•vegetation of piermont marsh, erik kiviat (hudsonia)

8/11/2019 Vegetation of Piermont Marsh, Erik Kiviat (Hudsonia)

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What was there in 1948?

Cattail was most abundant; Phragmites, cordgrasses (Spar-

tina alterniflora, S. pectinata) common; SAV present)

Phragmites


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What was there in the 1970s?

Phragmites 1000 gdw/m2

Of which 7% associated species

Smooth cordgrass (Spartina alterniflora)

800 gdw/m2

Cattail (Typha spp.) 680 gdw/m2

All 3 had less aboveground biomass at Piermont than in

other major Hudson River brackish marshesBiomass graphs and data from Buckley & Ristich 1977

Phragmites


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What was there in the early 1980s?

Panne

High marsh salt meadow*

Phragmites

*Meadows with saltmeadow cordgrass (Spartina patens), Olneythreesquare (Scirpus americanus), swamp rose mallow (Hibiscus

moscheutos), marsh straw sedge (Carex hormathodes), saltgrass

(Distichlis spicata), cattails (Typha spp.), saltmarsh fleabane (Pluchea)

Erik Kiviat photos scanned by Lisa Graichen


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From Winogrond & Kiviat 1997

Phragmites cover

increased 1965 - 1991


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Laba et al. 2008 from

2004 imagery

What was there in 2004?

Possible regression ofPhragmites or methodological

differences?


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HRNERR 1997-2007 composite

SAV map

Wheres the SAV?

Is the sparse SAV of1948 and 1984 gone,

or undetected by

mapping method?

Five species in

Sparkill Creek, 1984;

two E of marsh, 1948

?

Sparse SAV

(1948, 1984)

?

Small SAV beds (recent)

?


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Are weeds other than Phragmites of concern?

Japanese knotweed on seawall and landfill at N end


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Factor in change Evidence

Phragmites + Has spread and replaced other patches

Nutrient loading + Spartina vulnerable; Phragmites resistant

Salinity increase - Should help, not harm, Spartina spp.

Sediment accretion - Phragmites, S. patens, thrive in high marsh

Sea level rise,

hydrodynamic energy ?

Would have affected marsh from E to W, or

from major creeks to interior

Salt hay harvest or its

cessation +

Known to promote Phragmites replacement

of Spartina elsewhere

Pollution from landfill,

railroad, paper mill -

Would have affected marsh from N to S

Saltmarsh dieback ? Widespread phenomenon probably due to

combination of several factors

Muskrat decline ? Feeding preference: Cattail > Phragmites >

Cordgrass


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Implications of vegetation change for ecosystem

services?

Sediment accretion and stability +

Wave attentuation +

Carbon sequestration +

Detritus food chains +?

Other non-habitat services +

Muskrat -

Bird use of marsh : shortgrass specialists

Roosting and some breeding songbirds +

Nonpasserines : some ok, some need more-open habitat -+

Terrapins : access to nesting habitat -?

Fish early life stages especially mummichog

Invertebrates : varies by taxon -+

Vascular plant diversity, especially rare plants


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Places for biodiversity management

-Sweetgum swamp at south end

-Clusters of extant or historic salt meadows in south

-River edge; upland edge including edge of talus

-Major creekbanks

-Rare plant occurrences or potential to restore

These management targets are plant- and habitat-based.

Many other important species or habitats may be present.


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Some needs for surveys and research:

-What is the vegetation composition and structure in the mapped

patches on the various wetland vegetation maps?

-What is the status of sweetgum, tall cordgrass (Spartina cynosuroides),

pectinate cordgrass (S. pectinata), marsh straw sedge (Carex

hormathodes), Olney threesquare (Scirpus americanus), and other

historic species?

-What is the status of the muskrat population and are muskrats

affecting the incursion of Phragmites into the salt meadows?

-What is the cover, species composition and structure of the SAV E of

Piermont Marsh and in the tidal creeks? Wigeon-grass (Ruppia), sago

pondweed (Stuckenia pectinata), etc.?

-Is native Phragmites present (e.g., along the upland edge)?


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Midsummer: Marsh and Distances (Alan Gussow)

•vegetation of piermont marsh, erik kiviat (hudsonia)

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