Scenario analyses have been used in multiple science-policy assessments to better understand complex plausible futures. Scenario archetype approaches are based on the fact that many future scenarios have similar underlying storylines, assumptions, and trends in drivers of change, which allows for grouping of scenarios into typologies, or archetypes, facilitating comparisons between a large range of studies. The use of scenario archetypes in environmental assessments foregrounds important policy questions and can be used to codesign interventions tackling future sustainability issues. Recently, scenario archetypes were used in four regional assessments and one ongoing global assessment within the Intergovernmental Science-Policy Platform for Biodiversity and Ecosystem Services (IPBES). The aim of these assessments was to provide decision makers with policy-relevant knowledge about the state of biodiversity, ecosystems, and the contributions they provide to people. This paper reflects on the usefulness of the scenario archetype approach within science-policy processes, drawing on the experience from the IPBES assessments. Using a thematic analysis of (a) survey data collected from experts involved in the archetype analyses across IPBES assessments, (b) notes from IPBES workshops, and (c) regional assessment chapter texts, we synthesize the benefits, challenges, and frontiers of applying the scenario archetype approach in a science-policy process. Scenario archetypes were perceived to allow syntheses of large amounts of information for scientific, practice-, and policy-related purposes, streamline key messages from multiple scenario studies, and facilitate communication of them to end users. In terms of challenges, they were perceived as subjective in their interpretation, oversimplifying information, having a limited applicability across scales, and concealing contextual information and novel narratives. Finally, our results highlight what methodologies, applications, and frontiers in archetype-based research should be explored in the future. These advances can assist the design of future large-scale sustainability-related assessment processes, aiming to better support decisions and interventions for equitable and sustainable futures.

Interspecific competition can influence patterns of habitat use by small mammals. We examined the effects of interspecific interactions on habitat use by prairie voles (Microtus ochrogaster) and meadow voles (M. pennsylvanicus), two species that co-occur in grass habitats in east-central Illinois, but differ in their tolerance of sparse cover (prairie voles are more tolerant than meadow voles of sparse cover). We conducted a species-removal study in open populations, a species-addition study with enclosed populations, and dyadic encounters in the field, using mown and unmown grass areas, and in the laboratory. In the species-removal study, we found a positive response of prairie voles to removal of meadow voles from unmown grass habitat, and of meadow voles to removal of prairie voles from mown grass habitat. Additionally, when both species were present in control sites, prairie voles were most abundant in mown grass and meadow voles in unmown grass. In enclosures we confirmed greater tolerance of sparse cover by prairie voles (similar numbers of individuals in mown and unmown sites) than meadow voles (more individuals in unmown than mown sites), and these patterns were unaffected by addition of the other species. In dyadic encounters conducted in the field, male prairie voles were dominant over male and female meadow voles in mown grass habitat, whereas female meadow voles were dominant over male and female prairie voles in unmown grass habitat. These dominance relationships, which are consistent with the known social systems of the two species, were not observed when dyadic encounters were conducted in the laboratory in a neutral arena that lacked structural habitat cues. Taken together, our data confirm differences between prairie voles and meadow voles in tolerance for sparse cover and indicate a role, though limited, for interspecific competition in reinforcing patterns of habitat use by each species.

Population densities of Microtus ochrogaster and M. pennsylvanicus were monitored from 1972 to 1986 in three habitats: alfalfa, bluegrass, and tallgrass prairie. Microtus ochrogaster displayed two apparent multiannual population cycles in alfalfa and bluegrass from 1972 to 1976; thereafter only annual (alfalfa) or erratic (bluegrass) fluctuations were apparent. Except for extremely high densities during 1984–1985, population fluctuations of M. ochrogaster in tallgrass were erratically low and there was no evidence of multiannual cycles. During 15 of 29 changes in population density of M. ochrogaster, the amplitude of fluctuations was more than 10-fold; 14 of these changes were preceded by marked population declines or very low densities the previous winter and spring. Microtus pennsylvanicus displayed annual fluctuations in abundance in alfalfa and bluegrass and was erratically high at all times in tallgrass. Only 7 of 32 population fluctuations of M. pennsylvanicus had amplitudes of at least 10-fold; in all 7 cases population density had been high the previous year. We conclude that distinct multiannual population cycles were not characteristic of either species in any habitat over the 14 years. Most previous assumptions of multiannual cycles in these species may be artifacts of short-term studies.

Journal Article Vegetation Characteristics of Microtus ochrogaster and M. pennsylvanicus Habitats in East-Central Illinois Get access Brian J. Klatt, Brian J. Klatt Department of Ecology, Ethology, and Evolution, University of Illinois, Urbana, IL 61801 Search for other works by this author on: Oxford Academic Google Scholar Lowell L. Getz Lowell L. Getz Department of Ecology, Ethology, and Evolution, University of Illinois, Urbana, IL 61801 Search for other works by this author on: Oxford Academic Google Scholar Journal of Mammalogy, Volume 68, Issue 3, 28 August 1987, Pages 569–577, https://doi.org/10.2307/1381593 Published: 28 August 1987 Article history Received: 05 April 1986 Accepted: 26 June 1986 Published: 28 August 1987

Small mammal populations were censused monthly on a 1.6-ha grid located in a restored Illinois tallgrass prairie. Over 23 months, the principal species, Microtus pennsylvanicus, had densities ranging between 30 and 141 individuals/ha (enumeration technique), with several periods of fluctuation, a prolonged decline and a culminating stabilization of density. Reproduction was strongly seasonal (MarchNovember) and females had a bimodal periodicity of pregnancy/lactation. Survival rates per 30 days were significantly correlated for adult males and females and never fell below 50%; no significant correlations existed for survival rates and density. Adult male body weights showed strong seasonal trends and no correlation with density. Immigration was an important component of growth, especially during the last increase period, and immigrants were significantly heavier and predominantly male as compared to adult residents (individuals first caught as juveniles/subadults and therefore considered recruits from in situ reproduction). Lifespans and levels of reproductive activity were similar in adult immigrants and residents; nonpregnant females of both groups were significantly lower in body weight and had longer lifespans than males. The only significant correlations between various demographic factors and density were those of immigration rates (same period) and of percent pregnant/lactating females (2 months earlier). The importance of one component of dispersal, immigration, in this parallels documentation of an important role of the second component, emigration, in cycling populations, However, the lack of confirmation of a number of other generalizations characterizing cycling populations here suggests that this was not cycling. Three possible explanations for the absence of cycling include isolation, the role of fire in altering vole demography and plant community structure, and possible inherent differences in habitat heterogeneity and subsequent predator-prey or plant-herbivore interactions occurring in native perennial vs. introduced annual grasslands. INTRODUCTION In Krebs and Myers' (1974) review of cycles, they state: We conclude that microtine rodent populations normally undergo cycles with a period of 3-4 years and this density pattern should be assumed to be the normal configuration (p. 278); consequently, . . the burden of proof [that microtine populations do not cycle] should be shifted to those who would claim to have a noncyclic population (same paragraph). While several studies have revealed annual or noncyclic fluctuations in fenced or insular microtine populations (Krebs et al., 1969; Lidicker, 1973; Tamarin, 1978; Abramsky and Tracy, 1979), this has been attributed to reduced opportunities for normal dispersal and therefore not inconsistent with the above statements (Krebs, 1978). Recently, however, a number of additional studies failed to confirm the universality of cycling in open populations of Microtus spp.; the communities documented range from native perennial grasslands (Getz et al., 1979; Krohne, 1982), to annual grasslands (Garsd and Howard, 1981, 1982), and upland meadows (Birney et al., 1976; Baird and Birney, 1982a, b). Although microtines appeared to have evolved from seedand fruit-eating f6rms and to have entered grasslands relatively late in their evolution 'Present address: Department of Ecology, Ethology and Evolution, University of Illinois, Urbana 61801.

Levels of male aggressiveness, determined by observation of dyadic encounters, were compared during low, increase, peak, and decline phases of the population cycle in free-living populations of Microtus ochrogaster and M. pennsylvanicus. There were no significant differences in the proportions of nonaggressive, aggressive, and highly aggressive males during the low, increase, and peak phases of M. ochrogaster populations in an alfalfa and in a bluegrass habitat. Large numbers of nonaggressive voles were present during the decline phases. The aggressiveness of individual males appeared greater at peak densities only in the bluegrass field. Phase of cycle explained 18.6% of the variation in behavioral variables for the bluegrass area population and 5.8% for the alfalfa area population. The proportions of aggressive types for M. pennsylvanicus populations in bluegrass and prairie habitats did not vary significantly with phase of the population cycle and there was no indication of an increased level of individual aggressiveness at peak densities. Phase of cycle explained 25.2% of the variation in behavioral data for the bluegrass area population and 12.2% for the prairie population. Seasonal heterogeneity was found in the behavior of M. ochrogaster and season accounted for more of the behavioral variation in each population than had phase of cycle. Although seasonal trends were not entirely consistent, the data suggested that males may be more aggressive in winter and autumn. For M. pennsylvanicus the proportions of nonaggressive males were lower during spring and autumn (which correspond to the breeding seasons) than during summer and winter. The results of the present study were not consistent with the polymorphic behavior hypothesis.