Interactions between density‐dependent processes, population dynamics and control of an invasive plant species, Tripleurospermum perforatum (scentless chamomile)

Abstract

Tripleurospermum perforatum is an invasive weedy species which exhibits strong over‐compensating density dependence. Interactions between density‐dependent survival, probability of flowering and fecundity were modelled and their impact on the population dynamics were examined. When only fecundity was density‐dependent, the dynamics were similar to those observed in the model containing all three density‐dependent terms. Density‐dependent survival was a stabilizing process when acting in combination with density‐dependent fecundity and probability of flowering; removing density‐dependent survival from the model produced two‐point cycles. The addition of a seed bank was also stabilizing. Simulations of control strategies at different life‐history stages indicated that full control would be difficult due to the strong over‐compensating density dependence, with severe reductions in fecundity and late season survival necessary in order to reduce equilibrium seed density and biomass.

Habitat-Specific Impacts of Multiple Consumers on Plant Population Dynamics

“…While the importance of density dependence and seed banks in mediating plant population responses to consumers are well appreciated in theory (Harper 1977), empirical estimations of the magnitude of compensatory density dependence and the life stages where this may be manifest are rare (but see Buckley et al 2001, Goldberg et al 2001. As well, our general understanding of how seed bank dynamics influence aboveground dynamics is limited (Kalisz andMcPeek 1992, Cabin et al 2000).…”

Genome size variation in some representatives of the genus Tripleurospermum

“…It is mainly distributed in Europe (South East) and in temperate Asia (South West), with a few species also in North America and North Africa, and one widespread species (Tripleurospermum perforatum, often considered a synonym of T. inodorum, Applequist 2002). Some Tripleurospermum are used as ornamentals, others for medical purposes, like T. maritimum, which is claimed to repel fleas, beetles and other insects (Herrera 1995) or T. decipiens, in which saponines with a possible pharmacological application have been found (Mojab et al 2003), whilst still others are invasive weeds (T. inodorum / T. perforatum, Buckley et al 2001).…”

A seasonal, density‐dependent model for the management of an invasive weed

“…Harvest may even increase overall density (overcompensation; e.g., Lundberg 1999, Zipkin et al 2009). Compensation and overcompensation have been observed in many pest species (e.g., Buckley et al 2001, Jonze´n et al 2002, Zipkin et al 2008, Pardini et al 2009) and may underlie the persistence of invasive populations under management.…”

“…Timing also influences compensatory effects, in that harvest prior to reproduction often leads to compensation, whereas later harvests are more effective in reducing populations (Buckley et al 2001, Ratikainen et al 2008). 3 E-mail: eshyu@whoi.edu In this paper, we present a harvest model framework that uses periodic nonlinear matrix population models.…”