Evaluating Biodiversity Metric Response to Forecasted Land Use Change in the Northern Rio Grande Basin.

The effects of future land use change on arid and semi-arid watersheds in the American Southwest have important management implications. Seamless, national-scale land-use-change scenarios for developed land were acquired from the US Environmental Protection Agency Integrated Climate and Land Use Scenarios (lCLUS) project and extracted to fit the Northern Rio Grande River Basin, New Mexico relative to projections of housing density for the period from 2000 through 2100. Habitat models developed from the Southwest Regional Gap Analysis Project were invoked to examine changes in wildlife habitat and biodiversity metrics using five ICLUS scenarios.

Use of matrix population models to estimate the efficacy of euthanasia versus trap-neuter-return for management of free-roaming cats.

Objective: To evaluate the efficacy of trap-neuter-return and trap-euthanatize management strategies for controlling urban free-roaming cat populations by use of matrix population models.

Design: Prospective study.

Sample Population: Estimates of free-roaming cat populations in urban environments.

Spatial risk assessment across large landscapes with varied land use: lessons from a conservation assessment of military lands.

Spatial decision-support tools are necessary for assessment and management of threats to biodiversity, which in turn is necessary for biodiversity conservation. In conjunction with the U.S.

Risk analysis for invasive species: general framework and research needs.

A joint workshop was convened by the Society for Risk Analysis Ecological Risk Assessment Specialty Group and the Ecological Society of America Theoretical Ecology Section to provide independent scientific input into the formulation of methods and processes for risk assessment of invasive species. In breakout sessions on (1) the effects of invasive species on human health, (2) effects on plants and animals, (3) risk analysis issues and research needs related to entry and establishment of invasive species, and (4) risk analysis issues and research needs related to the spread and impacts of invasive species, workshop participants discussed an overall approach to risk assessment for invasive species. Workshop participants agreed on the need for empirical research on areas in which data are lacking, including potential invasive species, native species and habitats that may be impacted by invasive species, important biological processes and phenomena such as dispersal, and pathways of entry and spread for invasive species.

Risk assessment for invasive species.

Although estimates vary, there is a broad agreement that invasive species impose major costs on the U.S. economy, as well as posing risks to nonmarket environmental goods and services and to public health.

DIASPORE MORPHOLOGY AND SEED DISPERSAL IN SEVERAL WIND-DISPERSED ASTERACEAE.

I made measurements of morphology and settling velocity on seeds of 19 species of wind-dispersed Asteraceae. From the morphological measurements I calculated Reynolds numbers and approximate plume loadings for the species. Diaspore settling velocity increases linearly with the square root of plume loading.

VARIABLE SELECTION ON EUROSTA'S GALL SIZE, I: THE EXTENT AND NATURE OF VARIATION IN PHENOTYPIC SELECTION.

Natural fluctuations in environmental conditions are likely to induce variation in the intensity or direction of natural selection. A long-term study of the insect, Eurosta solidaginins Fitch (Diptera; Tephritidae), which induces stem galls on the perennial herb Solidago altissima (Asteraceae) was performed to explore the patterns of variation in phenotypic selection. The intensity of selection imposed by parasitoids and predators on gallmaking larvae, for gall size, was measured across 16 populations over the course of 4 generations, for a total of 64 population-generations.

AN ANALYSIS OF VARIABILITY IN SEED SETTLING VELOCITIES OF SEVERAL WIND-DISPERSED ASTERACEAE.

Dispersal is an important life history component. Seed settling velocity may be a useful surrogate for the measurement of dispersal ability in wind-dispersed plants, particularly those whose seeds have plumose dispersal structures. I measured settling velocities on seeds of eight species of Asteraceae, including annuals, biennials, and perennials, and including both native and introduced species.