Ecology and Evolutionary Biology Commons^™

A Seasonal, Density-Dependent Model For The Management Of An Invasive Weed, Esther Shyu, Eleanor A. Pardini, Tiffany M. Knight, Hal Caswell

Biology Faculty Publications & Presentations

The population effects of harvest depend on complex interactions between density dependence, seasonality, stage structure, and management timing. Here we present a periodic nonlinear matrix population model that incorporates seasonal density dependence with stage-selective and seasonally selective harvest. To this model, we apply newly developed perturbation analyses to determine how population densities respond to changes in harvest and demographic parameters. We use the model to examine the effects of popular control strategies and demographic perturbations on the invasive weed garlic mustard (Alliaria petiolata). We find that seasonality is a major factor in harvest outcomes, because population dynamics may …

Use Of Seeded Exotic Grasslands By Wintering Birds, Andrew D. George, Timothy J. O'Connell, Karen R. Hickman, David M. Lesliee Jr.

The Prairie Naturalist

Despite widespread population declines of North American grassland birds, effects of anthropogenic disturbance on wintering habitat of this guild remain poorly understood. We compared avian abundance and habitat structure in fields planted to the exotic grass Old World bluestem (Bothriochloa ischaemum; OWB) to that in native mixed-grass prairie. During winters of 2007–2008 and 2008–2009, we conducted bird and vegetation surveys in six native grass and six OWB fields in Garfield, Grant, and Alfalfa counties, Oklahoma. We recorded 24 species of wintering birds in native fields and 14 species in OWB monocultures. While vegetation structure was similar between field …

Effects Of Natural Flooding And Manual Trapping On The Facilitation Of Invasive Crayfish-Native Amphibian Coexistence In A Semi-Arid Perennial Stream, Lee Kats, Gary Bucciarelli, Thomas Vandergon, Rodney Honeycutt, Evan Mattiasen, Arthur Sanders, Seth Riley, Jacob Kerby, Robert Fisher

Lee Kats

Aquatic amphibians are known to be vulnerable to a myriad of invasive predators. Invasive crayfish are thought to have eliminated native populations of amphibians in some streams in the semi-arid Santa Monica Mountains of southern California. Despite their toxic skin secretions that defend them from native predators, newts are vulnerable to crayfish attacks, and crayfish have been observed attacking adult newts, and eating newt egg masses and larvae. For 15 years, we have observed invasive crayfish and native California newts coexisting in one stream in the Santa Monica Mountains. During that period, we monitored the densities of both crayfish and …

The Effects Of Invasive Plants On Biodiversity Across Spatial Scales, Kristin Irene Powell

All Theses and Dissertations (ETDs)

Although introduced plant species are often considered to be one of the most notable anthropogenic threats to biodiversity, their influence on biodiversity remains controversial. Some studies have shown large declines in biodiversity in plant-invaded areas, whereas others have noted that plant invasions are rarely implicated as the cause of species extinctions. This dissertation aims to synthesize this seemingly conflicting literature on the effects of invasive plants on biodiversity. The overarching hypothesis in this research is that the effect of invasive plant species on biodiversity is scale-dependent, and the discrepancy among studies can be explained by a difference in the scales …

Nature Notes: Environews # 6, Richard B. Philp

Richard B. Philp

This paper reviews rewcent informaion regarding invasive species and vindicates the lowly beaver

Partners In Spread Prevention, Nancy C. Balcom

Wrack Lines

Working together to stop the spread of aquatic invasive species.

Aquatic Macroinvertebrate Response To Invasion And Subsequent Removal Of Typha × Glauca From Great Lakes Coastal Marshes, Kimberly Anne Greene

Master's Theses

Aquatic macroinvertebrates are important in wetland ecosystems; many fish and wildlife species depend upon them for food resources and they aid in nutrient cycling. Wetland macroinvertebrate communities are influenced by plant community composition; as such, this study examined two implications of invasive hybrid cattail, Typha × glauca (Typha), on aquatic macroinvertebrate communities in northern Great Lakes coastal wetlands: 1) how the presence of nearly monotypic stands of Typha alters wetland aquatic macroinvertebrate communities and 2) how manual removal of Typha, via mowing and manual tilling, impacts these invertebrate communities along with wetland plant communities. I found that …

Improving Model Performance For Invasive Plant Species Distribution Using Global-Scale Presence-Only Data: Parameterization And Data Quality, Feng Yu

Open Access Theses

Invasive species have significant ecological and economic impacts. To control species' invasion, risk assessment provides the most essential information for identification and evaluation of the potential risk of the invasive species, especially in their early invasion stages. Species distribution models (SDMs) is the foundation for risk assessment, in terms of both the practical and theoretical interest in our understanding of species invasion process. SDMs contribute to the proactive invasion management and the test of ecological or biogeographical hypotheses about species distributions in relation to their environment.

However, modeling of invasive species at large spatial scale (i.e., cross-continental) is rarely discussed. …

Differential Allocation To Photosynthetic And Non-Photosynthetic Nitrogen Fractions Among Native And Invasive Species, Jennifer L. Funk, Lori A. Glenwinkle, Lawren Sack

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Invasive species are expected to cluster on the “high-return” end of the leaf economic spectrum, displaying leaf traits consistent with higher carbon assimilation relative to native species. Intra-leaf nitrogen (N) allocation should support these physiological differences; however, N biochemistry has not been examined in more than a few invasive species. We measured 34 leaf traits including seven leaf N pools for five native and five invasive species from Hawaii under low irradiance to mimic the forest understory environment. We found several trait differences between native and invasive species. In particular, invasive species showed preferential N allocation to metabolism (amino acids) …

Physiological And Behavioral Mechanisms Of Range Expansion In The House Sparrow (Passer Domesticus), Andrea Lyn Liebl

USF Tampa Graduate Theses and Dissertations

Introduced species cause both considerable ecological and economic damage every year. However, not much is known about how certain species are able to establish and spread beyond the site of initial introduction, whereas others do not. Species undergoing range expansion following an introduction may prove to be a valuable resource to invasion biology, but may also be informative in light of species' responses to changing environments (i.e. global climate change). Here, I took advantage of an ongoing range expansion of an introduced vertebrate species. House sparrows (Passer domesticus) were introduced to Mombasa, Kenya in the 1950s and have subsequently expanded …