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Endangered species laws seek to prevent extinction by outlawing actions that may cause harm or lead to extinction. In doing so, these laws are sometimes criticized for limiting management flexibility and subjecting landowners to regulatory burdens. One proposed solution to this challenge is development of payment for ecosystem service (PES) programs. These programs provide an economic incentive to conserve endangered species by compensating landowners for the costs of conservation or forgoing other profitable uses of land and resources. To assess the utility of PES as a means of overcoming opposition to endangered species regulations, we surveyed ranch operators in Arizona and New Mexico facing new regulations related to endangered jaguars (Panthera onca). Our findings suggest that PES cannot overcome the perceived burdens of species protection regulations and are unlikely to increase collaboration between landowners and government agencies. PES approaches are only likely to succeed where there is strong fit between institutional design and resource manager preferences. In the context of endangered species, PES proponents must pay particular attention to institutional arrangements that reduce concerns about regulatory risk. To this end, to effectively meet endangered species conservation goals, we recommend: 1) framing PES programs as voluntary conservation incentives, 2) focusing incentives on healthy ecosystems rather than a single species, and 3) using private funding to support incentives. Under these circumstances, PES may be an effective endangered species conservation tool.

In the Desert Grassland, second and subsequent defoliations on perennial grasses during the active growing season can have substantial impacts on grass recovery and reproduction following herbivory. Land managers implement tactics to avoid multiple defoliations on plants by way of rotational grazing, reduced stocking rates, and/or reduced time spent within a given pasture. We explored frequency and rate of defoliation by cattle on perennial bunchgrasses within an 11-day grazing period in three pastures including distance to water (300 and 600 m) and plant height to determine their influence on animal diet selection. Results indicate that 32% of all marked plants were defoliated by cattle and only 5% of defoliated plants were defoliated a second time by day 10 of the grazing period. Defoliation patterns in the studied pastures did not differ between two distances from water, or in relation to plant height. However, at the second defoliation cattle grazed plants that were shorter than at the first defoliation suggesting a selection for high quality re-growth over larger forage on offer. The results of this study show that a 10-day grazing period during the growing season of the Desert Grassland is an effective strategy to avoid second defoliations on individual perennial grass plants while maintaining sufficient forage for use during the dormant winter grazing season.

In the western United States, the management and use of public lands for livestock grazing is a frequent source of conflict among environmentalists, federal agencies, and ranchers. Since at least the early 1980s, the rhetoric of the “sagebrush rebellion” has reinforced a public perception that ranchers are both antigovernment and anticonservation. Sustainable management of public lands used for livestock grazing depends on both federal agency personnel, who enforce regulations, and ranchers, who use the land and implement management plans on a day-to-day basis. As a result, the attitudes of ranchers toward conservation can have a significant impact on the overall ecological health of public rangelands. We conducted a study of ranchers in southeastern Arizona and southwestern New Mexico using Q Methodology to understand their views and motivations about ranching, conservation, and the government. Our results show three complex viewpoints, which we term radical center ranchers (20% of variance), innovative conservationists (19% of variance), and traditional ranchers (12% of variance). A commitment to conservation and corresponding lack of anticonservation sentiment is held across these viewpoints. Mistrust of government coexists with conservation values for two groups. This information is useful for finding common ground between ranchers and government officials, conservationists, and extension agents on range management and conservation goals.

Observation is a simple method of acquiring information and is a critical step in the scientific method for both developing and investigating testable hypotheses. Cameras have long played a role in observation, and as technology advances, new tools and methods for collecting, interrogating, and displaying large quantities of high-resolution images have evolved. We describe an automated digital time-lapse camera system and present an example field deployment to observe the temporal and spatial patterns of riparian use by humans and animals during a 3-mo period. We also describe software tools for image interrogation and visualization, as well as new information gathered through their use. The system was tested in 2014, in a 2.4-ha site within the Apache-Sitgreaves National Forest in east central Arizona, United States where elk (Cervus elaphus nelsoni) and cattle grazed. Photographs were taken every 30 sec for 38 d, afterwhich an electric fencewas installed to restrict cattle access and the time s...

On the Ground Rangelands provide a wide array of ecosystem services — the direct benefits people receive from nature. There is increasing interest by policymakers and conservationists in managing for these ecosystem services. Because of complex land tenure arrangements in the Intermountain West, it is important to understand the impacts of federal resource management laws on ecosystem services flowing from public and private lands. All major federal land management laws are supportive of managing for ecosystem services. We review the implications of FLPMA, NFMA, NEPA, ESA, and CWA on ecosystem services on public and private lands.

On the Ground The designation of jaguar critical habitat in April 2014 in southern Arizona and southwestern New Mexico created concern for livestock ranchers in the region. We interviewed ranchers to understand their concerns with the jaguar critical habitat designation and their attitudes toward jaguars, wildlife conservation, and resource management in general. Ranchers we interviewed were concerned about direct impacts of designated critical habitat on ranching, as well as possible alternative agendas of critical habitat advocates and issues specific to the borderlands region. The ranchers were less concerned about the presence of jaguars but were more concerned about possible limiting effects of the Endangered Species Act (ESA), distrust of government entities, and litigious environmental groups. To maximize effectiveness, government agencies should work to foster trust in the ranching community, be cognizant of sensitive issues specific to the region that may challenge endangered species conservation...

In a previous article, Beschta et al. (Environ Manag 51(2):474-491, 2013) argue that grazing by large ungulates (both native and domestic) should be eliminated or greatly reduced on western public lands to reduce potential climate change impacts. The authors did not present a balanced synthesis of the scientific literature, and their publication is more of an opinion article. Their conclusions do not reflect the complexities associated with herbivore grazing. Because grazing is a complex ecological process, synthesis of the scientific literature can be a challenge. Legacy effects of uncontrolled grazing during the homestead era further complicate analysis of current grazing impacts. Interactions of climate change and grazing will depend on the specific situation. For example, increasing atmospheric CO₂ and temperatures may increase accumulation of fine fuels (primarily grasses) and thus increase wildfire risk. Prescribed grazing by livestock is one of the few management tools available for reducing fine fuel accumulation. While there are certainly points on the landscape where herbivore impacts can be identified, there are also vast grazed areas where impacts are minimal. Broad scale reduction of domestic and wild herbivores to help native plant communities cope with climate change will be unnecessary because over the past 20-50 years land managers have actively sought to bring populations of native and domestic herbivores in balance with the potential of vegetation and soils. To cope with a changing climate, land managers will need access to all available vegetation management tools, including grazing.

Beef and Beyond: Paying for Ecosystem Services on Western US Rangelands DOI:10.2458/azu_rangelands_v33i5_goldstein

AGWA: The Automated Geospatial Watershed Assessment Tool to Inform Rangeland Management DOI:10.2458/azu_rangelands_v33i4_goodrich

Rangeland monitoring often includes repeat photographs as a basis for documentation. Whereas photographic equipment and electronics have been evolving rapidly, photographic monitoring methods for rangelands have changed little over time because each picture is a compromise between resolution and area covered. Advances in image sensors, storage media, and image-processing software allow enormous amounts of information to be collected efficiently and inexpensively, so multiple pictures taken at full zoom can be combined into a single high-resolution panoramic image. This project was initiated to integrate very-high-resolution panoramic images with conventional rangeland monitoring methods addressing three resource management categories: riparian areas, wildlife, and invasive species.

Free-grazing ruminants forage in environments containing multiple levels of complexity; the forage selection process operates at the landscape scale, when selecting feeding sites, and at the plant part level when selecting actual bites. Pen trials have shown that livestock associate visual cues with feeding sites, however, no field study has shown that animals generalise from training with visual cues in pens in order to choose feeding sites in the field. Our study tested nine beef heifers’ ability to generalise a learned visual cue association to select feeding sites in a rangeland setting offering a novel forage, Lehmann lovegrass (LL). Initially, animals were trained to associate high quality feed with a visual cue during pen trials. We then tested animal response to the cue before and after they gained 14-day grazing experience with LL. Two identical field experiments (i.e., novel, before animals had experienced foraging LL versus familiar, after the animals had 14-day grazing experience with LL) were conducted over 3-day periods. Each experiment consisted of 27, 10-min trials. Animals were tested in plots containing high quality (HQ) and low quality (LQ) LL patches. For each trial, one of three randomly selected scenarios was presented: (1) the visual cue was placed in the HQ patch, (2) the visual cue was placed in the LQ patch, or (3) no visual cue was placed in either patch. Dependent variables were first patch-type chosen, bite rate in each patch, and number of observations of grazing in each patch. Cue presence influenced initial patch choice, bite rate, and grazing tallies within patch type. Heifers took 212 more HQ bites than LQ bites when the cue was placed in the HQ patch ( P P P

Social learning can be of critical importance to cattle grazing rangeland environments with high variability of food resources across space and time. Experienced individuals can greatly facilitate foraging decisions (what to eat and where to eat) of naïve peers in such settings. We conducted an experiment with cattle to investigate strength and persistence of socially induced food and feeding site avoidance behaviours. Sixteen naïve yearling steers were paired with 16 social models that had either not been trained (control) or been trained with an emetic (LiCl), electrical shock or both to avoid: (a) an unsafe high-quality food (LiCl); (b) an unsafe high-quality feeding site (shock); or (c) both the unsafe high-quality food and the unsafe high-quality feeding site (LiCl + shock). Ten-minute trials were conducted in an experimental arena containing three artificial feeding sites each consisting of groups of bowls with either high- (HQ) or moderate-quality (MQ) foods (HQ = barley and oat grain; MQ = Bermuda grass hay). Unsafe high-quality (UHQ, surrounded by traffic cones) and safe moderate-quality (SMQ) feeding sites consisted of nine rubber bowls containing either HQ or MQ foods. The safe high-quality (SHQ) feeding site consisted of two groups of eight bowls containing HQ food, which surrounded the UHQ and SMQ feeding sites. Social models did not induce diet and feeding site avoidance behaviours in naïve steers; they exerted small and transient changes in the feeding behaviour of their naïve counterparts. Consequences to the individual outweighed social influences; when naïve animals experienced the same punishment contingencies as their social models, their behavioural patterns closely resembled those of their social model. Conditioned food and location aversions via LiCl were apparently influenced by prior exposure to target foods and the experimental arena. Conversely, conditioned feeding site avoidance via shock was apparently not influenced by prior exposure to target foods or the experimental arena.

This study reports the results of a survey of Coronado National Forest grazing permittees about their attitudes regarding the Endangered Species Act (ESA) and the management of threatened and endangered (T&E) species on grazing allotments in southeastern Arizona. A majority of respondents perceived negative impacts from ESA implementation. However, the degree of impact remained independent of the number of listed species on allotments and of the potential for restrictions on those allotments. Perceptions of negative impact and attitudes toward T&E species policies were more related to attitudes toward federal regulation. Permittees broadly supported the idea of species conservation and expressed willingness to work with federal agencies but did not perceive the federal agencies as having the same responsiveness to their concerns. A more proactive agency strategy with science-based, focused recovery objectives coupled with economic incentives could improve support for species recovery efforts.

Ongoing conflicts over the management of western rangelands can be attributed in part to the lack of reliable information about current ecological conditions and their causes due, in turn, to insufficient monitoring. To meet the monitoring shortfall, land management agencies increasingly are enlisting permittees to monitor their grazing allotments. We surveyed grazing permittees in 5 Arizona counties and land management agency employees throughout Arizona to compare their attitudes toward permittee monitoring on public rangelands, the role of government in rangeland management, rangeland conditions in Arizona, and the credibility of information sources about rangelands. Permittees and agency employees differed in most of the attitudes measured by our survey. However, both populations agreed that permittees should participate in monitoring their allotments, and many respondents agreed with making permittee monitoring mandatory. Many respondents in both groups also agreed that collaboration can be beneficial. Joint monitoring, which can be considered a type of “joint fact-finding,” may help improve agency–permittee relationships and bridge the gap in attitudes and underlying values. Permittee-monitoring programs deserve careful evaluation to determine their impacts on social relationships, management decisions, and ecological conditions.

We evaluated Arizona Cooperative Extension's Rangeland Monitoring Program with the use of focus groups and a self-administered mail survey of grazing permittees and natural resource agency employees. Our primary objectives were to 1) determine whether Extension is reaching its target audience, 2) describe the monitoring practices and attitudes of permittees and agency staff, 3) determine whether there is a relationship between permittees' exposure to Cooperative Extension and their monitoring and management practices, and 4) identify the monitoring information needs and preferences of permittees and natural resource agency staff. We found that Arizona's rangeland monitoring Extension program has been effective in reaching a large part of its target audience, and a significant proportion of Arizona permittees monitor on public, private, and state-owned rangelands. However, overall monitoring adoption rates remain low. Extension contact is associated with use of monitoring and other beneficial mana...

Animals possess an external or skin-defense system that protects them from aggressions inflicted by predators, and an internal or gut-defense system that deters them from over-ingesting toxins. We conducted a study with cattle to investigate the relation between skin- and gut-defense systems and their influence on diet and habitat selection. Sixteen yearling steers were randomly assigned to one of four treatment groups and were exposed individually to an experimental arena during multiple 10 min trials during which they were allowed to select between an unsafe high quality habitat (UHQ) surrounded by traffic cones (visual cues), a safe, uncued high quality habitat (SHQ), or a safe, uncued moderate quality habitat (SMQ). Experimental habitats were made up of groups of bowls containing barley and oat grain (UHQ and SHQ habitats) or Bermuda grass hay (SMQ habitat). Treatments consisted of no aversions (control group), or of averted groups using: (a) electric shock; (b) lithium chloride (LiCl); or (c) both LiCl and electric shock. Steers in the shock group avoided UHQ almost completely, spending significantly less time there than control steers ( P< 0.05), but consumed as much HQ forage from SHQ habitat as control steers. Thus, steers in this group did not become averted to the HQ food in uncued locations. Moreover, location avoidance of steers in this group did not extinguish after shock collars were removed or when location of the UHQ habitat was switched. Steers in the LiCl group consumed significantly less HQ forage than control steers, both in UHQ habitat and SHQ habitat, and spent significantly less time than control steers in UHQ and SHQ habitats. Whereas food aversion remained unchanged during experimentation and extinction trials, location avoidance of steers in the LiCl group rapidly extinguished when location of habitats was switched. Thus, steers averted with LiCl avoided HQ food irrespective of its location or association with visual cues. Steers in the LiCl + shock group almost completely avoided HQ forage in UHQ and SHQ habitats and spent less time than the control steers in both of these

Field experiments were conducted at the University of Jordan Research Station at Al-Muwaqqar village to develop a simple technique for establishing Atriplex seedlings, and to evaluate the browse production under natural precipitation compared with shrubs receiving additional harvested water. Overall survival of the transplants after three growing seasons averaged 67% under strictly rainfed conditions compared to 95% when additional harvested water of 39 mm was applied. Production of grazable browse of 3-year old shrubs averaged 380 and 1151 kg DM (dry matter) ha −1 without and with additional water, respectively. Rain use efficiency averaged 1.14 and 4.48 kg DM ha −1 year −1 mm −1 for strictly rainfed conditions and additional harvested water, respectively. Intensity of cutting had a highly significant effect on the potential of shrub regrowth. Cutting shrubs at a height of 15 and 30 cm above ground level reduced regrowth substantially, whereas cutting at 45 cm enhanced the amount of regrowth. The different cutting intensities had no significant effect on survival of the severed shrubs, which indicates the high tolerance of saltbushes to cutting or browsing. Water-harvesting contour furrows are reasonable for establishing saltbush plantations in low rainfall areas (100–200 mm). Additional harvested water in small amounts from macro-catchements had a substantial effect on shrub survival, biomass production and water use efficiency.

The foliage of Atriplex halimus contained higher levels (P < 0.05) of ash (28.03%) than that of Atriplex nummularia (23.11%). Spring growth of the two saltbushes contained less ash than the fall regrowth. The foliage of A. halimus contained higher levels of macro-minerals than A. nummularia plants except sodium. The two saltbushes contained higher levels of P, K and Mg during spring, but lower levels of Ca and Na compared to the growth of the fall season. Levels of Fe, Cu, Mn and Se present in the foliage of A. nummularia plants were higher than A. halimus. Clipping had no significant effect on ash content of saltbushes, but it affected the composition of the ash significantly. Clipping decreased the concentrations of Ca, P, Na, Mg and Fe in the foliage of clipped shrubs. The mineral composition of the two species of Atriplex appeared adequate to meet the requirements of sheep and goats grazing such types of forage.

Construction of the Rangelands of the Western U.S. web site provides a dynamic model for information outreach. Central to its success is the collaboration between librarians, other information professionals, and rangeland experts committed to working together for a common goal: a selective, centralized, web-based resource designed to help meet the information needs of rangeland scientists, range professionals, students, faculty, ranchers, environmentalists, librarians, and other stakeholders. Begun over eight years ago by a University of Arizona AgNIC Project team, the effort is extending to include participation of range and information professionals from the other Western states. In addition to linking to existing digital content, the project seeks to create or support the creation of critical electronic information resources through an integrated user interface.

For more than six years, a multidisciplinary team at the University of Arizona, along with a variety of outside partners, have been developing a series of Web sites and Web modules on topics related to the management of western rangelands. This article describes collaborations that have led to the development of the Arizona Rangelands Web site. The site is organized around distinct modules that provide access to data and other information previously only available through agency or other technical specialists. Also described is a companion Web site, which provides a template for storage and retrieval of archived information central to the management of public land grazing allotments.

Through seeding and subsequent spread, Lehmann lovegrass Eragrostis lehmanniana Nees. has transformed the structure and function of at least 145 000 ha of semi-desert grassland in southern Arizona since its introduction in 1932. Our study of its spread on the Santa Rita Experimental Range since 1954 showed that by 1989 it was present on >85% of 75 relatively widely dispersed non-seeded permanent plots and accounted for >40% of all perennial grass plants on these plots. In addition, it represented >50% of the perennial grass plants on sites 90% of the grass biomass and produce 2–4 times more biomass annually than native grass vegetation. In the future, strong consideration of these plant composition changes, and the likely decrease in wildlife diversity and increase in fire frequencies accompanying Lehmann lovegrass dominance, should be made before seeding the species.

We tested the hypothesis that cattle aided by visual cues would be more efficient than uncued animals in locating and consuming foods placed in either fixed or variable locations within a 0.64-ha experimental pasture. Eight yearling steers were randomly selected and trained to associate traffic barricades and traffic cones with high- (oat–barley mixture) and low- (straw) quality foods, respectively. Initially steers were randomly assigned to 1 of 4 food location/visual cue treatments: fixed locations/with cues (F/C), variable locations/with cues (V/C), fixed locations/no cues (F/NC), or variable locations/no cues (V/NC). High- and low-quality foods and their respective cue (or no cue) were placed in the experimental pasture. Individual animals were allowed to explore the pasture for 10 min twice per day every other day for 1 week. Minutes until feeding, first feed type consumed (i.e., high-quality, low-quality, or no food consumed), animal location and activity (i.e., feeding, standing, or moving), and total intake of high- and low-quality feed were recorded during each 10-min trial. At the end of each week, location/visual cue treatments were randomly assigned to another 2 steers, which permitted an independent test of each animal in each treatment over a 4-week period. Animals in the F/C and V/C treatments took about 2 min to initially locate and consume a food, compared to F/NC and V/NC animals who took nearly 4 and 6 min, respectively. The high-quality food was the first food located and consumed by F/C, V/C, F/NC, and V/NC animals during 79, 77, 67, and 54% of sampling occasions, respectively. Cued animals typically spent more time feeding (P=0.0004) and less time standing (P=0.005) than uncued animals. Cued animals had a higher mean intake than uncued animals of high- (P=0.001) and low- (P=0.04) quality food. Mean high-quality intake for F/C, V/C, F/NC, and V/NC treatments was 266, 245, 214, and 126 (±22) g, respectively; mean low-quality intake for the same treatments was 36, 32, 12, and 10 (±10) g. Cued animals also consumed more food per distance traveled than uncued animals (P=0.005). Animals located food quicker (P=0.03) and consumed more high-quality food (P=0.02) when food locations were constant than when they were variable. Our data strongly indicate that cattle can learn to associate visual cues with disparate food qualities and use this information to forage more efficiently in both fixed and variable foraging environments.

Wired without the barbs: using the Internet for rangeland information. DOI:10.2458/azu_rangelands_v22i6_Hutchinson

The study was conducted at 3 locations in the arid region of Jordan to assess the seasonal changes of oxalate and tannins in Atriplex halimus L. and A. nummularia L. plants commonly used for revegetation of degraded rangelands. During spring and fall seasons, 20 shrubs of each species were selected randomly at each location, 20 similar twigs per shrub were clipped and analyzed for oxalate and tannins. Atriplex halimus contained higher levels of oxalate (7.00%) compared with A. nummularia plants (6.20%) (P < 0.001). Oxalate levels averaged 8.29 and 4.92% in spring and fall season, respectively. Plants of A. halimus accumulated more oxalate in spring than those of A. nummularia. Clipping had no effect on oxalate concentration. The seedlings of A. nummularia contained more oxalate than old plants whereas old shrubs of A. halimus contained more oxalate than the young seedlings. The browse of A. halimus contained more condensed and hydrolyzable tannins (1.05% and 0.67%, P < 0.0001) than A. nummularia (0.80% and 0.39%, P < 0.0001), respectively. Clipping had no effect on the levels of tannic phenols, condensed and hydrolyzable tannins. Young plants of the 2 species had higher levels of condensed tannins compared to older plants. However, seedlings of A. nummularia contained significantly higher levels of condensed tannins compared to A. nummularia seedlings (1.57% and 1.47%, respectively). Atriplex halimus synthesized more oxalate, tannic phenols, condensed and hydrolyzable tannins than A. nummularia. These secondary metabolites may explain the low palatability of Atriplex halimus compared to A. nummularia. DOI:10.2458/azu_jrm_v56i4_abu-zanat

The Walker Basin Allotment grazing system in central Arizona is designed to allocate resource use under elk (Cervus elaphus L.) and cattle (Bos taurus L.) grazing. The grazing system was designed to promote biologically acceptable levels of forage use on the half of the allotment scheduled for cattle grazing and to rest the other half by attracting elk to pastures recently grazed by cattle. The objectives of our 2-year study were to determine whether the grazing system facilitated proper forage use as defined by recent forage use and residual stubble height guidelines (i.e., 30 to 40% use and an 8- to 10-cm stubble height) and whether the system rested one half of the allotment from elk and cattle grazing. Mean (+/- SEM) total elk and cattle forage use for western wheatgrass (Pascopyrum smithii Rydb.), the key forage species, was 32 and 61% +/- 7 in 1997 and 1998, respectively; corresponding mean (+/- SEM) stubble heights were 11 and 10 cm +/- 0.6. Mean total cattle and elk forage use in 1998 (61%) exceeded the 30 to 40% use guidelines. However, mean end-of-year stubble height was never below 10 cm. The grazing system did not provide half the allotment with complete rest; elk used all study pastures. Elk use was higher in pastures with heavier tree cover and steeper terrain in both years, regardless of where cattle grazing occurred. Elk grazing patterns were apparently more dependent on tree cover and topography than any changes in forage caused by the grazing system. DOI:10.2458/azu_jrm_v55i4_halstead

Forage use data can help rangeland and wildlife managers make informed decisions. However, managers need to know if forage use techniques that are commonly used to estimate ungulate herbivory under field conditions produce comparable results. The objective of this 2-year study was to directly compare forage use measurements obtained via the paired-plot method and 2 height-weight methods (using on-site height-weight curves and the pre-established United States Forest Service height-weight gauge). In June, July, and October of 1997 and 1998, we measured forage use of western wheatgrass (Pascopyrum smithii Rydb.) by cattle (Bos taurus L.) and wild ungulates, mainly elk (Cervus elaphus L.). On-site height-weight curves and the USFS gauge consistently produced lower estimates (overall means = 8 and 7%, respectively) than the paired-plot method (overall mean = 31%). Height-weight estimates did not differ (P > 0.05) when calculated with either on-site curves or the USFS gauge. Within sampling areas, paired-plot estimates were relatively more precise (mean CV = 63%) than on-site curves (mean CV = 238%) or the USFS gauge (mean CV = 271%). Selective grazing likely contributed to higher CVs for height-weight techniques. Our findings are important for rangeland and wildlife managers because the forage monitoring technique they use may influence the results obtained and, consequently, grazing management and wildlife harvest decisions. Managers should ensure that chosen monitoring techniques provide an appropriate evaluation of management goals and objectives. DOI:10.2458/azu_jrm_v53i5_halstead

On semi-arid rangelands, stems and other standing dead material may accumulate in bunch-grasses and restrict access to new growth by grazing animals. We found that the presence and heights of residual stems in Lehmann lovegrass ( Eragrostis lehmanniana Nees) increased the times between successive bites taken by grazing cows, thus decreasing biting rates when compared to bites taken where these stems were reduced. As new tillers elongated, biting rates increased but remained lower on those plants with the greatest amounts of residual stems. Ingestive behavior of cows may be influenced by distinctive features of the vegetation available at each bite taken. The number of bites cows take on grass plants containing large amounts of residual herbage could influence the average biting rate during a foraging bout. Methods of collecting biting-rate data should account for these influences.

Effective natural resource management relies on accurate and timely information on the natural environment, which may be obtained by formal (“scientific”) or informal (“local” or “traditional”) methods. Formal monitoring methods are well documented and widely accepted among the rangeland science community, yet adoption by U.S. ranchers is inconsistent. In contrast, informal monitoring appears to be widely used by ranchers, but its practice and importance have rarely been documented or assessed. By interviewing ranchers and government agency personnel, we evaluated informal monitoring in and around the Altar Valley, Arizona, United States. Informal monitoring techniques included qualitative visual appraisals of forage quantity, indicator species and erosion, and incorporated local environmental history. The environmental knowledge embedded in informal monitoring was generally compatible with natural science. Informal monitoring was conducted continuously throughout the year and provided near real-time assessments that integrated observations of most land in individual pastures and ranches. In contrast, formal monitoring was generally performed only once per year, in a limited number of areas and with a delay of a few months between observation and completion of analysis. Thus informal monitoring had higher spatial coverage and temporal resolution and provided assessments faster than formal monitoring. Consequently, ranchers generally considered informal monitoring to be more relevant than formal monitoring to formulating yearly grazing plans and responding rapidly to unpredictable changes in the natural environment. Ranchers incorporated informal monitoring into assessments of rangeland trends and outcomes of conservation measures and thereby into choices of grazing system and planning of brush management and erosion control. Thus informal monitoring was foundational to long-term conservation, annual rangeland management planning, and adaptive natural resource management on subyearly timescales. If informal monitoring is of comparable utility in other rural communities, it would appear advantageous to document and evaluate informal approaches and to incorporate them into formal conservation planning.

(1) Density of jojoba (Simmondsia chinensis) was similar but plant size and cover were greater inside than outside a 48-year-old livestock exclosure in central Arizona. (2) Branch diagrams and destructive samples of ungrazed, moderately grazed and heavily grazed shrubs were taken over a 2-year period to determine twig responses to herbivory. (3) Twig growth was greatest in the spring while greatest herbivory occurred in late spring and summer after senescence of annual herbaceous plants. Grazed shrubs had greater twig growth than ungrazed shrubs resulting in similar net increases in twig length and biomass. The ability of jojoba to regrow from lower lateral or apical buds after removal of outer twig ends allows it to tolerate herbivory in the ecological context of the study site. (4) Grazed shrubs had lower male and female flower densities than ungrazed shrubs. (5) Periodic spring rest or control of stocking to limit grazing intensity is recommended to maintain shrub size and total production.

Jojoba (Simmondsia ch&sens&) is a major evergreen browse species for livestock and wildlife throughout its range from central Arizona to northwest Mexico and Baja California. Current guidelines for grazing management are based on utilization levels as estimited from determining the percentage of twigs grazed. Utlllzation can be estim8ted more 8ccurately from twig diameter masurements. On 3 sites in southern Arizona, leaf weight, stem weight and total weight were correlated witb tbe quare of twig internode diameter, h8ving average P values of 0.81,0.73, and 0.83, respectively, for small diameter twigs (I 3mm) most frequently browsed. Estimates of twig weight from regression quations for the 3 sites varied less than 0.3 g and low standard errors of estimate (10.33) indicate twig diameter measurements can give precise estimates of twig weight. Percent utilization of current yerr’s growth can be calculated from estimates of twig weight remaining and twig weight removed by grazing from diameter measurements at initiation of current year’s growtk and at the point of grazing, respectively. On 2 sites, mean grazed twigs and mean weight utilization were similar for skruks moderately grazed by cattle. However, regressions of weigkt utiliz8tion on percent twigl grazed indicated tbrt percent twigs grazed could overestimate weight utilization of total twigs and underestimate weight utilization of current year’s twigs, especially when utilization ia bigb. An alternative to basing management of jojob on time-consuming utilization measurements and 8rbitrary utilization limits is to monitor size of marked shrubs and manage for stable or gradually increasing shrub size.