Dana Gumb, on behalf of Green Sanctuary and Buildings and Grounds Committee, recently attended a talk on the value of the combined woods of UUCSR, Greentree and neighboring golf courses. Dana’s meeting notes highlight the importance of our combined property as open space in NY State.  Important native plants and pesky invasive plants are identified. Dana’s attendance at the Greentree event also speaks to our efforts at community building with like-minded entities.

May 4, 2023

Notes on Meeting Prepared by Dana Gumb

The meeting was called to order by Jim Stevenson, the chief horticulturalist at Greentree.  The purpose of the meeting was to hear the report of Greg Edinger on the fauna of the Greentree property.  Greentree engaged the Natural Heritage Program to complete this inventory.  The Program is a non-profit organization affiliated with the SUNY Research Foundation and based at Syracuse University School of Environmental Science and Forestry.  Field work for the study was conducted in the summer of 2021.

Greg explained that the underlying geology of the site sets the stage for the surficial soils which in turn determines the plant life, the actors on the geological stage.  The site is a hilly till moraine landscape produced by glacial action.

Data on plant life was collected by establishing plots and points.  A major vegetative community is the Oak Tulip Tree Forest which includes black birch and beech trees.  This forest, called Whitney Woods, encompasses the Greentree site (163 acres), the Unitarian Universalist property (80 acres), and the two golf courses (20 acres) for a total Oak Tulip Tree Forest of 263 acres.

Regarding the significance of the Oak Tulip Tree Forest in New York State, the occurrence of this community at Whitney Woods is the 10th largest in the state, the second largest on Long Island and the largest of three currently known in Nassau County.  The Landscape Condition Assessment (LCA) score falls around the middle of the range of current LCA scores for Oak Tulip Tree Forest occurrences in the state but is among the best scores of these forest types in Nassau County.  (Only the forest at Sagamore Hill scores better in terms of its currently known condition.)

Major threats to this natural community are the invasive species of Norway maple, winged euonymus, and English ivy.  The deep shading of Norway maples in the subcanopy tends to suppress any growth in the herbaceous layer on the forest floor.  Beech leaf disease is a threat to that native tree.  Another forest community type is labelled Successional Southern Hardwoods, dominated by invasives such as Norway maple, carpets of ivy, ailanthus and cork trees.

Vernal pond occurrences are features of the Greentree site and adjoining properties.  Soil borings were taken from the substrata under these pools, and a clay layer or lens was found that prevents infiltration of the water that collects in them.  These clay lenses may separate the pools from the effects of groundwater pumping which would lower the water table below the lenses.  There are six such pools on the Greentree property.  One such pool called Shrub Pond is dominated by buttonbush.  Greg described the pool on the UUCSR property as eutrophic with much leaf detritus and a tree canopy that almost completely covers it.  The less vegetation in these pools means that they are of higher natural resource value.

Regarding the significance of the Greentree vernal pool complex, this feature is of statewide significance.  The NY Natural Heritage Program (NYNHP) recently conducted an EPA-funded, 5-year project to determine the importance of vernal pools in New York.  While there are at Least 300 vernal pools on Long Island (as per John Turner of Seatuck), the vernal pool complex at Greentree is only the second one documented on Long Island by NYNHP with the other being at Muttontown Preserve, also in Nassau County.

The Greentree site unlike the UUCSR property has a variety of vegetative cover types with grasslands like Semi-natural Grassland and Semi-natural Forb Field, dominated by flowering perennials.  Another grassland type is Successional Old Field with many golden rod plants and clump forming grasses.  Greentree in recent years has modified their mowing regimen considerably to allow for these grasslands to persist.  They mow some of the fields only once a year in early spring.

One hundred-year-old maps of the Greentree estate show the same Oak Tulip Tree Forest and grasslands that still exist today.  All this information about the vegetative community types on the Greentree site was utilized to create a map that presents the locations of these community types.  Greentree will use this map to inform their land management strategies.  Unfortunately, the UUCSR Land Management Plan does not include such a map.

The final part of the presentation was about rare and endangered plants found on the Green Tree property, as follows:

  • Green milkweed (Asclepias viridiflora) – largest NYS population
  • Strawberry bush (Euonymus americanus)
  • White edged sedge (Carex debilis)
  • Pale duckweed (Lemna valdiviana) – found in vernal pools
  • Lowland yellow loosestrife (Lysimachia hybrida) – blooms in mid-July
  • Nodding lady’s tresses (Spiranthes cernua) – species of orchid
  • Nodding trillium (Trillium cernuum) – subject to deer browse

Contact info for Greg Edinger:
New York Natural Heritage Program
625 Broadway, 5th floor
Albany, N.Y. 12233-4757