Maternal Environment Influences Propagule Pressure of an Invasive Plant, Raphanus raphanistrum (Brassicaceae)

2015 ◽  
Vol 176 (4) ◽  
pp. 393-403 ◽  
Author(s):  
Lesley G. Campbell ◽  
Rebecca J. Parker ◽  
Graham Blakelock ◽  
Natalia Pirimova ◽  
Kristin L. Mercer
Keyword(s):  
Invasive Plant ◽  
Propagule Pressure ◽  
Raphanus Raphanistrum ◽  
Maternal Environment

scholarly journals Does Altering Local Water Availability for an Invasive Plant (Raphanus raphanistrum) Affect Floral Morphology and Reproductive Potential?

2015 ◽  
Vol 12 (2) ◽  
Author(s):  
Natalia Pirimova ◽  
Alison Parker ◽  
Lesley Campbell
Keyword(s):  
Soil Moisture ◽  
Foraging Behavior ◽  
Water Availability ◽  
Community Dynamics ◽  
Invasive Plant ◽  
Floral Morphology ◽  
Insect Community ◽  
Raphanus Raphanistrum ◽  
Anther Length ◽  
Corolla Diameter

Abiotic environmental variation can have dramatic effects on plant floral morphology and nectar or pollen rewards. In response, pollinators may change their foraging behavior and distribution and if pollinators change their foraging behavior or distribution, this could have dramatic effects on the reproductive success of plant populations. To start tackling this problem, we measured the response of floral morphology (corolla diameter, stamen length, and ovule number) of Raphanus raphanistrum to experimental manipulations of field soil moisture. As soil moisture increased, corolla diameter and anther length grew. We expect these changes to provide more visitation rewards for insects in moist conditions. Therefore, water availability influences growth and development of flowers, and may have dramatic effects on insect community dynamics. KEYWORDS: Floral Rewards, Climate, Rain-out Shelters, Flower Morphology, Raphanus raphanistrum, Brassicaceae

Reviewing the Role of Wildfire on the Occurrence and Spread of Invasive Plant Species in Wildland Areas of the Intermountain Western United States

2010 ◽  
Vol 3 (4) ◽  
pp. 347-364 ◽  
Author(s):  
Lisa J. Rew ◽  
Mara P. Johnson
Keyword(s):  
Plant Species ◽  
Invasive Plant ◽  
Propagule Pressure ◽  
Vegetation Type ◽  
Fire Dynamics ◽  
Long Distance ◽  
Nonnative Plants ◽  
Lactuca Serriola ◽  
Common Dandelion ◽  
And Control

AbstractFire is unlikely to be a simple, deterministic process that will result in increased rates of invasion by nonnative plants. Relative dominance of nonnative plants at any postfire site likely results from a combination of factors, including propagule pressure (aboveground and belowground), time since invasion, interspecific competition, disturbance history, rainfall patterns, soil nutrients, environmental heterogeneity, land use, plus the actual fire dynamics. Consequently, the role different factors play in nonnative plant invasion is still relatively unexplained, and the possibility that wildfire may promote nonnative plant species remains a concern. Our aim was to evaluate the state of knowledge concerning how nonnative plant species establish, survive, and spread following wildfire in wildland areas for the main vegetation types of the Intermountain West. Although the particular invading species varied with vegetation type, the most frequently reported species were annual grasses (e.g., downy brome [Bromus tectorum], Japanese brome [Bromus japonicus]) and long-distance, dispersing forbs (e.g., Canada thistle [Cirsium arvense], common dandelion [Taraxacum officinale], and prickly lettuce [Lactuca serriola]). Overall, many of the reviewed studies found an increase, followed by a long-term decline, in nonnative species after wildfire, particularly when other disturbances were minimal. Regardless of this finding, many people consider rapid detection and control of new, nonnative plant populations after wildfire one of the most effective management activities. That axiom may be correct, if the nonnative propagule pressure is high and the anthropogenic disturbances are frequent, but if this is not the case the question to answer is whether immediate management, including reseeding, will benefit the system or whether off-target effects could make that approach undesirable. Continued investigation and increased quantitative analysis of the complex factors that likely contribute to changes in nonnative plants dynamics following wildfire should improve our understanding of the issue and assist managers in allocating limited resources.

Pathways of Invasive Plant Spread to Alaska: III. Contaminants in Crop and Grass Seed

2012 ◽  
Vol 5 (2) ◽  
pp. 270-281 ◽  
Author(s):  
Jeffery S. Conn
Keyword(s):  
Invasive Plant ◽  
Propagule Pressure ◽  
Canada Thistle ◽  
Regulatory Enforcement ◽  
Crop Species ◽  
Plant Dispersal ◽  
Grass Seed ◽  
Significant Relationships ◽  
Retail Outlets ◽  
Crop Seed

AbstractInvasive plants disperse to new areas via numerous pathways. Study of these pathways helps to focus limited budgets toward prevention and early detection. This study examined potentially invasive seed contaminants in imported crops and grass seed as pathways for plant dispersal to Alaska. Crop and grass seed were purchased from 13 Alaska retail outlets representing 14 seed suppliers. Seed bags were sampled using federally mandated protocols and were analyzed for crop seeds that were not supposed to be included and for weed contaminants. Ninety-five weed and 36 contaminant crop taxa were found. Crop seed contained 43 weed taxa and 15 other crop species contaminants, a mean of 6.4 taxa and 3,844 contaminant seed kg−1. Grass seed samples contained 73 weed taxa and 21 crop contaminants, a mean of 3.5 contaminant species and 1,250 seeds kg−1. Two species prohibited by the Alaska seed law were found: Canada thistle was found in a single crop sample, and quackgrass was found in two grass samples. There were no significant relationships between either seed type or supplier and either the number of contaminant species or number of seeds. Labels of 33% of crop samples and 8% of grass samples claimed 0.00% weed seeds, but low (0.007% by weight, 2 species) to high (1.18% by weight, 13 species) amounts of weed contaminants were found. Importation of crop seed is a large pathway for seed movement, causing significant propagule pressure and an increased likelihood of establishment by new invasive plant populations. Prevention of spread via this pathway would be enhanced by changes to seed laws, by greater regulatory enforcement, and by including on the label, the names of all weed and contaminant crop species found in the law-required samples. Consumers could then make decisions on whether to purchase seed based on the potentially invasive species that would be planted with the desired seed.

Invasive Plant Ecology

2014 ◽  
Vol 32 (2) ◽  
pp. 212-213
Author(s):  
E. K. Espeland
Keyword(s):  
Invasive Plant ◽  
Plant Ecology
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