Invasive Plant Ecology and Interaction with Native Plant Communities John Madsen, Chair Mississippi...
-
Upload
brian-bruce -
Category
Documents
-
view
214 -
download
0
Transcript of Invasive Plant Ecology and Interaction with Native Plant Communities John Madsen, Chair Mississippi...
Invasive Plant Ecology and Interaction with Native Plant
Communities
John Madsen, Chair
Mississippi State University
Toni Pennington, Portland State University
John Titus, SUNY-Binghamton
Plant Autecology
•Plant demography
•Population Dynamics
• Life History
•Reproduction
•Growth
•Nutrition
•Light Requirements
•Temperature Requirements
•Habitat Requirements
•Response to disturbance
•Herbivory
Plant Life HistoryExploitable for Long-Term Management
Annual
Herbaceous Perennial
Evergreen Perennial
Woody Perennial
Plant Demography
PropaguleSeedling/Sproutling
Mature Plant
Plant Density
Survival/Establishment
Production
Dispersal
Germination/Sprouting
Clonal Growth
Invasion Process of Eurasian watermilfoil
Dispersal
Establishment
Colony Formation
Phenological Studies
Purple loosestrife – Katovich et al. 1998 Waterhyacinth – Madsen et al. 1993 Eurasian watermilfoil – Madsen 1997 Hydrilla – Madsen and Owens 1998 Curlyleaf pondweed – Woolf and Madsen
2003 Application to management: Poovey et al.
2002
Carbohydrate Storage and Allocation
Purple loosestrife – Katovich et al. 1998 Waterhyacinth – Madsen et al. 1993 Eurasian watermilfoil – Madsen 1997 Hydrilla – Madsen and Owens 1998 Curlyleaf pondweed – Woolf and Madsen 2003 Management implications – Kimbel and Carpenter
1981, Painter 1988, Owens and Madsen 1998
Modeling of plants
Biomass models – Best et al. 2001 Individual-based models – Uchmanski and
Grimm 1996. Spatial and GIS models: Vis et al. 2003,
Lehmann 1998.
Plant Synecology
DiversityCompetitionCommunity Dynamics
“Succession” Ecosystem response
Plant Competition
• Wetland ecology: Typha latifolia versus Typha domingensis– Grace and Wetzel 1981,
Grace 1987, 1988, 1989
• Najas v. Myriophyllum– Agami and Waisel 2002
Grace and Wetzel 1981
Shoot versus Root Competition
• Shoot versus root competition (Wetland)– Twolan-Strutt and Keddy 1996
• Submersed plants– Spencer and Ksander 2005
Invasive Plants reduce Native plant diversity and abundance
Eurasian watermilfoil: Madsen et al.
1991.
Management can reverse competition
• Chemical control: Getsinger et al. 1997, Madsen et al. 2002
• Biological control: Gross et al. 2001, Newman and Biesboer 2000.
• Mechanical control: Eichler et al. 1993
• Physical control: Eichler et al. 1995
Community Dynamics
• Few “working theories” of aquatic plant community dynamics
• Need for understanding of system to explain what invasive species do to system
• In contrast to terrestrial plant ecosystems– Increase in fire frequency – Reduction in colonization rates (Yurkonis et al.
2005)
Long-term Aquatic Plant Community Studies
• Few long term studies are available
• Field sampling, Chenango Lake – Titus et al. 2004
• Paleoecological studies – Davidson et al. 2005
Aquatic Plant Community Dynamics
Succession – no real aquatic model Hydrarch succession not a community dynamic model
Environmental sieve model van der Valk 1981 Wetland cycle – van der Valk and Davis 1978 Wetland Continuum - Euliss et al. 2004 Shallow Lake Alternate Stable State Hypothesis
(Scheffer 1998) We do not have a current working conceptual
model of aquatic plant community dynamics
Environmental Sievevan der Valk 1981
Marsh Cyclevan der Valk and Davis 1978
Shallow Lake Alternate Stable States
Turbid State Clear State
Benthivorous omnivorous fishHigh TSS loadingHigh nutrient loadingCatastrophic events
Reduced resuspension
Macrophyte growth
Increased sedimentation
Reduced TSS loading
Abundant plant growthLow turbidityHigh transparency
High turbidityLow transparencyLittle or no plant growth
Community Response to Stability and Disturbance
• Drawdown• Hydrology – Englehardt and Ritchie 2002,
van Geest 2005 • Nitrogen or nutrient loading – Tracy et al.
2003, James et al. 2005, Anderson et al. 2005
• Physical predictors – Hawes et al. 2003 – Water level fluctuation, wave exposure, etc.
What makes a Species Invasive?
• Theories for plant invasiveness (Galatowitsch et al. 1999)– Growth is more favorable under new
environmental conditions– Herbivores [and pathogens] may be absent
from new locale– Interspecific hybridization may occur, resulting
in novel phenotypes
Invasion Concepts at Opposition
• Species traits drive invasion– Mechanistic; Invasives as a “Superplant”– “Hydrilla is the Perfect Weed”
• Habitat invasibility (niche) allows invasion– Ecosystem as a “sick” superorganism– ‘Invasives are a symptom of poor ecosystem health”– Open habitat for species
• Convergence of both – Milbau and Nijs 2004, Lonsdale 1999
Species Traits
• Invasiveness
• Propagule pressure
• Climatic compatibility
• Superior performance
• Canopy structure
• Superior resource competition
Invasibility
• The poor get richer – poor sites are more susceptible to invasion – Espinosa-Garcia 2004
• The rich get richer – species-rich sites are more invasible (Stohlgren et al. 2003, Stohlgren 2002
• Disturbed Resource-Flux Invasion Matrix Sher and Hyatt 1999.
Invasive Plant Models – Peters 2004
• Nonspatial models – exponential and logistic models
• Spatially Implicit Models – nonspatial models run using spatially-structured data
• Spatially Explicit models – Model considers neighbor effects and contagious phenomena
Examples of Range Models
• GARP model including hydrilla – Peterson et al. 2003
• Egeria najas and Egeria densa – Bini and Thomasz 2005
• Spatial model of purple loosestrife – Welk 2004
What We Lack
• Complete plant demographic / life history analysis
• Seasonal life histories of invasive species
• Coherent theory of community dynamics
• Spatially-relevant models of invasion
• Predictive tools for invasion probability
• Predictive tools for management
Possible Research Topics• Life history and management• Vectors of spread and prevention• Co-dispersal and positive feedback between invasive
aquatic species• Competition and preemption of invasive plants• Prediction of potential invasion sites• Spread pathway analysis and prevention• Prevention, early detection, and rapid response• Alteration of community dynamics by invasive species