Change in winter snow depth and its impacts on vegetation in China

Snow on land is an important component of the global climate system, but our knowledge about the effects of its changes on vegetation are limited, particularly in temperate regions. In this study, we use daily snow depth data from 279 meteorological stations across China to investigate the distribution of winter snow depth (December–February) from 1980 to 2005 and its impact on vegetation growth, here approximated by satellite‐derived vegetation greenness index observations [Normalized Difference Vegetation Index (NDVI)]. The snow depth trends show strong geographical heterogeneities. An increasing trend (>0.01 cm yr^?1) in maximum and mean winter snow depth is found north of 40°N (e.g. Northeast China, Inner Mongolia, and Northwest China). A declining trend (?1) is observed south of 40°N, particularly over Central and East China. The effect of changes in snow depth on vegetation growth was examined for several ecosystem types. In deserts, mean winter snow depth is significantly and positively correlated with NDVI during both early (May and June) and mid‐growing seasons (July and August), suggesting that winter snow plays a critical role in regulating desert vegetation growth, most likely through persistent effects on soil moisture. In grasslands, there is also a significant positive correlation between winter snow depth and NDVI in the period May–June. However, in forests, shrublands, and alpine meadow and tundra, no such correlation is found. These ecosystem‐specific responses of vegetation growth to winter snow depth may be due to differences in growing environmental conditions such as temperature and rainfall.     

Variations in bark-stripping by red deer Cervus elaphus across Europe

• 1 The literature on bark‐stripping by red deer Cervus elaphus in Europe is reviewed to reveal quantitative variation in this behaviour and relate it to deer density and local characteristics such as dominant tree species, occurrence of artificial feeding, altitude, region and size of the study site. We also review the importance of bark in red deer diets over the seasons and discuss the causes of bark‐stripping, focusing on the significance of bark as food.
• 2 Over the 36 sites examined, the rate of bark‐stripping was highly variable (from 0 to 84% of susceptible trees debarked), with less damage in Scotland than in other European sites for which bark‐stripping rates were higher at high red deer density. Altitude, the size of the study site, the number of dominant tree species and the occurrence of artificial feeding do not significantly relate to the rate of bark‐stripping.
• 3 Bark sometimes made up a large proportion of red deer diet (> 10%), especially in areas with severe winters (high levels of snow), whereas in study sites with mild winters, bark was practically not eaten at all.
• 4 These results suggest that severe bark‐stripping could be related to a reduction in food resource availability. This food availability hypothesis needs to be better documented, dealing particularly with the possible interaction between food availability and red deer density.

     

Characterization of microsatellite loci in longnose dace (Rhinichthys cataractae) and interspecific amplification in five other Leuciscinae species

The longnose dace (Rhinichthys cataractae) appears as a relevant model to address environmental and ecological issues in an evolutionary perspective. Eleven microsatellite markers were characterized for this species. Eight of these loci were highly polymorphic for populations of this species. Between four to 10 loci were also successfully amplified in five closely related species. These markers are believed to be valuable tools for genetic analysis of populations of longnose dace and other Leuciscinae species.     

Stress intensity and fitness in the parasitoid Aphidius ervi (Hymenoptera: Braconidae): temperature below the development threshold combined with a fluctuating thermal regime is a must

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Inclusive fitness in human relationships

For Homo sapiens , inclusive fitness theory goes well beyond 'kin'. As William Hamilton hypothesized, genes can increase the probability of their own survival by bringing about the reproduction of not only family members with whom they share copies, but also of any individuals with whom they share copies. Research with Hamilton's theory on people is less well known and remains controversial. This review shows: (1) spouses and close friends assort on blood groups and that similarity predicts fertility; (2) twin and adoption studies find genes rather than upbringing cause people to positively assort; (3) phenotype matching is more pronounced on more heritable items within sets of homogeneous traits; (4) bereavement studies find grief is greater following the death of a more similar co-twin or child; (5) studies of face perception find people prefer and trust those who look like them; and (6) DNA variance within and between ethnic groups is equivalent to that within and between families.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 96 , 8–12.     

Changes in satellite‐derived vegetation growth trend in temperate and boreal Eurasia from 1982 to 2006

Monitoring changes in vegetation growth has been the subject of considerable research during the past several decades, because of the important role of vegetation in regulating the terrestrial carbon cycle and the climate system. In this study, we combined datasets of satellite‐derived Normalized Difference Vegetation Index (NDVI) and climatic factors to analyze spatio‐temporal patterns of changes in vegetation growth and their linkage with changes in temperature and precipitation in temperate and boreal regions of Eurasia (> 23.5°N) from 1982 to 2006. At the continental scale, although a statistically significant positive trend of average growing season NDVI is observed (0.5 × 10^?3 year^?1, P = 0.03) during the entire study period, there are two distinct periods with opposite trends in growing season NDVI. Growing season NDVI has first significantly increased from 1982 to 1997 (1.8 × 10^?3 year^?1, P < 0.001), and then decreased from 1997 to 2006 (?1.3 × 10^?3 year^?1, P = 0.055). This reversal in the growing season NDVI trends over Eurasia are largely contributed by spring and summer NDVI changes. Both spring and summer NDVI significantly increased from 1982 to 1997 (2.1 × 10^?3 year^?1, P = 0.01; 1.6 × 10^?3 year^?1P < 0.001, respectively), but then decreased from 1997 to 2006, particularly summer NDVI which may be related to the remarkable decrease in summer precipitation (?2.7 mm yr^?1, P = 0.009). Further spatial analyses supports the idea that the vegetation greening trend in spring and summer that occurred during the earlier study period 1982–1997 was either stalled or reversed during the following study period 1997–2006. But the turning point of vegetation NDVI is found to vary across different regions.