Geographia Polonica (1999) vol. 72, iss. 2

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Ecosystem process studies along a climatic transect at 52-53 N (12-32 E): pine litter decomposition

Alicja I. Breymeyer, Ryszard Laskowski

Geographia Polonica (1999) vol. 72, iss. 2, pp. 45-64

Abstract

The response of litter decomposition to changing climate was studied on a transect set in Central Europe along parallel 52°N. Rates of decomposition of pine forest litter were measured for one year in 15 stands of Scots pine (Pinus sylvestris) along the 1500 km (20°) W-E transect. The stands were carefully selected on the basis of existing maps and data banks, and were similar as regards topography, soil type, tree-stand age and composition of the herb-layer. Long-term climatic data were assigned to each stand from surrounding climate stations and indexes of climate continentality - an important characteristic for a lati-tudinal transect - were determined.Litter-bags with Scots pine needles, wood material, cones or mixed litter were used. Of the different litters tested, needles and natural mixed litter displayed the best correlation between decomposition rate and climatic indices. No effect of climate on wood decay was found. Along the gradient of oceanic and continental climates, with only minor differences in average annual temperature or AET (Actual Evapotranspiration) between sites, almost 40% of the variability in rates of needle and mixed-litter decomposition was explained by the degree of continentality, expressed as annual temperature amplitude, temperatures of the coldest and warmest months (January and July) and annual amplitude of precipitation. The relationship with precipitation amplitude is especially interesting as this index is not usually used in studies on litter decomposition.The relationship between decomposition rate and the aforementioned climatic indices, was augmented by significant differences between sites classified in three categories according to diversity of plant cover. Decay was slowest on pure stands of Scots pine, significantly faster on mixed pine stands and fastest on anthropogenically-modified pine stands.

Keywords: decomposition, pine forest litter, transects, pine needles, cones

Alicja I. Breymeyer [a.breym@twarda.pan.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, 00-818 Warsaw, Twarda 51/55, Poland
Ryszard Laskowski, Department of Ecosystem Ecology, Institute of Environmental Biology, Jagiellonian University, Ingardena 6, 30-060 Krakow, Poland.