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Future drought is projected to occur under warmer temperature conditions as climate change progresses, referred to here as global-change-type drought, yet quantitative assessments of the triggers and potential extent of drought-induced vegetation die-off remain pivotal uncertainties in assessing climate-change impacts. Of particular concern is regional-scale mortality of overstory trees, which rapidly alters ecosystem type, associated ecosystem properties, and land surface conditions for decades. Here, we quantify regional-scale vegetation die-off across southwestern North American woodlands in 2002-2003 in response to drought and associated bark beetle infestations. At an intensively studied site within the region, we quantified that after 15 months of depleted soil water content, >90% of the dominant, overstory tree species (Pinus edulis, a piǫn) died. The die-off was reflected in changes in a remotely sensed index of vegetation greenness (Normalized Difference Vegetation Index), not only at the intensively studied site but also across the region, extending over 12,000 km2 or more; aerial and field surveys confirmed the general extent of the die-off. Notably, the recent drought was warmer than the previous subcontinental drought of the 1950s. The limited, available observations suggest that die-off from the recent drought was more extensive than that from the previous drought, extending into wetter sites within the tree species' distribution. Our results quantify a trigger leading to rapid, drought-induced die-off of overstory woody plants at subcontinental scale and highlight the potential for such die-off to be more severe and extensive for future global-change-type drought under warmer conditions.

Management regimes of varying types and intensities can have profound impacts on grassland soil quality. Plus, there has recently been increased interest in finding soil quality indicators that are reflective of historical and current land management. We surveyed soil quality of privately owned grasslands in northeastern Kansas differing in their cultivation histories and current land-use (cool-season hay and grazed, warm-season native hay and grazed, and Conservation Reserve Program). We found significant differences in individual soil characteristics among management regimes when using both chemical and physical soil quality indicators. Principal components analysis showed that cultivation history and current land-use of these fields could be reflected by overall soil quality. Also, within cultivated fields, overall soil quality significantly increased with time since last cultivation. Our results suggest that using soil quality indicators such as nitrogen, carbon and organic matter are reflective of historical land use, but are not as useful when trying to determine current land use.

The Conservation Reserve Program (CRP) began in 1986 with the primary purpose of reducing soil erosion. It also was intended to help the development of sustainable agriculture and associated environmental harmony. However, its effectiveness has been questioned because of the large costs and extensive staff required to conduct the program. The objectives of our study were to test procedures for integrating remote sensing and geographic information systems (GIS) techniques to evaluate the present CRP in terms of its main goal, and to give recommendations for the future of the program in Finney County, Kansas. Three seasonal Landsat Thematic Mapper (TM) images were used to derive the land-use/land cover (LULC) map. This information was incorporated with spatial dimensions of soil surface horizon thickness, surface horizon texture, soil family, soil subgroup, and soil erodibility index (EI), all of which were extracted or calculated from the Natural Resources Conservation Service (NRCS) soil survey geographic (SSURGO) data base. With GIS techniques, calculation of EI was more efficient and the value was more accurate than that calculated by hand. We found the average EI of the county to be 20, with the highest EI of 77 in the southwest portion of the study area. CRP land had higher soil fertility and a lower EI than land currently used for farming; therefore, the CRP for this county did not necessarily include the lands most susceptible to erosion. We suggest continuing the CRP program in Finney County, because the soils are generally at serious risk of erosion. We also suggest modifying the eligibility rules of the program in order to target the most environmentally sensitive lands.

Cliffrose (Cowania mexicana var. stansburiana [Torr.] Jepson) community measurements were taken in central Utah. Data revealed a high between-site similarity of 78.5%. Soil analysis for sites showed most macronutrients, and some micronutrients, relatively low. Cover of cliffrose was found to increase with increases in soil magnesium (p ≤ 0.01). Plants growing on the sites have adapted life cycles to exploit moisture and nutrients during seasons of maximum availability. Prevalent species in the community were cheatgrass (Bromus tectorum), cliffrose, madwort (Alyssum alyssoides), and bluebunch wheatgrass (Agropyron spicatum). Annual grasses were the most important life form to community composition; the second was shrubs. Ratios between soil nutrients and cliffrose tissue nutrients indicate active transport of some elements. Data indicated a steady decline in establishment of new cliffrose individuals on the sites since 1957. This lack of reproductive success is most likely due to a combination of factors but appears most influenced by the elevated levels of annual plants (mainly cheatgrass) on the sites. If the cliffrose communities in central Utah are to be maintained, special attention to their management must be considered and implemented.

A new species, Myrsidea willardi, is described from the Schlegel's Asity, Philepitta schlegeli, from Madagascar. The only previously described species from the host family Philepittidae, Myrsidea minuscula (Piaget), is redescribed and illustrated. These two species of lice show pronounced genetic divergence based on partial mitochondrial cytochrome oxidase I sequences.

In this paper, we present a content analysis of Demography, the official journal of the Population Association of America. Our results reflect patterns of change and stability in a number of areas, including: subjects covered, number of authors, gender of authors, type of data used, source of data used, affiliation of authors and statistical procedures employed. The data suggest that the field of population research has become increasingly bureaucratized and complex, while at the same time continuing to focus on familiar research subjects. A relatively small number of population research centers contribute disproportionately to the journal.

The primacy of men's economic provision and the substantial impact of their economic resources on families suggests that marital status should be an important correlate of men's labor market behavior. In this article we investigate the relationship between men's marital status and duration of spells of joblessness. We outline a rationale for expecting men's marital status to be related to duration of joblessness and provide empirical estimates for a sample of 2,851 white men from Washington state followed from approximately ages 16-18 to approximately ages 29-31. The results suggest that men's marital status exerts a negative and direct causal influence on length of joblessness.

We examine the impact of employment histories on union dissolution in Puerto Rico for two groups of women: all women either married or living with a partner consensually, and women who did not cohabit before legal marriage. Results, using discrete-time proportional hazards models, indicate that: (a) transitions in female employment status within a union increase the risk of union disruption; (b) transitions in female employment status relative to union inception increase the risk of union dissolution, but this effect disappears when employment transitions within the union are controlled for; (c) working in jobs that pay a wage or salary increases union disruption as compared to women who do not work and women who work in more home-oriented occupations; and (d) working in types of occupations that are conducive to home-oriented roles does not affect the likelihood of union disruption.