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Full-Text Articles in Life Sciences
A New Perspective On Trait Differences Between Native And Invasive Exotic Plants, A. Joshua Leffler, Jeremy J. James, Thomas A. Monaco, Roger L. Sheley
A New Perspective On Trait Differences Between Native And Invasive Exotic Plants, A. Joshua Leffler, Jeremy J. James, Thomas A. Monaco, Roger L. Sheley
Natural Resource Management Faculty Publications
Functional differences between native and exotic species potentially constitute one factor responsible for plant invasion. Differences in trait values between native and exotic invasive species, however, should not be considered fixed and may depend on the context of the comparison. Furthermore, the magnitude of difference between native and exotic species necessary to trigger invasion is unknown. We propose a criterion that differences in trait values between a native and exotic invasive species must be greater than differences between co-occurring natives for this difference to be ecologically meaningful and a contributing factor to plant invasion. We used a meta-analysis to quantify …
Native Insect Herbivory Limits Population Growth Rate Of A Non-Native Thistle, James O. Eckberg, Brigitte Tenhumberg, Svata M. Louda
Native Insect Herbivory Limits Population Growth Rate Of A Non-Native Thistle, James O. Eckberg, Brigitte Tenhumberg, Svata M. Louda
Brigitte Tenhumberg Papers
The influence of native fauna on non-native plant population growth, size, and distribution is not well documented. Previous studies have shown that native insects associated with tall thistle (Cirsium altissimum) also feed on the leaves, stems, and flower heads of the Eurasian congener Cirsium vulgare, thus limiting individual plant performance. In this study, we tested the effects of insect herbivores on the population growth rate of C. vulgare. We experimentally initiated invasions by adding seeds at four unoccupied grassland sites in eastern Nebraska, USA, and recorded plant establishment, survival, and reproduction. Cumulative foliage and floral herbivory …
Individual Phenotypic Variation Reduces Interaction Strengths In A Consumer–Resource System, Jean P. Gibert, Chad Brassil
Individual Phenotypic Variation Reduces Interaction Strengths In A Consumer–Resource System, Jean P. Gibert, Chad Brassil
School of Biological Sciences: Faculty Publications
Natural populations often show variation in traits that can affect the strength of interspecific interactions. Interaction strengths in turn influence the fate of pairwise interacting populations and the stability of food webs. Understanding the mechanisms relating individual phenotypic variation to interaction strengths is thus central to assess how trait variation affects population and community dynamics. We incorporated nonheritable variation in attack rates and handling times into a classical consumer–resource model to investigate how variation may alter interaction strengths, population dynamics, species persistence, and invasiveness. We found that individual variation influences species persistence through its effect on interaction strengths. In many …
Root Growth Of Two Perennial Grass Types And Musk Thistle (Carduus Nutans) In Temperate Grasslands Of North America, Chengchou Han, Stephen L. Young
Root Growth Of Two Perennial Grass Types And Musk Thistle (Carduus Nutans) In Temperate Grasslands Of North America, Chengchou Han, Stephen L. Young
West Central Research and Extension Center, North Platte
Root architecture of prairie grasslands, which depends on plant phenology and edaphic conditions, strongly influences susceptibility to invasion by nonindigenous plant species. Field studies were conducted to compare in situ root growth patterns of warm-season (WS) and cool-season (CS) perennial grasses and musk thistle during a 2-yr period that included a drought in the second year. In 2 yr, CS grasses had the highest amount of roots (1,296 m roots m–2 [395 ft roots ft–2]) across shallow (0 to 28 cm [0 to 11 in.]), medium (28 to 56 cm), and deep (56 to 98 cm) depths …