Impact of the Black-Tailed Jackrabbits (Lepus Californicus) on Vegetation in Curlew Valley, Northern Utah

The interrelations of black- tailed jackrabbits and the desertshrub vegetation on which they were feeding were studied in Curlew Valley, Northern Utah. The vegetation was described as a threecornered continuum, the corners being types dominated respectively by Artemisia tridentata, Atriplex ~ onfertifolia, and Sarcobatus vermiculatus. Jackrabbit diet was studied by microscopic analysis of plant fragments in stomachs from shot animals. The method was inaccurate, apparently because the ratio of identifiable tissues to all ingested tissues was very low, and varied between plant taxa, and seasonally. This problem seems intractable for desert shrub vegetation. The diet was similar to that reported by other workers on this species, with perennial grasses and forbs most important in sprlng and summer, shrubs in autumn and win ter. Features new to this vegetat ion were large percentages of Halogeton glomeratus, particularly in autumn and winter, and intense selection for Kochia americana. Attempts to explain the foods chosen ln terms of t heir nutrient contents were partically successful. Diet selection by large generalist herbivores was conceptualized as optimization of nutrient intake, mediated by long-delay learning, and constrained by food availability only at very low levels of availaoility. Spatial variation in jackrabbit diets confirmed this cut-offll response to ava i 1 all i 1 i ty . Percentage utilization was estimated indirectly as jackrabbit density, times yearly food consumption per jackrabbit, times yearround percentage of each taxon in the diet, div i ded by available biomass of each taxon. Less abundant plants were more intensely used, which is expected if consumption does not vary continuously with availability. Perennial grasses, Kochia americana and possibly Grayia spinosa seemed to be under damaging pressure at high jackrabbit densities. Kochia had almost disappeared from outside a sheep- and jackrabbitproof exclosure since the 1950 1 s. In other exc1osures, the presence or absence of jackrabbits seemed to make no difference to the rate of vegetation recovery over 5-7 years after exclusion of sheep. Jackrabbit use of a crested wheatgrass seeding was concentrated ln a 300 m band around its edge

On Limits to Seed Production

Organismic and Evolutionary Biolog

Parent-Specific Gene-Expression and the Triploid Endosperm

No abstractOrganismic and Evolutionary Biolog

Patterns and drivers of plant diversity across Australia

Biodiversity analyses across continental extents are important in providing comprehensive information on patterns and likely drivers of diversity. For vascular plants in Australia, community-level diversity analyses have been restricted by the lack of a consistent plot-based survey dataset across the continent. To overcome these challenges, we collated and harmonised plot-based vegetation survey data from the major data sources across Australia and used them as the basis for modelling species richness (α-diversity) and community compositional dissimilarity (β-diversity), standardised to 400 m2, with the aim of mapping diversity patterns and identifying potential environmental drivers. The harmonised Australian vegetation plot (HAVPlot) dataset includes 219 552 plots, of which we used 115 083 to analyse plant diversity. Models of species richness and compositional dissimilarity both explained approximately one-third of the variation in plant diversity across Australia (D2 = 33.0% and 32.7%, respectively). The strongest environmental predictors for both aspects of diversity were a combination of temperature and precipitation, with soil texture and topographic heterogeneity also important. The fine-resolution (≈ 90 m) spatial predictions of species richness and compositional dissimilarity identify areas expected to be of particular importance for plant diversity, including south-western Australia, rainforests of eastern Australia and the Australian Alps. Arid areas of central and western Australia are predicted to support assemblages that are less speciose or unique; however, these areas are most in need of additional survey data to fill the spatial, environmental and taxonomic gaps in the HAVPlot dataset. The harmonised data and model predictions presented here provide new insight into plant diversity patterns across Australia, enabling a wide variety of future research, such as exploring changes in species abundances, linking compositional patterns to functional traits or undertaking conservation assessments for selected components of the flora

Perspectives on the scientific legacy of J. Philip Grime

Perhaps as much as any other scientist in the 20th century, J.P. Grime transformed the study of plant ecology and helped shepherd the field toward international prominence as a nexus of ideas related to global environmental change. Editors at the Journal of Ecology asked a group of senior plant ecologists to comment on Grime's scientific legacy. This commentary piece includes individual responses of 14 scientists from around the world attesting to Grime's foundational role in plant functional ecology, including his knack for sparking controversy, his unique approach to theory formulation involving clever experiments and standardized trait measurements of large numbers of species, and the continued impact of his work on ecological science and policy

Open Science principles for accelerating trait-based science across the Tree of Life.

Synthesizing trait observations and knowledge across the Tree of Life remains a grand challenge for biodiversity science. Species traits are widely used in ecological and evolutionary science, and new data and methods have proliferated rapidly. Yet accessing and integrating disparate data sources remains a considerable challenge, slowing progress toward a global synthesis to integrate trait data across organisms. Trait science needs a vision for achieving global integration across all organisms. Here, we outline how the adoption of key Open Science principles-open data, open source and open methods-is transforming trait science, increasing transparency, democratizing access and accelerating global synthesis. To enhance widespread adoption of these principles, we introduce the Open Traits Network (OTN), a global, decentralized community welcoming all researchers and institutions pursuing the collaborative goal of standardizing and integrating trait data across organisms. We demonstrate how adherence to Open Science principles is key to the OTN community and outline five activities that can accelerate the synthesis of trait data across the Tree of Life, thereby facilitating rapid advances to address scientific inquiries and environmental issues. Lessons learned along the path to a global synthesis of trait data will provide a framework for addressing similarly complex data science and informatics challenges