Welcome to the Rangeland Ecology & Management archives. The journal Rangeland Ecology & Management (RE&M; v58, 2005-present) is the successor to the Journal of Range Management (JRM; v. 1-57, 1948-2004.) The archives provide public access, in a "rolling window" agreement with the Society for Range Management, to both titles (JRM and RE&M), from v.1 up to five years from the present year.

The most recent years of RE&M are available through membership in the Society for Range Management (SRM). Membership in SRM is a means to access current information and dialogue on rangeland management.

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Print ISSN: 0022-409x

Online ISSN: 1550-7424


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Recent Submissions

  • Potential Climate Change Impacts on Four Biophysical Indicators of Cattle Production from Western US Rangelands

    Reeves, M.C.; Bagne, K.E.; Tanaka, J. (Society for Range Management, 2017)
    We examined multiple environmental factors related to climate change that affect cattle production on rangelands to identify sources of vulnerability among seven regions of the western United States. Climate change effects were projected to 2100 using published spatially explicit model output for four indicators of vulnerability: forage quantity, vegetation type trajectory, heat stress, and interannual forage variability. Departure of projections from the baseline (2001-2010) was used to estimate vulnerability of present-day cattle operations. The analysis indicated 1) an increase in forage quantity in northern regions; 2) a move from woody dominance toward grassier vegetation types overall but with considerable spatial heterogeneity; 3) a substantial increase in the number of heat-stress days across all regions beginning as early as 2020-2030; and 4) higher interannual variability of forage quantity for most regions. All four factors evaluated in tandem suggest declining production in southern and western regions. In northern and interior regions, the benefits of increased net primary productivity or increasing abundance of herbaceous vegetation are mostly tempered by increases in heat stress and forage variability. Multiple indicators point toward increasing vulnerability of cattle production in southwestern regions providing strong support for the need for adaptation measures and suggest significant change to the industry. Opposing indicators in northern regions point toward the need for cattle operations to increase flexibility to take advantage of periods of favorable production while preparing for uncertainty, variability, and increasing stress from individual factors. © Published by Elsevier Inc. on behalf of The Society for Range Management.
  • Ecological Protection and Restoration Program Reduced Grazing Pressure in the Three-River Headwaters Region, China

    Zhang, L.; Fan, J.; Zhou, D.; Zhang, H. (Society for Range Management, 2017)
    The Ecological Protection and Restoration Program (EPRP), initiated in 2005 in the Three-River Headwaters (TRH, the headwaters of the Yangtze, Yellow, and Lantsang rivers) region, is the largest project for nature reserve protection and reconstruction in China. This massive effort was expected to improve the trade-off between grassland productivity and grazing pressure in the region. However, the impacts of EPRP on forage supply and livestock carrying capacity remain poorly understood. Using the Global Production Efficiency Model and grazing pressure index, we investigated the influences of the EPRP by comparing the grassland yield and grazing pressure index before (1988-2004) and after (2005-2012) implementation of the program. Vegetation cover, represented by the annual maximum Normalized Difference Vegetation Index (NDVI), increased by 11.2% after implementation of the EPRP. The increase of NDVI, together with increasing temperature and precipitation, led to a 30.3% increase of the mean annual grassland yield in 2005-2012 relative to that in 1988-2004 (694 kg ha-1 vs. 533 kg ha-1 dry matter). We show that grazing pressure was largely alleviated by the EPRP due to increased grassland yield and decreased livestock number. This was indicated by a 36.1% decline of the grazing pressure index. The effects of the EPRP varied spatially. As examples, there were larger increases of grassland yield in the southeast of the region dominated by alpine meadow and greater reduction of grazing pressure in the central and eastern parts. Nevertheless, the ecological effectiveness of the EPRP may vary with the measures used and is indicated to be coupled with climate change. This calls for more detailed comparison and attribution analyses to predict the ongoing consequences of the EPRP in order to attain sustainable implementation of restoration practices in the TRH region. © 2017 The Society for Range Management. Published by Elsevier Inc. All rights reserved.
  • Hedonic Pricing of Grass-Fed Cattle in Uruguay: Effect of Regional Resource Endowments

    Lanfranco, B.A.; Castaño, J.P. (Society for Range Management, 2017)
    A hedonic model of feeder and replacement cattle prices in Uruguay was specified to include both permanent agroecological factors (soil productivity and water holding capacity [WHC]) and nonpermanent factors (season, available soil moisture, and pasture conditions) as explanatory variables. Results indicate that predominant agroecological endowments (soil characteristics, water availability, and average seasonal climatic conditions) determine geographic price patterns for cattle produced under extensive production systems. In addition, weather variability and especially extreme events have an important impact on short-run cattle markets. As pasture conditions improve or precipitation increases (e.g., both soil moisture and surface runoff), livestock prices tend to fall, ceteris paribus. A cattle price gap between different regions of Uruguay based on permanent resource endowments (e.g., soil productivity and WHC) and temporary agroecological conditions exists and is illustrated using a series of iso-price maps. The hedonic price model also included various cattle characteristics and marketing conditions as explanatory variables. Grass-fed cattle in Uruguay are not a homogeneous commodity; video auction prices incorporate information about a range of agroecological factors that influence cattle production, marketing patterns, as well as perceived and actual cattle quality and performance. © 2017 The Society for Range Management. Published by Elsevier Inc. All rights reserved.
  • Targeted Sheep Grazing to Suppress Sulfur Cinquefoil (Potentilla recta) on Northwestern Montana Rangeland

    Mosley, J.C.; Frost, R.A.; Roeder, B.L.; Kott, R.W. (Society for Range Management, 2017)
    Sulfur cinquefoil (Potentilla recta L.), a perennial forb native to the eastern Mediterranean region of Eurasia, is a major noxious weed on rangelands of the northwestern United States and southwestern Canada. We assessed targeted sheep grazing to suppress sulfur cinquefoil in a 2-yr rangeland field experiment in northwestern Montana. We evaluated targeted sheep grazing with and without protein-energy supplementation (37 g crude protein [CP] sheep-1 d-1 and 0.17 kg total digestible nutrients [TDN] sheep-1 d-1) during late June (sulfur cinquefoil in early flowering stage) and mid-July (sulfur cinquefoil in late flowering-early seedset stage). Sheep readily consumed sulfur cinquefoil stems, leaves, flowers, and developing seed heads, with or without supplementation. Sulfur cinquefoil comprised the largest proportion of sheep diets during both late June and mid-July, averaging 46%, but more sulfur cinquefoil dry matter (DM) was consumed by sheep during mid-July (0.6 vs. 1.0 kg DM sheep-1 d-1 in June vs. July, respectively). Supplementation did not increase DM intake (DMI) of sulfur cinquefoil, nor did supplementation improve the nutritive quality of sheep diets. We also documented that 1) targeted sheep grazing achieved heavy utilization of sulfur cinquefoil (67%) while keeping perennial graminoid use light to moderate (18-41%); 2) targeted sheep grazing reduced viable seed production of sulfur cinquefoil by 97% in June-grazed paddocks and 95% in July-grazed paddocks; and 3) targeted sheep grazing reduced sulfur cinquefoil yield the next summer by 41% in June-grazed paddocks and 47% in July-grazed paddocks without decreasing yield or plant community composition of perennial graminoids. We conclude that supplemented or nonsupplemented targeted sheep grazing applied in either late June or mid-July can effectively suppress sulfur cinquefoil. Sheep nutrition and sulfur cinquefoil DMI will be optimized by targeted sheep grazing applied during mid-July. © 2017 The Society for Range Management. Published by Elsevier Inc. All rights reserved.
  • Ring-Necked Pheasant Use of Post - Conservation Reserve Program Lands

    Geaumont, B.A.; Sedivec, K.K.; Schauer, C.S. (Society for Range Management, 2017)
    The Conservation Reserve Program (CRP) has provided millions of ha of cover for numerous wildlife species. Many CRP contracts have expired or will expire, resulting in the loss of critical wildlife cover. The purpose of the current study was to evaluate the potential response of ring-necked pheasant (Phasianus colchicus) to future changes in land use. We selected four land uses that may potentially occur on CRP lands being converted back to agriculture: 1) season-long grazing, 2) hay land, 3) no-till corn (Zea mays), and 4) no-till barley (Hordeum spp.). As a control, 32 ha of CRP grasslands were left idle to mimic land in CRP. Using data from 193 ring-necked pheasant nests, we found nest density was different among land uses (P < 0.01). The control and season-long grazing treatment did not differ from one another (P = 0.42; 0.43 and 0.24 nests-ha-1, respectively), but both had greater nest densities than no-till corn and no-till barley treatments (P < 0.01; 0.04 and 0.03 nests-ha-1, respectively). The nest density in the hay treatment (0.16 ± 0.04 nests-ha-1) and control were different (P = 0.02). Ring-necked pheasant nest site selection was influenced by visual obstruction and vegetation height as hens chose nest sites with taller vertical structure and vegetation heights. Daily survival rates of nests were not influenced by treatment but did increase with greater visual obstruction, increased as a nest aged and throughout the nesting season, and were negatively affected by precipitation events. Our results suggest that maintaining CRP-type grasslands will be beneficial for ring-necked pheasants because of the nesting cover they provide. However, the conversion of CRP to livestock production may be a viable option that provides nesting opportunities for ring-necked pheasant, given vertical structure is available for nesting hens. © 2017 The Society for Range Management. Published by Elsevier Inc. All rights reserved.
  • Energy Disturbance and Productivity of Mule Deer Habitat in Sage-Grouse Core Areas

    Gamo, R.S.; Beck, J.L. (Society for Range Management, 2017)
    Anthropogenic development impacts habitat use by many rangeland species including mule deer (Odocoileus hemionus). Recent policies, including Wyoming's Sage-Grouse Executive Order, have been implemented to conserve habitat and populations of greater sage-grouse (Centrocercus urophasianus). Core Areas (CAs), designated for sage-grouse conservation by the Wyoming policy, are likely less disturbed than non - CA, predictably providing protection for nontarget species, such as mule deer, that share substantial habitat with sage-grouse. Our objectives focused on examining the influence of Wyoming's CAs on mule deer including 1) quantifying oil and gas development within crucial winter range and Hunt Areas (HAs) with respect to CA overlap and 2) using fawn-to-female ratios (fawns · 1 adult female-1) to evaluate whether deer populations overlapping CAs were more productive. We used oil and gas well data from the Wyoming Oil and Gas Conservation Commission and fawn-to-female ratios for 103 mule deer HAs derived from Wyoming Game and Fish Department data across designated mule deer crucial winter ranges (1980-2013) and statewide mule deer HAs (1995-2013). Numbers and trends in well pads were lower within CA-overlapped deer winter range than non - CA-overlapped winter ranges during 1980-2013. Mule deer HAs overlapped by CAs also displayed lower trends of well pads as the percentage of CA overlap increased. Trend in fawn-to-female ratios (mean = 0.69, range: 0.55-0.83) was higher in HAs with ≥70% CA overlap compared with a slight but significant negative trend in fawn-to-female ratios (mean = 0.64, range: 0.53-0.73) in HAs with no CA overlap (≤1%) from 1995-2013. HAs with CA overlap ≥ 70% exceeded 0.66 fawns-to-female, a threshold indicative of an increasing population. The relative change in fawn-to-female ratios has important implications to conservation of mule deer populations. © 2017 The Society for Range Management Published by Elsevier Inc. All rights reserved.
  • Evaluation of Plasma Cholinesterase Activity in Native Birds from Pesticide-Exposed Agricultural Lands

    Ruvalcaba-Ortega, I.; León, M.B.D.; Mendiola-Castillo, S.; González-Escalante, L.; Canales-Del-Castillo, R.; Mercado-Hernández, R.; Guzmán-Velasco, A.; González-Rojas, J.I. (Society for Range Management, 2017)
    Wildlife near agricultural lands is exposed to pesticides, particularly organophosphorus and carbamates, where birds appear to be more sensitive to their toxic effects than other vertebrates. One of the main effects of pesticides is the disruption of the nervous system through the inhibition of cholinesterase enzymes. The aim of this study was to determine the plasma cholinesterase activity in native birds of pesticide-exposed agricultural lands within the Grassland Priority Conservation Area El Tokio, located in northeastern Mexico. The study was conducted during three summer seasons (2008-2010), when the reproduction of birds and pesticide spraying occurred. Forty-four birds of 13 different species were captured, sampled, and released. High variability values among individuals and species were found, ranging from 0.200 ± 0.055 to 4.960 ± 0.150 μmol/min/L. White-winged doves' values were significantly smaller than basal reference, showing 29-49% of plasma cholinesterase inhibition and possible pesticide exposure. Mean plasma cholinesterase activity values for 10 of the species had not been reported previously. These data can serve for future interpretations of plasma cholinesterase activity values in wild birds within agricultural lands and for decision making in priority conservation areas. © 2017 The Society for Range Management. Published by Elsevier Inc. All rights reserved.
  • Arthropods and Fire: Previous Research Shaping Future Conservation

    Kral, K.C.; Limb, R.F.; Harmon, J.P.; Hovick, T.J. (Society for Range Management, 2017)
    Fire is a natural process in grasslands that maintains an open canopy and creates variable vegetative structure and composition over time. Although there is a wealth of knowledge on plant and avian responses to fire in the Great Plains, there are few generalizations for arthropods. We conducted a literature review to synthesize research on arthropod responses to fire in the Great Plains to offer more insights to land managers, policy makers, and researchers. Overall, we found that there was variation in how arthropod communities responded to fire; metrics of both abundance and diversity were found to respond positively, negatively, or not at all. We then delved into two potential factors that might help us understand this important variation. First, we looked for effects from the amount of time since fire. Although much of the literature focused on arthropod responses to burning in the first 6 mo after fire, there were still both positive and negative results regardless of timeframe. We also hypothesized that taxonomy may provide insights and found that some orders tended to respond negatively (Araneae, Lepidoptera) or positively (Coleoptera, Orthoptera) to fire; however, responses were still variable and likely dependent on additional factors. To help enable managers to make better decisions about fire application, we used the literature to identify three traits-mobility, life stage, and feeding guild-that can predict responses to fire at a species level when research is lacking. Management recommendations vary on a species-by-species basis, but available research suggests that arthropod communities do not simply respond negatively to fire. Knowledge gaps remain concerning the origin of those community responses, particularly in terms of individual species' responses and specific mechanisms that allow individuals to persist after fire. Future research should focus on theoretical and applied basis for arthropod conservation using prescribed fire. © 2017 The Society for Range Management. Published by Elsevier Inc. All rights reserved.
  • Effectiveness of Burning, Herbicide, and Seeding Toward Restoring Rangelands in Southeastern North Dakota

    Link, A.; Kobiela, B.; Dekeyser, S.; Huffington, M. (Society for Range Management, 2017)
    Many rangelands in southeastern North Dakota are invaded by Kentucky bluegrass (Poa pratensis L.) and/or smooth brome (Bromus inermis Leyss.). It may be especially difficult for native species to reestablish in rangelands dominated by Kentucky bluegrass and/or smooth brome due to these species' competitive advantages. Relatively few studies have specifically compared the effectiveness of methods intended to reduce competition from Kentucky bluegrass and/or smooth brome before seeding with native species in southeastern North Dakota. In our current study, we evaluated the effects of five restoration treatments: 1) control (no seeding or competitionreduction treatments), 2) interseed (native seeds drilled into the existing plant community), 3) spring burn before drill seeding native species, 4) glyphosate application before drill seeding native species, and 5) spring burn plus glyphosate application before drill seeding native species on a degraded rangeland plant community. We installed the five treatments in fifteen 40 × 100 m plots in 2010. In 2015, we sampled the vegetation within each plot to determine whether the restoration methods increased total and/or native warm-season grass biomass, reduced Kentucky bluegrass and/or smooth brome biomass, or increased grass species richness. Although none of our restoration treatments impacted Kentucky bluegrass biomass, each of our restoration treatments increased grass species richness over the control. Including a glyphosate application before seeding with natives also increased total biomass, reduced smooth brome biomass, and increased native warm-season grass species richness. Thus, we suggest that the glyphosate application was a worthwhile addition at this location because it resulted in additional improvements to the invasive-dominated plant community. © 2017 The Society for Range Management. Published by Elsevier Inc. All rights reserved.
  • Using Activated Carbon to Limit Herbicide Effects to Seeded Bunchgrass When Revegetating Annual Grass-Invaded Rangelands

    Davies, K.W.; Madsen, M.D.; Hulet, A. (Society for Range Management, 2017)
    Revegetation of exotic annual grass - invaded rangelands is challenging as annuals rapidly reinvade after control treatments. The most effective control of exotic annual grass is usually achieved with pre-emergent herbicides; however, species seeded simultaneously with these herbicides will likely experience nontarget damage. Thus, seeding often occurs 1 yr later to reduce herbicide effects to seeded vegetation, but by this time annual grasses may already be reinvading and limiting revegetation success. Activated carbon can be used to protect seeded species from herbicide damage because it has a high absorption capacity that can deactivate many herbicides. A pot study in a grow-room suggested that a pod containing activated carbon and seeds, herbicide protection pods (HPPs), may allow desired species to be seeded simultaneously with annual grass control with the preemergent herbicide imazapic. However, HPPs have not been field tested. We evaluated two seeding treatments (crested wheatgrass (Agropyron desertorum [Fisch.] Schuft.) incorporated into HPPs and bare seed, simultaneously with an imazapic application to control annual grasses at two sites invaded by cheatgrass (Bromus tectorum L.) and medusahead (Taeniatherum caput-medusae [L.[ Nevski). Crested wheatgrass abundance was 300% greater with HPPs compared with bare seed in late June. Imazapic application reduced exotic annual grass density at both sites by approximately half. These results suggest that HPPs can be used to allow desired species to be seeded simultaneously with imazapic application. This will allow seeded species a longer window to become established before experiencing pressure from exotic annuals and enable a single-entry approach compared with multiple entries currently employed to revegetate annual grass - invaded rangelands. Though further field testing is needed, in particular with multiple species and higher herbicide applications rates, these results suggest that HPPs could improve our ability to restore and revegetate exotic annual grass - invaded rangelands. © Published by Elsevier Inc. on behalf of The Society for Range Management.
  • Understory Plant Community Responses to Fuel-Reduction Treatments and Seeding in an Upland Piñon-Juniper Woodland

    Havrilla, C.A.; Faist, A.M.; Barger, N.N. (Society for Range Management, 2017)
    Woody plant expansion and infilling into nonwooded rangeland ecosystems have been observed worldwide. Such expansion may lead to declines in herbaceous understory plant communities and increased fuel loads in rangelands. Under the US National Fire Plan, fuel-reduction treatments have been implemented over vast expanses of western forest types to reduce the risk of catastrophic wildfire and restore historical ecosystem structure, function, and diversity. The benefits of fuel-reduction may, however, also carry inherent ecological risk such as promoting non-native species colonization. Here, we compare understory plant community responses to three commonly used fuel-reduction treatments with seeding applications in an upland piñon (Pinus edulis Engelm.)- juniper (Juniperus osteosperma [Torr.] Little) woodland on the Colorado Plateau: 1) mechanical mastication, 2) lop and slash piled then burned (pile burn), and 3) lop and scatter followed by a broadcast burn (broadcast burn). Data were collected pretreatment (2009) and one (2010), two (2011), and six (2015) growing seasons post treatment. We found while understory perennial herbaceous plant cover remained low 1 and 2 yr post treatment, it increased by > 700% in all fuel-reduction treatment plots six growing seasons post treatment. Furthermore, while we observed minor increases in invasive annual grass, Bromus tectorum L. (cheatgrass), colonization in 2010 and 2011, there were substantial increases in B. tectorum cover by 2015. B. tectorum cover varied among treatments with the greatest cover in the unseeded mastication plot at nearly 30%. Seeding applications did not increase overall seed mix species cover but enhanced seed mix species richness and, thus, may have increased resistance to B. tectorum invasion in seeded treatment plots. Our findings offer valuable insights to the ecological consequences of fuel-reduction activities in piñon-juniper woodlands through comparison of common fuel-reduction treatments and seeding applications and highlight differences in understory plant community responses to treatments across short to longer time scales. © 2017 The Society for Range Management. Published by Elsevier Inc. All rights reserved.
  • Influence of Soil Color on Seedbed Microclimate and Seedling Demographics of a Perennial Bunchgrass

    Boyd, C.S.; Davies, K.W.; Lemos, J.A. (Society for Range Management, 2017)
    Perennial bunchgrasses are critical to maintaining sagebrush plant communities, but seeding of native bunchgrasses following fire has had limited success. Previous research indicated that blackened soils beneath burned sagebrush canopies have increased bunchgrass seeding success when compared with interspace locations. We investigated soil moisture and temperature across white, neutral, and black soils and tested the relationship between soil color and seedling demographics for bluebunch wheatgrass. We used a randomized block design with three treatments and five replications conducted in a Wyoming big sagebrush community in southeast Oregon. The study site was rototilled before establishing 50 × 50 cm plots in each of 2 yr. We installed soil temperature/ moisture probes at 3-cm depth in each plot. Plots were seeded in November of each year with 125 viable seeds and covered in a < 1-mm layer of white, brown, or black aquarium sand. We counted emergent seedlings weekly through May of the year following planting. Soil moisture during the emergence period (March-May) was highest for white soils and lowest for black or neutral soils (P < 0.001); soil temperature was highest for black or neutral soils and lowest for white soils (P < 0.001). Year 1 was characterized by a relatively warm and dry emergence period, and year 2 was relatively cool and moist. Emergent seedling density was highest (P < 0.05) for white soils; surviving seedling density (on June 1) was highest (P < 0.05) for white soils in year 1 and black soils in year 2. Black soils had greater success in a year with lower soil temperatures and adequate soil moisture. When soil moisture was limited, and spring temperatures warmer, increased soil temperature on black soils led to seedling desiccation and death. © Published by Elsevier Inc. on behalf of The Society for Range Management.
  • Comparison of Postfire Seeding Practices for Wyoming Big Sagebrush

    Ott, J.E.; Cox, R.D.; Shaw, N.L. (Society for Range Management, 2017)
    Wildfires in the Great Basin have resulted in widespread loss of Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle &amp; Young), an ecologically important shrub that has proven difficult to establish from seed. We sought to identify optimal seeding practices for Wyoming big sagebrush in the context of postfire seeding operations involving rangeland drills. In an experiment replicated at three burned sites in the northern Great Basin, we compared Wyoming big sagebrush establishment across treatments differing by seed delivery technique, timing, and rate of seed application. A seed mix containing bunchgrasses was drill-seeded in alternate rows using one of two drill-types (conventional or minimum-till), and a mix containing sagebrush was either delivered by drill to the soil surface in remaining rows or broadcast by hand (simulating aerial seeding) following drilling in fall or winter. Drill-delivery of sagebrush seed was accompanied by drag chains (conventional drill) or imprinter wheels (minimum-till drill) to improve seed-soil contact and was carried out at multiple seeding rates (ca. 50,250, and 500 pure live seed m-2). During 2 yr following seeding, sagebrush establishment was lower at two sites (yr 1: ≤ 1.2 plants m-2; yr 2: ≤ 0.8 plants m-2) compared with a third site (yr 1: ≤ 4.1 plants m-2; yr 2: ≤ 2.0 plants m-2) where treatment differences were more pronounced and significant. Wherever density differed between treatments, it was consistently higher in certain treatment levels (minimum-till &gt; conventional drill, drill-delivery &gt; broadcast-delivery, fall broadcast &gt; winter broadcast, and higher rates &gt; lower rates). Densities declined between years at two sites, but we did not find evidence that declines were due to densitydependent mortality. Results indicate that seeding success can likely be enhanced by using a minimum-till imprinter seeding method and using seeding rates higher than typical postfire seeding recommendations for Wyoming big sagebrush. © Published by Elsevier Inc. on behalf of The Society for Range Management.
  • Seed Production Estimation for Mountain Big Sagebrush (Artemisia tridentata ssp. vaseyana)

    Landeen, M.L.; Allphin, L.; Kitchen, S.G.; Petersen, S.L. (Society for Range Management, 2017)
    Seed production is an essential component of postdisturbance recovery for mountain big sagebrush (Artemisia tridentata Nutt, ssp vaseyana [Rydb] Beetle; MBS). We tested a method for rapid estimation of MBS seed production using measurements of inflorescence morphology. We measured total stem length, stem length from first branchlet to stem tip, stem diameter, fresh weight, and number of stem branchlets for 750 inflorescences collected from five central and southern Utah sites. Florets per inflorescence were counted to provide an estimate of seed production potential. We used regression analysis to assess associations between morphological traits and potential seed production and evaluated the efficiency and scalability of each measure for field application. Site means for morphological measures varied ∼2 to 11-fold while mean number of florets per inflorescence varied ∼ 8-fold. Inflorescence weight was the best predictor of seed production potential (P &lt; 0.0001, r2 = 0.897), although correlations for all tested variables were highly significant. Among-site differences in regression equations for this relationship were not significant (P = 0.226), suggesting that a single conversion factor may have broad application. However, validation will require additional testing across a broader range of sites and field conditions. Scalable methods for efficient estimation of sagebrush seed production potential, such as those evaluated in this study, could be useful for managers charged with assessing variability in sagebrush community stability. © 2017 The Society for Range Management. Published by Elsevier Inc. All rights reserved.
  • Effect of Environmental Factors on Germination of Salsola foetida: Potential Species for Rehabilitation of Degraded Rangelands

    Hanif, Z.; Naeem, M.; Ali, H.H.; Tanveer, A.; Javaid, M.M.; Peerzada, A.M.; Chauhan, B.S. (Society for Range Management, 2017)
    Information relating to germination and seedling emergence of a plant aids in determining the species potential distribution and also helps in designing appropriate plant management strategies within an agroecosystem. Salsola foetida Del. ex Spreng, a naturally occurring perennial shrub, is traditionally used as a medicinal plant and a promising camel fodder in the hypersaline, semiarid, and arid areas across the globe. A series of laboratory and greenhouse experiments were conducted to determine the effect of various environmental factors such as temperature, light, salinity, osmotic stress, pH, and seed burial depth on seed germination and seedling emergence of S. foetida. A decline in germination was observed with increases in temperature. The maximum germination of 95% was observed at 25/15°C followed by 83% at 30/20°C; however, minimum germination (35%) was observed at 40/30°C. Maximum seed germination (95%) was observed under 24-h darkness while a decrease in germination (72%) was recorded when seeds were kept in 24-h light. Under saline conditions, 67% of seeds germinated at 100 mM sodium chloride (NaCl) and germination decreased to 12% with an increase in salinity to 500 mM NaCl. The optimum pH for seed germination of S. foetida was 7 (97% germination), although 36% and 75% of seeds germinated at the pH levels of 5 and 10, respectively. About 5% of seeds germinated at an osmotic potential of - 0.8 MPa compared with 40% at - 0.2 MPa. However, seeds of S. foetida were found sensitive to increased burial depth. The maximum germination was observed at the soil surface, and emergence inhibited completely from the seeds buried at the 5-cm depth. The high germination ability of S. foetida over a wide range of environmental factors suggests that this species is likely to thrive easily under harsh arid conditions. Therefore, it is used as a potential candidate for the rehabilitation of rangelands and will be helpful in mitigating the adverse effect of climatic changes on humans and livestock in the degraded areas. © 2017 The Society for Range Management. Published by Elsevier Inc. All rights reserved.
  • Integrating Remotely Sensed Imagery and Existing Multiscale Field Data to Derive Rangeland Indicators: Application of Bayesian Additive Regression Trees

    McCord, S.E.; Buenemann, M.; Karl, J.W.; Browning, D.M.; Hadley, B.C. (Society for Range Management, 2017)
    Remotely sensed imagery at multiple spatial scales is used increasingly in conjunction with field data to estimate rangeland indicators (e.g., vegetation cover) and meet the growing need for landscape-scale monitoring and assessment of rangelands. Remote sensing studies that produce rangeland indicators often require intensive and costly field-data collection efforts to produce accurate model predictions. Existing monitoring data, such as those collected by the Bureau of Land Management's Assessment, Inventory, and Monitoring (AIM) program, are potentially useful sources of field data in remote sensing modeling studies. Given their data-hungry nature, common regression tree - based modeling approaches may be inadequate for reliably predicting rangeland indicators with the smaller sample sizes of AIM data than typically used for remote sensing studies. Current literature suggests that Bayesian models, such as Bayesian additive regression trees (BART), may provide a suitable alternative to traditional regression tree - based modeling approaches to overcome the sample size limitation of the AIM data. In this study, we used 182 AIM field plots together with both high (RapidEye) and moderate (Landsat OLI) spatial resolution satellite imagery to predict bare ground and bare soil, total foliar, herbaceous, woody, and shrub cover indicators on rangelands in a 14 625-km2 area of northeastern California. We demonstrate that a BART model performed similarly to other regression tree approaches when field data and high spatial resolution imagery predictions were combined to predict indicator values using the medium spatial resolution Landsat image. The BART models also provided spatially explicit uncertainty estimates, which allow land managers to more carefully evaluate indicator predictions and to identify areas where future field data collection might be most useful. This study demonstrates that existing field data and freely available, remotely sensed imagery can be integrated to produce spatially explicit and continuous surface estimates of rangeland indicators across entire landscapes. © Published by Elsevier Inc. on behalf of The Society for Range Management.