The adaptive value of autumn colours is still a puzzle for evolutionary biology. It has been suggested that autumn colours are a warning signal to insects that use the trees as a host. I show that aphids (Dysaphis plantaginea) avoid apple trees (Malus pumila) with red leaves in autumn and that their fitness in spring is lower on these trees, which suggests that red leaves are an honest signal o...

This study describes the time-course of the accumulation of total soluble proteins (TSPs) and vegetative storage proteins (VSPs) and of the transcripts of cold-inducible (CI) and VSP-encoding genes in taproots of two alfalfa cultivars (AC Caribou and Europe) during their acclimation to natural autumn hardening and overwintering conditions in eastern Canada. The impact of a defoliation in Septem...

OBJECTIVES To determine both the prevalence and severity of dehydration of forestry workers harvesting trees in autumn and winter. METHODS Two cross-sectional observational studies were conducted on convenience samples of 103 and 79 workers in autumn and winter, respectively. The prevalence of dehydration pre- and post-shift was determined using urine specific gravity (U(SG)), and the severit...

Ponds are sites of high biodiversity and conservation value, yet there is little or no statutory monitoring of them across most of Europe. There are clear and standardised protocols for sampling aquatic macroinvertebrate communities in ponds, but the most suitable time(s) to undertake the survey(s) remains poorly specified. This paper examined the aquatic macroinvertebrate communities from 95 p...

Plasma gonadotrophin and testosterone levels during the prepuberal period have been compared in spring and autumn-born Romanov lambs; the somatic and germ cell populations of these lambs have also been compared at birth and at adulthood. At 1 and 3 months of age, the number of LH pulses per hour and mean plasma LH levels were significantly higher in spring than in autumn lambs. In adults, no su...

In the Baltic Sea the autumn spawning herring forms a smaller number of groups than the spring herring does. This is probably connected with the different location of their spawning grounds. Spawning grounds of the spring herring are concentrated in favorable sites near the coast (in gulf, estuaries, etc.) while between such spawning centers gaps occur usually. Contrary to it, in most parts of ...

The initiation, progression, and natural variation of autumn senescence in European aspen (Populus tremula) was investigated by monitoring chlorophyll degradation in (1) trees growing in natural stands and (2) cloned trees growing in a greenhouse under various light regimes. The main trigger for the initiation of autumn senescence in aspen is the shortening photoperiod, but there was a large de...

In this paper, the nutrient distribution, its structural characteristic and controlling mechanism around the Changjiang River estuary during Autumn 1997 and Spring 1998 were discussed, and a clear seasonal variation of nutrient distribution and structure was observed in this area. The concentrations of NO3(-)-N, SiO3(2-)-Si, PO4(3-)-P, DOP, PP and TP in Autumn 1997 were higher than those in Spr...