Litter fall in some European coniferous forests as dependent on climate: asynthesis

Litter fall data was available for 64 sites in Europe, most of them in Fenn oscandia. Included were 48 sites with pine (Pinus spp.), mainly Scots pine (Pinus sylvestris L.), and 16 sites with spruce (Picea spp.), mainly Norway spruce (Picea abies (L.) Karst.). Regressions were calculated for needle a nd total litter fall against a set of climatic parameters, and the best sim ple relationships were obtained with annual actual evapotranspiration (AET) and other parameters including temperature, whereas for example, precipita tion gave lower r values. For needle litter fall and AET using all data, th e R-adj(2) value was 0.635 (n = 64), and for needle litter for pine and spr uce separately, the R-adj(2) were 0.576 (n = 48) and 0.775 (n = 16), respec tively. AET plus stand age gave highly significant relationships for both c oniferous genera combined (R-adj(2) = 0.683), and for pine and spruce separ ately the corresponding values were 0.655 and 0.843, respectively. Using al l available data we found highly significant relationships between needle l itter fall and total litter fall. For Fennoscandia, litter fall for Scots p ine and Norway spruce were compared. AET versus needle litter fall gave hig hly significant relationships for Scots pine (R-adj(2) = 0.448, n = 34) and for Norway spruce (R-adj(2) = 0.678, n = 13); the relationships were signi ficantly different from each other.