LEC 15 LOCAL FLORA - Lecture 15 Dr. Donald P. Althoff Ideal Invader Sericea lespedeza Feral hog Cane toad

First….defining “an invasive species” Two basic elements: 1) ___________ to the ecosystem 2) ___________ causing environmental, economic, or human _______ Synonyms include: harmful exotic plant pest pest plant nonindigenous aquatic nuisance species non-native invasive species 1 2

An “_________” species…. Not necessarily harmful….some species are exotic (or introduced) and they are not causing measurable problems in ecosystems or for humans Examples: ring-necked pheasant (?) (in some areas) chukar Hungarian partridge Many exotics are ______________ (some grain crops, for example)

Some problematic INVASIVES.... Japanese honeysuckle Japanese knotweed Autumn olive, Russian olive Canada thistle Purple loosestrife Garlic mustard _________________ Honeysuckle (amur, morrow, & tatarian) Shattercane White & yellow sweet clover Sericea lespedeza Johnsongrass Musk thistle Nodding thistle Canada thistle Bur ragweed Leafy spurge _____________(sort of?) PLANTS OHIOKANSAS

Some other OHIO INVASIVES … European gypsy moth Codling moth Emerald ash borer ________________ Feral hog ________________ Chestnut Blight Dutch Elm disease European corn borer ANIMALS, etc.

Further west… Pacific Northwest, some major invasives include: Plants: diffuse knapweed, Scotch brome, Himalayan blackberry Fish: Atlantic salmon, ______________________: European green crab ______________: American bullfrog Mammal: nutria Bird: European starling Insect: gypsy moth Disease: white pine blister rust

Some immediate conclusions…. Invasives can be from _____ taxon Invasives can be ___________________, be ok in one region (native) but problematic in another (introduced) ______ ecosystems seem to be particularly vulnerable to exotic species—thus causing problems. This may be because of the dominance of top-down control of predators and the ____________________________ ________ are processed in aquatic food webs

Large numbers of invaders, multiple ways they’ve “arrived” The numbers are “huge”….in North America over the last 200 years more than 70 species of fish, 80 species of mollusks, 2,000 species of plants, and 2,000 species of insects have been introduced “Short list” of how they got here basically into 2 broad categories: ____________ ____________

Ways of ‘getting here’ basically Accidentally: earthworms zebra mussels (ship ballast) etc. Deliberate: introduction of crops introduction as ornamental introduction of game species biological control agents

How can nonnatives become problematic? In ______________: 1) by displacing native species 2) by hybridizing with native pop n 3) by altering ecological factors, thus disrupting the functioning of native ecosystems (including habitat alteration) 4) by transmitting diseases and parasites not found in native species

How can nonnatives become problematic? For __________: 1) by causing health problems 2) by causing economic damage (e.g. in agriculture) or increasing the costs of upkeep (e.g., on railway lines, road, shorelines, military training installations)

According to IUCN (International Union for Conservation of Nature) #1 threat to biodiversity (i.e., reduction of it) is HABITAT DESTRUCTION/LOSS #2 threat to biodiversity is invasive alien species

What makes an ideal invader? One, two, or 3 or more of the characteristics listed on the next series of slides The _______________ characteristics an exotic possess, the more potential it has to become widespread and troublesome.

One way to look at ideal invader traits… _______________—i.e., prolific _________—easily spread by people, wind, water or wildlife _____________________________—leaf out earlier (plants) or grow more rapidly to maturity (plants & animals) _________________________—natural predators, diseases, or other pests that help control them in native range not present

“Long list” of ideal invader characteristics… 1. High rate of reproduction, pioneer speices, short generation time 2. Long-lived 3. High dispersal rates 4. Single-parent reproduction (for example, gravid or pregnant female can colonize 5. Vegetative or clonal reproduction 6. High genetic variablity 7. Phenotypic plasticity

“Long list” of ideal invader characteristics… con’t 8. Broad native range 9. Abundant native range 10. Tolerant of wide range of conditions (either to “lay dormant” or grow) 11. Habitat generalist 12. Broad diet 13. Gregarious 14. Human commensal

More specifically, for …. ___________ and short life cycle: --go from seed to producing seed very rapidly (closer to weeks than months) _________ systems (especially compared to natives for area), rapid early root growth ______________ Able to grow in ___________ of habitats PLANTS

More specifically, for ….con’t ______________ of seeds produced _____________ and staggered germination __________ method of seed dispersal Able to reproduce: __________ by seed….or… __________ (vegetatively) by sending out above- (runners) or below- ground (rhizomes) or grow new plants from cuttings PLANTS

More specifically, for ….con’t If reproduce sexually, use insects, birds, bats, or other pollinators in new location Growth and reproduction ________ not match with native plants Provide _____ negatively impacting natives Benefit from ____________ (release of chemicals into the surrounding soil that prohibits growth of other plants __________ to grazing PLANTS

When can plants with invader characteristics be helpful? _______________ (reproduce by runners and rhizomes) Nothing else “takes hold” Seed costs for securing/planting native species are prohibitive and have limited availability Food or cover for animal species that is being threatened to loss of critical habitat—short term ?

Common Characteristics of ___________ Susceptible to Plant Invaders _________________ (natural or human-caused) common. Examples fire, flood, overgrazing, land clearing for housing and golf courses Low _____________ Added __________ and ____________ _________ (mesic) conditions (versus dry-xeric) Contain __________________ vegetation—(i.e., early successional stages) __________ slowly from a previous disturbance Relatively rich soils _____________________ (ex. riparian zones)