Re-Envisioning Global Rangeland Stewardship: An Ecosystem Services Assessment Framework

Rangeland stewardship may be enhanced by transforming the global narrative from one of ‘resource scarcity and unpredictability’ to one of ‘global rangeland value’. This may be accomplished by devising a stewardship strategy founded on a more complete accounting of rangeland ecosystem services to inform land use planning and decision making. An ecosystem services framework may provide the necessary feedbacks to identify and assess potential tradeoffs among ecosystem services prior to implementing land use actions and policy. The ultimate goal of this alternative stewardship strategy would be to provide optimal combinations of ecosystem services to meet the needs of global citizens, while improving the well-being of millions of rangeland residents who are highly dependent upon provisioning services

Rangeland Systems: Processes, Management and Challenges

environmental management; environmental law; ecojustice; ecolog

Professional ecological knowledge: an unrecognized knowledge domain within natural resource management

Successful natural resource management is dependent on effective knowledge exchange and utilization. Local/traditional/indigenous knowledge derived from place-based experience and scientific knowledge generated by systematic inquiry are the most commonly recognized knowledge domains. However, we propose that many natural resource decisions are not based on local or scientific knowledge, but rather on a little recognized domain that we term professional ecological knowledge (PEK). Professional ecological knowledge is founded upon codification of broad ecological principles, but not necessarily scientific evidence, to legitimize agency programs, support operational efficiency, and encourage user compliance. However, in spite of these benefits, PEK may reduce program effectiveness by inhibiting the exchange of local and scientific knowledge and minimizing the development of evidence-based conservation. We describe what we consider to be common facets of PEK through case studies examining the sources of knowledge utilized by forestry agencies in India and by rangeland conservation programs of the USDA Natural Resource Conservation Service. Three propositions are presented regarding the origins and continued existence of PEK: (1) minimal information feedbacks regarding the efficacy of agency programs contributes to development of PEK; (2) a narrow scientific agenda and a perception that most scientific knowledge is not relevant to management decisions encourages a divide between scientists and managers; and (3) political interests often benefit from existing applications of PEK. By calling attention to the existence of PEK as a distinctive knowledge domain, we aim to encourage more explicit and critical consideration of the origins of knowledge used in environmental decision making. Explicit recognition of PEK may provide greater understanding of the dynamics of knowledge exchange and decision making in natural resource management

Adaptive, Multi-Paddock, Rotational Grazing Management: An Experimental, Ranch-Scale Assessment of Effects on Multiple Ecosystem Services

Decisions on how to move livestock in space and time are central to rangeland management. Despite decades of small-scale research, substantial uncertainty exists regarding the relative importance of cattle stocking rates per se, versus the movement of cattle in both space and time, in achieving desired vegetation and livestock outcomes at scales relevant to livestock producers. We report on a ranch-scale experiment comparing effects of collaborative, adaptive, multi-paddock, rotational management (CARM) versus more traditional, season-long, continuous rangeland management (TRM) on perennial grass density and production, cattle performance, and wildlife habitat, while holding the annual stocking rate the same in both systems. We collaborated with stakeholders to develop an adaptive grazing management plan, collected pre-treatment data in 2013, and implemented treatments during 2014 – 2020. Results for 2014 – 2018 were reported by Augustine et al. (2020); here we report on two additional years of results, covering a 7-year period of treatments from 2014 – 2020. With two additional years of measurements, we found no significant difference in total forage production in CARM vs. TRM treatments, averaged across all soil types in the experiment. In one year, we found that CARM increased forage production on loamy soils and decreased forage production on alkaline soils, but these differences were minor and in opposite directions, resulting in no net overall effect. Furthermore, we found that adaptive, rotational grazing management substantially reduced livestock weight gains in each of the first 6 years of the experiment, when cattle were managed as a single, large herd occupying each paddock sequentially. Across the 6 years, cattle weight gain averaged 15% lower in CARM vs. TRM. In the 7th year, stocking density in CARM was reduced 50% by giving cattle access to two paddocks at a time. This year also coincided with a drought. Under these conditions, cattle weight gains were identical in both treatments. Results emphasize the importance of replicated controls in assessing grazing management effects. Even in heterogeneous landscapes where livestock are moved adaptively among paddocks to match seasonal patterns of forage growth, such management may not lead to desired outcomes for vegetation and livestock

Adaptive Rotational Grazing and the Story of the Regrazed Grass Plant

Livestock stocking rates and decisions about how to move animals in time and space impact plant responses to livestock grazing. We report on a ranch-scale collaborative experiment comparing adaptive rotational grazing management to season-long continuous grazing during a 4.5-month grazing period during the growing season. As part of this project, stakeholders and scientists worked together to articulate their hypotheses about the mechanisms linking rotational grazing with expected vegetation outcomes. Several stakeholders expected rotational grazing to enhance the production and diversity of grazing-sensitive perennial grass species. The main hypothesized mechanism underlying this expectation was that rotation grazing should reduce regrazing of these grass plants. To test this hypothesis, we monitored patterns of grazing and regrazing on individual tillers (ramets) of a grazing-sensitive grass species, Pascopyrum smithii (western wheatgrass) for three consecutive years. We measured regrazing rates in paddocks managed using moderate stocking and adaptive rotational grazing as well as paddocks grazed continuously, season-long at light, moderate, or heavy stocking rates. Tillers in heavily grazed paddocks were regrazed more than three times as frequently as tillers in moderately grazed pastures, reinforcing the importance of stocking rate as a driver of vegetation impact. At the ranch-scale, tillers were regrazed equally often under adaptive rotational and season-long continuous grazing management, and this result did not vary across years. Adaptive rotational grazing greatly increased heterogeneity among paddocks in patterns of regrazing, with some paddocks experiencing high utilization and others experiencing low utilization. In this semi-arid rangeland, tiller defoliation data do not support the hypothesis that adaptive rotational grazing leads to less regrazing at the ranch-scale. In line with these mechanistic results, the production and diversity of grazing-sensitive perennial grasses also failed to respond to adaptive rotational grazing after five years. However, adaptive rotational grazing may enhance management flexibility and provide opportunities to work towards other objectives, such as wildlife habitat

Phenological Mismatch Between Season Advancement and Migration Timing Alters Arctic Plant Traits

Climate change is creating phenological mismatches between herbivores and their plant resources throughout the Arctic. While advancing growing seasons and changing arrival times of migratory herbivores can have consequences for herbivores and forage quality, developing mismatches could also influence other traits of plants, such as above‐ and below‐ground biomass and the type of reproduction, that are often not investigated. In coastal western Alaska, we conducted a 3‐year factorial experiment that simulated scenarios of phenological mismatch by manipulating the start of the growing season (3 weeks early and ambient) and grazing times (3 weeks early, typical, 3 weeks late, or no‐grazing) of Pacific black brant (Branta bernicla nigricans), to examine how the timing of these events influence a primary goose forage species, Carex subspathacea. After 3 years, an advanced growing season compared to a typical growing season increased stem heights, standing dead biomass, and the number of inflorescences. Early season grazing compared to typical season grazing reduced above‐ and below‐ground biomass, stem height, and the number of tillers; while late season grazing increased the number of inflorescences and standing dead biomass. Therefore, an advanced growing season and late grazing had similar directional effects on most plant traits, but a 3‐week delay in grazing had an impact on traits 3–5 times greater than a similarly timed shift in the advancement of spring. In addition, changes in response to treatments for some variables, such as the number of inflorescences, were not measurable until the second year of the experiment, while other variables, such as root productivity and number of tillers, changed the direction of their responses to treatments over time. Synthesis. Factors affecting the timing of migration have a larger influence than earlier springs on an important forage species in the breeding and rearing habitats of Pacific black brant. The phenological mismatch prediction for this site of earlier springs and later goose arrival will likely increase above‐ and below‐ground biomass and sexual reproduction of the often‐clonally reproducing C. subspathacea. Finally, the implications of mismatch may be difficult to predict because some variables required successive years of mismatch to respond