Ryszard Laskowski

Articles

What Determines Forest Litter Decomposition? Global Trends And Local Variance

Ryszard Laskowski

Geographia Polonica (2012) vol. 85, iss. 2, pp. 39-46 | Full text
doi: https://doi.org/10.7163/GPol.2012.2.9

Further information

Abstract:

Global patterns in forest leaf litter decomposition has been studied for decades. The result has been the formulation ofa range of models relating organic matter decay rate to climatic and litter-specific factors. It is now commonly acceptedthat the prime factor determining the litter decomposition rate on a global scale, is actual evapotranspiration (AET).However, this main effect can be seriously modified by the chemical composition of organic matter itself, resulting in largevariance at local scales. Among leaf litter components, the lignin concentration, content of water-soluble compounds,concentration of nitrogen and some other nutrients have been indicated by different authors as the major determinantsof litter decomposition rate. Unfortunately, our understanding of the factors regulating the decomposition is still far fromsatisfactory as indicated by the failure of existing models to predict properly litter decay rate in many cases. These includeespecially ecosystems from outside the temperate climate, such as boreal and wet tropical forests. The existing modelsstill cannot explain the large differences in litter decomposition rates between species, even within reasonably wellstudiedtemperate forests. My article presents several reasons for the problem of finding satisfactory litter decompositionmodels. The most important reason is the bias in studies towards temperate ecosystems, high inter-correlations betweenchemical characteristics of litter and soil, and the lack of properly designed studies on very broad geographic scales.

Keywords: chemistry, climate, decay, models, organic matter, soil, turnover

Ryszard Laskowski, Department of Ecosystem Ecology, Institute of Environmental Biology, Jagiellonian University, Ingardena 6, 30-060 Krakow, Poland.

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 | Full text

Further information

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.