Post on 18-Jan-2016
description
Native and Invasive Native and Invasive PlantsPlants
Invasive plant Invasive plant • Ability to spread aggressively
outside its natural range• Especially in new habitat
Invasive plant Invasive plant • Lack insects, diseases and
foraging animals
Where are they a Where are they a problem?problem?Disrupted habitats•Thrive on disturbed sites like construction areas and road cuts
Why are they a problem?Why are they a problem?• Threaten native plants and
animals• Insects, micro-organisms, birds,
etc…• Alter habitats and reduce
biodiversity
Native PlantsNative Plants
Plants growing here for a long time>500 years
◦Christopher Columbus (1492)
Native Plant DatabasesNative Plant Databaseshttp://www.se-eppc.org/southcar
olina/http://www.scnps.org/http://www.namethatplant.net/http://www.wildflower.org/
collections/collection.php?start=0&collection=SC&pagecount=10&pagecount=100
BiodiversityBiodiversityThe diversity of animals is linked
to the diversity of plants◦Greater number of plant species
means less competition and increased niches
BiodiversityBiodiversity2.5 acres of Amazonian rainforest
supports 473 species of treesOnly 134 species of trees in
Pennsylvania
BiodiversityBiodiversity
Trophic level is the position an organism occupies in food chain.First trophic level: PlantsPlants capture sun’s energy and
turn it into food for the rest of us
BiodiversityBiodiversity
Second trophic level: HerbivoresTransfer energy from plants to predators and parasites in higher trophic levels
◦Mainly insects
BiodiversityBiodiversityWorldwide, 37% of animal
species are herbivorous insectsPound for pound, insects contain
more protein than beef96% of birds rely on insects and
spiders to feed young
Keystone SpeciesKeystone SpeciesKeystone species essential role in maintaining diversity◦Robert T. Paine research
Tidal pool on Pacific Coast◦Simple ecosystem
Keystone SpeciesKeystone Species
Simple Ecosystem◦Rivet example
Some rivets on airplane more important than others◦Seat versus engine
Keystone SpeciesKeystone Species
Simple EcosystemRemoving some species had little effect on populations of remaining speciesBut removal of a predatory starfish (Pisaster ochraceus) caused a collapse of half the remaining species’ population
Keystone SpeciesKeystone SpeciesComplex SystemNo central players
◦Jenga exampleHow vital a block’s role to the tower’s stability is based on the presence of other blocks
Keystone SpeciesKeystone Species
Complex SystemEvery time block is removed, role and importance of other blocks changesAlmost any species can be a keystone species depending on circumstances
Trophic CascadesTrophic CascadesThe impact on other species when removing a keystone species
◦Predator exampleYellowstone wolf population reducedMoose spend less time looking around
◦More time grazingOvergrazing led to erosion, impacting streams, fish, plants, etc.http://www.twp.org/
Non-Native (Alien)Non-Native (Alien)Aliens colonize areas faster than
nativesAlien plants interact minimally
with ecosystem and pass along very little energy to herbivores (2nd trophic level)
Non-Native (Alien)Non-Native (Alien)“Pest-free” ornamentals are
primarily selected for landscapeIt takes time for insects to adapt
to specific chemical composition of leaves
Non-Native (Alien)Non-Native (Alien)Paperbark tea
tree introduced to Everglades in 1900
Presently, 8 species of arthropods feed on leaves, opposed to 409 back in Australia
Non-Native (Alien)Non-Native (Alien)90% of herbivorous insects are
specialists that have evolved with a plant
Non-Native (Alien)Non-Native (Alien)Insects develop ability to
overcome physical and chemical defenses of host, but limited to feed on that host only◦Mainly due to leaf chemistry
Insects develop enzymes that detoxify chemistry
Non-Native (Alien)Non-Native (Alien)Tannins in oak leaves would bind
protein if we eat them, starving us
Lima beans contain cyanide unless boiled
Cucumber leaves are lethal
Non-Native (Alien)Non-Native (Alien)10% of insect
herbivores are generalists that eat several types of plants
Ability to produce very powerful gut enzymes called mixed-function oxidases
Feed on many alien plants, but not enough
Non-Native (Alien)Non-Native (Alien)
Compare diversity and biomass of insects on 4 woody natives versus 5 aliensNative plants produce 4x more biomassSupported 3.2x more species
Non-Native (Alien)Non-Native (Alien)
Compare diversity and biomass of insects on 4 woody natives versus 5 aliensIn terms of caterpillars (most important to birds), 35x more than alien plantsNatives produced 2x as many generalists
Non-Native (Alien)Non-Native (Alien)A plant can become
native regardless of origins
Norway maple introduced from Europe in 1756Still has few insect
feedersCompare to 80 millions
years of coevolution, 250 years isn’t much
Non-Native (Alien)Non-Native (Alien)Native applies to local regionsHuman influence is too rapid for
adaption
Non-Native (Alien)Non-Native (Alien)Birds eat fruit after reproductionMost species depend on insect
protein for egg laying and feeding young and nesting
Non-Native (Alien)Non-Native (Alien)
Non-invasive qualities of alien does not make it nativeClematis vitalba introduced 100 years agoSupports 40 herbivores in homeland but only 1 after 100 years since introduction here
http://www.wildflower.org/collections/
http://www.wildflower.org/collections/collection.php?start=0&collection=SC&pagecount=10&pagecount=100
http://www.se-eppc.org/http://www.dnr.sc.gov/
invasiveweeds/illegal1.htmlhttp://www.scnps.org/
http://arstechnica.com/science/2013/03/by-building-fairy-circles-termites-engineer-their-own-ecosystem/
Fragmentation Biological Dynamics of Forest Fragments Project
Island ecosystem stabilityhttp://www.stri.si.edu/english/
research/facilities/affiliated_stations/bdffp/