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Full-Text Articles in Weed Science
Local Filters Limit Species Diversity, But Species Pools Determine Composition, Tara K. Rajaniemi, Deborah E. Goldberg, Roy Turkington, Andrew R. Dyer
Local Filters Limit Species Diversity, But Species Pools Determine Composition, Tara K. Rajaniemi, Deborah E. Goldberg, Roy Turkington, Andrew R. Dyer
Faculty Publications
In a series of three experiments, we tested for effects of species pools, resource stress, and species interactions on four aspects of community structure: species richness, evenness, species composition, and functional group composition. We also examined whether the impacts of species interactions on the community varied with resource availability or species pool. Communities of sand dune annuals grew from seed bank samples collected from two sites in three different years, so that the species pool differed at two levels: the source site and the year of seed bank collection. Communities experienced one of three irrigation treatments and a range of …
Influence Of Microsite Disturbance On The Establishment Of Two Congeneric Invasive Thistles, Emily S.J. Rauschert, Katriona Shea
Influence Of Microsite Disturbance On The Establishment Of Two Congeneric Invasive Thistles, Emily S.J. Rauschert, Katriona Shea
Biological, Geological, and Environmental Faculty Publications
The successful establishment of invasive species has been shown to depend on aspects of the invaded community, such as gap characteristics. Biotic resistance may be particularly critical for stopping invaders at early life history stages, but new species can often invade following disturbances, which may create microsites with very different characteristics than are usually present. We examine the response of two invasive thistle species, Carduus nutans L. and C. acanthoides L., to three different microsite characteristics: disturbance type, size, and water availability. The two species initially responded differently to the type of disturbance: C. acanthoides had higher emergence and survival …
Invasional Interference Due To Similar Inter- And Intraspecific Competition Between Invaders May Affect Management, Emily S.J. Rauschert, Katriona Shea
Invasional Interference Due To Similar Inter- And Intraspecific Competition Between Invaders May Affect Management, Emily S.J. Rauschert, Katriona Shea
Biological, Geological, and Environmental Faculty Publications
As the number of biological invasions increases, the potential for invader– invader interactions also rises. The effect of multiple invaders can be superadditive (invasional meltdown), additive, or subadditive (invasional interference); which of these situations occurs has critical implications for prioritization of management efforts. Carduus nutans and C. acanthoides, two congeneric invasive weeds, have a striking, segregated distribution in central Pennsylvania, USA. Possible hypotheses for this pattern include invasion history and chance, direct competition, or negative interactions mediated by other species, such as shared pollinators. To explore the role of resource competition in generating this pattern, we conducted three related experiments …
Coexistence Patterns Of Two Invasive Thistle Species, Carduus Nutans And C. Acanthoides, At Three Spatial Scales, Emily S.J. Rauschert, Katriona Shea, Ottar N. Bjørnstad
Coexistence Patterns Of Two Invasive Thistle Species, Carduus Nutans And C. Acanthoides, At Three Spatial Scales, Emily S.J. Rauschert, Katriona Shea, Ottar N. Bjørnstad
Biological, Geological, and Environmental Faculty Publications
To better understand the competitive processes involved in invasion by congeners, we examine coexistence patterns of two invasive species, Carduus nutans and C. acanthoides, at three spatial scales. A roadside survey of 5 × 5 km blocks in a previously identified overlap zone provided information about the regional scale. At smaller scales, we surveyed four fields of natural co-occurrence, quantifying the spatial patterns at the field scale by randomly placed 1 × 1 m quadrats and at the smallest scale by detailing plant position within the quadrats. The patterns observed are strikingly different at the different scales. At the regional …