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CHOH 09 Plummers Island

Chesapeake & Ohio Canal NHP


         The biota of Plummers Island, including lichens, has been studied by members of the Washington Biologists' Field Club for nearly 100 years.

         Lichen studies on the Island include floristic treatments, growth studies and element accumulation studies.

         The lichen community on the Island in the early 1900's included numerous species known to be sensitive to air pollution that cannot be found there now.

         The Island is located just below the American Legion Bridge, built in 1965,  that carries the Capital Beltway (Interstate 495) across the Potomac River.

         Studies of lead accumulation by the rock-inhabiting lichen Flavoparmelia baltimorensis indicate that fallout patterns have changed significantly in the past 100 years.

Site data

38.9702N  77.1782W

Hardwood floodplain forest

Corticololous lichens in plot 2004 (abundance)

Candelaria concolor (2)

Dirinaria aegialita (1)

Flavoparmelia caperata (4)

Flavopunctelia flaventior (2)

Parmotrema dilatatum (2)

Parmotrema hypotropum (2)

Phaeophyscia adiastola (2)

Physcia millegrana (3)

Punctelia rudecta (2)

Pyxine caesiopruinosa (2)

Pyxine sorediata (2)


compare with results of previous surveys done since the 1900's at Plummers Island.

Element data (mean g/g SD, N = 3)



Cd  < 0.55

Cu  16.15 1.56

Cr   2.35 1.80

Pb  26.6 2.53

Ni   2.46 1.93

Zn  35.85 8.22

S  1191.0 91.5

Hg  0.11 0.02


Cd  < 0.50

Cu  22.79 0.79

Cr   4.08 0.41

Pb  76.72 1.47

Ni   2.55 0.10

Zn  38.47 14.4

S  1307.01 48.8

Hg  —


compare with results of elemental analyses of lichens collected at Plummers Island since the early 1900's.




  PI site

Plummers Island is located beneath the American Legion Bridge supporting Interstate 495 across the Potomac River.

F balt

Flavoparmelia baltimorensis