Kari E. Veblen

Kari E. Veblen
Utah State University | USU · Department of Wildland Resources

PhD

About

91
Publications
22,710
Reads
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1,797
Citations
Additional affiliations
July 2017 - present
Utah State University
Position
  • Professor (Associate)
July 2011 - June 2017
Utah State University
Position
  • Professor (Assistant)
September 2002 - March 2008
University of California, Davis
Position
  • PhD
Education
September 2002 - June 2008
University of California, Davis
Field of study
  • Ecology

Publications

Publications (91)
Article
In drylands, there is a need for controlled experiments over multiple planting years to examine how woody seedlings respond to soil texture and the potentially interactive effects of soil depth and precipitation. Understanding how multiple environmental factors interactively influence plant establishment is critical to restoration ecology and in th...
Book
Full-text available
Utah contains a variety of shrub species adapted to its unique environmental conditions ranging from salt-deserts at lower elevations to woodlands at higher elevation mountain foothills and plateaus. Decades of management experience and research have led to a greater understanding of the complex relationships among vegetation, soil and climate, and...
Article
Full-text available
On the Ground •Available rangeland data, from field-measured plots to remotely sensed landscapes provide much needed information for mapping and modeling wildlife habitats. •Better integration of wildlife habitat characteristics into rangeland monitoring schemes is needed for most rangeland wildlife species at varying spatial and temporal scales....
Article
Full-text available
Ecological stability in plant communities is shaped by bottom-up processes like environmental resource fluctuations and top-down controls such as herbivory, each of which have demonstrated direct effects but may also act indirectly by altering plant community dynamics. These indirect effects, called biotic stability mechanisms, have been studied ac...
Article
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Over a quarter of the world's land surface is grazed by cattle and other livestock, which are replacing wild herbivores, potentially impairing ecosystem structure and functions. Previous research suggests that cattle at moderate stocking rates can functionally replace wild herbivores in shaping understory communities, but it is unclear whether this...
Article
Recent country and continental-scale digital soil mapping efforts have used a single model to predict soil properties across large regions. However, different ecophysiographic regions within large-extent areas are likely to have different soil-landscape relationships so models built specifically for these regions may more accurately capture these r...
Article
Full-text available
Restoration of degraded drylands is urgently needed to mitigate climate change, reverse desertification and secure livelihoods for the two billion people who live in these areas. Bold global targets have been set for dryland restoration to restore millions of hectares of degraded land. These targets have been questioned as overly ambitious, but wit...
Article
A full list of affiliations appears at the end of the paper. R estoration ecology is rapidly advancing in response to the ever-expanding global decline in ecosystem integrity and its associated socioeconomic repercussions 1-4. Nowhere are these dynamics more evident than in drylands, which help sustain 39% of the world's human population 5 but rema...
Article
Management of tree cover - either to curb bush encroachment or to mitigate losses of woody cover to over-browsing- is a major concern in savanna ecosystems. Once established, trees are often "trapped" as saplings, since interactions among disturbance, plant competition, and precipitation delay sapling recruitment into adult size classes. Saplings c...
Article
Full-text available
Both termites and large mammalian herbivores (LMH) are savanna ecosystem engineers that have profound impacts on ecosystem structure and function. Both of these savanna engineers modulate many common and shared dietary resources such as woody and herbaceous plant biomass, yet few studies have addressed how they impact one another. In particular, it...
Preprint
Full-text available
Both termites and large mammalian herbivores (LMH) are savanna ecosystem engineers that have profound impacts on ecosystem structure and function. Both of these savanna engineers modulate many common and shared dietary resources such as woody and herbaceous plant biomass, yet few studies have addressed how they impact one another. In particular, it...
Article
Full-text available
Grassland and savanna ecosystems, important for both livelihoods and biodiversity conservation, are strongly affected by ecosystem drivers such as herbivory, fire, and drought. Interactions among fire, herbivores and vegetation produce complex feedbacks in these ecosystems, but these have rarely been studied in the context of fuel continuity and re...
Article
Shrubs create heterogeneity in resource availability, yet the influences of shrub age and size on these conditions in semiarid ecosystems is largely unknown. In order to inform restoration and conservation efforts in global shrub-steppe ecosystems that are currently imperiled, we assessed plant age-size relationships within an Artemisia tridentata...
Article
Full-text available
Rangelands are governed by threshold dynamics, and factors such as drought, wildfire, and herbivory can drive change across thresholds and between ecological states. Most work on this topic has focused on shifts in a single response variable, vegetation, and little research has considered how to reconcile responses of more than one variable to dete...
Article
Full-text available
In the western United States, fire has become a significant concern in the management of big sagebrush (Artemisia tridentata Nutt.) ecosystems. This is due to large‐scale increases in cover of the fire‐prone invasive annual cheatgrass (Bromus tectorum L.) and, concurrently, concerns about declining quantity and quality of habitat for Greater Sage‐g...
Article
Full-text available
Despite the critical need to improve degraded herbaceous understory conditions in many semiarid ecosystems, the influence of soil properties on seedling emergence of species seeded in shrubland plant communities is largely unexplored. We evaluated emergence patterns of 6 restoration species in soils from wyomingensis (i.e., Wyoming big sagebrush, A...
Article
Rangelands are governed by threshold dynamics, and factors such as drought, wildfire and herbivory can drive change across thresholds and between ecological states. Most work on this topic has focused on shifts in a single response variable, vegetation, and little research has considered how to reconcile responses of more than one variable to deter...
Article
Full-text available
1.Savanna tree cover is dynamic due to disturbances such as fire and herbivory. Frequent fires can limit a key demographic transition from sapling to adult height classes in savanna trees. Saplings may be caught in a ‘fire trap’, wherein individuals repeatedly resprout following fire top‐kill events. Saplings only rarely escape the cycle by attaini...
Article
Management of restored ecosystems for multiple use is a modern necessity given a growing human population and dwindling supplies of ecosystem goods and services. Multiple use management refers to managing resources simultaneously for sustainable output of many goods and services. Within any restoration, thoughtful planning and early stakeholder eng...
Article
Full-text available
Treatments to reduce shrub cover are commonly implemented with the objective of shifting community structure away from shrub dominance and toward shrub and perennial grass codominance. In sagebrush (Artemisia L.) ecosystems, shrub reduction treatments have had variable effects on target shrubs, herbaceous perennials, and non-native annual plants. T...
Article
Feral (wild) horses present significant challenges for landscape managers. A major effect of horses is trampling, which erodes soil and alters vegetation cover, which is often critical habitat for threatened animals. We examined the direct and indirect impacts of horses, kangaroos, and rabbits on the broad-toothed rat (Mastacomys fuscus), a threate...
Article
Full-text available
Herbivores alter plant biodiversity (species richness) in many of the world’s ecosystems, but the magnitude and the direction of herbivore effects on biodiversity vary widely within and among ecosystems. One current theory predicts that herbivores enhance plant biodiversity at high productivity but have the opposite effect at low productivity. Yet,...
Article
Full-text available
Overabundance of woody plants in semiarid ecosystems can degrade understory herbaceous vegetation and often requires shrub reduction and seeding to recover ecosystem services. We used meta‐analysis techniques to assess the effects of fire and mechanical shrub reduction over two post‐treatment timeframes (1‐4 years and 5‐10 years) on changes in cove...
Article
Theory predicts that intraspecific competition should be stronger than interspecific competition for any pair of stably coexisting species, yet previous literature reviews found little support for this pattern. We screened over 5400 publications and identified 39 studies that quantified phenomenological intraspecific and interspecific interactions...
Article
Full-text available
Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis) is a widespread shrub across the western United States, and there is great interest among scientists and land managers in its ecology and conservation, particularly with regard to maintaining structural heterogeneity of sagebrush stands for wildlife habitat and livestock forage. Yet lit...
Article
Full-text available
The functional relationship between arbuscular mycorrhizal fungi (AMF) and their hosts is variable on small spatial scales. Here, we hypothesized that herbivore exclusion changes the AMF community and alters the ability of AMF to enhance plant tolerance to grazing. We grew the perennial bunchgrass, Themeda triandra Forssk in inoculum from soils col...
Article
Full-text available
On rangelands worldwide, cattle interact with many forms of biodiversity, most obviously with vegetation and other large herbivores. Since 1995, we have been manipulating the presence of cattle, mesoherbivores, and megaherbivores (elephants and giraffes) in a series of eighteen 4-ha (10-acre) plots at the Kenya Long-term Exclosure Experiment. We re...
Article
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African savannas support an iconic fauna, but they are undergoing large-scale population declines and extinctions of large (>5 kg) mammals. Long-term, controlled, replicated experiments that explore the consequences of this defaunation (and its replacement with livestock) are rare. The Mpala Research Centre in Laikipia County, Kenya, hosts three su...
Article
Restoration islands are concentrated plantings in strategic locations, created to efficiently use resources to achieve restoration goals. These methods have been used effectively in mesic ecosystems, particularly tropical forests, where the goal of island plantings is often to “nucleate” across a degraded area, providing a seed source for spread ou...
Article
Full-text available
Human land use, such as livestock grazing, can have profound yet varied effects on wildlife interacting within common ecosystems, yet our understanding of land-use effects is often generalized from short-term, local studies that may not correspond with trends at broader scales. Here we used public land records to characterize livestock grazing acro...
Article
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Understanding the effects of anthropogenic disturbance on zoonotic disease risk is both a critical conservation objective and a public health priority. Here, we evaluate the effects of multiple forms of anthropogenic disturbance across a precipitation gradient on the abundance of pathogen-infected small mammal hosts in a multi-host, multi-pathogen...
Article
Full-text available
Although disturbance theory has been recognized as a useful framework in examining the stability of ant-plant mutualisms, very few studies have examined the effects of fire disturbance on these mutualisms. In myrmecophyte-dominated savannas, fire and herbivory are key drivers that could influence ant-plant mutualisms by causing complete colony mort...
Article
Full-text available
In many savanna ecosystems worldwide, livestock share the landscape and its resources with wildlife. The nature of interactions between livestock and wildlife is a subject of considerable interest and speculation, yet little controlled experimental research has been carried out. Since 1995, we have been manipulating the presence and absence of catt...
Article
Full-text available
Positive plant–plant interactions have been documented across ecosystems worldwide (Brooker et al. 2008), including many range-land systems (He et al. 2013). According to the stress gradient hypothesis (Bertness and Callaway 1994), the frequency and importance of positive (i.e., facilitative) plant–plant interactions are predicted to increase with...
Article
Full-text available
Prescribed burning is used in tropical savannas to improve habitat conditions for domestic and wild herbivores, but its effects on the ecological interactions between these herbivore guilds have never been assessed experimentally. Understanding such effects will contribute towards more informed management of both guilds in landscapes where they sha...
Article
Full-text available
Wild herbivores and livestock share the majority of rangelands worldwide, yet few controlled experiments have addressed their individual, additive, and interactive impacts on ecosystem function. While ungulate herbivores generally reduce standing biomass, their effects on aboveground net primary production (ANPP) can vary by spatial and temporal co...
Article
Full-text available
The widespread replacement of wild ungulate herbivores by domestic livestock in African savannas is composed of two interrelated phenomena: (1) loss or reduction in numbers of individual wildlife species or guilds and (2) addition of livestock to the system. Each can have important implications for plant community dynamics. Yet very few studies hav...
Article
Although diet supplementation is a well-established tool for managing livestock distributions and improving vegetation, the principle is less commonly applied to wild ungulates. One reason for this is that it is not known whether wildlife species, such as elk (Cervus elaphus), will habituate to novel supplements and feeders in the landscape. We, th...
Article
Full-text available
As environmental stress increases positive (facilitative) plant interactions often predominate. Plant-plant associations (or lack thereof) can indicate whether certain plant species favor particular types of microsites (e.g., shrub canopies or plant-free interspaces) and can provide valuable insights into whether "nurse plants" will contribute to s...
Data
Site characteristics for sites sampled during 2012, 2013, and 2014 field seasons. PRISM rainfall refers to annual rainfall values predicted by PRISM data [36]. ESD rainfall refers to annual rainfall ranges based upon ecological site descriptions (Natural Resources Conservation Service 2006). MLRA refers to Major Land Resources Areas. ARTR refers to...
Data
Pairwise correlations for site-level variables and focal grass species cover for canopy and interspace microsites. P values test the null hypotheses that Pearson’s pairwise correlations between 2 variables = 0 versus the alternative hypothesis that Pearson’s pairwise correlations between 2 variables ≠ 0. (DOCX)
Data
Site level data for environmental covariates and focal species cover, density, basal width, and height means. Means were been averaged over shrub-level (subsample) data values. (DOCX)
Data
Sampling scheme for Poa secunda as seen from above, depicting a sagebrush canopy and transect extending from the base. Numbers correspond to placement of 20 cm x 20 cm quadrats for estimating percent cover of P. secunda. 1) Canopy: quadrat placed at approximate midpoint of canopy region; 2) Interspace: quadrat placed at approximate midpoint of tran...
Article
Anthropogenic disturbances involving land use change, climate disruption, pollution, and invasive species have been shown to impact immune function of wild animals. These immune changes have direct impacts on the fitness of impacted animals and, also, potentially indirect effects on other species and on ecological processes, notably involving the s...
Article
Full-text available
Disturbance is a crucial determinant of animal abundance, distribution, and community structure in many ecosystems, but ways in which multiple disturbance types interact remain poorly understood. The effects of multiple-disturbance interactions can be additive, sub-additive, or super-additive (synergistic). Synergistic effects in particular can acc...
Article
Full-text available
Herbivory by both grazing and browsing ungulates shapes the structure and functioning of terrestrial ecosystems worldwide, and both types of herbivory have been implicated in major ecosystem state changes. Despite the ecological consequences of differences in diets and feeding habits among herbivores, studies that experimentally distinguish effects...
Article
1.Recent elevated temperatures and prolonged droughts in many already water-limited regions throughout the world, including the southwestern U.S., are likely to intensify according to future climate-model projections. This warming and drying can negatively affect perennial vegetation and lead to the degradation of ecosystem properties.2.To better u...
Article
Worldwide, many rangelands are managed for multiple uses, and it is increasingly important to identify livestock management practices that maximize rangeland productivity, biodiversity, and wildlife conservation. In sub-Saharan Africa, pastoralists and ranchers use temporary thorn-fence corrals (“bomas”) to protect livestock at night. Traditional b...
Conference Paper
Full-text available
Background / Purpose: Discourse around the understanding and management of rangelands often centers around the fundamental question as to whether domestic ungulates compete with wild ungulates. Yet few studies have attempted replicated experimental manipulations to test the exact nature of these interactions. This study summarizes lessons from 18...
Conference Paper
Full-text available
Background/Question/Methods Shrub-grass interactions play an important role in the structure and function of plant communities, especially in semi-arid ecosystems of the Great Basin. Evidence suggests that as environmental stress increases, facilitative plant interactions predominate, resulting in positive plant-plant spatial associations. Canopy...
Conference Paper
Full-text available
Background/Question/Methods Livestock and wild ungulates co-exist on many of the world’s rangeland ecosystems, and alone or in combination can cause major changes to soils and plant communities. Distinguishing between the effects of domestic livestock and wild ungulates (e.g., deer and elk) which differ in diets and feeding habits is of both ecolo...
Conference Paper
Full-text available
Background/Question/Methods Arid rangelands in North America have experienced significant changes in herbivory pressure in the last 200 years, including introduction and use by multiple species of wild ungulates and domestic livestock. Herbivory pressure can greatly affect arid plant communities by causing state shifts from one stable configuratio...
Conference Paper
Background/Question/Methods Species interactions change through time, for example ontogenetically, successionally, and evolutionarily. They also change as environmental conditions change, both within years (seasonally) and between years (year effects). The former are relatively well-studied, but the latter have received less attention. For exampl...
Article
Full-text available
Despite the importance of fire and herbivory in structuring savanna systems, few replicated experiments have examined the interactive effects of herbivory and fire on plant dynamics. In addition, the effects of fire on associated ant-tree mutualisms have been largely unexplored. We carried out small controlled burns in each of 18 herbivore treatmen...
Article
Full-text available
Despite the importance of fire and herbivory in structuring savanna systems, few replicated experiments have examined the interactive effects of herbivory and fire on plant dynamics. In addition, the effects of fire on associated ant-tree mutualisms have been largely unexplored. We carried out small controlled burns in each of 18 herbivore treatmen...
Article
Full-text available
Public land management agencies, such as the Bureau of Land Management (BLM), are charged with managing rangelands throughout the western United States for multiple uses, such as livestock grazing and conservation of sensitive species and their habitats. Monitoring of condition and trends of these rangelands, particularly with respect to effects of...