Robert R. Blank

Robert R. Blank
United States Department of Agriculture | USDA · Agricultural Research Service (ARS)

PhD

About

152
Publications
16,889
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3,803
Citations
Citations since 2016
12 Research Items
1457 Citations
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250
2016201720182019202020212022050100150200250

Publications

Publications (152)
Article
Full-text available
Long-term control of the invasive annual grass cheatgrass is predicated on its biological suppression. Perennial grasses vary in their suppressive ability. We compared the ability of a non-native grass (“Hycrest” crested wheatgrass) and two native grasses (Snake River wheatgrass and bluebunch wheatgrass) to suppress cheatgrass. In a greenhouse in s...
Article
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Respiratory ammonification and denitrification are two evolutionarily unrelated dissimilatory nitrogen (N) processes central to the global N cycle, the activity of which is thought to be controlled by carbon (C) to nitrate (NO 3 −) ratio. Here we find that Intrasporangium calvum C5, a novel dual-pathway denitrifier/respiratory ammonifier, dispropor...
Article
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Fire is an important component of forests in the western United States. Not only are forests subjected to wildfires, but fire is also an important management tool to reduce fuels loads. Charcoal, a product of fire, can have major impacts on carbon (C) and nitrogen (N) cycling in forest soils, but it is unclear how these effects vary by dominant veg...
Article
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On the Ground • Cheatgrass has transformed secondary succession in arid sagebrush plant communities in the Great Basin by providing a fine-textured, early maturing fuel that increases the chance, rate, spread, and season of wildfires. • The best known method to suppress cheatgrass densities and associated fuels is through the establishment of pere...
Article
Wildfires occurring in Artemisia (sagebrush) ecosystems can temporarily increase soil nutrient availability in surface soil. Less is known, however, on how soil nutrient availability changes over time and microsite post-wildfire. In October 2013 a wildfire approximately 30 km north of Reno, Nevada, occurred in an Artemisia tridentata ssp. vaseyana...
Article
Because of concerns about salinity in the Colorado River, this study focused on saline and sodic soils associated with the Mancos Shale formation with the objective of investigating mechanisms driving sediment yield and sa-linity loads and the role of vegetation in altering soil chemistry in the Price-San Rafael River Basin. Rainfall simulations us...
Article
Invasion by the exotic annual grass Bromus tectorum often increases soil nutrient availability. It is unclear, however, if other grasses benefit from this higher nutrient status. Soil from three sites in the northern Great Basin U.S.A. conditioned by B. tectorum invasion (BTCS=B. tectorum conditioned soil), paired with adjacent areas conditioned by...
Article
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Although several invasive species have induced changes to the fire regime of invaded communities, potential intraspecific shifts in fire-related traits that might enhance the invasion success of these species have never been addressed. We assumed that traits conferring persistence and competitiveness in postfire conditions to downy brome, a quintes...
Article
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Integration of knowledge regarding impacts of historical cultivation on soils for restoration planning is limited even though these legacies can affect land productivity and future land uses for decades. Old fields are often actively transformed through restoration, afforestation, or rehabilitation seeding. Rehabilitation seeding with the introduce...
Article
Invasion by Bromus tectorum L. may condition the soil and increase nutrient availability. We hypothesized that nutrient poor soils of the arid Honey Lake Valley of northeastern California U.S.A., similar in physical and chemical properties, but conditioned by either B. tectorum, Krascheninnikovia lanata, or Artemisia tridentata, would differ as a r...
Article
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Success of invasive annual grasses is often linked to increases in resources, and restoration ecologists have suggested that decreasing nitrogen (N) availability and restoring more conservative N cycles with lower N turnover should decrease the competitive advantage of these invaders and facilitate establishment of native perennials. We developed a...
Article
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Worldwide, exotic invasive grasses have caused numerous ecosystem perturbations. Rangelands of the western USA have experienced increases in the size and frequency of wildfires largely due to invasion by the annual grass Bromus tectorum. Rehabilitation of invaded rangelands is difficult; but long-term success is predicated on establishing healthy a...
Article
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Background and Aims Fire has profound effects on ecosystem properties, but few studies have addressed the effect of repeated burns on soil nutrients, and none have been conducted in cold desert ecosystems where invasion by exotic annual grasses is resulting in greater fire frequency. Methods In a 5 year study, we examined effects of repeated burnin...
Article
Thinning and prescribed fire are common management tools used to eliminate thick fuel loads that could otherwise facilitate and encourage a more severe catastrophic wildfire. The objective of this study was to quantify the lasting effects of prescribed fire on forest floor and soil nutrients approximately 9 yr after a burn occurred near Truckee, CA...
Conference Paper
Background/Question/Methods Invasion and expansion of cheatgrass (Bromus tectorum L.) into cold desert shrublands is often linked to increases in resources, and restoration ecologists have suggested that decreasing nitrogen availability and restoring a more conservative nitrogen cycle should decrease the competitive advantage of cheatgrass. Repea...
Article
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Lepidium latifolium (perennial pepperweed) is a weedy alien crucifer that has invaded wetlands throughout the western United States. We monitored L. latifolium invasion of an Elytrigia elongata (tall wheatgrass) community at the Honey Lake Wildlife Refuge in northeastern California. In 1993, a 40-m ² plot was delineated, at which time only two sing...
Article
Cheatgrass (Bromus tectorum) has recently invaded marginal low-elevation salt desert habitats across the Great Basin. We tested the hypothesis that cheatgrass seed produced in populations from the more stressful salt desert vs. upland sagebrush habitats should grow differently in salt desert soils compared to adjacent upland sagebrush soil, and vic...
Article
The effects of thinning followed by residue mastication (THIN), prescribed fire (BURN), and thinning plus residue mastication plus burning (T+B) on nutrient budgets and resin-based (plant root simulator [PRS] probe) measurements of soil nutrient availability in a mixed-conifer forest were measured. Because of site differences, removals of carbon (C...
Article
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This is the final part of a three part series specifically addressing lessons learned concerning the management of rehabilitated cheatgrass-infested rangelands.
Article
Pack and saddle stock, including, but not limited to domesticated horses, mules, and burros, are used to support commercial, private and administrative activities in the Sierra Nevada. The use of pack stock has become a contentious and litigious issue for land management agencies in the region inter alia due to concerns over effects on the environm...
Article
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Soil engineering by downy brome may be a facet of its competitiveness. Using rhizotrons in the greenhouse, we compared the growth and plant-soil relationships of downy brome grown in two field soil types: soil invaded for 12 yr by downy brome and a similar soil not yet invaded. For each soil type, downy brome was grown for two growth cycles. At har...
Conference Paper
Background/Question/Methods Restoration of cheatgrass dominated rangelands depends on controlling cheatgrass while simultaneously providing conditions necessary for native species establishment. Growth and reproduction of cheatgrass is highly responsive to available soil nitrogen (N), and decreasing soil N levels may decrease the competitive abil...
Article
Increasingly biologists and ecologists are becoming aware of the vital importance of soil to processes observed aboveground and are incorporating soil analyses into their research. Because of the dynamic and heterogeneous nature of soil, proper incorporation of soil analysis into ecological studies requires knowledge and planning. Unfortunately, ma...
Article
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This is the second part of a three part series specifically addressing lessons learned in the process of applications and practices used to rehabilitate cheatgrass-infested rangelands. Link to publication ---> http://www.progressiverancher.com/sept-oct2013prog.html
Article
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Cultivation legacies affect native vegetation in old fields of the Great Basin, USA for nearly a century after these fields are abandoned. We hypothesized that cultivation lowered soil nutrients and that this legacy would differentially impact plant performance of four representative Great Basin species. To test these hypotheses, we compared soil n...
Article
Bromus tectorum (cheatgrass) has replaced native Artemisia (sagebrush)/bunchgrass communities throughout the Intermountain West. Using the framework of Jenny (1941), we hypothesized that invasion by B. tectorum could alter pedogenic trajectories. Hypothesis testing involvedmonitoring the invasion of a Krascheninnikovia lanata (winterfat) community...
Article
We investigated impacts of biocontrol of Tamarix spp. by Diorhabda carinulata on soil nitrogen (N) transformations by surveying organic and mineral soils from three sites. Potential net N mineralization was assayed using laboratory incubations. Results partially supported our hypothesis that herbivory would result in stimulated net N mineralization...
Article
Full-text available
Soil resource availability in semi-arid and arid shrubland ecosystems is highly heterogeneous and includes patterns of accumulation primarily beneath shrubs as opposed to shrub interspaces. These resource islands contribute to ecosystem resilience after natural disturbances such as fire, yet very little is known regarding their redevelopment follow...
Conference Paper
Background/Question/Methods Restoration of sagebrush ecosystems dominated by cheatgrass depends on both controlling the invader and providing the conditions for native species establishment. Reducing available soil nitrogen (N) decreases cheatgrass growth and reproduction and native species opportunities for establishment. A mechanism for decreas...
Conference Paper
Background/Question/Methods Restoration of cheatgrass dominated rangelands depends on controlling cheatgrass while simultaneously providing conditions necessary for native species establishment. Growth and reproduction of cheatgrass is highly responsive to available soil nitrogen (N), and decreasing soil N levels may decrease the competitive abil...
Article
Full-text available
Bromus tectorum L. (cheatgrass) is an Eurasian annual grass that has invaded ecosystems throughout the Intermountain west of the United States. Our purpose was to examine mechanisms by which established perennial grasses suppress the growth of B. tectorum. Using rhizotrons, the experiment was conducted over 5 growth cycles: (1) B. tectorum planted...
Article
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Sagebrush-steppe ecosystems are one of the most threatened ecosystems in North America due to woodland expansion, wildfire, and exotic annual grass invasion. Some scientists and policy makers have suggested that woodland expansion will lead to increased carbon (C) storage on the landscape. To assess this potential we used data collected from a Join...
Article
El pasto cheatgrass (Bromus tectorum L.) es un pasto exótico anual que está causando degradación en el ecosistema en los pastizales del oeste de los Estados Unidos. Investigamos los mecanismos potenciales por los cuales los pasto (Agropyron cristatum L. Gaertn. y Agropyron desertorum [Fisch. {Ex Link} Scult.]) suprimen el crecimiento y la habilidad...
Article
Vegetation changes associated with climate shifts and anthropogenic disturbance can have major impacts on biogeochemical cycling and soils. Much of the Great Basin, U.S. is currently dominated by sagebrush (Artemisia tridentate (Rydb.) Boivin) ecosystems. Sagebrush ecosystems are increasingly influenced by pinyon (Pinus monophylla Torr. & Frém and...
Article
High concentrations of inorganic N, P, and S have been reported in overland and litter interflow within forested uplands of the Tahoe basin and surrounding watersheds. In this study we compared runoff nutrient concentration and load as well as soil nutrient fluxes at three watershed locations; an upland forest, a transitional ecotone consisting of...
Conference Paper
Background/Question/Methods Cultivation is an exotic disturbance that can create long-term changes (“land-use legacies”) in native vegetation and soils that require decades to centuries to recover. Recovery following cultivation in sagebrush ecosystems of the Great Basin, USA remains largely unexamined even though millions of acres of land were d...
Article
Increasing atmospheric carbon dioxide and its feedbacks with global climate have sparked renewed interest in quantifying ecosystem carbon (C) budgets, including quantifying belowground pools. Belowground nutrient budgets require accurate estimates of soil mass, coarse fragment content, and nutrient concentrations. It has long been thought that the...
Article
Aboveground litter decomposition is controlled mainly by substrate quality and climate factors across terrestrial ecosystems, but photodegradation from exposure to high-intensity ultraviolet-B (UVB) radiation may also be important in arid and semi-arid environments. We investigated the interactive effects of UVB exposure and litter quality on decom...
Article
Full-text available
Cheatgrass (Bromus tectorum L.), an invasive annual grass, is displacing native species and causing increased fire frequency in the Great Basin of the southwestern United States. Growth and nitrogen uptake patterns by cheatgrass were examined in a greenhouse study using soils from sites with the same soil type but different fire histories: 1) an ar...
Article
Full-text available
Vegetation changes associated with climate shifts and anthropogenic disturbance have major impacts on biogeochemical cycling. Much of the interior western United States currently is dominated by sagebrush (Artemisia tridentata Nutt.) ecosystems. At low to intermediate elevations, sagebrush ecosystems increasingly are influenced by cheatgrass (Bromu...
Article
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Resource availability and propagule supply are major factors influencing establishment and persistence of both native and invasive species. Increased soil nitrogen (N) availability and high propagule inputs contribute to the ability of annual invasive grasses to dominate disturbed ecosystems. Nitrogen reduction through carbon (C) additions can pote...
Article
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Calcium (Ca(2+)) signals regulate many aspects of plant development, including a programmed cell death pathway that protects plants from pathogens (hypersensitive response). Cytosolic Ca(2+) signals result from a combined action of Ca(2+) influx through channels and Ca(2+) efflux through pumps and cotransporters. Plants utilize calmodulin-activated...
Article
Insect herbivory can strongly influence ecosystem nutrient dynamics, yet the indirect effects of herbivore-altered litter quality on subsequent decomposition remain poorly understood. The northern tamarisk beetle Diorhabda carinulata was released across several western states as a biological control agent to reduce the extent of the invasive tree T...
Article
Limited data exist on quantification of soil nutrient pools in montane meadow ecosystems. Along Big Grizzly Creek in the Plumas National Forest, CA (June 1999-September 2005), soil nutrient pools were quantified by livestock grazing treatment (grazed, ungrazed), floodplain location (stream edge, midfloodplain, forest edge), and season using resin c...
Article
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Few studies have examined plant-soil relationships in competitive arenas between exotic and native plants in the western United States. A pair-wise competitive design was used to evaluate plant-soil relationships between seedlings of the exotic annual grasses Bromus tectorum and Taeniatherium caput-medusae and the native perennial grasses Elymus el...
Article
Increases in pinyon and juniper woodland cover associated with land-use history are suggested to provide offsets for carbon emissions in arid regions. However, the largest pools of carbon in arid landscapes are typically found in soils, and aboveground biomass cannot be considered long-term storage in fire-prone ecosystems. Also, the objectives of...
Article
Full-text available
In the course of investigating nutrient availability in a montane meadow ecosystem of the Sierra Nevada range, it was determined that resin availability of Na+ and K+ was significantly affected by season (winter vs. summer and fall). The underlying mechanism(s) controlling this seasonal effect was investigated in the laboratory. Four replicate A ho...
Conference Paper
Vegetation changes associated with climate shifts and anthropogenic disturbance can have major impacts on biogeochemical cycling and soils. Much of the Great Basin, U.S. is currently dominated by sagebrush (Artemisia tridentate ssp. (Rydb.) Boivin) ecosystems. At intermediate elevations, sagebrush ecosystems are increasingly influenced by pinyon (P...
Article
Full-text available
Quantifying root biomass is critical to an estimation and understanding of ecosystem net primary production, biomass partitioning, and belowground competition. We compared 2 methods for determining root biomass: a new soil-coring technique and traditional excavation of quantitative pits. We conducted the study in an existing Joint Fire Sciences dem...
Article
Full-text available
Prescribed burning is a management option to reduce fire hazard in the Lake Tahoe Basin. However, subsequent nutrient loading to the lake is of major concern. The effect of prescribed burning and residual ash on soil chemical properties and anion concentrations was studied in both the field (Tahoe National Forest) and laboratory. Sawtooth and Marle...
Article
Full-text available
Invasion of western North America by the annual exotic grass Bromus tectorum L. (cheatgrass) has been an ecological disaster. High soil bioavailability of nitrogen is a contributing factor in the invasive potential of B. tectorum. Application of labile carbon sources to the soil can immobilize soil nitrogen and favor native species. We studied the...
Conference Paper
Background/Question/Methods Vegetation changes associated with climate shifts and anthropogenic disturbance are thought to have major impacts on biogeochemical cycling and soils. Much of the Great Basin, U.S. is currently dominated by sagebrush (Artemisia tridentate ssp. (Rydb.) Boivin) ecosystems. At intermediate elevations, sagebrush ecosystem...
Conference Paper
Background/Question/Methods Saltcedar (Tamarix ramosissima) invasion and subsequent dominance in biologically and functionally diverse riparian ecosystems across the western U.S. has lead to release of the leaf beetle (Diorhabda elongata) as a biological control agent, and has resulted in large-scale rapid defoliation of saltcedar across several w...
Article
Nitrogen-fixing species contribute to ecosystem nitrogen budgets, but background resource levels influence nodulation, fixation, and plant growth.We conducted a greenhouse experiment to examine the separate and interacting effects of water and N availability on biomass production, tissue N concentration, nodulation, nodule activity, and rhizodeposi...
Article
Much of the Great Basin, U.S. is currently dominated by sagebrush (Artemisia tridentate ssp. (Rydb.) Boivin) ecosystems. At intermediate elevations, sagebrush ecosystems are increasingly influenced by pinyon (Pinus monophylla Torr. & Frém.) and juniper (Juniperus osteosperma Torr.) expansion. Some scientists and policy makers believe that increasin...
Article
Full-text available
Limited data exist on the affect of downy brome invasion on biogeochemical cycling. Biogeochemical cycling was quantified in a winterfat community in northeastern, CA that was separated into three invasion classes: noninvaded (NI), invaded for 3 yr (I3), and 10 yr (I10) by downy brome. On each plot, all aboveground vegetation was harvested and sepa...
Article
Full-text available
Woodland expansion affects grasslands and shrublands on a global scale. Prescribed fire is a potential restoration tool, but recovery depends on nutrient availability and species responses after burning. Fire often leads to longterm losses in total nitrogen, but presence of native legumes can influence recovery through addition of fixed nitrogen.We...
Article
Cheatgrass (Bromus tectorum L.) is the most widespread invasive weed in sagebrush ecosystems of North America. Restoration of perennial vegetation is difficult and land managers have often used introduced bunchgrasses to restore degraded sagebrush communities. Our objective was to evaluate the potential of 'Vavilov' Siberian wheatgrass (Agropyron f...
Article
Two forest soils from the Sierra Nevada Mountains of California were brought into the laboratory and subjected to simulated burning in a muffle furnace at several durations, oven temperatures, and water contents. Soils were analyzed for NO 3- , NH 4+ , total N, total C, and C:N responses to the treatments. Ammonium, which was the dominant form of i...
Article
Full-text available
Pinyon and juniper expansion into sagebrush ecosystems results in decreased cover and biomass of perennial grasses and forbs. We examine the effectiveness of spring prescribed fire on restoration of sagebrush ecosystems by documenting burn effects on soil nutrients, herbaceous aboveground biomass, and tissue nutrient concentrations. This study was...
Data
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To better understand why medusahead (Taeniatherum caput-medusae) is invasive, we quantified soil N availability and characterized soil microbial communities between native and inva-sive populations. No consistent differences in soil N mineralization potentials were noted between native medusahead sites in Spain, Turkey, France, and Greece and two i...
Article
Pinyon and juniper have been expanding into sagebrush (Artemisia tridentata) ecosystems since settlement of the Great Basin around 1860. Herbaceous understory vegetation is eliminated as stand densities increase and the potential for catastrophic fires increases. Prescribed fire is increasingly used to remove trees and promote recovery of sagebrush...
Article
Soil nutrient availability influences plant invasions. Resin capsules were used to examine soil nutrient bioavailability along 2 sagebrush-grassland elevation transects in the east Tintic Range (Utah) and Shoshone Range (Nevada). In the fall of 2001, treatments were applied to 3 replicate plots at each site, which included prescribed burning, herba...
Article
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Cabernet Sauvignon grapevines were exposed to sudden chilling (5 degrees C), water deficit (PEG), and an iso-osmotic salinity (120 mM NaCl and 12 mM CaCl(2)) for 1, 4, 8, and 24 h. Stomatal conductance and stem water potentials were significantly reduced after stress application. Microarray analysis of transcript abundance in shoot tips detected no...
Article
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The annual grass Taeniatherum caput-medusae (L.) Nevski (medusahead) is highly invasive on rangelands of the western United States. It originates from the Mediterranean basin and was introduced accidentally into North America in the late 1800s. To increase our knowledge of the soil factors that may contribute to its invasiveness, we conducted a rec...
Article
Few studies have addressed the natural pollution potential of pristine subalpine forested watersheds on a site-specific basis. Consequently, specific source and amounts of nutrient discharge to tributaries of the Tahoe Basin are difficult to identify. The sediment content and nitrate and ammonium levels in surface runoff from two soil types (Meeks...
Article
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Increases in the growth rate of plants and microbes in the Mojave Desert in response to predicted increases in precipitation and CO₂ due to global climate change may induce nutrient limitations. This study was designed to measure the pool of potentially bioavailable nutrients in soils of the Mojave Desert. Soils were collected from shrub and inters...
Article
Ecosystem susceptibility to invasion by nonnative species is poorly understood, but evidence is increasing that spatial and temporal variability in resources has large-scale effects. We conducted a study in Artemisia tridentata ecosystems at two Great Basin locations examining differences in resource availability and invasibility of Bromus tectorum...
Article
Full-text available
We sampled eight California rice fields every two days from May 1 to June 1, 2004 for algal biomass, species composition, and water quality parameters. Soil samples were collected prior to filling the fields with water and analyzed for selected nutrients. Algal abundance shifted from dominance by genera of green algae (Sphaeroplea, Tribonema, Ankis...