Andrew RohrbaughBureau of Forestry

Conservation Science & Ecological Resources

Invasive Species & Biodiversity

What is an invasive species?

Invasive plants are those that:-Are not native to an area-Spread quickly-Cause economic or environmental harm, or harm to

human health

Purple Loosestrife (Lythrum salicaria) Burning Bush (Euonymus alatus)

What is DCNR’s Role?

• Noxious Weeds and Harmful Insects– PA Department of Agriculture is jurisdictional agency

• DCNR– Native Wild Plants: DCNR Forestry has jurisdictional

authority; severely impacted by invasive species

– BOF Forest Health manages forest insects and diseases

– 300,000 acres of State Parks

– 2.2 million acres of State Forest lands

• Member of PA Invasive Species Council (PISC)

DCNR:

• Recognizes 117 invasive plant species

– 15 additional species are on the “watch list”

• Surveys and treats ~20 pests and diseases

• Monitors DCNR lakes and streams for invasive plants, algae and mussels

• Monitors Feral Swine damage

• Monitor/Protect Bats--WNS

Invasive species

Invasive Don’t Provide Services that Natives ProvideoAquatic organisms and native treesoNative plant support of butterflies, moths &

birds

Invasive Plant Impacts

• Outcompetes native vegetation and wildflowers

• Toxic Decoy to West Virginia white butterfly

• Lays Eggs on same plant family

• Eggs on garlic mustard—caterpillars always die– Monarch butterflies & black swallow-wort

Invasive Plant Impacts

Invasive Plant Impacts

Ward, et AL, 2011:

When barberry is controlled:27% fewer larval ticks & 58% decrease in adult tick density

Ticks infested with Lyme disease:166 infected ticks per acre in untreated barberry infestations50 infected ticks where barberry was controlled20 infected ticks per acre in adjacent forest without barberry

• Introduced in 1852; by 1930’s, spread across Southeast US

• Decreasing abundance and diversity of native herbaceous plants and tree seedlings along streams in infested plots

• Removed privet; compared treated to untreated

• Native plants returned within 2 years

• 4-5x more bee species in Privet-free areas than invested plots (40 or 50 compared to 10)

• 3x more butterfly species in free plots vs infested

Invasive Plant Impacts

Strategies to Decrease Invasive Impacts on Biodiversity

• DCNR Invasive Species Plan

• Bureau of Forestry Strategy

• PISC 5 Year Plan

• Strategy can be boiled down to:

– Prevention (Education), Inventory, Prioritize (EDRR), Treatment (Mechanical, Chemical, Biological)

DCNR’s Strategy

Prevention

Prevent the Spread

TransportationCorridorsVehiclesShipping MaterialsBarge ballast water

Plant MaterialFirewoodSeed mix contaminationHabitat Plantings

RecreationHiking TrailsEquestrian wasteAttached to hullsFragmented by propellers

DisturbanceTimber harvestsVacant lotsOld fieldsForest firesAgriculture

ConstructionFill materialVehiclesMowingImproper herbicide use

WildlifeBirdsWaterfowlLarge mammals

DCNR’s Strategy

Education & Training

Education

Training

DCNR’s Strategy

Inventory & Detection

Current Data

Tracking

DCNR’s Strategy

Prioritization

Early Detection Rapid Response

Early Detection Rapid Response (EDRR)

DCNR’s Strategy

Treatment

Mechanical/Chemical Control

Biological Control