The relative importance of latitude matching and propagule pressure in the colonization success of an invasive forb

ABSTRACTPredicting whether individuals will colonize a novel habitat is of fundamental ecological interest and is crucial to both conservation efforts and invasive species management. A consistently supported predictor of colonization success is the number of individuals introduced, also called propagule pressure. Propagule pressure increases with the number of introductions and the number of individuals per introduction (the size of the introduction), but it is unresolved which process is a stronger driver of colonization success. Furthermore their relative importance may depend upon the environment, with multiple introductions potentially enhancing colonization of fluctuating environments. To evaluate the relative importance of the number and size of introductions and its dependence upon environmental variability, we paired demographic simulations with a microcosm experiment. Using Tribolium flour beetles as a model system, we introduced a fixed number of individuals into replicated novel habitats of stable or fluctuating quality, varying the number of introductions through time and size of each introduction. We evaluated establishment probability and the size of extant populations after 7 generations. In the simulations and microcosms, we found that establishment probability increased with more, smaller introductions, but was not affected by biologically realistic fluctuations in environmental quality. Population size was not significantly affected by environmental variability in the simulations, but populations in the microcosms grew larger in a stable environment, especially with more introduction events. In general, the microcosm experiment yielded higher establishment probability and larger populations than the demographic simulations. We suggest that genetic mechanisms likely underlie these differences and thus deserve more attention in efforts to parse propagule pressure. Our results highlight the importance of preventing further introductions of undesirable species to invaded sites, and suggest conservation efforts should focus on increasing the number of introductions or re-introductions of desirable species rather than increasing the size of those introduction events.

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Faculty Opinions recommendation of Role of propagule pressure in colonization success: disentangling the relative importance of demographic, genetic and habitat effects.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.718017702.793478054 ◽

2013 ◽

Author(s):

Patrick Tobin

Keyword(s):

Propagule Pressure ◽

Relative Importance ◽

Colonization Success

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A native species does not prevent the colonization success of an introduced submerged macrophyte, even at low propagule pressure

Hydrobiologia ◽

10.1007/s10750-019-04116-w ◽

2019 ◽

Vol 847 (7) ◽

pp. 1619-1629 ◽

Cited By ~ 1

Author(s):

Nayara Louback-Franco ◽

Mário S. Dainez-Filho ◽

Douglas C. Souza ◽

Sidinei M. Thomaz

Keyword(s):

Native Species ◽

Propagule Pressure ◽

Submerged Macrophyte ◽

Colonization Success

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Assessing the relative importance of disturbance, herbivory, diversity, and propagule pressure in exotic plant invasion

Ecological Monographs ◽

10.1890/08-0221.1 ◽

2009 ◽

Vol 79 (2) ◽

pp. 265-280 ◽

Cited By ~ 151

Author(s):

Anne K. Eschtruth ◽

John J. Battles

Keyword(s):

Plant Invasion ◽

Propagule Pressure ◽

Exotic Plant ◽

Relative Importance ◽

Exotic Plant Invasion

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Patterns of success in game bird introductions in the United States

10.7287/peerj.preprints.1765 ◽

2016 ◽

Author(s):

Michael P Moulton ◽

Wendell P Cropper ◽

Andrew J Broz ◽

Salvador A Gezan

Keyword(s):

Propagule Pressure ◽

The United States ◽

Relative Importance ◽

Careful Evaluation ◽

Large Numbers ◽

The Usa ◽

Unique Method ◽

Species Characteristics ◽

Successful Establishment ◽

Number Of Individuals

Better predictions of the success of species’ introductions require careful evaluation of the relative importance of at least three kinds of factors: species characteristics, characteristics of the site of introduction, and event-level factors such as propagule pressure. Historical records of bird introductions provide a unique method for addressing the relative importance of these factors. We compiled a list of introductions of 17 Phasianid species released in the USA during the Foreign Game Investigation Program (FGIP). These records indicate that releases for some Phasianid species in the USA continued long after establishment. For many of the 13 species that always failed, even numerous releases and large numbers of individuals per release were not enough for successful establishment, yet several of these species were successfully introduced elsewhere. Only four species were successful in at least one state. Yet, all four were unsuccessful either in other states, or in other regions of states where they were not already successfully established, or both. These results support the notion that the number of individuals released and the number of releases are less important than characteristics of the location where the introductions occurred.

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The role of preadaptation, propagule pressure and competition in the colonization of new habitats

10.1101/697342 ◽

2019 ◽

Author(s):

Adriana Alzate ◽

Renske E. Onstein ◽

Rampal S. Etienne ◽

Dries Bonte

Keyword(s):

Spider Mite ◽

Propagule Pressure ◽

Community Context ◽

Negative Effects ◽

Tetranychus Evansi ◽

Final Population ◽

Red Spider Mite ◽

Colonization Success ◽

Set Up ◽

New Habitats

ABSTRACTTo successfully colonize new habitats, organisms not only need to gain access to it, but also need to cope with the selective pressures imposed by the local biotic and abiotic conditions. The number of immigrants, the preadaptation to the local habitat and the presence of competitors are important factors determining the success of colonization. Here, using an experimental set-up, we test the combined effect of propagule pressure, preadaptation and interspecific competition on the colonization success of new habitats using the two-spotted spider mite (Tetranychus urticae) as our model system and the red spider mite (Tetranychus evansi) as a competitor. Our results show that propagule pressure and preadaptation positively affect colonization success. More successful populations reach larger final population sizes either by having higher per capita growth rate (due to preadaptation effect) or by starting a population with a larger number of individuals. Although populations are more successful colonizing non-competitive environments than competitive ones, propagule pressure and preadaptation counteract the negative effects of competition, promoting colonization success. Our results show the importance of propagule pressure and preadaptation to cope both with the exigencies of the new environment and the community context for successful colonization of new habitats.

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Parsing propagule pressure: Number, not size, of introductions drives colonization success in a novel environment

Ecology and Evolution ◽

10.1002/ece3.4226 ◽

2018 ◽

Vol 8 (16) ◽

pp. 8043-8054 ◽

Cited By ~ 6

Author(s):

Michael J. Koontz ◽

Meagan F. Oldfather ◽

Brett A. Melbourne ◽

Ruth A. Hufbauer

Keyword(s):

Propagule Pressure ◽

Novel Environment ◽

Colonization Success

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Susceptibility of a tallgrass prairie to invasion by the herbicidal producing species, Festuca rubra

SURG Journal ◽

10.21083/surg.v2i2.979 ◽

1969 ◽

Vol 2 (2) ◽

pp. 11-17

Author(s):

Jesse Harnden

Keyword(s):

Tallgrass Prairie ◽

Mycorrhizal Fungi ◽

Native Species ◽

Propagule Pressure ◽

Arbuscular Mycorrhizal ◽

Festuca Rubra ◽

Relative Importance ◽

Sorghastrum Nutans ◽

Native Grasslands ◽

Native Grassland

Disturbance, nutrients, propagule pressure, and the presence of arbuscular mycorrhizal fungi (AMF) have been shown to influence invasion in plant communities, although the relative importance of each remains unclear. A remnant of tallgrass prairie outside Cambridge, ON appears to be resilient to invasion by Festuca rubra, despite its herbicidal properties. A greenhouse experiment was conducted to determine what factors are responsible for the resilience of the native grassland, using synthesized fescue and native sod. The effects of disturbance, nutrient enrichment, propagule pressure, and the presence of AMF and phytotoxin on the establishment ability of F. rubra and the native species Sorghastrum nutans were examined. Propagule pressure was the only factor shown to influence fescue invasion and establishment of S. nutans was unaffected by all factors. These results suggest that the resilience of the native grassland may be due to decreased seed production or viability of F. rubra and not any characteristics of the grassland. Also, the restoration of native grasslands will not be limited by remnants of phytotoxin in the soil, following removal of exotic species.

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The roles of demography and genetics in the early stages of colonization

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2014.1073 ◽

2014 ◽

Vol 281 (1792) ◽

pp. 20141073 ◽

Cited By ~ 56

Author(s):

Marianna Szűcs ◽

Brett A. Melbourne ◽

Ty Tuff ◽

Ruth A. Hufbauer

Keyword(s):

Genetic Diversity ◽

Population Growth ◽

Genetic Background ◽

First Generation ◽

Genetic Factors ◽

Initial Population ◽

Relative Importance ◽

Establishment Success ◽

Founding Population ◽

Colonization Success

Colonization success increases with the size of the founding group. Both demographic and genetic factors underlie this relationship, yet because genetic diversity normally increases with numbers of individuals, their relative importance remains unclear. Furthermore, their influence may depend on the environment and may change as colonization progresses from establishment through population growth and then dispersal. We tested the roles of genetics, demography and environment in the founding of Tribolium castaneum populations. Using three genetic backgrounds (inbred to outbred), we released individuals of four founding sizes (2–32) into two environments (natal and novel), and measured establishment success, initial population growth and dispersal. Establishment increased with founding size, whereas population growth was shaped by founding size, genetic background and environment. Population growth was depressed by inbreeding at small founding sizes, but growth rates were similar across genetic backgrounds at large founding size, an interaction indicating that the magnitude of the genetic effects depends upon founding population size. Dispersal rates increased with genetic diversity. These results suggest that numbers of individuals may drive initial establishment, but that subsequent population growth and spread, even in the first generation of colonization, can be driven by genetic processes, including both reduced growth owing to inbreeding depression, and increased dispersal with increased genetic diversity.

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