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Full-Text Articles in Life Sciences

Biogeographical Patterns, Ecological Drivers, And Evolutionary Mechanisms Of Plant Invasions, Rafael Dudeque Zenni Aug 2014

Biogeographical Patterns, Ecological Drivers, And Evolutionary Mechanisms Of Plant Invasions, Rafael Dudeque Zenni

Doctoral Dissertations

Understanding and predicting organisms’ responses to novel environments is a key issue for global change biology. In this dissertation, I study biogeographical patterns of plant invasions in Brazil, explore some of their ecological drivers, and disentangle the gene-level mechanisms that cause introduced organisms to become successful or failed invaders. I found that, for the invasive flora of Brazil, species were not introduced to new regions at random and that a species’ reason for introduction and continent of origin were associated. Asian ornamental and African forage plants are overrepresented, and two families (Poaceae and Fabaceae) dominate the invasive flora of Brazil. …


Invasive Plants As Drivers And Passengers Of Community Change In A Disturbed Urban Forest., Jeffery A. Masters May 2014

Invasive Plants As Drivers And Passengers Of Community Change In A Disturbed Urban Forest., Jeffery A. Masters

Electronic Theses and Dissertations

Invasive species can impact local ecosystems by decreasing biodiversity and local abundances of native species. Invasive species also frequently establish in disturbed habitats. An invasive species may dominate a habitat because the introduced species is a superior competitor (driver model) for resources or because the introduced species is more tolerant of noncompetitive processes such as anthropogenic disturbance that reduces the diversity and abundance of native species (passenger model). Ranunculus ficaria (Ranunculaceae) is an invasive plant species in the northeastern United States, and can be especially dense in urban riparian habitats. It emerges early and forms thick mats of vegetation that …


Hydrologic And Erosion Responses To Wildfire Along The Rangeland-Xeric Forest Continuum In The Western Us: A Review And Model Of Hydrologic Vulnerability, Christopher Jason Williams, Frederick B. Pierson, Peter R. Robichaud, Jan Boll Feb 2014

Hydrologic And Erosion Responses To Wildfire Along The Rangeland-Xeric Forest Continuum In The Western Us: A Review And Model Of Hydrologic Vulnerability, Christopher Jason Williams, Frederick B. Pierson, Peter R. Robichaud, Jan Boll

Articles

The recent increase in wildfire activity across the rangeland–xeric forest continuum in the western United States has landscape-scale consequences in terms of runoff and erosion. Concomitant cheatgrass (Bromus tectorum L.) invasions, plant community transitions and a warming climate in recent decades along grassland–shrubland–woodland–xeric forest transitions have promoted frequent and large wildfires, and continuance of the trend appears likely if warming climate conditions prevail. These changes potentially increase overall hydrologic vulnerability by spatially and temporally increasing soil exposure to runoff and erosion processes. Plot and hillslope-scale studies demonstrate burning may increase event runoff or erosion by factors of 2–40 over …


Incorporating Risk Of Reinvasion To Prioritize Sites For Invasive Species Management, Todd R. Lookingbill, Emily S. Minor, Nadia Bukach, Joseph R. Ferrari, Lisa A. Wainger Jan 2014

Incorporating Risk Of Reinvasion To Prioritize Sites For Invasive Species Management, Todd R. Lookingbill, Emily S. Minor, Nadia Bukach, Joseph R. Ferrari, Lisa A. Wainger

Geography and the Environment Faculty Publications

The relationship between landscape pattern and the distribution and spread of exotic species is an important determinant of where and when management actions are best applied. We have developed an interdisciplinary approach for prioritizing treatment of harmful, nonnative, invasive plants in National Park landscapes of the Mid-Atlantic USA. The approach relies upon a detailed model of reinvasion risk that combines information on: (1) global factors representing park-level infestation from seed and sprout, (2) landscape factors including disturbance-based spread vectors and neighborhood seed density, and (3) local factors determining establishment probability based on habitat suitability. Global seed rain estimates are derived …


Native Warm-Season Grasses Resist Spotted Knapweed Resurgence, Neil W. Macdonald, William J. Bottema Jan 2014

Native Warm-Season Grasses Resist Spotted Knapweed Resurgence, Neil W. Macdonald, William J. Bottema

Peer Reviewed Publications

No abstract provided.


Native Plant Establishment Success Influenced By Spotted Knapweed (Centaurea Stoebe) Control Method, Laurelin M. Martin, Neil W. Macdonald, Tami E. Brown Jan 2014

Native Plant Establishment Success Influenced By Spotted Knapweed (Centaurea Stoebe) Control Method, Laurelin M. Martin, Neil W. Macdonald, Tami E. Brown

Funded Articles

Invasive species frequently need to be controlled as part of efforts to reestablish native species on degraded sites. While the effectiveness of differing control methods are often reported, the impacts these methods have on the establishment of a native plant community are often unknown. To determine methods that effectively reduce spotted knapweed (Centaurea stoebe) while enhancing native species establishment, we tested 12 treatment combinations consisting of an initial site preparation (mowing, mowing + clopyralid, or mowing + glyphosate), in factorial combination with annual adult knapweed hand pulling and/or burning. We established 48 plots and applied site preparation treatments …