Extra terrestrials: drought creates niche space for rare invertebrates in a large-scale and long-term field experiment.

Freshwater habitats are drying more frequently and for longer under the combined pressures of climate change and overabstraction. Unsurprisingly, many aquatic species decline or become locally extinct as their benthic habitat is lost during stream droughts, but less is known about the potential 'winners': those terrestrial species that may exploit emerging niches in drying riverbeds. In particular, we do not know how these transient ecotones will respond as droughts become more extreme in the future. To find out we used a large-scale, long-term mesocosm experiment spanning a wide gradient of drought intensity, from permanent flows to full streambed dewatering, and analysed terrestrial invertebrate community assembly after 1 year. Droughts that caused stream fragmentation gave rise to the most diverse terrestrial invertebrate assemblages, including 10 species with UK conservation designations, and high species turnover between experimental channels. Droughts that caused streambed dewatering produced lower terrestrial invertebrate richness, suggesting that the persistence of instream pools may benefit these taxa as well as aquatic biota. Particularly intense droughts may therefore yield relatively few 'winners' among either aquatic or terrestrial species, indicating that the threat to riverine biodiversity from future drought intensification could be more pervasive than widely acknowledged.

The television school and family smoking prevention and cessation project. 1. Theoretical basis and program development.

Program development processes for the Television, School, and Family Project, a school-based smoking prevention and cessation project, are presented in this article. We first review applications of social-psychological and communications theory to school-based and mass media program development. These include the three broad areas of (a) mediators of mass media effects on behavior change, (b) the social influences approach to smoking prevention, and (c) a self-management and social support approach to smoking cessation. A program development model for school-based mass media efficacy trials, with a summary of formative research and pilot study processes, is then presented. The importance of reciprocal support among school district administrators, project research staff, and television station personnel is emphasized with recommendations for future research and demonstration efforts.