, harebells reduced to tiny basal parts that hang on in cracks in the rock, and the touch-me-nots long gone, having dispersed their seeds in late summer. Rivershores are dynamic places, and because of the severity of the natural forces acting on them, they are unique in the largely forested northeast. Two rivershore types are described here: Riverside Outcrop and Erosional River Bluff. Five other rivershore communities are technically wetlands. Like many rivers flowing out of the mountains, the Huntington River responds quickly to heavy rainfall and melting snow and has a floodplain that changes frequently. Lakeshores The natural communities that inhabit the shores of our lakes and ponds are as varied as the lakes and ponds themselves. No two are alike. Many lakeshore communities are wet for much of the growing season and are therefore classified as wetlands. On many lakes and ponds, there is practically nothing that can be called shore; forest meets lake abruptly, with no fanfare. It is only where there is something to challenge the forest that one finds open, dry shoreline communities on a lake. Ice challenges the forest by pushing upward onto the shore as a lake freezes, scarring the bark of trees and shrubs, and ultimately killing them. Water challenges the forest in lakes where spring flooding lasts long enough to drown trees. Wind challenges the forest by stressing trees, or by depositing sand and moving it about year after year, as on a beach or dune. We recognize three dry, open communities of lakeshores: Lake Shale or Cobble Beach, Lake Sand Beach, and Sand Dune.

Spruce-Fir Northern Hardwood ForestUpland Formation Shores / 191
HOW TO IDENTIFY

Upland Shore Natural Communities Read the short descriptions that follow and choose the community that fits best. Then go to the page indicated to confirm your decision. Riverside Outcrop: These are bedrock exposures along rivers and streams, where flooding and ice scour combine with summer drought to keep trees and shrubs from becoming established. Vegetation is very sparse, with plants growing in small patches of soil that accumulate in cracks. Go to page 193. Erosional River Bluff: These are steep, eroding areas of sand, gravel, clay, or silt, on riverbends where natural movement causes continued sloughing of sediments. Go to page 197. Lake Shale or Cobble Beach: These are lake beaches made of coarse fragments such as shale or cobble. They are kept open by spring flooding, ice scour, and wave action. Moisture is not abundant during the growing season, in contrast with Lakeshore Grassland, which is a wetland community. Go to page 200. Lake Sand Beach: These are lake beaches made from finer soil fragments (sand). They are kept open by spring flooding, ice scour, wave action, wind, and regular deposition of new sediments. Go to page 203. Sand Dune: These are always associated with Sand Beaches and are found land- ward of them. They are areas of sand movement due to wind. Vegetation is sparse. Go to page 206.

192 / Wetland, Woodland, Wildland RIVERSIDE OUTCROP

ECOLOGY AND PHYSICAL SETTING Riverside Outcrops are places along rivers and streams where bedrock is exposed and treeless. They are most common where waters are swift, such as at narrows, gorges, rapids, and falls. The large rivers, like the Connecticut, Winooski, Lamoille, Missisquoi, and White, have the most extensive areas of Riverside Outcrops. Smaller rivers and streams, with less extensive flooding and less ice to scour banks, tend to have smaller outcrop areas. Although Riverside Outcrops are similar to outcrops that are not near water in their exposure to the heat of the sun and their lack of soil, most are distinct in that they are influenced by river processes. Where outcrops are within a few feet of river level, they are scoured regularly in the winter by ice as it expands and pushes up on the banks, and also in spring as the great floes move downstream on DISTRIBUTION/ABUNDANCE spring floods. This scouring kills most woody plants by Riverside Outcrops are damaging the growing tissue in their bark. Where outcrops found on rivers and streams are within the zone of flooding, high water deposits throughout Vermont, though they are nowhere abundant or sediments in the rock crevices, creating miniature pockets of large. They are found on all alluvial silt or silt loam, soil types that are more commonly the larger rivers, including the found in floodplain forests. These loamy pockets of soil Connecticut, White, West, tend to be nutrient-enriched and hold moisture well, in Black, Ottauquechee, Deerfield, Winooski, Lamoille, contrast to the nutrient-poor soils that develop in place on and Missisquoi, and very some other kinds of rock outcrops. And where outcrops are likely others. Communities near falls, they are bathed in mist, which provides needed with similar groups of species moisture. Valley fog gives Riverside Outcrops added are known to occur in all New England states and in New moisture, too, especially in late summer and fall. York and are likely to occur in Riverside Outcrops can be nearly level to gently sloping, adjacent Canada as well. Out- or they can be completely vertical, as in a gorge. The crop communities on rivers in steeper the slope, the more difficult the accumulation of other parts of North America and the world may rely on soil, and the sparser the vegetation tends to be. Some similar ecological process, Riverside Outcrops are formed by erosion of bedrock over but the species are different.

Upland ShoresProfile / 193 RIVERSIDE OUTCROP

millennia – this process creates gorges, and ANIMALS in some gorges the exposed rock can be The mammals and birds that one sees far above the present-day river. on Riverside Outcrops are probably more Any kind of rock can form the substrate a factor of the habitat that surrounds the for a Riverside Outcrop. Schists and outcrop than the outcrop itself. Small phyllites line much of the Connecticut, mammals such as river otter and mink will schists and grey limestones are common pass through, moving to or from a river. on the White, and white limestone can be Large mammals may use a riverside outcrop found on the lower Winooski. Granite is as access to water. Shorebirds can be found seen very locally, as on a short stretch of occasionally on rocky shores, though they the West River in southern Vermont and are more likely to feed on muddy shores. in a few localities on the Moose River in From a Riverside Outcrop, one may see northeastern Vermont. These variations kingfishers, great blue heron, green heron, in bedrock chemistry and structure are osprey, or eagles, depending on the size reflected in the vegetation. and characteristics of the river. Other birds VEGETATION seen or heard will be determined by the nature of the surrounding forests, fields, or Botanists recognize that substrate is developed lands. everything to plants. Just as cattails thrive We know little about the invertebrates in mucky soils, harebells are one of the few that inhabit rivershores. The red-spotted species that can survive the harsh condi- ground beetle is a rare insect known to tions created by open bedrock. Many of the inhabit Riverside Outcrops. plants that grow on Riverside Outcrops are there as much because there is rock as VARIANTS because there is a river. In fact, many No variants of this community are plants, like harebell, seem to be indifferent recognized at this time. Further study might to the presence of water nearby. Downy reveal variants based on climate and goldenrod and spreading dogbane are as biogeography, as well as variants based common away from rivers as they are near on the nature of the substrate, moisture them. On the other hand, there are a few availability, size of the river, and flooding species that seem to do best where there is regime. alluvial soil deposited by a river each year, filling the cracks in the rock with fine, RELATED COMMUNITIES fertile soil. Wild chives and shining ladies- Calcareous Riverside Seep: This tresses are among these. Others, like cut- community may be found where bedrock leaved anemone and many species of is exposed, but it differs in having a more- bryophytes, seem to thrive where there is or-less constant supply of seepage water, a constant supply of mist from a waterfall. which creates wetland conditions. The openness of the habitat, resembling Rivershore Grassland: This commu- as it does an open field or roadside, is also nity may share some similarities with quite hospitable to a number of non-native Riverside Outcrop, but it differs in its moist species that are adapted to disturbed soils. and cobbly substrate where vegetation is Riverside Outcrops, therefore, have more more dense. than their share of species of Eurasian origin.

194 / Wetland, Woodland, Wildland RIVERSIDE OUTCROP

Big bluestem is a tall native grass found on several rivershore communities.

CONSERVATION STATUS AND Vermont has very few endemic species – species that are found only in this state and MANAGEMENT CONSIDERATIONS nowhere else in the world. Among the Riverside Outcrops may be one of the plants, only one was ever known, and this most permanently altered community types plant, Robbins’ milk-vetch, was found on in the northeast. Because the largest and an outcrop on the lower Winooski River. best examples tend to be found near falls This plant is now extinct, probably due to and gorges on major rivers, a number of a power generating facility that was built in them have been blasted, riprapped, the 19th century in the gorge where the covered with concrete, or flooded by the plant grew. This is only one story of one building of dams for power generation. plant; many large and diverse natural This alteration began in small ways in the Riverside Outcrops were destroyed, and late-18th century, with a small mill on every what was lost will never be known. minor stream near a settlement. It escalated Today, the value of these communities to major dam-building on the largest rivers is recognized by conservation organizations th with the industrialization of the 19 century. and local planners, and several examples th The 20 century saw the advent of numer- are protected on private and public ous new power-generating dams, and the conservation lands. most recent blow to Vermont’s Riverside Outcrops came in the name of property PLACES TO VISIT protection, with flood control dams built Quechee Gorge, Hartland, Quechee State from the 1930s to the 1950s to prevent a Park, Vermont Department of Forests, repeat of what happened in 1927. Parks, and Recreation White River Wildlife Managament Area, Sharon, Vermont Department of Fish and Wildlife

Upland ShoresProfile / 195 RIVERSIDE OUTCROP

CHARACTERISTIC PLANTS

HERBS AND WOODY VINES Queen Anne’s lace – Daucus carota Abundant Species Black swallowwort – Vincetoxicum nigrum Harebell – Campanula rotundifolia Morrow’s honeysuckle – Lonicera morrowii Balsam ragwort – Senecio pauperculus Dame’s rocket – Hesperis matronalis Shining ladies-tresses – Spiranthes lucida Yarrow – Achillea millefolium Pointed-leaved tick trefoil – Desmodium Common mullein – Verbascum thapsus glutinosum Purple loosestrife – Lythrum salicaria Poison ivy – Toxicodendron radicans Cypress spurge – Euphorbia cyparissias Canada anemone – Anemone canadensis Fringed loosestrife – Lysimachia ciliata RARE AND UNCOMMON PLANTS Joe-pye weed – Eupatorium maculatum Cut-leaved anemone – Anemone multifida Spreading dogbane – Apocynum Rand’s goldenrod – Solidago simplex androsaemifolium Smooth cliff brake – Pellaea glabella Virgin’s bower – Clematis virginiana Hyssop-leaved fleabane – Erigeron hyssopifolius Northern bugleweed – Lycopus uniflorus Tradescant’s aster – Aster tradescantii Wild columbine – Aquilegia canadensis Spiked oatgrass – Trisetum spicatum Thimbleweed – Anemone virginiana Dwarf bilberry – Vaccinium cespitosum Occasional to Locally Abundant Species Stout goldenrod – Solidago squarrosa Big bluestem – Andropogon gerardii Jesup’s milkvetch – Astragalus robbinsii var. Downy goldenrod – Solidago puberula jesupii Marsh bellflower – Campanula aparinoides Wild chives – Allium schoenoprasum var. Tufted hairgrass – Deschampsia cespitosa sibiricum Shining ladies’ tresses – Spiranthes lucida NON-NATIVE PLANTS Great St. Johnswort – Hypericum pyramidatum Canada bluegrass – Poa compressa Snowy aster – Solidago ptarmicoides White sweet clover – Melilotus alba Whorled milkwort – Polygala verticillata Ox-eye daisy – Chrysanthemum leucanthemum

196 / Wetland, Woodland, Wildland EROSIONAL RIVER BLUFF

ECOLOGY AND PHYSICAL SETTING An Erosional River Bluff is a steeply sloping bank where soil movement is frequent and dramatic. There is great variety within this theme: the substrate may be gravel, sand, silt, or clay, and each of these substrates has different character- istics of stability, slope, and moisture holding capacity. The coarse sediments, like sand and gravel, move almost constantly and vegetation is sparse. On finer sediments such as clay, soils can be stable for long periods of time, slumping only during major flood events. Clays also hold more moisture, so these slopes can have good vegetation cover, including mosses and liverworts. A typical setting for an Erosional River Bluff is at a bend in a river or stream, in an area of deep glaciofluvial or glaciolacustrine deposits. The Erosional River Bluff is found on the outside of the bend, the eroding shore, whereas sand and gravel bars build up on the inside of such a bend, gathering sediments from other bends upstream.

VEGETATION Very little is known about the biology of these communities, perhaps in part because they are so unstable that long- term studies of biota have seemed either inappropriate or difficult. But dynamic as they are, there are certain processes that are constant to them, and there are surely DISTRIBUTION/ some constant species as well. ABUNDANCE Because soils are often unstable and Erosional River the habitat is sunny, Erosional River Bluffs Bluffs are found on provide a natural habitat that is similar to all rivers and streams throughout anthropogenic habitats, like gravel pits, Vermont and the roadsides, and plowed fields. Therefore, Northeast. The best some of the non-native species that developed examples characterize those places thrive in are on the largest rivers, especially Erosional River Bluffs. Of the non-native where sand and plants listed, black swallowwort is of gravel deposits are particular concern, as it is invasive and common. Large can cause serious damage to natural examples are known communities. The others tend to occur in on the Connecticut and Winooski Rivers. low numbers, behaving like native members of the community. The native species found here are those that are adapted to shifting soils or to natural openness.

Upland ShoresProfile / 197 EROSIONAL RIVER BLUFF

ANIMALS CONSERVATION STATUS AND Bank swallows are perhaps the most MANAGEMENT CONSIDERATIONS characteristic species of Erosional River Rivers are vulnerable to human distur- Bluffs – their numerous holes in the upper bances, perhaps more than any other banks of sand or clay cliffs are a common natural system. Changes in land use within sight along rivers. Kingfishers use these a watershed, the building of dams upstream banks as well. Tiger or downstream, and direct beetles are very character- alteration of banks in the istic of sandy Erosional name of stabilization or River Bluffs. beautification can dramati- cally affect a river’s natural VARIANTS tendency to move in its No variants are channel. These changes described at this time. alter the natural Erosional Further study would likely River Bluff communities reveal variations based that occur on a river’s outer on soil type, size of river, bends. Many examples of and climate. this community have been RELATED COMMUNITIES at least temporarily altered by riprapping or other River Cobble Shore: stabilization measures; These are similar to others have probably been Erosional River Bluffs in created by upstream their sparse cover and alterations that have caused coarse substrate, but they Jointweed is a small plant restricted increased erosion. The net to exposed, dry, sandy beaches. differ in being closer to result is unknown, but river level, and therefore there are probably fewer having moist pockets of natural Erosional River Bluffs today than soil in the spaces between cobbles. This there were prior to European settlement. moisture allows certain wetland plants to In any case, these features are difficult to colonize, and River Cobble Shores are protect using conventional conservation technically wetlands. techniques such as the designation of River Sand or Gravel Shore: These nature preserves or state parks. They are are also technically wetlands, because they probably best protected in the long term are close to river level and remain moist for by recognizing that rivers are changing, a significant part of the growing season. active systems, and that erosion is a natural Lake Sand Beach: These beaches have part of the life of a river. Avoiding develop- some processes – soil movement) and ment in the vicinity of existing Erosional vegetation – certain sedges) in common River Bluffs will minimize future conflicts with Erosional River Bluffs, but they tend to with protecting them and will eliminate the be more stable during the growing season, need for artificial bank stabilization, a and they tend to flood almost completely practice that interferes with natural river during spring high water. processes. On a larger scale, we should Sand Dune: These communities have recognize that flood control dams do more some similarities to Erosional River Bluffs in harm to these and other natural river that they are unstable, but they do not communities than they do good. usually experience wholesale slumping and vegetation loss as Erosional River Bluffs do.

198 / Wetland, Woodland, Wildland EROSIONAL RIVER BLUFF

An Erosional River Bluff is best seen by CHARACTERISTIC PLANTS canoe on a river. Bring along binoculars, and see what plants and animals you can HERBS AND WOODY VINES identify without leaving the boat. Visiting Slender-stemmed flatsedge – Cyperus filiculmis an Erosional River Bluff on foot is danger- Depauperate panic grass – Panicum ous and is a threat to the organisms that depauperatum live there, especially the birds and insects Hidden panic grass – Panicum clandestinum that nest in the banks. Stiff aster – Aster linariifolius Poison-ivy – Toxicodendron radicans PLACES TO VISIT Jointweed – Polygonella articulata None known on public land. NON-NATIVE PLANTS Evening primrose – Oenothera biennis Black swallowwort – Vincetoxicum nigrum Coltsfoot – Tussilago farfara

RARE AND UNCOMMON PLANTS Wild lupine – Lupinus perennis Plains frostweed – Helianthemum bicknellii Canada frostweed – Helianthemum canadense Molested sedge – Carex molesta Short-headed sedge – Carex brevior Silver-flowered sedge – Carex argyrantha

Upland ShoresProfile / 199 LAKE SHALE OR COBBLE BEACH

ECOLOGY AND PHYSICAL SETTING This variable community can be found on almost any lakeshore where there is enough disturbance to keep the shore open and to break rock into small fragments but where sand is lacking. The rock fragments, such as cobble (rounded fragments) or shingle (flattened pieces of shale or slate) may be formed from the breakup of rocks nearby or brought from a short distance away by water. The rocks are shifted around each winter and spring with ice and flood- ing, so very few perennial plants can become established. In the summer, wave action creates more movement. Sunlight also heats the rock, further adding to the stresses that plants must withstand and thereby limiting the number of species that can occur here. There is great variety in these beaches, depending on the shape and size of the rocks and on available moisture. DISTRIBUTION/ABUNDANCE Lake Shale or Cobble Shingle beaches are less stable habitats than cobble beaches Beaches can be found on because the flattened rock fragments move about more larger lakes throughout easily. Thus they tend to be sparsely vegetated. On cobble Vermont, but the best beaches soil can accumulate between the rounded, slightly developed examples are more stable, rocks, so they tend to have more perennial on Lake Champlain, where many miles of this plants. community can be found. Although Lake Shale or Cobble Beaches are not wetland Similar communities are communities, they are often found adjacent to and likely found throughout the interfingering with wetland communities, and they them- region on larger lakes. selves have some wetland characteristics and plants. This situation is typical on shores, where environmental change happens over very short distances and where communities readily intermingle.

200 / Wetland, Woodland, Wildland LAKE SHALE OR COBBLE BEACH

VEGETATION Lakeshore Grassland: This wetland Lake Shale or Cobble Beaches are very community can be very similar to Lake sparsely vegetated, with a mix of annual Shale or Cobble Beach, and the two often herbs, perennial herbs, a few shrubs, and occur side by side. The difference is that often a line of trees at the upper edge of Lakeshore Grassland occurs on more stable the beach. As in other naturally open substrates and has more available moisture communities, many non-native plants find throughout the growing season, either this a suitable habitat, and some are because it is closer to breaking waves or abundant. because it has groundwater seepage. Because of these differences, it is more ANIMALS densely vegetated. Spotted sandpipers nest on these and CONSERVATION STATUS AND other open shoreline communities. The rare spiny softshell turtle nests on these cobble MANAGEMENT CONSIDERATIONS beaches on Lake Champlain. Certain This community type is threatened by tiger beetles may be characteristic of this increasing development of shoreline on the community, though they are poorly known larger lakes in the state, but it is only the at present. most severe alterations that will actually eliminate areas of Lake Shale or Cobble VARIANTS Beach. The species that occur in these None described at present. communities seem well adapted to minor disturbance, including the disturbance of RELATED COMMUNITIES humans walking, wading, and launching Lake Sand Beach: This community can small boats. be found near Lake Shale or Cobble Beach, Several examples of this community and the two may intermingle on a stretch type are found on protected lands in of shore. Lake Sand Beaches develop and Grand Isle County. persist where there is a constant supply of sand brought in from distant sources, such PLACES TO VISIT as from the mouth of a large river. On Lake Alburg Dunes State Park, Alburg, Vermont Champlain, most Lake Sand Beaches are Department of Forests, Parks, and found on south facing shores. Recreation (VDFPR) River Cobble Shore: This community is Knight Point State Park, North Hero, VDFPR very similar to Lake Shale or Cobble Beach North Hero State Park, North Hero, VDFPR in many respects, but differs in the periodicity of flooding and in species composi- tion. It is also a moister commu- nity, and is technically a wetland.

The rare spiny softshell turtle nests on the cobble beaches of northern Lake Champlain.

Upland ShoresProfile / 201 LAKE SHALE OR COBBLE BEACH

CHARACTERISTIC PLANTS

TREES Green ash – Fraxinus pennsylvanica White ash – Fraxinus americana Cottonwood – Populus deltoides Silver maple – Acer saccharinum

SHRUBS Woolly-headed willow – Salix eriocephala Shining willow – Salix lucida

HERBS Indian hemp – Apocynum cannabinum Cocklebur – Xanthium strumarium Clammyweed – Polanisia dodecandra Joe-pye weed – Eupatorium maculatum Freshwater cordgrass – Spartina pectinata Silverweed – Potentilla anserina Water horehound – Lycopus uniflorus Schreber’s muhlenbergia – Muhlenbergia schreberi Wild mint – Mentha arvensis Reed canary grass – Phalaris arundinacea Hog peanut – Amphicarpaea bracteata Showy tick trefoil – Desmodium canadense Canada anemone – Anemone canadensis Fringed loosestrife – Lysimachia ciliata Marsh hedge nettle – Stachys palustris Marsh skullcap – Scutellaria galericulata

NON-NATIVE PLANTS Coltsfoot – Tussilago farfara White sweet clover – Melilotus alba Purple loosestrife – Lythrum salicaria

RARE AND UNCOMMON PLANTS Canadian milk-vetch – Astragalus canadensis Border meadow rue – Thalictrum venulosum Sneezeweed – Helenium autumnale

202 / Wetland, Woodland, Wildland LAKE SAND BEACH

ECOLOGY AND PHYSICAL SETTING The formation of a beach requires two things: a supply of sediment (sand, gravel, shale, or cobble) and a way for the sediment to be moved about. A river or stream entering a lake may carry enough debris to supply a beach system; wave action on existing bluffs may release still more sediment. The sand that supplies Lake Sand Beaches in northern Lake Champlain probably comes from the major rivers, especially the Lamoille and the Winooski. The largest and best Sand Beaches on Lake Champlain are found on south facing shores, where prevailing southerly winds provide a constant supply of sand as well as the wind necessary to keep the communities open. A typical Lake Sand Beach has a relatively flat area, including a beach face that receives wave action and a DISTRIBUTION/ABUNDANCE beach berm above it, and perhaps a higher dune field The largest and most above the berm. Behind the berm, or dune field if there is important Sand Beaches in the one, there may be a wetland, a cliff, or a bedrock feature state are on Lake Champlain, but there are a few excellent that limits the movement of sand. examples on other lakes, Beaches change and move over time, responding to particularly on Lake Memphre- wind, storms, and currents. There may be more sand magog, Averill Lake, Little Averill movement on a beach with a wetland behind it than on Lake, and Lake Willoughby in northeastern Vermont. one backed by a confining bedrock cliff or ridge. In fact, it Artificial sand beaches have seems that the best developed beaches on Vermont lakes been created in a number of are those that sit at the lakeward edges of wetlands that places on different lakes by occupy old lake coves. We have examined aerial photo- trucking in sand. With their an- thropogenic origin, their heavy graphs of one such beach, and the pictures show that sand recreational use, and their lack has been blowing for many years back into the wetland in of native vegetation, these are a process known as overwash. When we dig deep beneath not considered natural commu- the sand on this beach, we finds peat, or wetland deposits, nities. Freshwater sand beaches of that have over thousands of years been buried by the similar species composition are overwash. It is likely that many such sand beaches have found throughout the north- peat beneath them. east. Magnificent examples are found on the Great Lakes.

Upland ShoresProfile / 203 LAKE SAND BEACH

A low spot on a beach where water ANIMALS collects may show evidence of a peaty Shorebirds such as spotted sandpiper are undersoil, too. Water can move laterally commonly found feeding on sand beaches, through the sand and the peat, picking up where small insects are abundant. Black- tannic acids from the peat and emerging backed gulls and herring gulls rest and feed brown at the surface. These low places on sand beaches as well. Large mammals can be well vegetated with a number of such as white-tailed deer and moose, as wetland-loving plants, and in some cases well as smaller mammals such as raccoon, they may actually be wetlands. beaver, mink, and river otter may be seen VEGETATION on sand beaches, moving to and from If a beach is not water to feed. completely re- Two tiger beetles shaped by overwash, that typically live on it is at least scoured Lake Sand Beaches on an annual basis are Cicindela by lake ice pushing repanda and the upward onto the rare Cicindela shore. Ice-scour, hirticollis. flooding, and wind combine to keep the VARIANTS permanent vegeta- None recognized tion on a beach to a at this time. minimum. At the upper edge of most RELATED beaches, cotton- COMMUNITIES woods, willows, and other trees survive in Sand Dune: a narrow forested The larger Lake strip, but these often Sand Beaches on bear the scars of ice Lake Champlain damage at their are associated with bases. A beach can Sand Dunes, and also have bands of these two communi- low shrubs closer to ties are very closely the water – willows related to one are common. These The rare Champlain beach grass is related to the another, both in bands may be short- more common beach grass found along the east geomorphology and lived, surviving for coast and Great Lakes. in vegetation. Sand only a few years Dunes are much between major spring floods. drier overall, as they Many of the herbs found on a sand are above the influence of seasonal high beach are annuals. Nodding bur marigold water. Typically, their vegetation is more and clammyweed are examples. Annuals dense than the vegetation of Sand Beaches. are well adapted to an environment where Lake Shale or Cobble Beach: Lake the substrate may completely shift from one Sand Beaches are also very similar to these year to the next and where flooding can communities, with which they share similar last a long time in the spring. More stable vegetation. On any stretch of beach, in fact, areas, and places that are higher and less the substrate may change in a few feet from flood prone, have perennial herbs such as shale to sand or cobble. silverweed and freshwater cordgrass along with shrubs and tree saplings.

204 / Wetland, Woodland, Wildland LAKE SAND BEACH

Lakeshore Grassland: Wetter or more CHARACTERISTIC PLANTS stable parts of Lake Sand Beaches may be very similar to Lakeshore Grasslands, TREES which have denser and more permanent Black willow – Salix nigra vegetation than sand beaches. The two Cottonwood – Populus deltoides communities can be found at the same site American elm – Ulmus americana and can interfinger with one another, Boxelder – Acer negundo making it difficult to distinguish or map Green ash – Fraxinus pennsylvanica White ash – Fraxinus americana them. SHRUBS CONSERVATION STATUS AND Sandbar willow – Salix exigua MANAGEMENT CONSIDERATIONS Shining willow – Salix lucida Sand Beaches are uncommon in Woolly-headed willow – Salix eriocephala Vermont. Most good examples have been HERBS developed as recreation areas, either with Silverweed – Potentilla anserina private homes or with public swimming Dogbane – Apocynum androsaemifolium facilities. Fortunately, Vermont’s largest Freshwater cordgrass – Spartina pectinata remaining Lake Sand Beach, along with Cocklebur – Xanthium strumarium its most intact natural dune system, is Clammyweed – Polanisia dodecandra protected at Alburg Dunes State Park. Frondose beggar’s ticks – Bidens frondosa Nodding bur marigold – Bidens cernua Very few other beaches in public owner- Tall beggar’s ticks – Bidens vulgata ship are protected as natural areas. Yellow nutsedge – Cyperus esculentus Owners of private sand beaches can Creeping cyperus – Cyperus squarrosus maintain them as natural communities Two-parted cyperus – Cyperus bipartitus by avoiding building in areas of moving Three-way sedge – Dulichium arundinaceum sand, avoiding any grading or clearing, Creeping love grass – Eragrostis hypnoides and allowing natural vegetation to grow. Poison ivy – Toxicodendron radicans Hidden-spike dropseed – Sporobolus PLACES TO VISIT cryptandrus Alburg Dunes State Park, Alburg, Vermont Groundnut – Apios americana Department of Forests, Parks, and NON-NATIVE PLANTS Recreation Crack willow – Salix fragilis North Beach, Burlington, City of Burlington Downy chess – Bromus tectorum Department of Parks and Recreation Butter-and-eggs – Linaria vulgaris Lake Willoughby Beach, Westmore, Town RARE AND UNCOMMON PLANTS of Westmore Creeping love grass – Eragrostis hypnoides Beach pea – Lathyrus maritimus Champlain beach grass – Ammophila breviligulata var. champlainensis Matted spikerush – Eleocharis intermedia Umbrella flatsedge – Cyperus diandrus Ovate spikerush – Eleocharis ovata Sandbur – Cenchrus longispinus Beach wormwood – Artemisia campestris ssp. caudata Pursh’s bulrush – Scirpus purshianus (S. smithii) Smith’s bulrush – Scirpus smithii Hay sedge – Carex siccata

Upland ShoresProfile / 205 SAND DUNE

ECOLOGY AND PHYSICAL SETTING Dunes are areas of windblown sand, where constant southerly winds keep sand moving. When the Champlain Sea occupied the Champlain Valley 11,000 to 13,500 years ago, sand was abundant – thousands of tons had been carried in on rushing glacial meltwater and currents were moving it around. New sand was being formed all the time by constant wave action cutting into rocky shores. Fossil beaches from that time can be found well above the current lake level in Colchester, Milton, and other towns in the Champlain Valley. Today, shores are more stable, and humans have worked hard to tame the sands. But sand is still available and is moving naturally throughout the lake, forming and maintaining natural beach and dune systems. Dunes are defined by sand movement. Water moves DISTRIBUTION/ABUNDANCE sand, depositing it on beaches at high water. Constant wind Only a handful of Sand moves the sand, sculpting it up into high hills and shaving Dune sites are known in those same hills down again. Prevailing summer winds in Vermont, and all are on the Champlain Basin come from the south. Water and wind Lake Champlain. Similar inland Sand Dune communi- move south to north much of the time. Dunes and beaches ties are described in New are therefore most likely to be found on south-facing York, Ontario, Michigan and shores, and in fact all the largest Vermont examples fit that Wisconsin. pattern. A typical setting for a dune-beach complex is a very flat, south-facing shore with a long, unimpeded reach to the south. Sand Dunes are a rarity in Vermont, found in only a few scattered localities on Lake Champlain. They are small in comparison with dunes on the Atlantic Coast or on the Great Lakes, and all of Vermont’s known examples are at least somewhat altered, as they are prime recreational areas. Because there are no undisturbed dunes in Vermont, their physical and vegetational characteristics cannot be fully known.

206 / Wetland, Woodland, Wildland SAND DUNE

Natural Sand Dunes are sometimes ANIMALS mimicked by human disturbance. The Tiger beetles are typical inhabitants of valleys of the Lamoille and Winooski sand dunes. Tiger beetles are so named for Rivers are especially sandy, and nineteenth their behavior during their larval stage, century agriculture caused the exposure when they live just an inch or so under of large areas of the surface of the sand there, sand at the creating bottom of a vase- blowouts of shaped pit. Other sometimes insects that pass immense near enough the proportions. In pit fall in, with the 1930s, many the help of these areas of the unstable were planted sand, and are with pines to quickly de- stabilize the voured. Adults soils, but are identified by blowout areas their habit of can still be seen jumping about on the hills on the sand. above those Beach Heather is rare in Vermont and restricted to sand The rare tiger rivers. The dunes and other areas of exposed sand. beetle, Cicindela blowouts are hirticollis, very similar to is known to natural dunes, with tiger beetles moving inhabit dunes on Lake Champlain, along about and slender flatsedge growing in the with the common sand. The difference is that, given time, the species Cicindela repanda. blowouts will become completely vegetated Small mammals pass through dune once again. These areas are therefore not areas, and may use them temporarily as considered natural Sand Dunes. nesting sites. Large mammals pass through VEGETATION dunes on occasion, moving from wetland to beach, and birds may perch in small Vegetation on a Sand Dune community trees adjacent to dunes. is sparse, with total cover generally under 20 percent. Woody plants are scattered, but VARIANTS in general do not thrive under the rigorous None recognized at this time. conditions of drought and constant wind. Perennial and annual herbs are mixed. A RELATED COMMUNITIES few plants that have adapted to windblown Lake Sand Beach: Sand Dunes are habitats on oceanic shores do well in these always associated with Sand Beaches. Sand habitats, and many plants that have adapted Dunes occur landward of Sand Beaches to other kinds of disturbance, human as and have deeper sand deposits. Certain well as natural, are also successful. plants such as slender flatsedge, umbellate Champlain beachgrass, beach pea, and sedge, and cottonwood can be found in beach heather all became established in the both communities. Champlain Basin during the time of the Champlain Sea and have persisted here on shifting sands for the 10,000 years since freshwater returned to the basin.

Upland ShoresProfile / 207 SAND DUNE

CONSERVATION STATUS AND CHARACTERISTIC PLANTS MANAGEMENT CONSIDERATIONS TREES Natural Sand Dunes are rare in Vermont. Gray birch – Betula populifolia They are apparently restricted to Lake Quaking aspen – Populus tremuloides Champlain because no other lakes are large Red maple – Acer rubrum enough to have sufficient wind and wave Cottonwood – Populus deltoides action to form dunes. Most dunes have been altered by human activity, from the HERBS building of seasonal homes to sand mining Hidden-spike dropseed – Sporobolus to use by off-road vehicles. cryptandrus Groundnut – Apios americana Owners of natural dunes can preserve Umbellate sedge – Carex umbellata them by building elsewhere, on more Common horsetail – Equisetum arvense stable ground, prohibiting off-road vehicle Slender-stemmed flatsedge – Cyperus filiculmis use, and allowing sand to move naturally Poison ivy – Toxicodendron radicans through them. Vermont’s most intact Sand Dune system NON-NATIVE PLANTS is protected at Alburg Dunes State Park, Big brome – Bromus inermis and efforts are underway to restore the Downy chess – Bromus tectorum Evening primrose – Oenothera biennis natural functioning of that system. Other Quackgrass – Elytrigia repens Sand Dunes are in private ownership. Butter-and-eggs – Linaria vulgaris Timothy – Phleum pratense PLACES TO VISIT Alburg Dunes State Park, Alburg, Vermont RARE AND UNCOMMON PLANTS Department of Forests, Parks, and Beach pea – Lathyrus maritimus Recreation Champlain beachgrass – Ammophila breviligulata var. champlainensis Beach heather – Hudsonia tomentosa

208 / Wetland, Woodland, Wildland