1. Invasive Species
An introduction

2. What is a native species?
Native species are those that normally live and thrive in a particular community. They occupy specific habitats and have specific niches in their native environment. They have natural predators that help to keep their populations in check.
Pink lady's slipper, Cypripedium acaule
Red fox, Vulpes vulpes

3. What is an invasive species?
An invasive species is a plant, animal or other organisms, like fungus, that is not native to a specific location.
It can spread easily and is believed to cause damage to the surrounding environment, human economy or human health.
Multiflora rose, Rosa multiflora, was introduced for use as an ornamental plant, to control erosion, and to use as “living” fences for livestock.

4. What is an invasive species?
It is a species that causes ecological or economic harm in a new environment where it is not native. Invasive species are capable of causing extinctions of native plants and animals, competing with native organisms for resources. Humans and their actions are the primary reason of invasive species in an environment.
Zebra mussels (Dreissena polymorpha), were accidentally introduced to North America, and are now found in some Pennsylvanian waterways

5. What is an invasive species?
A species that adversely affects habitats and biodiversity.
Emerald ash borer, Agrilus planipennis , has killed millions of ash trees in the mid-west and has recently been found in Pennsylvania
Japanese stilt grass, Microstegium vimineum, becomes established on recently disturbed areas and outcompetes native plants, reducing biodiversity.

6. Common characteristics of invasive species
Invasive species in general:
Have few natural predators, competitors, parasites or diseases
Have high reproductive rates
Are long-lived
Are generalists
Are pioneer species
Characteristics that make Zebra mussels a good invader include its ability to tolerate a wide-range of environments, and high reproduction rate; female mussels release up to 100,000 eggs ability to tolerate a wide-range of environments year.
Discussion: how would these characteristics enable a species to become invasive?

8. Invasive Plants 250,000 Plants in the World 22,000 Invasive Plants
Definitions
Invasive Plant = Weed
Noxious Weed = Regulated Weed
Melaleuca and Pond Apple – Tale of Two Weeds in North America and Australia
Melaleuca
Pond Apple

9. What traits are common to invasive plant species
Self-compatible
Flower early
Produces abundant seed
Disperse seed widely
Grow rapidly
Spread asexually
Strong competitors
Characteristics that make tree-of-heaven a good invader include its ability to flower early (within 2 years), ability to spread asexually, and fast growth rate.

11. Invasive Insects 30 Million Insect Species 500,000 Species of Beetles
Desert Locust
Africa, Middle East, Asia
Swarms –
1,200 km2
96 Billion Individuals
240,000 Metric Tons
Losses
Morocco – 1954 ($50 Million in 6 Weeks)
Ethiopia – 1958 (167,000 Tons of Grain – Feed 1 Million People for a Year
Mauritania, July, 1994

13. Invasive Fish-Sea Lamprey
Each lamprey preys on the commercial fish species, like trout.
They live off of the blood and body fluids of adult fish.
During its life as a parasite, one Sea Lamprey can kill 40 or more pounds of fish.
This fish is a major cause of the collapse of the lake trout, whitefish and chub populations in the Great Lakes during the 1940’2 and 1950’s.

14. Invasive Fish-Sea Lamprey
The Sea Lamprey are native to the Atlantic Ocean and were introduced through human made locks and shipping canals in the 1800’s.
They were first discovered in Lake Ontario in 1835, Lake Erie in 1921, Lake Huron in 1932, Lake Michigan in and Lake Superior in 1946.
By 1947, Sea Lampreys were found reproducing in all the Great Lakes.

16. Invasive Fish-Sea Lamprey
Today the adult Sea Lamprey population is nearly as large as it was 40 years ago.
The government created a granular Bayluscide to help diminish the Sea Lamprey population within the Great Lakes.
The Bayluscide was designed to kill the Sea Lamprey in the bottom sediments where they live and breed.
The Bayluscide was created to not impact the native organisms, the other fish and plant life. It only targets the Sea Lamprey.

17. Invasive Fish-Sea Lamprey

19. Invasive Animal-Burmese Python
They originally started out as pets in the 1990’s. But when these creatures grew too big to handle, pet owners dumped then into the wild.
Unlike many domesticated animals who can’t survive in the wild, pythons thrived and multiplied especially in the Everglades.

20. Invasive Animal-Burmese Python
In the Everglades the python became a scary, frightening problem, posing a threat to humans and feeding on native endangered species like the alligator.
Over 1,300 pythons have been removed from the Everglades, but there are still concerns over the species continuing to grow and thrive.

21. Invasive Animal-Burmese Python
In the Everglades the python became a scary, frightening problem, posing a threat to humans and feeding on native endangered species like the alligator.
Over 1,300 pythons have been removed from the Everglades, but there are still concerns over the species continuing to grow and thrive.

23. Impacts of invasive species
 Reduce forest health and productivity    
Monoculture of Japanese barberry prevents the establishment tree seedlings

24. Impacts of invasive species
Some invasive species kill native species
About ¼ of the hardwood trees in Pennsylvania used to be American chestnut. The invasive chestnut-blight fungus killed most American chestnut throughout the eastern US by 1950.
American chestnut, Castanea dentata, at Grey Towers National Historic Site in Milford, PA, circa 1905
American chestnut infected with chestnut blight fungus, Cryphonectria parasitica

25. Impacts of invasive species
Indirect impacts:
Hemlock woolly adelgid is killing Eastern hemlock trees throughout Pennsylvania and the northeast. Eastern hemlock forests play an important role in maintaining stream temperatures and oxygen levels favorable for brook trout. Hemlock mortality leads to increased water temperatures and oxygen levels, and therefore reduced brook trout populations.
Hemlock woolly adelgid
Hemlock woolly adelgid infestation
Hemlock mortality along stream bank

26. Impacts of invasive species
Economic impacts: Invasive species are responsible for tremendous economic losses through loss in forest and agricultural productivity, spread of diseases that impact humans, among other impacts.
European starlings, Sturnus vulgaris, spread diseases to wildlife, livestock, and humans, damage agricultural crops, and displace native birds. Their damage to agricultural crops is estimated at $800 million annually.

27. What you can do
When boating, clean your boat thoroughly before transporting it to a different body of water.
Clean your boots before you hike in a new area to get rid of hitchhiking weed seeds and pathogens.
Don’t move firewood (it can harbor forest pests like emerald ash borer).
Don't release aquarium fish and plants, live bait or other exotic animals into the wild. If you plan to own an exotic pet, do your research and plan ahead to make sure you can commit to looking after it. 
Volunteer at your local park, refuge or other wildlife area to help remove invasive species. Help educate others about the threat.