A simulation model of plant invasion: long-distance dispersal determines the pattern of spread

Abstract

Mechanisms and consequences of biological invasions are a global issue. Yet, one of the key aspects, the initial phase of invasion, is rarely observed in detail. Data from aerial photographs covering the spread of Heracleum mantegazzianum (Apiaceae, native to Caucasus) on a local scale of hectares in the Czech Republic from the beginning of invasion were used as an input for an individual-based model (IBM), based on small-scale and short-time data. To capture the population development inferred from the photographs, long-distance seed dispersal, changes in landscape structures and suitability of landscape elements to invasion by H. mantegazzianum were implemented in the model. The model was used to address (1) the role of long-distance dispersal in regional invasion dynamics, and (2) the effect of land-use changes on the progress of the invasion. Simulations showed that already small fractions of seed subjected to long-distance dispersal, as determined by systematic comparison of field data and modelling results, had an overproportional effect on the spread of this species. The effect of land-use changes on the simulated course of invasion depends on the actual level of habitat saturation; it is larger for populations covering a high proportion of available habitat area than for those in the initial phase of invasion.Our results indicate how empirical field data and model outputs can be linked more closely with each other to improve the understanding of invasion dynamics. The multi-level, but nevertheless simple structure of our model suggests that it can be used for studying the spread of similar species invading in comparable landscapes.

Can seed production and restricted dispersal limit recruitment in Pinus pinaster Aiton from the Spanish Northern Plateau?

“…These trees have critical importance because they work as new seed sources in expanding populations (Lavi et al, 2005). The importance of rare LDD events has also been noted for other forest tree species (Lavi et al, 2005;Nehrbass et al, 2007) or can be deduced from theoretical models Hastings et al, 2005;Higgins and Richardson, 1999;Le Corré et al, 1997). LDD events can also make novel niches available for establishment and growth, which could promote local adaptation and niche expansion, and mitigate the impact of the ongoing process of climate change in wide-breadth pine species, such as P. pinaster.…”

Improving prediction and management of range expansions by combining analytical and individual‐based modelling approaches

“…Almost all studies make use of either an analytical (e.g., Caswell, Lensink, & Neubert 2003; Buckley et al. 2005; Soons & Bullock 2008) or an IBM approach (e.g., Nehrbass & Winkler 2007; Nehrbass et al. 2007; Harris et al.…”

The effects of temporally variable dispersal and landscape structure on invasive species spread

“…Analytical and simulation models offer a tractable experimental setting to investigate the influence of demographic and dispersal (e.g., Shigesada et al 1995, Kot et al 1996, Neubert and Caswell 2000, Woolcock and Cousens 2000, Clark et al 2001, Yamamura 2004, Buckley et al 2005, Dwyer and Morris 2006, Nehrbass et al 2007, Skarpaas and Shea 2007, Jongejans et al 2008a, and landscape (e.g., Bergelson et al 1993, van Dorp et al 1997, Collingham and Huntley 2000, King and With 2002, So¨ndgerath and Schro¨der 2002, Matlack and Monde 2004, Nehrbass et al 2007, Sebert-Cuvillier et al 2008) parameters on spread. These studies highlight that spread models are extremely sensitive to the input dispersal parameters, emphasizing that accurate predictions require high-quality dispersal observations, such as may be provided by remote sensing.…”

“…These studies highlight that spread models are extremely sensitive to the input dispersal parameters, emphasizing that accurate predictions require high-quality dispersal observations, such as may be provided by remote sensing. Yet, to date, remote sensing has only rarely been used to parameterize (Lonsdale 1993, Buckley et al 2005, Nehrbass et al 2007) and validate (Higgins et al 2001) models of invasive plant spread.…”