Transcript Invasive non-native plants in the lower Elwha watershed

Invasive Non-Native Plants in
the Lower Elwha Watershed
Elwha Ecosystem Restoration
Preparing for the Revegetation of the Reservoirs
Olympic National Park
In partnership with
The Lower Elwha Klallam Tribe
Strait of Juan De Fuca
Lower Elwha Klallam Reservation
Highway 112
Port Angeles
Robyn
Hill
Elwha Dam
Highway 101
Olympic
National
Park
Glines Canyon Dam
Geyser Valley
Strait of Juan De Fuca
Lower Elwha Klallam Reservation
Highway 112
Port Angeles
Robyn
Hill
Elwha Dam
Highway 101
Olympic
National
Park
Glines Canyon Dam
Geyser Valley
Lake Aldwell
Lake Mills
Glines Canyon Dam
Elwha Dam
Critical Ecosystem processes will be severely damaged
(erosion, nutrient cycling, hydrology)
EXPECTED CONDITIONS
Natural succession of the middle areas of the reservoirs
expected to be slow
Managing Invasive Species in the
Lower Elwha
• Prioritize species to manage
– From 1991-2008, 147 exotic species have
been observed in the lower Elwha watershed
– Rank species according to invasive potential
• Resources:
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County and State noxious weed lists
NatureServe.org
Park data
Scientific literature
The Top “Species of Concern”
known to occur in the Lower Elwha
Species
Common Name
Species
Common Name
Bromus tectorum
cheatgrass
Lathyrus sylvestris
small everlasting peavine
Centaurea biebersteinii
spotted knapweed
Linaria vulgaris
butter and eggs
Centaurea debeauxii ssp. thuillieri
meadow knapweed
Phalaris arundinacea
reed canarygrass
Centaurea diffusa
diffuse knapweed
Polygonum cuspidatum
Japanese knotweed
Centaurea jacea
brown knapweed
Polygonum sachalinense
giant knotweed
Cirsium arvense
Canadian thistle
Polygonum x bohemicum
Bohemian knotweed
Cytisus scoparius
Scot's broom
Potentilla recta
sulfur cinquefoil
Geranium robertianum
herb Robert
Prunus laurocerasus
Laurel cherry
Hedera helix
English Ivy
Rubus discolor
Himalayan blackberry
Hypericum perforatum
common St. John's wort
Rubus laciniatus
evergreen blackberry
Ilex aquifolium
English holly
Senecio jacobaea
tansy ragwort
Lathyrus latifolius
perennial pea
Bromus tectorum (cheatgrass)
• Annual grass
• Cheatgrass mainly
threatens dry, grassland
ecosystems
Spikelets 15-20mm
– May be common in riparian
communities
• Can drastically change
fire regime
• Depletes soil moisture
early in growing season
Pubescent blades and sheaths
Cytisus scoparius (Scot’s broom)
• Evergreen, perennial
shrub
• Aggressive invader
currently infesting over 2
million acres in CA, WA,
and OR
• Alters soil nutrient regime
by adding nitrogen
• Creates monocultures
• Can change fire regimes
Geranium robertianum
(herb Robert, stinky Bob)
• Semi-evergreen, semiperennial forb
• Aggressive invader of
shady forests and sunny
sites
• Creates monocultures
• Seeds prolifically
• Seed dispersed by
ejecting out of pods and
sticking to travelers
Phalaris arundinacea
(reed canarygrass)
• Perennial,
rhizotomous grass
• Forms dense single
species stands
– Inhibits native
– Reduces diveristy
• Little value to wildlife
• Alters hydrology in
streams, wetlands
Ligules: membranous 4-10 mm
Polygonum spp.
(the BIG knotweeds)
• Includes P. sachalinense,
P. cuspidatum, and P. x
bohemicum
• Displaces streamside
vegetation
• Causes increased bank
erosion and clogs small
waterways
• Forms thickets up to 12
feet tall and produces
allelochemicals
• Spreads mainly by
rhizomes but also by
fragments of root
Rubus armeniacus
(Himalayan blackberry)
• Displaces streamside
and upland vegetation
• Forms thickets up to 12
feet tall
• Vegetatively spreads by
rhizomes and by
fragments of root
• Birds and mammals
disperse the seed
Managing Invasive Species in the
Lower Elwha
• Prioritize species to manage
– Locate populations of the primary species of
concern in the Elwha watershed
• 2001 mapping project
Roads
ONP Trails
Reveg Project Boundary
2001 Survey Points
Roads
ONP Trails
Reveg Project Boundary
2001 Survey Points
2008 Survey Points
Managing Invasive Species in the
Lower Elwha
• Treat priority species in watershed prior to
dam removal
• Prioritize sites to manage
– Areas directly adjacent to reservoirs
– Areas we will use as staging sites for
revegetation activities
– Use model of propagule movements to
identify invasive population “hot spots”
Managing Invasive Species in the
Lower Elwha
• Treatments
– Herbicides specific for each species/situation
– Hand-pull some species
• Scot’s broom
• Herb Robert
• Young seedlings of English holly