Soil organic carbon (SOC) pools in forest floors and mineral soil to a depth of 100 cm were determined in 234 well‐drained Nordic forest soils from latitude 55–68?‚??°‐N, and longitude 6–28?‚??°‐E. The data were compiled in a database of Nordic forest soils, from literature, and sources of validated data the authors had access to. The SOC pool increased with both mean annual temperature (MAT) and mean annual precipitation (MAP), and the increase with MAT was more pronounced for coarse‐textured soils than for medium‐textured soils. Soil organic carbon in fine‐textured soils was not correlated with MAT and MAP. Differences between texture classes were mainly due to different carbon stores in the upper 40 cm of the mineral soil and in the forest floor. The emphasis on well‐drained soils eliminated the impact of hampered decomposition in hydromorphic soils. Large carbon accumulation in such soils probably explains the negative relationship between SOC and temperature reported in other studies. The increase in SOC with temperature and precipitation is interpreted as an indirect effect of higher net primary production.

Aim The objectives of this study were to determine the relationships between climatic factors and litterfall in coniferous and broadleaf forests in Eurasia and to explore the difference in litterfall between coniferous and broadleaf forests as related to climate at a continental scale.Location We have used data from across Eurasia. MethodsThe relationships between litterfall and climatic factors were examined using linear regression analysis of a compilation of published data from coniferous and broadleaf forests in Eurasia. ResultsThe relationships between litterfall and climatic factors show that in the temperate, subtropical, and tropical areas, broadleaf forests had higher litterfall than coniferous ones, whilst the opposite was found for boreal forests. Combining all climatic zones, a multiple regression analysis using annual mean temperature (T) and annual precipitation (P) as independent variables gave an adjusted R 2 ( R 2 adj ) of 0.272 for total litterfall in coniferous forests ( n = 199, P < 0.001), 0.498 for broadleaf litterfall ( n = 240, P < 0.001), and 0.535 for combined coniferous and broadleaf litterfall ( n = 439, P < 0.001). The linear models for broadleaf stands have significantly higher coefficients for T and P than those for coniferous ones but the intercepts were similar. Thus, litterfall in broadleaf forests increased faster with T and P than that in coniferous forests. Further, a transformation of temperature and precipitation to relative units showed that a relative-unit change in T had a larger impact than P on total litterfall in broadleaf forests. The results indicate that at a continental scale, climatic controls over litterfall differ between coniferous and broadleaf forests.Conclusions A relative unit change in annual mean temperature has a greater effect on litterfall compared to the same change in annual precipitation across the Eurasian forests. Further, the higher response to T for broadleaf forests indicates a difference in climate control between coniferous and broadleaf forests at a continental scale, and consequently different litterfall responses to climate change. BIOSKETCHChunjiang Liu is a research scientist in the Ecology Centre, Christian-Albrechts University of Kiel. His research interests are focused on the environmental control of ecological processes in forest ecosystems at different geographical scales in the context of global change. The approaches used in his work include field studies, meta-analysis and theoretical simulation.

> Abstract The structure, biomass, and activity of the microbial community in the humus layer of boreal coniferous forest stands of different fertility were studied. The Scots pine dominated CT (Calluna vulgaris type) represented the lowest fertility, while VT (Vaccinium vitis-idaéa type), MT (Vaccinium myrtillus type), and OMT (Oxalis acetocella-Vaccinium myrtillus type) following this order, were more fertile types. The microbial community was studied more closely by sampling a succession gradient (from a treeless area to a 180-years-old Norway spruce stand) at the MT type site. The phospholipid fatty acid (PLFA) analysis revealed a gradual shift in the structure of the microbial community along the fertility gradient even though the total microbial biomass and respiration rate remained unchanged. The relative abundance of fungi decreased and that of bacteria increased with increasing fertility. The structure of the bacterial community also changed along the fertility gradient. Irrespective of a decrease in fungal biomass and change in bacterial community structure after clear-cutting, the PLFA analysis did not show strong differences in the microbial communities in the stands of different age growing on the MT type site. The spatial variation in the structure of the microbial community was studied at a MT type site. Semivariograms indicated that the bacterial biomass, the ratio between the fungal and bacterial biomasses, and the relative amount of PLFA 16:1omega5 were spatially autocorrelated within distances around 3 to 4 m. The total microbial and fungal biomasses were autocorrelated only up to 1 m. The spatial distribution of the humus microbial community was correlated mainly with the location of the trees, and consequently, with the forest floor vegetation.http://link.springer-ny.com/link/service/journals/00248/bibs/38n2p168.html

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The aim of this study is to determine the effect of site preparation on soil properties and, in turn, the emergence, mortality, and establishment of Pinus sylvestris L. (Scots pine) and Picea abies (L.) Karst. (Norway spruce) seedlings sown in spring and summer along a slope with variation in soil texture and moisture. Three site preparation treatments of varying intensities were studied: exposed C horizon, mound (broken L–F–H–Ae–B horizons piled over undisturbed ground), and exposed Ae–B horizons. Seedling emergence was higher in the moist growing season than in the dry one. During a dry growing season, mounds and exposed C horizon had negative effects on soil moisture that increased mortality. Moreover, frost heaving was an important cause of winter mortality on mounds and exposed C horizon, whereas frost heaving was low on exposed Ae–B horizons, even though soil moisture and the content of fine soil particles (<0.06 mm) were high. Frost heaving mortality was higher for summer-sown than for spring-sown seedlings and for P. abies than for P. sylvestris. Growing season mortality was high following a winter with frost heaving, suggesting that roots were damaged, thereby making seedlings more susceptible to desiccation.