An elevated concentration of water soluble carbohydrate (WSC) in grasses may increase the availability of readily degradable energy, increase milk production and improve the efficiency of nitrogen utilisation. Two ryegrasses with elevated WSC, a tetraploid Italian (IRG) and a diploid perennial selected for higher WSC (HSG), were compared against a standard diploid perennial (STG) during spring ...

Traditional perception of how tallgrass prairie responds to fire at times other than late spring is either anecdotal or extrapolated from studies that lack spatial or temporal variability. Therefore, we evaluated patterns of change in vegetation cover, species richness, diversity, and aboveground biomass production on 2 different topographic positions from ungrazed watersheds that were burned a...

Nothofagus dombeyi (Mirb.) Blume and Nothofagus nitida (Phil.) Krasser are closely related evergreen trees native to south central Chile. Nothofagus dombeyi is a pioneer in habitats subject to high daytime irradiances and nighttime freezing temperatures and has a wider altitudinal and latitudinal distribution than N. nitida, which is restricted to more oceanic climates. We postulated that N. do...

In autumn 1977 91% of the women who had graduated from United Kingdom medical schools in 1949-51 (early cohort) and 1965 (late cohort) were practising medicine. Over the first 12 years after qualification the late cohort was marginally more active in medicine and had more members in career and training posts than the early cohort. On the survey date 1 October 1977 (26-28 years after qualificati...

Changes in climate are leading to modifications the timing of seasonal events such as migrations and flowering. Erythronium americanum (trout lily) can break bud early response warming, but changes its growing season may be limited by shade from canopy trees frost. I experimentally assessed impact frost on senescence E. descriptively monitored vernal air soil temperatures a garden setting. Earl...

the purpose of this study is estimate waiting time of frost occurrence over iran. the daily data from 663 synoptic and climatology over iran during 1/1/1340 to 11/10/1383 have been used. data interpolated by kriging method on 15ã—15 km pixels. the data base with dimension 15992ã—7187 obtained that on the rows were days and on the column were pixels. by t student test the interval mean of waitin...

Stem tissues of red-osier dogwood (Cornus stolonifera Michx.) acclimated from -3 C to -40 or -50 C in 8 to 10 weeks under a short photoperiod (9 hours) and controlled temperature conditions. During the summer months plants did not acclimate as well as at other times. The sequence of day/night temperature regimes which induced maximum acclimation was 20/15 C for 5 to 6 weeks; 15/5 C for 2 to 3 w...