Evaluating the invasion risk of nonnative plants in Florida's natural areas Brazilian pepper (Brazilian pepper) Deah Lieurance, PhD Coordinator, UF/IFAS Assessment of Non-native Plants in Florida s Natural Areas Gainesville, FL
invasive species: an organism (plant, animal, fungus, or bacterium) that is not native and has negative effects on our economy, our Everglades National Park environment, or our health. CNN USDA/Flickr
Unique geography makes Florida particularly susceptible ~85% of all non-native plants enter through Florida 1400 non-native species established/124 in state parks Significant impacts to recreation/expensive to manage Cost $500 million/year to control exotic species in Florida Lygodium microphyllum Melaleuca quinquenervia Eichhornia crassipes
Outline Traits & ecology of invasive plants The assessment: history & tools The website
Biological Traits of Invasive Plants Higher relative growth rates Longer flowering & fruiting periods Greater seed production Efficient dispersal Fast germination/short minimum generation times Tolerant to a wide range of habitats/conditions Efficient resource utilization
Fast Growth
High Reproduction http://wildlifeofhawaii.com/flowers/698/schinus-terebinthifolius-brazilian-peppertree/ http://pesticide.ifas.ufl.edu/lygodium/images/photo_gallery/fertile-leaf.jpg
Efficient Dispersal USDA-ARS Andres Cadena Mireles http://aquaplant.tamu.edu/plant-identification/visual-index/water-hyacinth/
Photo by Jason Ferrell Tolerance
Ecosystem Effects Erosion/sedimentation Changes in water & nutrient cycling Altered disturbance regimes Reduction of native species Increases in resource competition =Changes in stand structure South Florida Water Management District http://tame.ifas.ufl.edu/
Ties to Landscaping Many prominent invasive plant species introduced for hort/landscaping ex. Lantana, Nandina, Coral Ardesia Sprawling over the earth
but not all bad Many non-native species are economically beneficial
Outline Traits & ecology of invasive plants The assessment: history & tools The website
What is The Assessment? Tool to assess the status of species currently present in the state Reduce cost & increase efficiency of management efforts
What is The Assessment? Tools to predict the potential invasiveness of species proposed for release Preemptively prevent future invasions
History & Purpose Developed in 1999 UF/IFAS Invasive Plants Working Group Descriptions & recommendations for use & management 2008 Predictive Tool & Infraspecific Taxon Protocol added
Status Assessment Evaluates species already in Florida 3 Zones Describe the status of the species Ecological impacts Potential for expanded distribution in Florida Management difficulty Economic value Incorporates field data from experts
Status Assessment Ecological impacts Document natural areas where present/#acres Long term alterations to ecosystem processes? Overall changes in community structure? Interactions with federal/state threatened or endangered species?
Status Assessment Management impacts Control methods? Is species difficult to control? Require retreatment? Costs of control >$1500/acre? Viable propagules?
Status Assessment 1. Not considered a problem species at this time & may be recommended (reassess in 10 years) 2. Caution may be recommended but manage to prevent escape (reassess in 2 years) 3. Invasive & not recommended (except for any specified & limited use) approved by IFAS Invasive Plants Working Group (reassess in 2 years) 4. Invasive & not recommended (reassess in 10 years)
Predictive Tool Evaluates species New to state Causes problems elsewhere Proposed for new use Correctly identified high and low risk species with 90 & 70% accuracy. (Gordon et al. 2009) > 80 species evaluated Eucalyptus grandis
Predictive Tool Series of 49 questions Domestication/cultivation Climate/distribution Weed elsewhere? Weedy traits Plant type Reproduction Dispersal mechanisms Persistence attributes Scoring <1 Low Risk for Invasion 1-6 Evaluate Further >6 High Risk for Invasion History/biogeography Life history/ecology
Secondary Screening Pacific second screening: decision rules for species with WRA scores between 1 and 6 (from Daehler et al. 2004) Tree or tree-like shrub A. (Shade tolerant OR known to form dense stands) AND B. Bird- OR clearly winddispersed no yes Life cycle < 4 years? no yes evaluate further reject accept Herb or low stature shrubby life form Reported as a weed of cultivated lands? no Unpalatable to grazers OR known to form dense stands? yes no reject Vines must pass both tests yes evaluate further
Invasion risk of biofuels 40 biofuels, 40 introduced in Hawaii Biofuels 2-4x more likely to be invasive Buddenhagen et al. 2009
Biomass Planting Rule to control the introduction into, or movement within, Florida of plant species intended for biomass plantings. Requires permit to plant >2 contiguous acres By law, include weed risk assessment
37 species with WRA results 22 low probability of invasion 8 high probability of invasion 7 further evaluation
Infraspecific Taxon Protocol Cultivars, varieties, or sub-species of resident species Determine if recommendations for resident species apply Request submitted to IFAS Assessment staff Supporting evidence indicating the taxon is a distinct entity Reasons for expecting the taxon to behave differently resulting in different recommendations
Infraspecific Taxon Protocol Will botanists/field personnel be able to distinguish the taxon? Regress, revert, or hybridize to characteristics of resident species? Invasive traits that cause greater ecological impacts? Increased or decreased propagule pressure?
Nandina The resident species. North, Central = Invasive Specified limited use (if approved) South = Caution may be recommended/m anage to prevent escape
Nandina cultivars Firepower, Harbour dwarf, & Gulf Stream: ok to recommend All zones Jaytee (Harbour Belle) = Same as resident species (North, Central = No unless limited use approved; South = Caution)
~800 species evaluated 120 re-evaluations scheduled for 2014
Status re-assessment
Outline Traits & ecology of invasive plants The assessment: history & tools The website
Website
Website View results Comprehensive list By zone By recommendation
New website Anticipated launch mid summer 2014 User friendly Search by species Useful links Generate lists
http://plants.ifas.ufl.edu/assessment/ Follow Us On Twitter/ Like Us On Facebook @IFASassessment UF IFAS Assessment dmlieurance@ufl.edu