2 SLU-5K0MA Soil development in the Nordic countries - Identification and quantification of factors and processes, and prerequisites for biological primary production. Extended abstracts from a Nordic workshop 6-9 September 1994, Asa, Sweden. Editor: Mats Olsson OSTfiWDON OF TW DOCUMENT IS UNLIMITED m Rapporter i skogsekologi och skoglig marklara Rapport 71 Reports in Forest Ecology and Forest Soils Report 71 Uppsala 1996 Institutionen for skoglig marklara Department of Forest Soils ISSN 0348-3398 Swedish University of Agricultural Sciences ISRN SLU-SKOMA-R—71 —SE PREFACE This report is a compilation of abstracts from research presentations during a Nordic workshop at Asa in Sweden September 6 - 9th 1994. The main goal with the workshop was to give insight in ongoing pedological research in Denmark Finland, Norway and Sweden. Further aims were to form a basis for co-ordinated research that takes advantage of the amplitude in soils and climate, and scientific competence in the Nordic countries. The intention was also to initiate a Nordic soil data-bank to be used in research and teaching. Focus was placed on podzolised soils. These are the predominating soils in the DISCLAJ Portions of this document may be illegible in electronic image products. Images are produced from the best available original document Content Page Soil carbon storage in a gradient of Swedish forest soils. 1 A Alriksson and M. T. Olsson Do some forest ecosystems have a maximum 2 limit for litter decomposition? A synthesis of data. B. Berg and M-B. Johansson Forest productivity on podzols along a south-north 3 gradient in Norway. J. Frank Accumulation of imogolite-type materials in the 6 Spodic B horizons of northern Scandinavia. J. P. Gustafsson, P. Bhattacharya, D.C. Bain, A R. Fraser and W.J. McHardy Effect of paludification on the chemical properties 8 of forest soils in eastern Finland. K. Kotoaro and H. Mannerkoski Amount of organic carbon, horizon thicknesses and 13 trees - heterogeneity of podzolized soil within a forest stand. J. Liski Use of the aluminium species composition in soil. 15 solution as an indicator of acidification U.S. Lunds from and R. Giesler Factors affecting the SOM/DOC relation in a humic podzol. 16 T. Magnusson andU. Skyllberg Clay mineralogy of Swedish podzol profiles. 19 P-A Melkerud Effect of tree species and soil properties on nutrient 24 immobilization in the forest floor. K. Raulund-Rasmussen and H. Vejre Podzolization in Finland. 26 M. Starr and Pekka Tamminen Pedogenic evaluation of some sandy, weakly podzolized 27 soil in Amli, southern Norway. L. Tau Strand Accumulation of C, N and Pin the forest floor: 1. Effects 30 of thinning and soil properties. L Vester dal and Karsten Rauland-Rasmussen Water holding capacity and water balance in 32 podzolised forest soil. CJ Westman SOIL CARBON STORAGE IN A GRADIENT OF SWEDISH FOREST SOILS by A. Alriksson and M.T. Olsson Department of Forest Soils, Swede ish Universityof Agricultural Sciences P.O. Box 7001, S-750 07Uppsala, Sweden Data on organic carbon was collected in a project concerning organic matter influence on weathering rates at the Dep. of Forest Soils. The 18 sites were chosen to represent a gradient of site geochemistry from northern to southern Sweden. The amount of carbon stored in the soil horizons to 1 m depth reflects influence from biomass production capacity and also site history. In southern Sweden most of the present forest soils once have been cultivated and many soil profiles show influence of antropogenic disturbance (Alriksson, A. and Olsson M.T. 1994, in prep). Temperature sum largely reflects a north-south gradient of Sweden and amounts of organic carbon to 1 m depth correlated well to temperature sum (R.2= 0.64). The amount of carbon stored in the soil to 1 m depth ranged between 40 and 110 tonnes ha'l with the highest amounts in southern Sweden. There is a strong correlation (R2= 0.63) between site productivity according to Landmark and Hagglund (1982) and the amount of organic carbon to 1 m dept. In southern Sweden a larger part of the carbon was present in the O plus A horizon compared to northern Sweden. The presence of a carbon rich A-horizon reflects pedo- turbation due to agricultural activities which historically predominated in southern Sweden. References Alriksson A. and Olsson, M.T. 1994. Soil carbon storage in a gradient of Swedish forest soils. (in prep). Hagglund, B. and Landmark, J-E 1982. Handledning i bonitering med skogshogskolans boniteringssystem, del 1-3. Nat. Board of Forestry, Jonkoping, Sweden (in Swedish). 1 DO SOME FOREST ECOSYSTEMS HAVAE A MAXIMUM LIMIT FOR LITTER DECOMPOSITION? A SYNTHESIS OF DATA Berg, B. and Johansson, M-B. Department of Forest Soils, P.0. Box 7001, Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden. Long-term litter decomposition data were used to estimate final decompostion levels using an asymptotic function. The estimated final limit values for decomposition were compared with available chemical data for the different litter types. A total of 41 limit values were estimated from as many different decompsition studies, with 20 different litter types incubated in eight different forest ecosystems. The limit values estimated varied with litter type. They ranged from about 35 percent decomposition to about 100 percent and were linearly related to the initial litter concentrations of N, M and Ca in the newly shed litter. For these three nutrients there are causal relationships to lignin degradation on the level of fungal physiology and to the lignin-degrading microbial community. Using all available data we made simple and multiple linear regressions and obtained a negative linear relationship between limit value and initial N concentration (R2adj=0.429;n=41 ;p<0.001). For needle litter alone we obtained a better relationship (R2adj=0.538;n=23;p<0.001). Manganese concentrations in litter gave a positive relationship (R2adj=0.399;n=25;p<0.001) , with a clear improvement when needle litter was tested for alone (R2atg=0.517;n=18;p<0.001). Calcium alone gave a barely significant relationship. When combining nutrients in multiple linear relationships we obtained high R2 values, indicating that the models were good. Thus for all sites and litter types N, Mn and Ca combined gave and R2ad ; value of 0.809 with n=25 (pcO.001). All needle litters combined gave and R adj of 0.873 (n=16;p<0.001). We concider the use of this finding to be a valuable tool for estimating humus layer buildup and thus forestry practice, as well as a tool for environmental purposes. 2 FOREST PRODUCTIVITY ON PODZOLS ALONG A SOUTH-NORTH GRADIENT IN NORWAY Jon Frank Agricultural University of Norway, Department of Forest Sciences P.O. Box 5044, N-1432 As, Norway. E-mail: [email protected] Key words: Needle analyses, Norway spruce, podzol, regression model, site index, soil properties. Extended abstract The productivity of the boreal spruce forests is a function of a great number of soil and climatic factors. An important aim of the soil-site research has been to develop methods for estimating site index (SI) in forest areas where trees are absent or where they are unsuitable for direct site index measurements, or on bare land suitable for afforestation. The main objectives of this study have been to identify relationships between site index of Norway spruce (Picea abies) and soil, topographic and climatic variables. The results will probably represent a quantitative expression of features related to site quality. The forest and soil of 23 permanent experimental plots (est 1930-79) in pure, even-aged stands (mean age 50 years) of Norway spruce {Picea abies) have been examined along a south-north gradient (1010 km). Needle samples have been collected from the seventh whorl of branches in October November (5 trees/plot). The soil analyses were mainly based on randomly distributed sample points where each horizon was sampled separately (10 to 20 subsamples, 3 replicates). The dominating plant community in the permanent plots is Eu-Piceetum dryopteridetosum, and the soils have been classified into Humo-Ferric or Ferro-Humic Podzol (18 plots), Humic 3 Gleysol (3 plots) and Dystric Brunisol (2 plots) according to the Canadian system. The climatic conditions and the atmospheric depositions are quite different within the very wide study area (Frank et al. 1995). The general pollution pattern shows that the amounts of strong acids, sulphate and nitrogen in the precipitation decrease significantly from south to north, while the pH increases from 4.3-5.1 (Norwegian State Pollution Control Authority 1993). The site index (top height at reference age 40 years at breast height, Tveite 1977) ranged from high (25.1 m) to medium (13.9 m), and decreases from south to north on the podzolic soils studied (R2=0.48). The nutrient status of the trees was sufficient for most elements, and a grouping of the plots into high (SI > 20 m) or medium site index class (SI < 20 m) led to significantly higher element values for calcium, copper, magnesium, nitrogen and sulphur in current needles from the high compared with the medium site class, but significantly lower value for boron (Frank et al. 1995). The nitrogen capital in the soil root zone is also significantly higher on the plots grouped into the high site class. Significant negative correlations exist between site index and the amount of iron in the upper part of the podzolic B-horizons (Figure 1). Pyrophosphate - exiractahte Fa (%) Dithionite-titrate extractable Fa (%) Figure 1. Relationships between site index of Norway spruce and pyrophosphate and dithionite-citrate extractable Fe, respectively, accumu­ lated in the upper part of the podzolic B horizon.