Dispersal Patterns, Dispersal Mechanisms, and Invasion Wave Speeds for Invasive Thistles

Understanding and predicting population spread rates is an important problem in basic and applied ecology. In this article, we link estimates of invasion wave speeds to species traits and environmental conditions. We present detailed field studies of wind dispersal and compare nonparametric (i.e., data‐based) and mechanistic (fluid dynamics model–based) dispersal kernel and spread rate estimates for two important invasive weeds, Carduus nutans and Carduus acanthoides. A high‐effort trapping design revealed highly leptokurtic dispersal distributions, with seeds caught up to 96 m from the source, far further than mean dispersal distances (approx. 2 m). Nonparametric wave speed estimates are highly sensitive to sampling effort. Mechanistic estimates are insensitive to sampling because they are obtained from independent data and more useful because they are based on the dispersal mechanism. Over a wide range of realistic conditions, mechanistic spread rate estimates were most sensitive to high winds and low seed settling velocities. The combination of integrodifference equations and mechanistic dispersal models is a powerful tool for estimating invasion spread rates and for linking these estimates to characteristics of the species and the environment.

[1]  A A Rawlinson,et al.  When will plant morphology affect the shape of a seed dispersal "kernel"? , 2001, Journal of theoretical biology.

[2]  R. Stull.  An Introduction to Boundary Layer Meteorology , 1988 .

[3]  Jon Wiernga.  Representative roughness parameters for homogeneous terrain , 1993 .

[4]  Ran Nathan,et al.  FIELD VALIDATION AND SENSITIVITY ANALYSIS OF A MECHANISTIC MODEL FOR TREE SEED DISPERSAL BY WIND , 2001 .

[5]  S. R. Jammalamadaka,et al.  Topics in Circular Statistics , 2001 .

[6]  T. L. Woodburn,et al.  Seasonal life‐history models for the integrated management of the invasive weed nodding thistle Carduus nutans in Australia , 2006 .

[7]  K. Shea,et al.  Establishment and spread of founding populations of an invasive thistle: the role of competition and seed limitation , 2007, Biological Invasions.

[8]  J. G. Skellam.  Random dispersal in theoretical populations , 1951, Biometrika.

[9]  Imon,et al.  Mechanistic models for tree seed dispersal by wind in dense forests and open landscapes , 2001 .

[10]  T. L. Woodburn,et al.  CONTEXT‐DEPENDENT BIOLOGICAL CONTROL OF AN INVASIVE THISTLE , 2005 .

[11]  KATRIONA SHEA,et al.  Models for Improving the Targeting and Implementation of Biological Control of Weeds1 , 2004 .

[12]  S. Warwick,et al.  THE BIOLOGY OF CANADIAN WEEDS.: 89. Carduus nutans L. and Carduus acanthoides L. , 1988 .

[13]  J. Greeff,et al.  Dispersal , 2019, The African Wild Dog.

[14]  S. Levin,et al.  Mechanistic Analytical Models for Long‐Distance Seed Dispersal by Wind , 2005, The American Naturalist.

[15]  M. Neubert,et al.  Projecting Rates of Spread for Invasive Species , 2004, Risk analysis : an official publication of the Society for Risk Analysis.

[16]  H. Caswell,et al.  A guide to calculating discrete-time invasion rates from data , 2006 .

[17]  D. Kelly,et al.  Wind dispersal of nodding thistle seeds and pappi , 1988 .

[18]  Michael R. Raupach,et al.  Simplified expressions for vegetation roughness length and zero-plane displacement as functions of canopy height and area index , 1994 .

[19]  Katriona Shea,et al.  ESTIMATING BIOCONTROL AGENT IMPACT WITH MATRIX MODELS: CARDUUS NUTANS IN NEW ZEALAND , 1998 .

[20]  Wesley Rodrigues Silva,et al.  Mechanistic models for tree seed dispersal by wind in dense forests and open landscapes. , 2002 .

[21]  Gabriel G. Katul,et al.  DETERMINANTS OF LONG-DISTANCE SEED DISPERSAL BY WIND IN GRASSLANDS , 2004 .

[22]  G. Katul,et al.  Dissipation methods, Taylor's hypothesis, and stability correction functions in the atmospheric surface layer , 1997 .

[23]  Eelke Jongejans,et al.  Field experiments on seed dispersal by wind in ten umbelliferous species (Apiaceae) , 2004, Plant Ecology.

[24]  Hal Caswell,et al.  DEMOGRAPHY AND DISPERSAL: CALCULATION AND SENSITIVITY ANALYSIS OF INVASION SPEED FOR STRUCTURED POPULATIONS , 2000 .

[25]  K. Shea,et al.  Environmental variability and the initiation of dispersal: turbulence strongly increases seed release , 2006, Proceedings of the Royal Society B: Biological Sciences.

[26]  R. Turkington,et al.  The biology of Canadian weeds , 1978 .

[27]  Simon A. Levin,et al.  A Theoretical Framework for Data Analysis of Wind Dispersal of Seeds and Pollen , 1989 .

[28]  M. Shaw,et al.  Simulation of population expansion and spatial pattern when individual dispersal distributions do not decline exponentially with distance , 1995, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[29]  Lincoln Smith,et al.  Using noxious weed lists to prioritize targets for developing weed management strategies , 2000, Weed Science.

[30]  Stephen R. Baillie,et al.  Modeling large-scale dispersal distances , 2002 .

[31]  R. Clarke,et al.  Long distance seed dispersal by wind: measuring and modelling the tail of the curve , 2000, Oecologia.

[32]  K. Shea,et al.  Spatial Segregation of Congeneric Invaders in Central Pennsylvania, USA , 2006, Biological Invasions.

[33]  S. Levin,et al.  The Ecology and Evolution of Seed Dispersal: A Theoretical Perspective , 2003 .

[34]  Hans F. Weinberger,et al.  Long-Time Behavior of a Class of Biological Models , 1982 .

[35]  O. Skarpaas,et al.  How far can a hawk's beard fly? Measuring and modelling the dispersal of Crepis praemorsa , 2004 .

[36]  M. Willson,et al.  Dispersal mode, seed shadows, and colonization patterns , 1993, Vegetatio.

[37]  David R. Anderson,et al.  Model Selection and Inference: A Practical Information-Theoretic Approach , 2001 .

[38]  L. Kok,et al.  Dispersal of Musk Thistle (Carduus nutans) Seeds , 1984, Weed Science.

[39]  Michael L. Cain,et al.  ARE LONG‐DISTANCE DISPERSAL EVENTS IN PLANTS USUALLY CAUSED BY NONSTANDARD MEANS OF DISPERSAL? , 2003 .

[40]  A. Lindroth.  Aerodynamic and canopy resistance of short-rotation forest in relation to leaf area index and climate , 1993 .

[41]  R. Fisher.  THE WAVE OF ADVANCE OF ADVANTAGEOUS GENES , 1937 .

[42]  J. G. Skellam.  Random dispersal in theoretical populations , 1951, Biometrika.

[43]  Katriona Shea,et al.  Measuring plant dispersal: an introduction to field methods and experimental design , 2006, Plant Ecology.

[44]  P. Driessche,et al.  Dispersal data and the spread of invading organisms. , 1996 .

[45]  J. Lewis,et al.  Output and dispersal of propagules of Carduus acanthoides L , 1990 .

[46]  M. Evans.  Statistical Distributions , 2000 .

[47]  Katriona Shea,et al.  Optimizing dispersal study design by Monte Carlo simulation , 2005 .

[48]  Ran Nathan,et al.  Spatial patterns of seed dispersal, their determinants and consequences for recruitment. , 2000, Trends in ecology & evolution.

[49]  N. J. Ouborg,et al.  Population genetics, molecular markers and the study of dispersal in plants , 1999 .

[50]  P. Schippers,et al.  Release thresholds strongly determine the range of seed dispersal by wind , 2005 .

[51]  P. Turchin.  Quantitative analysis of movement : measuring and modeling population redistribution in animals and plants , 1998 .

[52]  John A. Nelder,et al.  A Simplex Method for Function Minimization , 1965, Comput. J..

[53]  Janneke HilleRisLambers,et al.  Seed Dispersal Near and Far: Patterns Across Temperate and Tropical Forests , 1999 .

[54]  Michael L. Cain,et al.  Methods for estimating long-distance dispersal , 2003 .

[55]  James S. Clark,et al.  Invasion by Extremes: Population Spread with Variation in Dispersal and Reproduction , 2001, The American Naturalist.