Corcoran Woods:

Tree Heights and Forest Structure

Colby B. Rucker


This report provides the maximum heights reached by thirty-four species of trees measured in the Corcoran Environmental Study Area in April and May, 2002.  These measurements are laser-derived and aid in an overall understanding of the role of tree height capabilities in creating the existing forest structure. Correlations between maximum tree heights, habitat influences and indicator species are explored.


Overall Description of Site


The Corcoran Environmental Study Area, often referred to as Corcoran Woods, or the Corcoran Tract, comprises roughly 210 acres owned by the State of Maryland.  Named for Edward S. Corcoran, who once owned the 110-acre northwest portion noted for its old trees, the preserve is located at the northwest end of Sandy Point State Park, in Anne Arundel County, and is administered by the park.  Access is controlled by permit, and limited to hiking, nature interpretation and scientific study.  The property is roughly rectangular, with the greater depth extending from Tydings Road on the east to Bay Head Road on the west.


The property adjoins numerous privately-owned smaller parcels of wooded or residential character.  Corcoran Woods is protected by about 2.7 miles of fencing that completely encircles the property.  The fence is green chain-link, six feet in height, and topped with barbed wire.  Access gates are at Bay Head Road and Tydings Road.  The tract is entirely wooded, and in a natural state, with the exception of unpaved roads and paths which extend through the site.  An unpaved road is inside the fence, allowing access for fence maintenance.  This perimeter road veers inward to cross the head of a natural drainage swale via a small wooden bridge.  


The property is nearly flat, being entirely on the geologically recent terrace of the Talbot Deposit, at an elevation of about 25 to 30 feet.  Three natural swales and numerous manmade ditches provide drainage from the interior of the tract.  Soils over the southeast half of the property, especially toward Tydings Road, are Othello silt loam, with some Mattapex silt loam.  These are heavy, poorly drained soils, with a water retaining substrate.  Soils at the portion of the property toward Bay Head Road are Evesboro loamy sand and Galestown loamy sand.  These soils are well-drained and often droughty, but there are heavier substrates and wet spots in places.  Soils on much of the central section are transitional, and are light but fairly rich.  Heavier substrates provide some moisture retention.


Although much of the woodland is old-field forest, some areas appear to have been too wet for agricultural use, and retain much of their original forest diversity.  Several large groves of older trees, some in excess of 150 years, also have considerable diversity, and are the most useful for study of forest profiles.  For this purpose, the property is here divided into twelve sections displaying different forest characteristics.  These areas have been given names, which are more convenient than scientific.


Forest Study Areas


1.  Greenbrier Section: Entering the property from Tydings Road, this section is on the left.  It is bordered by the fence road at Tydings Road, the main woods road, a large drainage ditch and parallel road, and the Left Border.  This area has hydric soils, with standing water in places.  A low thick growth of greenbrier occurs in much of this section.  Clubmosses are abundant, and the soils are quite acidic.  Probably never cleared for agriculture, it appears that this area retains its original diversity.  It is dominated by an older stand of pin oak, willow oak, red maple, sweetgum and some blackgum.   White oak, pignut, tuliptree, and several northern red oaks were found on better-drained places.  These drier sites have little greenbrier, and are often separated from wetter regimes by transitional zones of New York fern.


2.  Front Section:  From the Tydings Road gate, this section is on the right, and includes a large sign and some seating, now unused.  This section is bordered by the fence at Tydings Road, the main woods road, and the side fence.  It extends back about the same distance as the Greenbrier Section at the main woods road, but is not so deep at the side fence.  It is bisected by the Swale Section.  The Front Section was once cleared for agriculture.  The silt loam soils are better drained than those in the Greenbrier Section, and probably less acidic. Tuliptree, sweetgum and red maple, perhaps 50-80 years old, dominate the old-field forest.  These have outgrown the earlier successional species.  Most of the black locusts have died and fallen, but some black cherries obtain solar access along the main woods road.  Flowering dogwoods occur throughout but many appear to have succumbed to the dense shade, or perhaps to blight.  At least one blackgum and an American elm occur at a low elevation by the main woods road, where the habitat is more like the nearby Greenbrier Section.


3.  Swale Section:  The Swale Section bisects the Front Section.  It is bordered on either side by a loop of the fence road.  This section includes two branches of the main swale, which extend to the rear border of the Front Section.  Near Tydings Road, the swale is quite large, with some standing water.  The woods/wetland interface provides solar access for a variety of species, including black cherry and black highbush blueberry.  The swale was never completely cleared for agriculture, as evidenced by some old trees and greater diversity.  The improved drainage and rich silt loam soils make the upper parts of the drainage good habitat for tall trees.  Numerous spicebush and occasional sycamores occur on the higher elevation between the two drainages tributary to the swale.  Some of the tallest sweet gums and the largest sycamore were found along a long-abandoned farm road that parallels the swale above the bridge.


4.  Holly Grove:  Located at a somewhat higher elevation perhaps one hundred yards beyond the bridge, this feature is an unusually thick grove of mature American hollies, forming a tall understory.   Although broken by occasional windthrows of larger trees, the grove has few shrubs or smaller trees, and the dense shade is probably equaled only by a hemlock stand.  The tallest measured holly is in this grove.  This site is at the near end of the Old Wire Section. 


5.  Old Wire Section:  This section is bordered by the Holly Grove (which is really part of it), the back of the Front Section, the side fence, and a much younger old-field stand behind it.  The name refers to barbed wire deeply embedded in an old pin oak at the rear of this section, and in a large sweetgum toward the Holly Grove.  Although probably once cleared for agriculture, the Old Wire Section has been untouched for over 100 years, and has more

diversity than the younger old-field stands around it. 


6.  Left Border:  On the left, much of the perimeter road is an old farm road, which separates a long border of mixed oaks, tuliptree and sweetgum along the fence from the younger old-field New Poplar Section.  This border is mostly 50-100 feet in width, and has pin oak in places, indicating the once-broader distribution of this species.


7.  New Poplar Section:  This section covers a large area, lying beyond the Greenbrier, Front, and Old Wire Sections.  It extends from the old farm road along the Left Border to an extension of the Pine Section on the right.  This area has a dense old-field stand perhaps 50 years old dominated by tuliptree, sweetgum and red maple in changing percentages.  This section is easily traversed; there is little understory, windthrow, or vine infestation.


8.  Pine Section:  Remnants of an old-field growth of Virginia pine occurs throughout this section, which extends from the side fence on the right, and extends behind the New Poplar Section to beyond the main woods road.  Many of the pines have died, and the intrusion of sunlight has promoted the growth of a dense understory.  This and fallen trees often make passage difficult.  Sassafras is common on the drier soils, but declining, and may give way to southern red oak.  Several rows of loblolly pines have been planted near the main woods road, and some randomly spaced specimens are thought to be of the same origin.  The rear of this section is increasingly infested by vines and multiflora rose.


9.  Big Poplar Grove:  This is an old-field stand of tuliptree, with some specimens in excess of 150 years old.  It extends from the side fence on the right to the Big Oak Grove on the left.  The soils are somewhat light, but rich.  Spicebush is common, but seldom reaches arborescent stature.  Showy orchis and hercules club also occur on rich soils at this site, and several old black oaks and hickories remain in the left portion.  Part of this grove shows evidence of a woods fire, with many trees having some charred bark.  The largest and tallest tuliptrees were found here.


10. Big Oak Grove:  This comparatively narrow band of old trees extends from the Old Poplar Grove nearly to the back gate path.  Many specimens are in excess of 150 years old.  Most of the old trees are well spaced, with large trunks and broad shapely crowns.  There is considerable diversity, the dry mesic habitat supporting trees of both sandy and richer environments.  Outstanding specimens of white oak, black oak, southern red oak, sweetgum and tuliptree were seen.  Some large black walnuts, bitternuts and other species also occur.  Although there is no indication that this site has been disturbed directly, the grove lies between the Pine Section and the Vine Section, and the side-intrusion of sunlight contributes to a dense understory, which often makes passage difficult.


11.  Vine Section:  Lying behind the Big Poplar Grove and the Big Oak Grove on the right, and the New Poplar Section on the left, this section extends to the fence road at Bay Head Road.  This area, once agricultural, is heavily infested by vines, both native and invasive aliens. Oriental bittersweet, multiflora rose and Japanese honeysuckle are common throughout.  Large grapevines and bittersweet have overwhelmed many old-field trees, and have greatly suppressed the regeneration of the forest.  Excepting the roadways, this section is essentially impenetrable.


12.  Back Corner:  Located toward the junction of Bay Head Road and Beacon Hill Road, this small area includes an abandoned cinder-block garage, and a dense stand of bamboo.  Nearby is a deep drainage swale.  Two chestnut oaks occur on the sandy bank of the swale.  Both are coppices, indicating their presence for over 100 years.  This suggests that a greater diversity of dominant species once occurred on the excessively drained soils, which are common at the northwest part of the property.  


Tree Heights: Methodology


The trees measured in this study were of thirty-three native and one naturalized species.   Maximum heights were quite varied, with a few species being represented by immature specimens.  The smaller trees, up to thirty feet in height, were measured directly, to within one-half inch, using an adjustable aluminum pole.

Heights of the larger trees were determined with a laser, in conjunction with a clinometer.  Dense growth often made sighting difficult, and care was taken to acquire accurate measurements.  In addition, the trunk circumference at breast height (CBH) was measured to the nearest half-inch at a point 4.5 feet above the contour passing through the center of the tree’s base.


Heights reflect the vertical distance between two horizontal planes, one passing through the afore-mentioned basal contour, and the second passing through the highest leaf or twig in the tree’s crown.  The use of a laser avoided errors caused by the top point not being over the tree’s base, or the creation of “false tops” common to clinometer/fixed baseline methods.  Use of a telescoping pole established a fixed sighting point above screening vegetation, and increased accuracy by eliminating multiple triangulations.


Tall trees were selected by quick laser readings.  Once chosen, more careful measurements were taken.  Angles were read to within one-tenth degree, and the laser was positioned to eliminate undisplayed fractional distances.  If the pole was not on the basal contour, a level was placed to that point, and a basal adjustment was made.  Each measurement component was recorded in the field, and final heights were derived later.


Attempts were made to accurately record the location of each tree measured.  Unfortunately, the dense canopy often blocked GPS signals, and many coordinates were not obtained.  Therefore, more general descriptions of locations were recorded, referencing natural landmarks, in the sequence in which encountered.  These field descriptions are not included in this presentation.


Although some species were represented by only a few specimens, and only the height of the tallest tree is used in the height profile, the method is consistent, and provides useful information for interpreting the effect of habitat and land use on forest structure within Corcoran Woods.  The tallest trees were usually growing under the optimum circumstances existing for that species, which prompts consideration of subtle differences in habitat. 


Field work was begun on April 8, 2002.  While it is possible that taller examples and additional species have been overlooked, significant additions are unlikely.  In the long term the height structure will change, and forest succession will continue; individual specimens will grow, and some will die.  Several species may be lost, due to suppression by non-native vines.  Maximum height measurements provide a profile that is unique to Corcoran Woods, and provide a useful comparison with other sites.


Maximum Heights

The following specimens were the tallest of their species seen in Corcoran Woods.  The list is divided into height groups, which correspond to general habitat requirements.  It should be noted that these groups are designed to show the optimum habitats for height development of each species, and do not show the height of all species within each habitat or named study area. 


There are critical height differences between species, indicating that inherent height capabilities affect species survival.  Opportunities for some species are created by excessively dry or wet habitats, where species of greater height potential are less well adapted.  The smaller species in each height group are often more shade tolerant, or were found in a stressed condition.  Some species obtain solar access at the edge of a wetland, roadway, or in disturbance openings.  These interfaces are limited, and windthrow openings are rare, due to the moderate age of the woodland in most sections.  In many areas, interfaces and openings are infested by vines, which have destroyed most of the smaller species.


In the following list, the numerals on the right refer to the twelve sections or groves previously discussed under Forest Study Areas.


Mesic dominants:  rich soils with adequate drainage.


Tuliptree                           Liriodendron tulipifera                        142.1’         12’  4.0”      9     

Sweetgum                        Liquidambar styraciflua                       120.9’             6.0”      3

American sycamore         Platanus occidentalis                           119.2’             8.5”      3

Mockernut hickory           Carya tomentosa                                  118.1’            6.5”       9

Bitternut hickory               Carya cordiformis                                115.9’            4.5”       5

Black walnut                    Juglans nigra                                          99.7’             9.5”     10


Dry-mesic dominants:  well-drained loamy sand.


Black oak                         Quercus velutina                                  122.2’          14’  0.5”    10

Southern red oak              Quercus falcata                                    109.7’          15’  9.5”    10         

Chestnut oak                    Quercus prinus                                       91.6’              3.0”    12


Lowland dominants: moist/wet silt loams.


White oak                        Quercus alba                                        119.4’          11’ 11.5”    1

Willow oak                      Quercus phellos                                    115.0’            9’ 10.0”    1

Pignut hickory                  Carya glabra                                        114.6’              9.0”     1

Pin oak                            Quercus palustris                                  110.1’              7.5”     1

Red maple                       Acer rubrum                                          106.9’              6.5”     3

Blackgum                        Nyssa sylvatica                                      106.1’              1.0”     1

Northern red oak             Quercus rubra                                      103.5’              9.0”     1

American elm                  Ulmus americana                                   95.3’              6.0”      2                        

Old-field successional series:    


Black cherry                    Prunus serotina                                   109.9’         10’ 10.0”*  11  

Black locust                     Robinia pseudoacacia                         107.8’             4.0”       8

Sassafras                         Sassafras albidum                                93.7’            2’ 11.5”       8

Loblolly pine                    Pinus taeda         (tree planted)           85.0’               4.0”       8

Pitch pine                         Pinus rigida                                         84.1’              4.5”       8

Virginia pine                     Pinus virginiana                                  82.8’            3’ 10.5”      8


Forest/field interface or disturbance openings: 


Persimmon                        Diospyros virginiana                           66.9’             7.5”       2

Mazzard cherry (nat’d)      Prunus avium                                      48.7’             5.0”       7

Eastern redcedar               Juniperus virginiana                            39.4’             7.5”     11

Hercules club                    Aralia spinosa                                      38.7’             6.0”       9

Common hackberry          Celtis occidentalis                                28.9’             7.0”       9


Understory species:  shade tolerant.        


American holly                   Ilex opaca                                           69.3’             2.0”       4

Flowering dogwood           Cornus florida                                     33.6’            4.0”      10

Spicebush                          Lindera benzoin                                   24.4’            9.5”      10

American beech                 Fagus grandifolia                               21.2’             6.0”       2

Black haw                         Viburnum prunifolium                          20.4’             9.0”       9

Black highbush blueberry   Vaccinium atrococcum                       16.8’             9.0”       3

*  Girth taken at 2 feet.



New Records


Seven species set new state height records.  Sweetgum, mockernut, black locust, American holly, hercules club, spicebush and black highbush blueberry exceed heights for Maryland champion trees, past or present, and recent records for accurately measured tall trees.  By the familiar point system, which includes height, girth and average spread, hercules club, spicebush and black highbush blueberry exceed the present state champions, and have been registered with the Maryland Forest Service as new state champions.




As a natural resource study area, forest succession has, quite properly, been allowed to proceed without human intervention, and the resulting differences in forest structure show a correlation between existing habitat, past agricultural activities, and the inherent capabilities of the indigenous tree species.  Few non- native trees were seen.  The bamboo grove, spreading vegetatively, may be of concern in the future.


Vines are a more serious matter.  English ivy was seen in several areas, and should be eradicated before it reaches the fruiting stage, which will greatly accelerate the spreading of seeds by birds.  Roundleaf (Oriental) bittersweet, which is spread by birds, has overwhelmed many acres of trees.  The largest sassafras and black cherry are nearly covered by vines, as are the remaining examples of hackberry and persimmon.  These trees will soon be lost unless efforts are taken to reduce non-native invasives.


Another serious problem is the unusual abundance of deer ticks; up to three dozen were found daily.   This health hazard is a deterrent to nature interpretation or scientific study of the property.   Fence repair, new gate design, deer exclusion and treated cotton for control of ticks on mice might be considered.




The author wishes to express his appreciation to Kenny Hartman, Assistant Park Manager at Sandy Point State Park, who kindly provided access into the

study area.


Appendix: Comments on Heights of Individual Species


Tuliptree  (142.1’):  Although this species is abundant on all but the driest or wettest soils, form is only average for the species, and few specimens retained a central leader above eighty feet.  The upper structures of older trees displayed successive arching, with minimal increase in height.   The largest specimens, some in excess of 150 years old, were in the Old Poplar Grove.  One measured 13’ 3.0” CBH.  Showy orchis was found near the tallest tree, indicating the higher fertility of the soil at this site. 


Black oak (122.2’ ):  Probably an important component of the original forest on the drier soils, some very large examples remain in the Big Oak Grove, and a few in the Old Poplar Grove.  Some of these aged specimens are in declining condition.  The

largest (14’ 0.5” CBH) was also the tallest. 


Sweetgum  (120.9’):  Sweetgum is abundant on the moist silt-loam soils, where it is height-competitive with tuliptree.  The tallest examples are on better- drained silt loams at the upper end of the swale, with a double-topped specimen reaching 120.9 feet.  An unusually large and handsome example was seen in the Big Oak Grove; CBH was 13’ 0.5”.   The excellent form of many specimens suggests that maximum heights will continue to increase rapidly.


White oak  (119.4’):  Undoubtedly once an important dominant throughout the original woodland, this adaptable and long-lived species is now absent from most sections of the preserve.  Several very large and aged specimens, up to 14’ 10” CBH, remain on loamy sand soils in the Big Oak Grove.  The tallest examples were seen with willow oak, pin oak and blackgum on silt loams in the Greenbrier Section, where it is the largest and tallest species.  Many of these white oaks are vigorous specimens of good form, and significant height increases seem likely.


American sycamore  (119.2’):  Soil acidity is probably a negative factor resulting in an absence of sycamore on the wet silt loam areas.  A few specimens were seen in tuliptree-dominated old-field areas.  Sycamore was frequently seen on the upper part of the Swale Section, where silt loams are better drained, and spicebush is common.  Barely height-competitive with tuliptree or sweetgum, most sycamores will become increasingly sunlight-deprived, and will remain

relatively slender.  The largest and tallest was a three-topped tree at the uppermost end of the Swale Section.


Mockernut  (118.1’):  This species is infrequent, and was found on the more mesic sites.   Several mature examples were found in the Big Oak Grove, and another in the Old Wire Section.  Most were sub-dominant.  The tallest was in the Big Poplar Grove.


Bitternut  (115.9’):  Several tall examples were seen in the Big Oak Grove.  This species is typical of moist silt loam soils; in this section, height may be limited by the drier conditions.  The largest and tallest was a specimen of excellent form in the Old Wire Section.


Willow oak  (115.7’):   This species is an important dominant with pin oak, white oak, and blackgum on the wetter soils in the Greenbrier Section, where the largest and tallest specimens were seen.  Some large well-formed examples were on seasonally flooded sites, nearly as wet as those occupied by pin oaks, and displayed large buttress roots.   A few willow oaks remain near the bridge in the Swale Section.


Pignut  (114.6’):  This species occurs on better-drained soils in the Greenbrier Section, where the tallest example was found.  The largest specimen (8’ 7.0” CBH) was with spicebush in a moist border of the Big Oak Grove.


Black cherry  (109.9’):  Starting as a common mid-successional, this species is seldom height-competitive, and remains as a few specimens of poor form gaining some solar access from the forest/wetland interface in the Swale Section, or benefiting from openings along the main woods road in the Front Section. The tallest tree is in the Vine Section; it is multiple trunked, with one of four trunks living, and that heavily encumbered by bittersweet. 


Southern red oak  (109.7):  Before clearing for agriculture, this species was probably an important dominant on the drier soils.  Modest-sized examples occur in the Pine Section.  Where it occurs near Virginia pine stands, it may succeed that relatively short-lived species.  A few aged specimens remain in the Big Oak Grove, where the tallest example was found.  This specimen has the greatest CBH (15’ 9.5”) of any tree in the preserve.  Unfortunately, much of this old tree is dead.


Pin oak (109.6’):  This species is common on the wetter sites in the Greenbrier Section, where the largest and tallest example was discovered.  Many pin oaks were found growing in seasonally flooded places, and are somewhat height-competitive with nearby willow oaks and white oaks.  This species also occurs in the Left Border, and a single old specimen with embedded barbed wire remains at the upper end of the Old Wire Section, suggesting that pin oaks once occurred throughout the wetter old-field areas.


Black locust  (107.8’):  Starting as a mid-successional with tuliptree on the better-drained silt loams, this species is no longer height-competitive.  Being highly intolerant, most of the locusts have died and fallen.  The tallest and largest example was found with hollies and Virginia pines in the Pine Section, about 100 yards below the Big Poplar Grove.


Red maple  (106.9’):  Common on the moist silt loam soils, this species is barely height-competitive with tuliptree and sweet gum.  Being somewhat shade- tolerant, it will remain as an important sub-dominant in the wetter areas.  The tallest is by the loop road in the Swale Section.


Black walnut  (99.7’):  Most specimens are not height-competitive, the soils being of marginal quality for this species.  A few specimens of poor form remain in former woodland/field interfaces near the Big Oak Grove, where they face increasing old-field competition, and much damage from vines.  The largest and tallest tree was found at the edge of the Big Oak Grove.  It is of good form, and grows in association with a number of very large spicebushes, indicating richer and moister soil conditions than most of the Big Oak Grove.  Without windthrow, black walnut is probably height-restricted from the tuliptree/sweetgum canopies.


Blackgum  (98.0’):  This species is of limited occurrence in the Greenbrier Section, where the more acidic soils seem favorable.  This species is rather shade tolerant, and the scarcity of immature specimens was unexpected.


American elm (95.3’):  But one specimen was seen, on moist silt loam soil, near the main woods road in the Front Section. 


Sassafras (93.7’):  This mid-successional species was frequently seen on the driest soils, where it often occurs in close grouping, owing to root-sprout origins.  Many specimens are in some competition with Virginia pine (82.8’), and are unusually tall and slender.   The largest specimen is in the Vine Section, and essentially covered by bittersweet.  The tallest, located on the berm of an old drainage ditch in the Pine Section, was only 2’ 11.5” CBH, and was surrounded by specimens of nearly the same slender proportions. 


Chestnut oak (91.6’):  But two specimens were seen.  These are multiple-trunked coppices, located on the sandy slope of a deep swale draining to Beacon Hill at the north end of the preserve, in the Back Corner area.  This species may once have been fairly common with other oaks on excessively-drained sandy soils in this area.


Loblolly pine  (85.0’):  This species has been planted in rows at several locations in the Pine Section.  A random group off the main woods road appears more natural, but is probably of similar origin.  Maximum heights were taken at this latter group.  This species should remain height-competitive on somewhat drier sites where tuliptree is less abundant.  It is possible that these trees are pitch-loblolly hybrids.


Pitch pine (84.1’):  But two examples were seen.  The tallest, located near the back gate path not far from the Bay Head Road gates, was fairly old, and in declining condition.


Virginia pine  (82.8’):  This species is a common old-field dominant on the driest soils in the Pine Section.  Most specimens are of similar size and probably of similar age.  Height is unremarkable.  Dead trees and windthrow are common, especially on the heavier soils, where the pines are not height-competitive with sweet gum and tuliptree. 


American holly  (69.3’):  Shade tolerant, this species is common in most areas, but benefits from additional sunlight at a forest/field interface or disturbance opening.  Most noteworthy is a large grove on a slight rise perhaps 100 yards beyond the bridge, where a dense growth of mature hollies in the Holly Grove casts a dark, hemlock-like shade over the forest floor.  The tallest specimen is in this area.  Another large specimen, also hollow, is at a board crossing for a footpath in the Swale Section.


Persimmon (66.9’):  But two examples were seen.  These are near the northeast fence corner at Tydings Road in the Front Section.  Both trees have been overwhelmed by Oriental bittersweet, and survival is doubtful.


Sweet cherry (48.7’):  Only one specimen of this naturalized species was seen.  Undoubtedly introduced by birds, it was found in the New Poplar Section, above the Swale Section.  Only slightly shade-tolerant, this modest-sized example has survived due to the irregular canopy of the grape-affected old-field forest at this location.


Eastern redcedar  (39.4’):  But one specimen was seen, in the Vine Section near the back gate path leading from Bay Head Road.  This tree is losing solar access due to vines and canopy closure by the larger trees; survival is doubtful.


Hercules club  (38.7’):  A group of perhaps six trees was found in an opening on rich soil near the tallest tuliptree in the Big Poplar Grove.  One specimen was unusually large, and proved to be a Maryland point champion.


Flowering dogwood  (33.6’):  This species is occasional on silt loam soils, with tuliptree and sweet gum in the Front Section, but apparently succumbing to heavy shade and perhaps blight.  The best examples remain on lighter soils in the Big Oak Grove.


Common hackberry  (28.9’):  Typically found on rich circumneutral soils, hackberry is uncommon in Anne Arundel County.  But one example was seen, near the largest white oak in the Big Oak Grove.  This tree has been almost completely overwhelmed by vines. 


Spicebush (24.4’):  Occurring as a tall shrub on the richer soils, a number of large examples were found under the largest black walnut, at the edge of the Big Oak Section.  Although most were of unremarkable height, one specimen near a large hickory is arborescent and attains a record height.  Its spread is 25.7’ x 18.7’ (average 22.2’).  CBH is 0’ 9.0”.  This tree is a Maryland point champion.  It is threatened by nearby vines.


American beech  (21.2’):  Some small specimens were seen on better-drained silt loams in the vicinity of the swale, especially near Tydings Road in the Swale Section.  Another is in the Greenbrier Section, near the main road.  They may, in time, become more numerous, and create an ever-higher intermediate canopy.


Blackhaw (20.4’):  But two specimens were seen.  Both were on well-drained rich soils.  One was in the Old Wire Section and the other, slightly larger, was just beyond the largest-trunked (13’ 2” CBH) tuliptree in the Big Poplar Grove. 


Black highbush blueberry  (16.8’):  Usually occurring as a large shrub, this species is fairly common on the wettest soils, especially along drainage ditches, the main swale, and seasonally flooded portions of the Greenbrier Section.  The tallest example was found by the lower swale in the Swale Section.  Its spread has been reduced somewhat by competition, but this specimen is still a new Maryland point champion.