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The Exotic (EXO) and Native (NAT) biodiversity features represent exotic and native plant species communities in the Georgia Basin. These features (or rasters) were created following similar methods as Schuster & Arcese (2013), wherein they modelled and mapped bird species distributions using presence-absence data from ebird (http://ebird.org/content/ebird/about/; Sullivan et al. 2009). Plant species occurrence data were drawn from several sources (Boag 2014; Dr. E Gonzales; Dr. Joe Bennett; E-Flora BC 2013). Data for the 20 most abundant native and exotic plant species (40 species total) identified by Bennett (2014) were used to map the NAT and EXO communities, respectively (species list can be found in Appendix...
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This data contains the height of shrubs found along transects on the south facing slopes of Santa Cruz Island, CA. It was used in the analysis for the Manuspcript "Long-term impacts of exotic grazer removal on native shrub recovery, Santa Cruz Island, California". These sites were sampled in 2004 and 2016 to gain a longer term view on native shrub reestablishment into exotic grasslands after exotic grazer removal.
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The Southwest Exotic Plant Mapping Program (SWEMP) is a collaborative effort between the United States Geological Survey and federal, tribal, state, county and non-governmental organization (NGO) partners in the southwest. This project is an ongoing effort to compile and distribute regional data on the occurrence of non-native invasive plants in the southwestern United States. The database represents the known sites (represented by a point location, i.e. site) of non-native invasive plant infestations within Arizona and New Mexico, and adjacent portions of California, Colorado, Nevada and Utah. These data, collected from 1911 to 2006, represent the field observations of various state, federal, tribal and county...
Invasion of natural ecosystems by exotic plant species is a major threat to biodiversity. Disturbance to native plant communities, whether natural or management induced, is a primary factor contributing to successful invasion by exotic plant species. Herbivory by both wild and domestic ungulates exerts considerable impact on structure and composition of native plant communities. Intensive herbivory by ungulates can enhance exotic plant invasion, establishment, and spread for three reasons: (1) many exotic plants are adapted to ground disturbances such as those caused by ungulate feeding, trampling, and movements; (2) many exotic plants are adapted for easy transport from one area to another by ungulates via endozoochory...
The primary hypothesis for the astonishing success of many exotics as community invaders relative to their importance in their native communities is that they have escaped the natural enemies that control their population growth ? the `natural enemies hypothesis'. However, the frequent failure of introduced biocontrols, weak consumer effects on the growth and reproduction of some invaders, and the lack of consistent strong top-down regulation in many natural ecological systems indicate that other mechanisms must be involved in the success of some exotic plants. One mechanism may be the release by the invader of chemical compounds that have harmful effects on the members of the recipient plant community (i.e., allelopathy)....
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Significant ecological, hydrologic, and geomorphic changes have occurred during the 20th century along many large floodplain rivers in the American Southwest. Native Populus forests have declined, while the exotic Eurasian shrub, Tamarix, has proliferated and now dominates most floodplain ecosystems. Photographs from late 19th and early 20th centuries illustrate wide river channels with largely bare in-channel landforms and shrubby higher channel margin floodplains. However, by the mid-20th century, floodplains supporting dense Tamarix stands had expanded, and river channels had narrowed. Along the lower Green River in eastern Utah, the causal mechanism of channel and floodplain changes remains ambiguous due to...
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This data contains the location of transects on the south facing slopes of Santa Cruz Island, CA that were used to collect percent cover and shrub abundance data. It was used in the analysis for the Manuspcript "Long-term impacts of exotic grazer removal on native shrub recovery, Santa Cruz Island, California". These same transects were sampled in 2004 and 2016 to gain a longer term view on native shrub reestablishment into exotic grasslands after exotic grazer removal.
This model was constructed to model the risk of invasion by exotic plant species. Roads may directly influence exotic plant dispersal via disturbance during road construction or via alterations in soil regimes. For example, in Californian serpentine soil ecosystems, exotic plant species can be found up to 1km from the nearest road and Russian thistle (Salsola kali), an exotic forb growing along roads, is wind-dispersed over distances greater than 4km. Roads may also indirectly facilitate the dispersal of exotic grasses, such as crested wheatgrass (Agropyron cristatum), via human seeding along road verges or in burned areas near roads as a management strategy to curb the establishment of less desirable exotic grass...
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Exotic plant survey polygon data representing infested or non-infested areas including inventory, treatment, and monitoring efforts. Polygons generated from point and line features using a buffer distance entered in the field or data was collected as a polygon for large or irregular sized patches. Data collected by field personnel using mapping grade GPS and a statewide data collection protocol. INSTRUCTIONS FOR USE: see supplemental section on how to use this GeoDatabase.
Tags: AKRO, ANIA, Alaska, Alaska Region NPS Regional Office, Alien / Noxious Plants, All tags...
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The Exotic (EXO) and Native (NAT) biodiversity features represent exotic and native plant species communities in the Georgia Basin. These features (or rasters) were created following similar methods as Schuster & Arcese (2013), wherein they modelled and mapped bird species distributions using presence-absence data from ebird (http://ebird.org/content/ebird/about/; Sullivan et al. 2009). Plant species occurrence data were drawn from several sources (Boag 2014; Dr. E Gonzales; Dr. Joe Bennett; E-Flora BC 2013). Data for the 20 most abundant native and exotic plant species (40 species total) identified by Bennett (2014) were used to map the NAT and EXO communities, respectively (species list can be found in Appendix...
Significant ecological, hydrologic, and geomorphic changes have occurred during the 20th century along many large floodplain rivers in the American Southwest. Native Populus forests have declined, while the exotic Eurasian shrub, Tamarix, has proliferated and now dominates most floodplain ecosystems. Photographs from late 19th and early 20th centuries illustrate wide river channels with largely bare in-channel landforms and shrubby higher channel margin floodplains. However, by the mid-20th century, floodplains supporting dense Tamarix stands had expanded, and river channels had narrowed. Along the lower Green River in eastern Utah, the causal mechanism of channel and floodplain changes remains ambiguous due to...
Annual brome grasses, Bromus japonicus and B. tectorum, are common invaders of northern mixed-grass prairie, and have been shown to alter the structure and function of prairie ecosystems, including plant biomass production and litter decomposition. To build on previous findings, our objective was to model the impact of annual brome grasses on soil organic carbon storage as a step towards forecasting ecological change. Specifically, we measured differences in carbon storage between patches dominated by annual bromes and perennial grasses, in addition to evaluating key plant functional characteristics that impact carbon storage. Using the CENTURY model, we simulated high- and low-brome vegetation based on differences...
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This data includes data and metadata of (1) the percent cover of all species found along transects on the south facing slopes of Santa Cruz Island, CA (2) the height of all shrub individuals on transects on the south facing slopes of Santa Cruz Island, CA and (3) location data of on the south facing slopes of Santa Cruz Island, CA. Data were used in the analysis for the Manuspcript "Long-term impacts of exotic grazer removal on native shrub recovery, Santa Cruz Island, California". These sites were sampled in 2004 and 2016 to gain a longer term view on native shrub reestablishment into exotic grasslands after exotic grazer removal.
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This data contains the percent cover of all species found along transect on the south facing slopes of Santa Cruz Island, CA. It was used in the analysis for the Manuspcript "Long-term impacts of exotic grazer removal on native shrub recovery, Santa Cruz Island, California". These sites were sampled in 2004 and 2016 to gain a longer term view on native shrub reestablishment into exotic grasslands after exotic grazer removal.
Plants growing in vegetationally diverse habitats or near taxonomically distinct neighbors often experience less herbivory than plants in more simple habitats. When plants experience more herbivory in these situations it is called associational susceptibility and is most common when herbivores spill from their preferred plant host onto neighboring plants. Cankerworms are common pests of urban trees that have been shown in forests to disperse from preferred to less preferred hosts. I found that two common characteristics of urban habitats, low vegetational diversity and exotic plants, affect cankerworm herbivory of non-host understory plants. In an urban landscape I measured cankerworm herbivory on native dogwood...
Although the impacts of exotic plant invasions on community structure and ecosystem processes are well appreciated, the pathways or mechanisms that underlie these impacts are poorly understood. Better exploration of these processes is essential to understanding why exotic plants impact only certain systems, and why only some invaders have large impacts. Here, we review over 150 studies to evaluate the mechanisms underlying the impacts of exotic plant invasions on plant and animal community structure, nutrient cycling, hydrology and fire regimes. We find that, while numerous studies have examined the impacts of invasions on plant diversity and composition, less than 5% test whether these effects arise through competition,...
1 Most theory and empirical research on exotic invasions is based on the assumption that problematic exotics are much more abundant in the regions where they invade than in the regions where they are native. However, the overwhelming majority of studies on exotic plants have been conducted solely within the introduced range. With few exceptions, ecologists know surprisingly little about the abundance, interaction strengths and ecosystems impacts of even the best-studied exotics in their native range. 2 We argue that taking a biogeographical approach is key to understanding exotic plant invasions. On a descriptive level, unambiguous quantification of distributions and abundances of exotics in native and introduced...


    map background search result map search result map Processes of Tamarix invasion and floodplain development along the lower Green River, Utah. AKR Exotic Plant Management (EPMT) Geodatabase Exotic Plant Invasion Risk in the Western United States Current Exotic Communities Exotic Communites, RCP 45 Southwest Exotic Mapping Program (SWEMP) Database, 2007 Channel Island Grazer Removal Data 2004-2016 Percent cover of plants on south facing slopes of Santa Cruz Island, CA, in 2004 and 2016 Height of shrubs on south facing slopes of Santa Cruz Island, CA, in 2004 and 2016 Location of transects on south facing slopes of Santa Cruz Island, CA, in 2004 and 2016 Channel Island Grazer Removal Data 2004-2016 Percent cover of plants on south facing slopes of Santa Cruz Island, CA, in 2004 and 2016 Location of transects on south facing slopes of Santa Cruz Island, CA, in 2004 and 2016 Height of shrubs on south facing slopes of Santa Cruz Island, CA, in 2004 and 2016 Processes of Tamarix invasion and floodplain development along the lower Green River, Utah. Current Exotic Communities Exotic Communites, RCP 45 Southwest Exotic Mapping Program (SWEMP) Database, 2007 Exotic Plant Invasion Risk in the Western United States AKR Exotic Plant Management (EPMT) Geodatabase