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Rate of change of pine litter fall and decay in response to changing climate along N-S transect

Breymeyer A.

Polish Journal of Ecology

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2003

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Vol. 51, nr 4

553-555

EN

The response of pine ecosystems to changing latitude and thermoclimate in Central/Northern Europe was investigated through the measurements of rates of two ecosystem processes: organic matter (litter production and decomposition. Studies were carried out at nine sites of pine and mixed pine forests placed along the N-S transect of about 2000 km crossing Finland, Estonia, Latvia, Lithuania and Poland. Warmer climater were observed with movement to southern sites; the coefficient of determination (R^2) between annual long-term temperature and latitude was at the level of 0.99. The rates of change of both processes were compared in terms of relative increment per 1 stopień C of long-term temperature and per -1 stopień of latitude, and expressed in %. Litter production responds stronger to the southward change of climate: the fall of litter is 18-19% greater per +1 stopień C of average annual temperature and by 8 % greater per each -1 stopień of latitude, compared to the decomposition process, which was accelerated at the rate of 9-12% per 1 stopień C and 4-5% per -1 stopień of latitude. These results are summarized by the statement that in pine ecosystems the OM Production Sub-system is more sensitive to change of climate than the Sub-system of OM Decay, which is more conservative.

2

Processes of litter fall and decomposition : boreal-temperate transect studies of pine ecosystem

Breymeyer A.

Polish Journal of Ecology

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2003

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Vol. 51, nr 4

529-543

EN

The processes of litter production and decomposition were studied in pine and mixed pine forests (10 sites) distributed along the N-S transect in Europe. The transect stretched from 70 stopni N in Northern Finland and Norway to 50 stopni N in Southern Poland. Mean annual temperatures change regularly along the transect from -1.9 to +7.4 stopni C, while precipitation does not show any distinct pattern. Annual production and decomposition of litter are stimulated by warming. The primary factors governing the rates of both processes are related to thermic regime, most frequently to the long-term temperatures registered in the meteorological stations in the vicinity of sites. Correlation between decomposition rate and temperature (R^2) range from 0.75 to 0.93, between decomposition rate and latitude from 0.72 to 0.80, and between decomposition rate and precipitation from 0.52 to 0.63 (in the last case only correlations with long-term precipitation are significant). Correlation coefficients R^2 between litterfall and temperature range from 0.53 to 0.80, between litterfall-latitude from 0.72 to 0.80, and between litterfall-precipitation from 0.52 to 0.63 (significant only for long-term precipitation). With increasing temperature decomposition rates increase from about 0.09 g.g^-1.y^-1 (needles 0.13 g.g^-1.y^-1, wood 0.06 g.g^-1.y^-1) in the North to about 0.32 g.g^-1.y^-1 (needles 0.41 g.g^-1.y^-1, wood 0.18 g.g^-1.y^-1) in the South. Litterfall increases from 103.19 g.m^-2.y^-1 (in this needles 56.73 g.m^-2.y^-1, wood 45.59 g.m^-2.y^-1) in the North, to about 419.36 g.m^-2.y^-1 (needles 203.95 g.m^-2.y^-1, wood 203.56 g.m^-2.y^-1) in the South. OM annual accumulation increases southward, ranging from about 100 (North) to about 370 (South) grams per m^2. Accumulation is strongly connected with air temperatures on the sites (correlation coefficients (R^2) at around 0.9).

3

Pine ecosystem response to warming along North-South climatic transect in Europe : presentation of research project

Breymeyer A.

Polish Journal of Ecology

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2003

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Vol. 51, nr 4

403-411

EN

An attempt was made to evaluate the response of the ecosystem to changes of climate in ten pine forest stands. It was assumed that the ecosystem response to environmental change can be evalued by examining differences in ecosystem structures and would be measured through the change in the rates of ecosystem processes. The changes of structures and rates are registered along the longest, N-S transect available on the European Continent above 50 stopni N. This transect in within the belt crossing Northern Scandinavia (Norvay and Finland up to 70 stopni N), the Baltic States (Estonia, Latvia, Lithuania) and Eastern Poland (from 50 stopni N). The transect covers 20 degrees oflatitude and is more than 2000 km long. The difference in average annual temperature (long-term measurements) between the two extreme sites exceeds 9 stopni C, and there is a regular soutward increase of average site temperature. Precipitation does not show any regular pattern of change along the transect. Average site elevation is 86 m a.s.l., and the average forest age 110 years. All sites are dominated by an overstory of Scots pine, and in the Braun-Blanquet classification they all belong to Vaccinio-Piceetea class of forests, which are common in Europe. During four years of study (1997, 1998, 1999 and 2000) four expeditions to the transect were organized. The Following studies were conducted on each site: the origin and structure as well as physical and chemical features of soils; tree stand age, height, basal area, biomass and carbon content; vertical and horizontal structure of ground vegetation, its diversity, biomass and carbon; litter fall, its decomposition and accumulation; and radial growth of trees.

4

Comparative analysis of eight neotropical savanna ecosystems : production-decomposition indexes

Breymeyer A.

Polish Journal of Ecology

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2001

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Vol. 49, nr 4

339-358

EN

Comparative studies of the functioning of eight neotropical savannas were conducted in Venezuela and Panama. Savannas were classified in the following 4 types of increasing productivity: Trachypogon savanna, "Bajio" savanna, Paspalum savanna and Hyparrhenia savanna. Each savanna type was reprezented by sites ungrazed orgrazed by cows. All stands, except for the flooded "Bajio" were burnt at the end of the rainy season. The rates of two ecosystem processes were measured: productivity (NPP) and decomposition. The index of productivity was the maximum biomass ofABVG (above ground biomass) and BLG (below ground mass of roots); this was measured at the end of the rainy season just before the fire. Decomposition rate was evalued using litterbags with local litter or filter paper exposed in different layers of savannas. ABVG production of biomass is highest in non-grazed Hyparrhenia savanna, where it reaches 19-20 g d.w.m^-2 daily and 2850-2950 g d.w.m^-2 in the rainy season. This is a very high figure rarely noted in grasslands. The lowest productivity -544 g d.w2.m^-2 ABVG in the rainy seasons - was noted in Trachypogon savannas. Roots constitute a small part of savanna biomass: 14-25% in Hyparrhenia savanna, and 6-45% in Venezuelan savannas. The biomas of roots is concentrated in the 0-10 cm layer: 86-90% in Hyparrhenia, 40-72% in Venezuelan savannas. The decomposition of litter evalued for 6 Venezuelan savannas and calculated for the wet season ranges from 180 to 1126 g d.w.^-2. Higher decomposition occur in stands with higher productivity. To the new findings can be assigned the results of comparative measures of decomposition on four levels (from soil to 40 cm above the ground surface). In the Hyparrhenia stand as much as 52% of decomposition takes place in the standing plants. The OM budget calculations suggest that all 8 stands are characterized by an accumulation of organic matter; however, decomposition rate is underestimated as the fraction of OM decomposed in standing plants is not considered.