Biology Reference
In-Depth Information
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Map 18. GPS data loggers from the Invasive Spartina Project record the exact loca-
tion, species, extent, cover, and treatment of invasive spartina at over 170 sites
around the bay on maps such as this one of Creekside Park, Marin (2009). Differ-
ent colors differentiate
S. densiflora
(purple),
anglica
(yellow), and various hybrids—
S. densiflora x foliosa
(blue) and
S. alterniflora x foliosa
(red). (Invasive Spartina
Project)
The patches that Bernstein is monitoring appear on his GPS as poly-
gons, squares, or plot lines. On this day Bernstein's mapping a grid in an
area where dense-flowered cordgrass (
S. densiflora
) and its hybrids are
found. First he walks around—stepping from bare patch to bare patch in
order to avoid vegetation where Clapper Rails may be hiding. Using GPS,
he tries to place himself at the center of a predetermined virtual grid
square. Then he looks for telltale characteristics such as in-rolling leaves to
determine he is among the dense-flowered cordgrass. When he finds
some, he eyeballs the grid area, estimates how much of it is covered by the
hybrid, and logs the percentage into his yellow handheld.
Bernstein says that being able to identify all the non-native plant spe-
cies was hard during his first year, but it became easier after several sea-
sons. When in doubt, he'll take a DNA sample. Project workers like Bern-
stein took 200-1,000 samples baywide per year between 2002 and 2009. In
