Mon, 07 Jul 2008 16:51:41 BST CiteULike: neteler drought http://www.citeulike.org/user/neteler/tag/drought CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/neteler/article/769998 <i>J Med Entomol, Vol. 37, No. 3. (May 2000), pp. 408-415.</i><br /><br />From 1990 through 1997, Ixodes scapularis Say larvae and nymphs were sampled between May and October along a 400-m segment of a nature trail in a Lyme disease endemic site in northern Illinois. Ticks were removed from Peromyscus leucopus mice and collected via tick drags at approximately 3-wk intervals. Mouse population estimates along the trail varied from 2, in the spring of 1996 following a year of drought, to > 200 in 1993, the wettest year on record. During the 8-yr period, there were major droughts during the summers of 1991 and 1995. Cumulative degree-days were positively correlated with the number of ticks collected on drags in the same year and negatively correlated with larval tick populations for the following year (P < 0.05). Cumulative rainfall was positively correlated with larval tick abundance for the following year. This was most readily apparent by examination of the larval density on captured mice. In the year following each of two drought years, larval densities were significantly depressed compared with the 8-yr average at the site. Populations of Ixodes scapularis (Acari: Ixodidae) are modulated by drought at a Lyme disease focus in Illinois. CJ Jones UD Kitron J Med Entomol, Vol. 37, No. 3. (May 2000), pp. 408-415. 2006-07-23T09:30:54-00:00 2000 J Med Entomol 0022-2585 37 3 408 415 climate disease drought ecology epidemiology habitat host host-parasite ixodes rodents small_mammals ticks http://www.citeulike.org/user/neteler/article/563230 <i>Canadian Journal of Botany, Vol. 79, No. 9. (September 2001), pp. 1039-1047.</i><br /><br />The question of what triggers masting in beech (Fagus) has been a source of uncertainty and curiosity. Analysing seed production series from Europe (Fagus sylvatica L.), eastern North America (Fagus grandifolia Ehrh.), and Japan (Fagus crenata Blume), for various periods (lasting between 6 and 34 years) over the last 150 years, we find a close relationship between masting (mast year) and preceding growing season climate events (mast year–1 and mast year–2) in eastern North America and Europe, with tentative indications of this pattern in Japan. A drought in the early summer preceding masting (mast year–1) is a very strong predictor in Europe and eastern North America, but drought events were not found for the Japan series. The predictive power is increased in all three regions if there has been an unusually moist, cool summer the year before the drought (mast year–2). We suggest that, in this initial moist summer (mast year–2), carbohydrate buildup within the trees "primes" them for floral induction the following year (year–1). In the European and eastern North American series, a drought event in the early part of the following summer (mast year–1) acts as a proximal trigger for the release of those reserves into flower initiation and then seed production. Key words: masting, Fagus spp., floral induction, drought, climatic variation, evolutionary ecology. Masting behaviour in beech: linking reproduction and climatic variation Gianluca Piovesan Jonathan Adams doi:10.1139/cjb-79-9-1039 Canadian Journal of Botany, Vol. 79, No. 9. (September 2001), pp. 1039-1047. 2006-03-25T21:26:24-00:00 2001 Canadian Journal of Botany 79 9 1039 1047 climate drought ecology fagus floral_induction masting