INTRODUCTION

The following report contains the results of a 1994 inventory of the natural communities present in the Borough of Mountain Lakes.  A community is defined as "...any grouping of populations of different organisms found living together in a particular environment," (Allaby 1992).  Some communities are very distinct, often containing species which can survive nowhere else.  Others occur on a continuum, and may share certain features of related types.  Although both plants and animals are found in a natural community, communities are usually defined by the plant species which occur in them.  In Mountain Lakes, natural communities present range from lacustrine (lake) habitats, palustrine (exposed lake shore, stream, or wooded) wetlands, to terrestrial (upland) forest.  Dominant species found in each community are discussed in the report, and a list of all species encountered during the period is contained in Appendix I.  Also included is a discussion of a number of unusual or rare species found during the survey.  An explanation of Heritage Program ranking terms which appear in the text can be found in Appendix II.

METHODS

Sampling visits, varying in duration from one to several hours, were conducted during July, August, September, and October of 1994, and covered most of the lacustrine (lake), wetland, and upland tracts present in the Borough.  Plant species were recorded when encountered, though no attempt was made to conduct a complete inventory of vascular plants present, as such a study is time-intensive and requires an entire growing season.  Roadsides, roadside shade tree plantings, or landscaped areas were not surveyed.  A total of twenty-three hours was spent in the field.

Community classifications used in this study have been adapted from three recent publications: A Preliminary Natural Community Classification for New Jersey (Breden 1989); Plant Communities of New Jersey (Robichaud and Anderson 1994); and Natural Community Inventory of Picatinny Arsenal, New Jersey (Windisch 1993).  Habitat types are not always sharply distinct; because of variations in soil type, topography, historical land use patterns, and other factors, they sometimes grade into one another and share certain characteristics.  Such transition zones are noted in the report.  For reasons of clarity, the technical names of plants do not appear in the body of the text except to distinguish species which share similar common names.  For example, "wintergreen" in this area can be one of two species, Gaultheria procumbens or Chimaphila maculata, while "blueberry" and "huckleberry" are often used interchangeably even though they constitute two distinct heath genera, Vaccinium and Gaylussacia.  A "sedge" can be any of several hundred species which occur in the state.  A list of citings giving both common and technical names appears at the end of this report.  Nomenclature in general follows that adopted in Manual of Vascular Plants of Northeastern United States and Adjacent Canada (Gleason and Cronquist 1991), and keys contained in this text were used in several identification problems.  Some common names have been adopted from Special Plants of New Jersey (Snyder 1992).

NATURAL COMMUNITIES PRESENT AT MOUNTAIN LAKES

LACUSTRINE SYSTEM

Open Water Lake Zone

This habitat occurs at depths of over six feet, and is generally devoid of vascular plants, though free-floating species such as lesser duckweed, star duckweed, and dotted Wolfia were seen in Birchwood and Mountain lakes.  As depths lessen, this zone grades into the following.

Submergent Lake Zone

Generally found at depths between three and six feet and containing usually-submerged aquatic plants such as common bladderwort, humped bladderwort, a number of pondweed species, naiad, fanwort, and low and slender water milfoils.  Again, this zone intergrades with the next as water depth lessens and emergent vegetation begins to appear.  This zone was noted to be present in Birchwood and Mountain lakes.

Emergent Lake Zone

Found at depths ranging from approximately three feet to the lake shore.  Dominated by emergent species such as common cattail, spatterdock, common arrowhead, arrow arum, bulrush species, floating heart , rush species, fragrant water lily, bur-reed, pickerel weed.  This habitat also contains some of the species which occur in the submergent and open water zones.  Present, in varying degrees, at all the borough's lakes.

PALUSTRINE SYSTEM

Open Canopy

Inland Noncalcareous Pond Shore

This habitat is generally present only along the undeveloped shores of Birchwood, Crystal, and Sunset lakes, where it appears seasonally in periods of low water in late summer.  Plants which occur in this habitat are adapted to cycles of inundation and exposure.  Species found here in 1994 include Engelmann's and spiny-spored quillworts, water smartweed, and Pennsylvania smartweed, as well as beached emergents and submergents such as fragrant water lily, spatterdock, water shield, and pondweeds.  Though not rare, the quillworts, which are relatives of the ferns, are often difficult to find unless exposed by low water.

Northern New Jersey Shrub Swamp

An uncommon community in the borough, and restricted to small areas in Wilcox and Frederick parks.  This type, termed shrub/scrub wetlands by some authorities (Tiner 1985), is often associated with streams.  Dominant shrubs include highbush blueberry and sweet pepperbush, with smaller numbers of winterberry, red and black chokeberry, smooth alder, red osier dogwood, arrowwood, and swamp rose.  Small red maples and sour gums are also present, along with herbaceous plants such as cinnamon fern, royal fern, sensitive fern, marsh fern, meadow rue, bugleweed, tussock sedge and peat moss species.  Shrub swamp is a habitat that often grades into the red maple swamp community (see below), and may be simply a successional stage.

Forested

Inland Red Maple Swamp

Fairly common in the borough, present in Wilcox and Frederick parks, and in private and conservation easement lands near Route 46.  Occurs along streams, areas with poor drainage, and along the undeveloped edges of Birchwood, Crystal, and Sunset lakes.  The predominant tree is red maple, with smaller numbers of sour gum, swamp ash, and swamp white oak.  The predominant shrub species in this community are highbush blueberry and sweet pepperbush, with markedly lower numbers of plants such as spicebush, buttonbush, and arrowwood.  Common ground cover includes royal, cinnamon, sensitive and marsh ferns, skunk cabbage, jack-in-the-pulpit, tussock sedge, and peat moss species. 

Inland Acidic Seepage Slope

A small area of this unusual and rare community type was found in mixed oak forest on a hillside in Wilcox Park.  Most wetlands occur in level terrain along watercourses, in poorly drained areas, or in sites where the water table is near the surface.  Seepage slopes may be created by the presence of a shallow fragipan in the soil which forces water to flow along or just beneath the surface (Breden 1989).  A seepage slope forms a microhabitat markedly different from surrounding uplands.  Skunk cabbage, peat moss species, and cinnamon fern are the predominant plants at this site.  Small numbers of club-spur orchid, matricary grape fern, triangle grape fern, and least grape fern were also found here, growing along the edges of the seep.  Although triangle and least grape ferns do not appear on any state threatened or endangered list, they are considered uncommon or rare by some authorities (Montgomery and Fairbrothers 1992).

TERRESTRIAL SYSTEM

Dry-mesic Inland Mixed Oak Forest

This is the most common community type present in Mountain Lakes, found in tracts ranging from small woodlots to the large expanses present in Wilcox and Frederick parks.  Oak species--white, red, scarlet, chestnut, and black--comprise the majority of tree species, though American beech, tulip tree, sugar and red maples, American ash, eastern hemlock, flowering dogwood, cherry, and birches can be found in lesser numbers.  This community was once called the oak/chestnut forest, and, judging from the number of resprouts present, particularly in Wilcox Park, American chestnut must have once been quite common here .  Although the species was destroyed as a viable forest tree in the early decades of this century by a fungus blight, the still-vital rootstocks continue to send up shoots, which grow into shrubs or small trees until they are girdled and killed back by the blight, which is still active.  One tree seen in Wilcox Park was approximately forty feet in height, with a trunk diameter of nine inches, and was mature enough to produce nuts--a rare event.  It is unusual for a chestnut to reach this height, breadth or maturity, though the tree's bark showed blight damage which will soon destroy it.  Unfortunately, a similar- -but more permanent--fate appears to be likely for the eastern hemlocks in the area, due to hemlock decline and the woolly adelgid, an insect pest.  Eastern hemlock may be eliminated as a major forest tree by the end of this decade over large areas in New Jersey, New York, and Connecticut (Benzinger 1994).  Almost all the hemlocks seen during the survey showed damage, and many were dead or dying.  At present, there appears to be no practical method to control the problem in forested tracts, though individual ornamentals can often be saved by spraying. 

Blueberry species, black huckleberry, blackberry species, sassafras, witch hazel, mountain laurel, and spicebush are the predominant shrub species in this habitat.  A wide variety of herbaceous species are also present, the most common of which include aster and goldenrod species, marginal and fancy woodferns, Canada mayflower, sedges (Carex species), garlic mustard, and a variety of clubmosses; a surprising number of orchid species were found here (see "Other Findings," below).  In certain areas this community grades into the next.

Mixed Hardwoods Mesic Forest

Largely restricted to the parkland located between the Conrail tracks and Intervail Road.  Although the species composition is similar to that of mixed oak forest, no one tree species or genus predominates, and there is a wider diversity.  Common trees present include tulip tree, red and sugar maples, oaks, black cherry, yellow birch, American beech, shagbark hickory, American ash, basswood, shadbush, American hornbeam, black birch, and American elm.  Shrub and herbaceous species are largely similar to those present in the mixed oak forest, though the tracts examined appeared to contain more "weedy" plants, such as garlic mustard, poison ivy, Japanese barberry, and greenbriar.

DISCUSSION

Threatened, Endangered or Rare Species

No federal or state listed threatened or endangered plant species was encountered during the survey period.  However, two species were found which are listed by the NJDEPE's Natural Heritage Program as S2, imperiled; or S3, rare (Snyder 1992; see Appendix II for an explanation of state rank codes).  Several hundred individuals of star duckweed (Lemna trisulca), a minute, free-floating aquatic plant were found in open water on both Birchwood and Mountain lakes.  This species, which has historically been found in some of the northern counties and in one Coastal Plain site, is ranked by the Heritage as an S2 species.  Also, a small population of floating heart (Nymphoides cordata), ranked as an S3 species, was found at Birchwood Lake.  This plant, which is a member of the gentian family, has been traditionally thought of as a Coastal Plain species in New Jersey, even though it ranges north to the Canadian Maritimes.  A few populations have been discovered recently in Morris and Sussex counties (Radis 1994).  Floating heart is listed as a protected plant by the Pinelands Commission.

Neither star duckweed or floating heart has any legal standing or protected status in northern New Jersey; very few plants do, outside of the Pine Barrens and the Coastal (CAFRA) Zone.  They should, however, be taken into consideration if activities such as weed control are considered at Birchwood or Mountain lakes.  Control methods such as the use of non-specific herbicides or plant-control fish, both of which can entirely eliminate all vegetation in lakes, would be highly detrimental to the two species.

Other Findings

A surprising variety of orchid species were found during the survey period, mostly in Wilcox and Frederick parks, and on conservation easement and private land near Route 46.  Although there are approximately fifty-five species of terrestrial orchids found in New Jersey, none of them are particularly common in comparison with most other plant families which occur in the state.  Nine species of orchids were found growing in the borough: pink lady's-slipper, yellow lady's-slipper, spotted coral-root, autumn coral-root, club-spur orchid, ragged-fringed orchid, rattlesnake plantain, helleborine, and large whorled pogonia.  None are threatened, endangered or rare listed species, but all except pink lady's slipper (sometimes called moccasin flower), are local, elusive, and not often seen.  Some, like the coral-roots, may not appear above ground every year.  Yellow lady's slipper, once a relatively common species in northern New Jersey, has greatly declined due to collecting and habitat destruction and degradation.  The population of small whorled pogonia, which is rather uncommon, is large and in an unusual location; this is a very showy species, though it does not frequently bloom.

SOURCES

Allaby, M.  1992.  The Concise Oxford Dictionary of Botany.  Oxford University Press, New York.

Benzinger J.  1994.  Hemlock Decline and Breeding Birds.  New Jersey Audubon Society, Records of New Jersey Birds XX (1): 2-12.

Breden, T.F.  1989.  A Preliminary Natural Community Classification for New Jersey.  In, E.F.  Karlin (ed.) New Jersey's Rare and Endangered Plants and Animals.  Institute for Environmental Studies, Ramapo College, Mahwah, New Jersey.

Collins, B.R.  and K.H.  Anderson.  1994.  Plant Communities of New Jersey.  Rutgers University Press, New Brunswick, New Jersey.

Gleason, H.A.  and A.  Cronquist.  1991.  Manual of the Vascular Plants of Northeastern United States and Adjacent Canada.  The New York Botanical Garden, Bronx, New York.

Hough, M.Y.  1983.  New Jersey Wild Plants.  Harmony Press, Harmony, New Jersey.

Luer, C.A.  1975.  The Native Orchids of the United States and Canada.  The New York Botanical Garden, Bronx, New York.

Montgomery, J.D.  and D.E.  Fairbrothers.  1992.  New Jersey Ferns and Fern Allies.  Rutgers University Press, New Brunswick, New Jersey.

Radis, R.P.  1994.  Threatened and Endangered Plant Survey of Picatinny Arsenal, Morris County, New Jersey.  Unpublished report prepared for Picatinny Arsenal and the New Jersey Office of Natural Lands Management, NJDEPE, Trenton, New Jersey.

Snyder, D.B.  1992.  Special Plants of New Jersey.  Office of Natural Lands Management, Division of Parks and Forestry, Department of Environmental Protection and Energy, Trenton, New Jersey.

Tiner, R.W.  1985.  Wetlands of New Jersey.  U.S.  Department of the Interior, Fish and Wildlife Service, National Wetlands Inventory.  Newton Corner, Massachusetts.

Windisch, A.G.  1993.  Natural Community Inventory of Picatinny Arsenal, New Jersey.  Unpublished report prepared for Picatinny Arsenal, U.S.  Department of Defense.  The Nature Conservancy, Eastern Heritage Task Force, Trenton, NJ
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STATE ELEMENT RANKS

S1.  Critically imperiled in New Jersey because of extreme rarity (5 or few occurrences or very few remaining individuals or acres).  Species ranked as S1 are often restricted to specialized habitats and/or restricted to an extremely small (+ or-3%) geographical area of the state.  Also included are species which were formerly more abundant, but because of habitat destruction or some other critical factor of its biology, they have been demonstratively reduced in abundance.  In essence, these are species for which, even with intensive searching, sizable additional occurrences are unlikely to be discovered.

S2.  Imperiled in New Jersey because of rarity (6 to 20 occurrences).  Historically many of these species may have been more frequent, but now, largely through habitat destruction, are known from fewer extant occurrences.  The S2 rank also includes species which occur in habitats restricted to +/- 10% of the total state area.

S3.  Rare in state with 21 to 50 occurrences.  Includes species which are widely distributed in the state but often occurring in small populations, and also in habitats which may be common or widespread.  Species having a moderately restricted distribution (but greater than 10%) in New Jersey, but are locally abundant, are also included.  Species ranked S3 are not yet imperiled in state but may soon be if additional populations are destroyed.