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Articles containing the keyword 'decomposition'.

Category: Research article

article id 1403, category Research article
Kristina Mjöfors, Monika Strömgren, Hans-Örjan Nohrstedt, Annemieke Ingrid Gärdenäs. (2015). Impact of site-preparation on soil-surface CO2 fluxes and litter decomposition in a clear-cut in Sweden. Silva Fennica vol. 49 no. 5 article id 1403. https://doi.org/10.14214/sf.1403
Highlights: Disturbances of the soil did not lead to higher CO2 emissions from the soil; Heavy mixing of the soil lead to lower CO2 emissions from the soil; Buried needles and coarse roots decomposed faster than those on the surface; Abundance of δ15N decreased in needles and roots after site preparation.

Boreal forest soil contains significant amounts of organic carbon. Soil disturbance, caused for example by site preparation or stump extraction, may increase decomposition and thus lead to higher CO2 emissions, contributing to global warming. The aim of this study was to quantify responses of soil-surface CO2 fluxes (Rs) and litter (needle and root) decomposition rates following various kinds of soil disturbance commonly caused by mechanical site preparation and stump harvest. For this purpose four treatments were applied in a clear-cut site in central Sweden: i) removal of the humus layer and top 2 cm of mineral soil, ii) placement of a humus layer and 2 cm of mineral soil upside down on top of undisturbed soil, forming a double humus layer buried under mineral soil, iii) heavy mixing of the humus layer and mineral soil, and iv) no disturbance (control). Rs measurements were acquired with a portable respiration system during two growing seasons. To assess the treatments’ effects on litter decomposition rates, needles or coarse roots (Ø = 6 mm) were incubated in litterbags at positions they would be located after the treatments (buried, or on top of the soil). The results indicate that site preparation-simulating treatments have no effect or may significantly reduce, rather than increase, CO2 emissions during the following two years. They also show that buried litter decomposes more rapidly than litter on the surface, but in other respects the treatments have little effect on litter decomposition rates.

  • Mjöfors, Swedish University of Agricultural Sciences (SLU), Department of Soil and Environment, P.O. Box 7014, 150 07 Uppsala, Sweden ORCID ID:E-mail: kristina.mjofors@slu.se (email)
  • Strömgren, Swedish University of Agricultural Sciences (SLU), Department of Soil and Environment, P.O. Box 7014, 150 07 Uppsala, Sweden ORCID ID:E-mail: Monika.stromgren@slu.se
  • Nohrstedt, Swedish University of Agricultural Sciences (SLU), Department of Soil and Environment, P.O. Box 7014, 150 07 Uppsala, Sweden ORCID ID:E-mail: Hans-orjan.nohrstedt@slu.se
  • Gärdenäs, Swedish University of Agricultural Sciences (SLU), Department of Soil and Environment, P.O. Box 7014, 150 07 Uppsala, Sweden ORCID ID:E-mail: Annemieke.gardenas@slu.se
article id 1403, category Research article
Kristina Mjöfors, Monika Strömgren, Hans-Örjan Nohrstedt, Annemieke Ingrid Gärdenäs. (2015). Impact of site-preparation on soil-surface CO2 fluxes and litter decomposition in a clear-cut in Sweden. Silva Fennica vol. 49 no. 5 article id 1403. https://doi.org/10.14214/sf.1403
Highlights: Disturbances of the soil did not lead to higher CO2 emissions from the soil; Heavy mixing of the soil lead to lower CO2 emissions from the soil; Buried needles and coarse roots decomposed faster than those on the surface; Abundance of δ15N decreased in needles and roots after site preparation.

Boreal forest soil contains significant amounts of organic carbon. Soil disturbance, caused for example by site preparation or stump extraction, may increase decomposition and thus lead to higher CO2 emissions, contributing to global warming. The aim of this study was to quantify responses of soil-surface CO2 fluxes (Rs) and litter (needle and root) decomposition rates following various kinds of soil disturbance commonly caused by mechanical site preparation and stump harvest. For this purpose four treatments were applied in a clear-cut site in central Sweden: i) removal of the humus layer and top 2 cm of mineral soil, ii) placement of a humus layer and 2 cm of mineral soil upside down on top of undisturbed soil, forming a double humus layer buried under mineral soil, iii) heavy mixing of the humus layer and mineral soil, and iv) no disturbance (control). Rs measurements were acquired with a portable respiration system during two growing seasons. To assess the treatments’ effects on litter decomposition rates, needles or coarse roots (Ø = 6 mm) were incubated in litterbags at positions they would be located after the treatments (buried, or on top of the soil). The results indicate that site preparation-simulating treatments have no effect or may significantly reduce, rather than increase, CO2 emissions during the following two years. They also show that buried litter decomposes more rapidly than litter on the surface, but in other respects the treatments have little effect on litter decomposition rates.

  • Mjöfors, Swedish University of Agricultural Sciences (SLU), Department of Soil and Environment, P.O. Box 7014, 150 07 Uppsala, Sweden ORCID ID:E-mail: kristina.mjofors@slu.se (email)
  • Strömgren, Swedish University of Agricultural Sciences (SLU), Department of Soil and Environment, P.O. Box 7014, 150 07 Uppsala, Sweden ORCID ID:E-mail: Monika.stromgren@slu.se
  • Nohrstedt, Swedish University of Agricultural Sciences (SLU), Department of Soil and Environment, P.O. Box 7014, 150 07 Uppsala, Sweden ORCID ID:E-mail: Hans-orjan.nohrstedt@slu.se
  • Gärdenäs, Swedish University of Agricultural Sciences (SLU), Department of Soil and Environment, P.O. Box 7014, 150 07 Uppsala, Sweden ORCID ID:E-mail: Annemieke.gardenas@slu.se
article id 1337, category Research article
Leszek Bujoczek, Małgorzata Bujoczek, Jan Banaś, Stanisław Zięba. (2015). Spruce regeneration on woody microsites in a subalpine forest in the western Carpathians. Silva Fennica vol. 49 no. 3 article id 1337. https://doi.org/10.14214/sf.1337
Highlights: The occurrence probability of Picea abies seedlings on fallen deadwood was found to increase with diameter and decay stage of deadwood and with the volume of living trees, and to decrease with the density of living trees, sapling density, and land slope. It was also higher on stumps with greater diameter and in plots with higher sapling density, but decreased with increasing stump height.

The density of Picea abies [L.] Karst. regeneration on different microsites, the quantity and quality of woody microsites, and seedling occurrence probability on stumps and fallen deadwood were studied in a subalpine forest that has been under protection for approximately 30–40 years (Gorce Mountains in the western Carpathians). Thirty percent of seedlings and 29% of saplings grew on stumps and fallen deadwood, while the remaining regeneration occurred on soil surface and mounds created by uprooted trees. The occurrence probability of Picea seedlings on fallen deadwood increased with deadwood diameter and decay stage and with the volume of living trees, and decreased with increased density of living trees, sapling density, and land slope. Furthermore, seedlings were more likely to grow on stumps with a greater diameter and in plots with higher sapling density, but less likely to grow on higher stumps. Stumps and fallen deadwood covered about 4% of the forest floor, but the material that is most important for promoting regeneration (strongly decomposed logs and those of a diameter exceeding 30 cm) took up only about 22 m2 ha-1. We have concluded that in a subalpine forest that has been protected for 30–40 years regeneration processes take place mostly on soil surface and stumps. The role of fallen deadwood increases over time as a greater number of suitable logs (in terms of size and decay stage) become available.

  • Bujoczek, University of Agriculture in Krakow, ORCID ID:E-mail: lbujoczek@gmail.com (email)
  • Bujoczek, University of Agriculture in Krakow, ORCID ID:E-mail: bujoczek.m@gmail.com
  • Banaś, University of Agriculture in Krakow, ORCID ID:E-mail: rlbanas@cyf-kr.edu.pl
  • Zięba, University of Agriculture in Krakow, ORCID ID:E-mail: rlzieba@cyf-kr.edu.pl
article id 1211, category Research article
Xiao Chen, Deborah Page-Dumroese, Ruiheng Lv, Weiwei Wang, Guolei Li, Yong Liu. (2014). Interaction of initial litter quality and thinning intensity on litter decomposition rate, nitrogen accumulation and release in a pine plantation. Silva Fennica vol. 48 no. 4 article id 1211. https://doi.org/10.14214/sf.1211
Highlights: Litter quality and thinning showed an interaction on one year litter decomposition rates, N accumulation, and net N release; N accumulated until the underlying critical acid-unhydrolyzable residue to nitrogen ratio (approximately 57–69) was met; Increased N concentration in litter and thinning intensity induced rapid litter decomposition and N cycling in coniferous plantation with a slow decomposition rate.
Thinning alters litter quality and microclimate under forests. Both of these two changes after thinning induce alterations of litter decomposition rates and nutrient cycling. However, a possible interaction between these two changes remains unclear. We placed two types of litter (LN, low N concentration litter; HN, high N concentration litter) in a Chinese pine (Pinus tabulaeformis Carrière) plantation under four thinning treatments to test the impacts of litter quality, thinning or their combination on decomposition rate and N cycling. In our study, N was accumulated to approach an underlying critical acid-unhydrolyzable residue to nitrogen ratio (approximately 57–69) in litter. Moreover, an interaction between litter quality and thinning on decomposition rates, N accumulation and net release did exist. On one hand, one year decomposition rate of LN was elevated after thinning while that of HN remained the same or even lower (under light thinning); N accumulation of LN declined with light thinning and was restored with the increase of thinning intensity whereas that of HN did not decline with thinning and increased under heavy thinning; Net N release from LN was only found in light and heavy thinning while that from HN was found in all treatments, moreover net N release from LN and HN were both elevated under heavy thinning. On the other hand, HN decomposed faster, accumulated less and released more N than LN did under all treatments. Generally, high N concentration in litter and high-intensity thinning can lead to rapid litter decomposition and N cycling in coniferous plantations.
  • Chen, Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Beijing, 100083, China ORCID ID:E-mail: chenxiao_0123@126.com
  • Page-Dumroese, U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, 1221 South Main Street, Moscow, ID 83843, USA ORCID ID:E-mail: ddumroese@fs.fed.us
  • Lv, College of Plant Science and Technology, Tarim University, Alar Xinjiang, 843300, China ORCID ID:E-mail: lvrh514723@126.com
  • Wang, Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Beijing, 100083, China ORCID ID:E-mail: fuyuerdejia@126.com
  • Li, Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Beijing, 100083, China ORCID ID:E-mail: glli226@163.com
  • Liu, Key Laboratory for Silviculture and Conservation of Ministry of Education, Beijing Forestry University, Beijing, 100083, China ORCID ID:E-mail: lyong@bjfu.edu.cn (email)
article id 98, category Research article
Meeri Pearson, Markku Saarinen, Kari Minkkinen, Niko Silvan, Jukka Laine. (2011). Mounding and scalping prior to reforestation of hydrologically sensitive deep-peated sites: factors behind Scots pine regeneration success. Silva Fennica vol. 45 no. 4 article id 98. https://doi.org/10.14214/sf.98
Watering up typically ensues after clearcutting forestry-drained peatland forests. Thus, the effectiveness of maintenance drainage and soil preparation procedures becomes paramount for establishing a new generation of commercial forest. Mounding is the primary method of soil preparation applied in regeneration sites lying on deep peat. As raised planting spots, mounds are resistant to waterlogging and assumed to be beneficial for organic matter (OM) decomposition via, e.g., increased soil aeration and temperature, which would also enhance seedling growth. In recent years, however, less intensive and cheaper alternatives like scalping have been sought with some reported cases of success. Our case study investigated the survival and growth of Scots pine outplants in mounds, scalps, and unprepared microsites along a moisture gradient. After three growing seasons, mounding accelerated neither seedling growth nor OM decomposition relative to the unprepared treatment. Survival in mounds was nonetheless superior overall. Scalps behaved as water collecting depressions leading to a catastrophic regeneration result. Based on our findings, water table level (WTL) overrides other growth-controlling factors in excess moisture conditions. To combat watering up coupled with greater than normal rainfall, we recommend reforestation strategies which provide elevated, prepared planting spots (i.e., mounds) or utilize unprepared, higher microforms.
  • Pearson, Finnish Forest Research Institute, Western Finland Regional Unit, Kaironiementie 15, FI-39700 Parkano, Finland ORCID ID:E-mail: meeri.pearson@metla.fi (email)
  • Saarinen, Finnish Forest Research Institute, Western Finland Regional Unit, Kaironiementie 15, FI-39700 Parkano, Finland ORCID ID:E-mail:
  • Minkkinen, University of Helsinki, Department of Forest Sciences, Helsinki, Finland ORCID ID:E-mail:
  • Silvan, Finnish Forest Research Institute, Western Finland Regional Unit, Kaironiementie 15, FI-39700 Parkano, Finland ORCID ID:E-mail:
  • Laine, Finnish Forest Research Institute, Western Finland Regional Unit, Kaironiementie 15, FI-39700 Parkano, Finland ORCID ID:E-mail:
article id 255, category Research article
Claude Vidal, Adrian Lanz, Erkki Tomppo, Klemens Schadauer, Thomas Gschwantner, Lucio di Cosmo, Nicolas Robert. (2008). Establishing forest inventory reference definitions for forest and growing stock: a study towards common reporting. Silva Fennica vol. 42 no. 2 article id 255. https://doi.org/10.14214/sf.255
International agreements such as the Kyoto protocol and Convention on Biological Diversity (1992), as well as, criteria and indicator processes require reports on the status of nations’ forests. Any comparison of the current status and trends of forest resources among nations presumes that the nations’ applied definitions and concepts produce comparable estimates of the status of forests. In spite of this, the FAO has already collected global information for 60 years and made noticeable efforts in creating common definitions, but forest related data are still collected using diverse definitions, even regarding basic concepts such as forest and forest area. A simple consequence is that the cross-countries estimates are not comparable. The reasons behind the differences in the definitions are diverse histories, and sometimes different use of forests. In an ideal case, national forest inventories should fulfil both national and international needs. In addition to the FAO’s Forest Resources Assessment process, other efforts are made to assess the status of forests in European countries, e.g. European Forest Information and Communication System (EFICS). EFICS produced reports about forest inventories but does not suggest any common definition or method to convert estimates from one definition to another one. This article presents principles and methods to create commonly acceptable and adoptable definitions for forest inventories. The principles and methods are demonstrated using two examples: the reference definitions of forest and growing stock. The article is based on the work of COST Action E43 (http://www.metla.fi/eu/cost/e43/).
  • Vidal, Inventaire Forestier National, Château des Barres, Nogent-sur-Vernisson, France ORCID ID:E-mail: claude.vidal@ifn.fr (email)
  • Lanz, WSL/FNP, Abteilung Landschaftsinventuren, Birmensdorf, Switzerland ORCID ID:E-mail:
  • Tomppo, Finnish Forest Research Institute, Vantaa Research Unit, Vantaa, Finland ORCID ID:E-mail:
  • Schadauer, Bundesamt und Forschungszentrum für Wald, Wien, Austria ORCID ID:E-mail:
  • Gschwantner, Bundesamt und Forschungszentrum für Wald, Wien, Austria ORCID ID:E-mail:
  • di Cosmo, ISAFA, Villazzano, Italy ORCID ID:E-mail:
  • Robert, Inventaire Forestier National, Ch‰teau des Barres, Nogent-sur-Vernisson, France ORCID ID:E-mail:
article id 294, category Research article
Ülle Püttsepp, Krista Lõhmus, Andres Koppel. (2007). Decomposition of fine roots and α-cellulose in a short rotation willow (Salix spp.) plantation on abandoned agricultural land. Silva Fennica vol. 41 no. 2 article id 294. https://doi.org/10.14214/sf.294
Decomposition of fine roots (<1 mm in diameter) of the clones of Salix viminalis, S. dasyclados and α-cellulose sheets (50 x 10 x 1 mm) was studied in a 6-years old Salix spp. plantation established on abandoned agricultural land in Estonia. The substrates were incubated in litterbags (mesh size 0.14 mm) in 5–10 cm topsoil, in non-fertilised plots for one year. Changes in the ash-free weight of the fine roots were best described by negative exponential models (S. viminalis R2 = 0.98, S. dasyclados R2 = 0.96), and by a linear model for α-cellulose (R2 = 0.63). The sheets of α-cellulose decomposed roughly twice as rapidly as the fine roots (S. viminalis k = 0.325, S. dasyclados k = 0.165). The remaining (of the initial) ash-free weights of the fine roots were 73.3 ± 0.8% (mean ± SE) and 85.8 ± 2.2% respectively, and of the α-cellulose 35.9 ± 8.5%, in the end of the one year of decomposition. The amount of acid detergent (AD) lignin in the fine-roots of S. viminalis increased significantly and did not change in S. dasyclados, suggesting higher activity of microbial decomposers in the first substrate. Of the studied quality parameters, the AD lignin was the major factor determining the different rate of decomposition of the fine roots of S. viminalis and S. dasyclados. Nitrogen was recycled in the fine root sub-system in both Salix species. This knowledge can be applied in the management of Salix plantations, aimed at bioenergy production.
  • Püttsepp, Department of Ecology, Swedish University of Agricultural Sciences, P.O. Box 7072, SE-75007 Uppsala, Sweden; Estonian University of Life Sciences, Kreuzwaldi 64, Tartu 51014, Estonia ORCID ID:E-mail: ulle.puttsepp@ekol.slu.se (email)
  • Lõhmus, Institute of Geography, University of Tartu, Vanemuise 46, Tartu 51014, Estonia ORCID ID:E-mail:
  • Koppel, Estonian University of Life Sciences, Kreuzwaldi 64, Tartu 51014, Estonia ORCID ID:E-mail:
article id 305, category Research article
Anna-Maria Veijalainen, Marja-Liisa Juntunen, Arja Lilja, Helvi Heinonen-Tanski, Leo Tervo. (2007). Forest nursery waste composting in windrows with or without horse manure or urea – the composting process and nutrient leaching. Silva Fennica vol. 41 no. 1 article id 305. https://doi.org/10.14214/sf.305
In order to find the best management practices for forest nursery waste composting, organic waste was composted without or with horse manure or urea in six windrows for two years. The windrows were built in four consecutive years during 1999–2002. In 1999, no extra-nutrients were added to the windrow (N99). In 2000, urea fertilizer was used as a nitrogen source (U00). Despite this, the process did not function properly. In 2001, two windrows were built, one (H01) with and the other (N01) without horse manure. Horse manure slightly accelerated the heating process. Consequently, two windrows with more horse manure were built in 2002. One was aerated passively (H02) as earlier windrows, and the other was aerated forcedly (HA02). Horse manure and forced aeration were needed to keep the temperature above 55°C for long enough to ensure microbial hygiene of the material. The degradation of cellulose was greater during the curing stage. Nutrient leaching was low, although the additives increased leaching in conjunction with the inefficient process. The results showed that forest nursery waste alone is ineffective at raising the temperature of the compost, and degrades slowly due to its low nutrient and easily available carbon content. The best management practice for forest nursery waste composting is to use horse manure and aeration to ensure the heating process. Environmental contamination can be avoided by collecting the leachates. Further research is needed to evaluate the usability of the compost.
  • Veijalainen, Finnish Forest Research Institute, FI-77600 Suonenjoki, Finland ORCID ID:E-mail:
  • Juntunen, Finnish Forest Research Institute, FI-77600 Suonenjoki, Finland ORCID ID:E-mail:
  • Lilja, Finnish Forest Research Institute, PO Box 18, FI-01301 Vantaa, Finland ORCID ID:E-mail:
  • Heinonen-Tanski, Univ. of Kuopio, Dept. of Environm. Sc., PO Box 1627, FI-70211 Kuopio, Finland ORCID ID:E-mail:
  • Tervo, Finnish Forest Research Institute, FI-77600 Suonenjoki, Finland ORCID ID:E-mail:
article id 599, category Research article
Chun-Jiang Liu, Carl J. Westman, Hannu Ilvesniemi. (2001). Matter and nutrient dynamics of pine (Pinus tabulaeformis) and oak (Quercus variabilis) litter in North China. Silva Fennica vol. 35 no. 1 article id 599. https://doi.org/10.14214/sf.599
In the mountainous area of North China, a distinguishing feature of climate is the serious drought of spring and the humidity and high temperature of summer by which the litter production and decomposition of forest litter were strongly characterized. We investigated the dynamic and nutrient characteristics of litter in a 30-year-old mixed stand of Chinese pine (Pinus tabulaeformis Carr.) and deciduous orient oak (Quercus variabilis Bl.) and two comparable pure stands. Oak litterfall peaked in November and pine litterfall in December. The oak stand had the largest annual litterfall (347 g m–2) and the forest floor mass (950 g m–2), the mixed stand the second (236 g m–2 and 634 g m–2), and the pine stand the least (217 g m–2 and 615 g m–2). The nutrient return through litterfall and the storage in forest floor followed corresponding order between three stands. The weight loss of pine and oak foliage litter in first year was 25% and 20%. For senesced pine and oak leaves, the translocation rates of N, P and K were 56–83%. Nutrient concentrations were higher in oak leaf litter than pine needle litter, and the concentration of N and Ca appeared to rise while K concentration decreased in both decomposing litter.
  • Liu, Department of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland ORCID ID:E-mail: cliu@silvia.helsinki.fi (email)
  • Westman, Department of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland ORCID ID:E-mail:
  • Ilvesniemi, Department of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland ORCID ID:E-mail:

Category: Research note

article id 91, category Research note
Raisa Mäkipää, Tapio Linkosalo. (2011). A non-destructive field method for measuring wood density of decaying logs. Silva Fennica vol. 45 no. 5 article id 91. https://doi.org/10.14214/sf.91
Decaying dead wood density measurements are a useful indicator for multiple purposes, such as for estimating the amount of carbon in dead wood and making predictions of potential diversity of dead wood inhabiting fungi and insects. Currently, qualitative decay phases are used as wood density estimates in many applications, since measuring the density is laborious. A quantitative measure of density would, however, be preferred over the qualitative one. Penetrometers, which are commonly used for measuring the density of standing trees, might also be applicable to dead wood density measurements. We tested the device for making quick, quantitative measurements of decaying logs. The penetrometer measures the depth into which a pre-loaded spring forces a pin in the wood. We tested pins of 5 and 10 mm diameter together with an original 2.5 mm pin and compared the results with gravimetric density measurements of the sample logs. Our results suggest that the standard pin works for less decayed wood, but for more decomposed wood, the thicker 5 mm pin gave more reliable estimates when the penetration measures were converted to densities with a linear regression function (R2 = 0.62, F = 82.9, p = 0.000). The range of wood densities successfully measured with the 5 mm pin was from 180 to 510 kg m–3. With the 10 mm pin, the measuring resolution of denser wood was compromised, while the improvement at the other end of density scale was not large. As a conclusion, the penetrometer seems to be a promising tool for quick density testing of decaying logs in field, but it needs to be modified to use a thicker measuring pin than the standard 2.5 mm pin.
  • Mäkipää, The Finnish Forest Research Institute, Vantaa, Finland ORCID ID:E-mail: raisa.makipaa@metla.fi (email)
  • Linkosalo, The Finnish Forest Research Institute, Vantaa, Finland ORCID ID:E-mail:

Category: Article

article id 7172, category Article
Ilmari Schalin. (1966). Studies on the microfungi in the forest floor of subarctic pine forests. Acta Forestalia Fennica vol. 81 no. 7 article id 7172. https://doi.org/10.14214/aff.7172

Dilution plate method was used in studying the density and composition of the microfungal populations of the organic layer of Scots pine forests, and the soil-plate method in studying the part of these populations decomposing cellulose. The media used were rose bengal agar (Martin’s medium for fungi) and cellulose medium.

The microfungal density depended to a considerable extent on the moisture content and temperature of the organic layer. Only the combination of relatively high moisture content and temperature, but neither of these factors alone, influenced considerably the microfungal population density. The correlation of the populations to the changes in this combined factor was stronger than the correlation to the seasonal variations of spring, summer and autumn.

The microfungal population consisted of only a few species. Mucor, Mortierella and Penicillium were the most common genera isolated from the rose bengal agar. The first and the last of these comprised almost 90% of the total population. For the Mucor fungi, increases in the moisture content up to the maximum values found (75%) were favourable; the Penicillium fungi, on the contrary, were intolerant of high moisture content.

Among the cellulose decomposing microfungi grown on cellulose medium, Trichoderma sp. was the most common; also, it formed the most colonies, tolerated the lowest temperatures, and was most efficient. The others were of the genera Pullularia, Verticillium, Scopulariopsis and Penicillium. In addition, there were some unidentified Phycomycetes fungi. Only the two first-mentioned caused observable changes in cellulose.

  • Schalin, ORCID ID:E-mail:
article id 7171, category Article
Erkki Lähde. (1966). Vertical distribution of biological activity in peat of some virgin and drained swamp types. Acta Forestalia Fennica vol. 81 no. 6 article id 7171. https://doi.org/10.14214/aff.7171

The objective of this project was to determine the amount of gas exchange in peat samples collected from several swamps, using the Warburg method in the laboratory measurements. Special attention was directed on the influence of the lowering of the ground water level through drainage, on oxidation-reduction conditions in the samples from both forested and treeless peatlands, by measuring oxygen uptake and CO2 release. The biological activity in situ was determined by the cellulose decomposition rate in the sample plots. The six areas examined were both in drained peatlands and peatlands in natural condition.

The results show that in the sample plots in open swamps there was no consistent differences in the CO2 release rate in peat samples taken from different depths. However, in the sample plots on forested swamps rapid decrease is seen with increasing depth. The decreased biological activity of peat is caused by the oxidation-reduction conditions. The CO2 release rate may also be due to the respiration of tree roots, which are very shallow in peatlands.

The rate of in situ cellulose decomposition experiment and CO2 release indicated by the Warburg measurements appear to be correlated. The results indicate improved conditions for cellulose-decomposing microbes after draining. It is also possible that the biological activity of peat after draining increases to a considerable depth until the decrease of easily decomposable substances limit the activity in an old drainage area. The cellulose decomposition rate would still increase as the oxidation-reduction conditions improve.

  • Lähde, ORCID ID:E-mail:
article id 7171, category Article
Erkki Lähde. (1966). Vertical distribution of biological activity in peat of some virgin and drained swamp types. Acta Forestalia Fennica vol. 81 no. 6 article id 7171. https://doi.org/10.14214/aff.7171

The objective of this project was to determine the amount of gas exchange in peat samples collected from several swamps, using the Warburg method in the laboratory measurements. Special attention was directed on the influence of the lowering of the ground water level through drainage, on oxidation-reduction conditions in the samples from both forested and treeless peatlands, by measuring oxygen uptake and CO2 release. The biological activity in situ was determined by the cellulose decomposition rate in the sample plots. The six areas examined were both in drained peatlands and peatlands in natural condition.

The results show that in the sample plots in open swamps there was no consistent differences in the CO2 release rate in peat samples taken from different depths. However, in the sample plots on forested swamps rapid decrease is seen with increasing depth. The decreased biological activity of peat is caused by the oxidation-reduction conditions. The CO2 release rate may also be due to the respiration of tree roots, which are very shallow in peatlands.

The rate of in situ cellulose decomposition experiment and CO2 release indicated by the Warburg measurements appear to be correlated. The results indicate improved conditions for cellulose-decomposing microbes after draining. It is also possible that the biological activity of peat after draining increases to a considerable depth until the decrease of easily decomposable substances limit the activity in an old drainage area. The cellulose decomposition rate would still increase as the oxidation-reduction conditions improve.

  • Lähde, ORCID ID:E-mail:
article id 7154, category Article
Ilmari Schalin. (1964). Some factors affecting the quantitative determination of aerobic bacteria in forest humus. Acta Forestalia Fennica vol. 78 no. 1 article id 7154. https://doi.org/10.14214/aff.7154

Quantitative investigation of bacteria in the humus is needed when the intensity of their function in decomposition in the soil is studied. In this study bacterial density of humus was measured using dilution plate method, which was subjected to thorough investigation. The method was chosen, despite its complexity, because it is quite consistent, each stage can be studied separately and the reliability can be tested. The aim of the study was to determine the best way to take samples so that the sample will represent the bacterial population as closely as possible, and to optimize homogenization and dilution of the sample and the assays.

On the basis of the results of the investigation, a procedure was developed for quantitative determination of aerobic bacteria in the humus by the dilution plate method. The paper recommends that subsamples are collected systematically from at least 25 different points. The moisture and temperature of the samples should remain similar to the natural environment until preparation of the dilution. The sample was homogenized with the Bühler homogenizer, which is constructed so that a certain degree of asepsis can be maintained and the speed of the apparatus can be regulated. The content of the mineral nutrients of the sample must be determined when choosing the way of homogenization to obtain the highest number of colonies per plate. The sample was diluted with either 0.1–0.01% peptone solution or 0.5% soil extract. The most advantageous degree of dilution was obtained by testing with the aid of Fisher’s dispersion index the probability of the Poisson distribution in the results.

  • Schalin, ORCID ID:E-mail:
article id 7111, category Article
Juhani Sarasto. (1960). Turpeen maatuneisuuden määrittämisestä : v. Postin maatumisasteen ja Pjavtshenkon maatumisprosentin vertailu. Acta Forestalia Fennica vol. 71 no. 2 article id 7111. https://doi.org/10.14214/aff.7111
English title: Determining decomposition decree of peat with von Post Humification Scale and Pjavtshenko's method.

Decomposition of the peat using von Post Humification Scale (1–10), developed by Lennart von Post, can be determined based on characteristics of peat, such as fibre integrity, colour and viscosity of exudate, and presence of colloidal particles, of handful of peat squeezed in the hand. It is easy to use and has proved useful in the practical work. The method developed by Pjavthenko is mostly based on specific weight off a dried sample in percentage, and requires analysis in the laboratory. The aim of this study was to compare the results of these two methods by measuring 156 peat samples representing different stages of decomposition.

The methods are based on different principles, which is reflected in small differences of the results. The maximum scores of the methods are clearly in different level. The maximum grade of 9–10 in von Post scale correspond decomposition percentage 51 in the scale of Pjavtsheko. However, the decomposition values in von Post scale are placed evenly on the scale of Pjavtshenko. This suggests that the von Post Scale is consistent and accurately developed. According to the study, the Pjavtshenko method is a good method to validate results of von Post Humification Scale, and can be used when decomposition of peat samples is determined in laboratory.

The PDF includes a summary in German.

  • Sarasto, ORCID ID:E-mail:
article id 7111, category Article
Juhani Sarasto. (1960). Turpeen maatuneisuuden määrittämisestä : v. Postin maatumisasteen ja Pjavtshenkon maatumisprosentin vertailu. Acta Forestalia Fennica vol. 71 no. 2 article id 7111. https://doi.org/10.14214/aff.7111
English title: Determining decomposition decree of peat with von Post Humification Scale and Pjavtshenko's method.

Decomposition of the peat using von Post Humification Scale (1–10), developed by Lennart von Post, can be determined based on characteristics of peat, such as fibre integrity, colour and viscosity of exudate, and presence of colloidal particles, of handful of peat squeezed in the hand. It is easy to use and has proved useful in the practical work. The method developed by Pjavthenko is mostly based on specific weight off a dried sample in percentage, and requires analysis in the laboratory. The aim of this study was to compare the results of these two methods by measuring 156 peat samples representing different stages of decomposition.

The methods are based on different principles, which is reflected in small differences of the results. The maximum scores of the methods are clearly in different level. The maximum grade of 9–10 in von Post scale correspond decomposition percentage 51 in the scale of Pjavtsheko. However, the decomposition values in von Post scale are placed evenly on the scale of Pjavtshenko. This suggests that the von Post Scale is consistent and accurately developed. According to the study, the Pjavtshenko method is a good method to validate results of von Post Humification Scale, and can be used when decomposition of peat samples is determined in laboratory.

The PDF includes a summary in German.

  • Sarasto, ORCID ID:E-mail:
article id 7451, category Article
Helge Gyllenberg, Pauli Hanioja, Unto Vartiovaara. (1954). Havaintoja eräiden viljelemättömien maatyyppien mikrobiston koostumuksesta. Acta Forestalia Fennica vol. 62 no. 2 article id 7451. https://doi.org/10.14214/aff.7451
English title: Observations on the composition of the microbial population in some virgin soils.

The purpose of this investigation was to obtain a preliminary picture of the composition of the microbial population in some virgin soils on forest land in Finland. Four different forest types were studied, Oxalis-Myrtillus type birch (Betula sp.) stand, Oxalis-Myrtillus type Norway spruce (Picea abies (L.) Karst.) stand, Vaccinium type Scots pine (Pinus sylvestris L.) stand, and drained pine bog. In addition, a flood meadow was selected as a comparison.

The methods used captured only part of the fungi growing in the soil. Rapidly growing types, especially Mucor and Penicillium species, were mainly isolated. In addition, fungi showing activity of decomposition, such as Fusarium, Monosporium and Spicaria, as well as an ascomycete of the genius Ascobolus, were isolated. Autochthonous bacteria were most abundant in the soils of Oxalis-Myrtillus type forests and in the flood meadow. In the birch stand 90% of the autochthonous bacterial flora were gram-negative bacteria, in the Oxallis-Myrtillus spruce and Vaccinium type pine stand 60% were gram-negative, while the share was only 25% in the pine bog. Nitrogen-fixing bacteria of the type Clostridium pasteurianum were found in all soils. Actinomycetes were found in all sites. The numbers of protozoa were highest in the soils of Oxalis-Myrtillus type forests.

There were no big differences between the forest soils and the flood meadow. Some groups of micro-organisms seem to be absent from the forest soils, which is probably due to the more favourable pH in the meadow. The occurrence of myxobacteria is interesting since no earlier data exist of this organism in Finnish soils.

The PDF includes a summary in English.

  • Gyllenberg, ORCID ID:E-mail:
  • Hanioja, ORCID ID:E-mail:
  • Vartiovaara, ORCID ID:E-mail:

Category: Special section

article id 290, category Special section
Mikko Peltoniemi, Esther Thürig, Stephen Ogle, Taru Palosuo, Marion Schrumpf, Thomas Wutzler, Klaus Butterbach-Bahl, Oleg Chertov, Alexander Komarov, Aleksey Mikhailov, Annemieke Gärdenäs, Charles Perry, Jari Liski, Pete Smith, Raisa Mäkipää. (2007). Models in country scale carbon accounting of forest soils. Silva Fennica vol. 41 no. 3 article id 290. https://doi.org/10.14214/sf.290
Countries need to assess changes in the carbon stocks of forest soils as a part of national greenhouse gas (GHG) inventories under the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol (KP). Since measuring these changes is expensive, it is likely that many countries will use alternative methods to prepare these estimates. We reviewed seven well-known soil carbon models from the point of view of preparing country-scale soil C change estimates. We first introduced the models and explained how they incorporated the most important input variables. Second, we evaluated their applicability at regional scale considering commonly available data sources. Third, we compiled references to data that exist for evaluation of model performance in forest soils. A range of process-based soil carbon models differing in input data requirements exist, allowing some flexibility to forest soil C accounting. Simple models may be the only reasonable option to estimate soil C changes if available resources are limited. More complex models may be used as integral parts of sophisticated inventories assimilating several data sources. Currently, measurement data for model evaluation are common for agricultural soils, but less data have been collected in forest soils. Definitions of model and measured soil pools often differ, ancillary model inputs require scaling of data, and soil C measurements are uncertain. These issues complicate the preparation of model estimates and their evaluation with empirical data, at large scale. Assessment of uncertainties that accounts for the effect of model choice is important part of inventories estimating large-scale soil C changes. Joint development of models and large-scale soil measurement campaigns could reduce the inconsistencies between models and empirical data, and eventually also the uncertainties of model predictions.
  • Peltoniemi, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland ORCID ID:E-mail: mikko.peltoniemi@metla.fi (email)
  • Thürig, Swiss Federal Institute for Forest, Snow and Landscape Research (WSL), Birmensdorf, Switzerland; European Forest Institute, Joensuu, Finland ORCID ID:E-mail:
  • Ogle, Natural Resources Ecology Laboratory, Colorado State University, Fort Collins, USA ORCID ID:E-mail:
  • Palosuo, European Forest Institute, Joensuu, Finland ORCID ID:E-mail:
  • Schrumpf, Max-Planck-Institute for Biogeochemistry, Jena, Germany ORCID ID:E-mail:
  • Wutzler, Max-Planck-Institute for Biogeochemistry, Jena, Germany ORCID ID:E-mail:
  • Butterbach-Bahl, Institute for Meteorology and Climate Research, Forschungszentrum Karlsruhe GmbH, Garmisch-Partenkirchen, Germany ORCID ID:E-mail:
  • Chertov, St. Petersburg State University, St. Petersburg-Peterhof, Russia ORCID ID:E-mail:
  • Komarov, Institute of Physicochemical and Biological Problems in Soil Science of Russian Academy of Sciences, Pushchino, Russia ORCID ID:E-mail:
  • Mikhailov, Institute of Physicochemical and Biological Problems in Soil Science of Russian Academy of Sciences, Pushchino, Russia ORCID ID:E-mail:
  • Gärdenäs, Dept. of Soil Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden ORCID ID:E-mail:
  • Perry, USDA Forest Service, Northern Research Station, St. Paul, MN USA ORCID ID:E-mail:
  • Liski, Finnish Environment Institute, Helsinki, Finland ORCID ID:E-mail:
  • Smith, School of Biological Sciences, University of Aberdeen, Aberdeen, UK ORCID ID:E-mail:
  • Mäkipää, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland ORCID ID:E-mail: raisa.makipaa@metla.fi
article id 288, category Special section
Björn Berg, Per Gundersen, Cecilia Akselsson, Maj-Britt Johansson, Åke Nilsson, Lars Vesterdal. (2007). Carbon sequestration rates in Swedish forest soils – a comparison of three approaches. Silva Fennica vol. 41 no. 3 article id 288. https://doi.org/10.14214/sf.288

Carbon sequestration rates in forest soil can be estimated using the concept of calculable stable remains in decomposing litter. In a case study of Swedish forest land we estimated C-sequestration rates for the two dominant tree species in the forest floor on top of the mineral soil. Carbon sequestration rates were upscaled to the forested land of Sweden with 23 x 106 ha with Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (Karst.) L.). Two different theoretical approaches, based on limit-value for litter decomposition and N-balance for vegetation and SOM gave rates of the same magnitude. For the upscaling, using these methods, 17 000 grids of 5 x 5 km were used.

The ‘limit-value approach’ gave a sequestration of 4.8   106 tons of C, annually sequestered in the forest floor, with an average of 180 kg C ha–1 yr–1 and a range from 40 to 410 kg C ha–1 yr–1. The ‘N-balance approach’ gave an average value of c. 96 kg ha–1 yr–1 and a range from –60 to 360 kg ha–1 yr–1. A method based on direct measurements of changes in humus depth over 40 years, combined with C analyses gave an average rate that was not very different from the calculated rates, viz. c. 180 kg ha–1 yr–1 and a range from –20 to 730 kg ha–1 yr–1. These values agree with forest floor C sequestration rate based on e.g. sampling of chronsequences but differ from CO2 balance measurements.

The three approaches showed different patterns over the country and regions with high and low carbon sequestration rates that were not always directly related to climate.

  • Berg, Dept. of Forest Ecology, University of Helsinki, Finland (present address: Dipartimento Biologia Strutturale e Funzionale, Complesso Universitario, Monte S. Angelo, Napoli, Italy ORCID ID:E-mail: bjorn.berg@helsinki.fi (email)
  • Gundersen, Forest & Landscape Denmark, University of Copenhagen, Denmark ORCID ID:E-mail:
  • Akselsson, Swedish Environmental Research Institute, IVL, Gothenburg, Sweden ORCID ID:E-mail:
  • Johansson, Department of Forest Soils, SLU, Uppsala, Sweden ORCID ID:E-mail:
  • Nilsson, Department of Forest Soils, SLU, Uppsala, Sweden ORCID ID:E-mail:
  • Vesterdal, Forest & Landscape Denmark, University of Copenhagen, Denmark ORCID ID:E-mail:

Category: Article

article id 5471, category Article
Hannu Fritze. (1992). Effects of environmental pollution on forest soil microflora - a review. Silva Fennica vol. 26 no. 1 article id 5471. https://doi.org/10.14214/sf.a15632

The article is a literature review focusing on the reaction of soil respiration, litter decomposition and microflora of forest soils to various pollutants like acidic deposition, heavy metals and unusual high amounts of basic cations. There is a great deal of evidence indicating that environmental pollution affects soil microbial activity and community structure. Much of the data originates from experimental designs where high levels of pollutants were applied to the soil under field or laboratory conditions. Furthermore, many were short-term experiments designed to look for large effects. These experiments have an indicative value, but it has to be kept in mind that environmental pollution is a combination of many pollutants, mostly at low concentrations, acting over long periods of time. There is therefore consequently a demand for research performed in natural forest environments polluted with anthropogenic compounds. 

  • Fritze, ORCID ID:E-mail:
article id 7601, category Article
Erkki Lähde. (1969). Biological activity in some natural and drained peat soils with special reference to oxidation-reduction conditions. Acta Forestalia Fennica no. 94 article id 7601. https://doi.org/10.14214/aff.7601

The aim of the present study was to collect information on biological activity in the topmost 30 cm peat layer in certain natural and drained peatlands of different fertility, covered by different stands.

The results showed that if the ground water table in peatland sites is located in the immediate vicinity of the ground surface (about 5-10 cm in depth), conditions are reducing, and often even anaerobic, up to the ground surface. By means of drainage the aerobic limit can be dropped to a greater depth. This will occur because of the aerobic limit closely follows the fluctuation of the ground water table.

Although, by means of drainage, the aerobic limit can be lowered to more than 50 cm in depth, rains are followed by a rise of a ground water table and the aerobic limit; hereby a change from oxidizing to reducing conditions takes place. Only by keeping the ground water table and the aerobic limit constantly at the depth of more than 50 cm is it possible to obtain oxidizing conditions in the topmost 20-30 cm peat layer. The anaerobic conditions prevent the tree roots penetrating deeper in the peat.

In reducing conditions cellulose decomposition as well as carbon dioxide release from peat samples is slower than in oxidizing conditions. The rate of cellulose decomposition, however, is essentially dependent on the nitrogen content and the acidity of the peat.

  • Lähde, ORCID ID:E-mail:
article id 4730, category Article
Erkki Lähde. (1966). Kokeita selluloosan hajaantumisnopeudesta erilaisissa metsiköissä. Silva Fennica no. 119 article id 4730. https://doi.org/10.14214/sf.a14288
English title: Experiments on the decomposition rate of cellulose in different stands.

The aim of this project was to investigate the cellulose decomposition rate in the soil on the ecological conditions created by different tree species, particularly birch (Betula sp.) and Norway spruce (Picea abies (L.) H. Karst.). Therefore, comparable sample plots were established in adjoining birch and spruce stands. Data on the stands, the vegetation, and the soil in the sample plots were collected. The experiment was carried out in the Ruotsinkylä Experimental Forest near Helsinki in Southern Finland.

Five pieces (3x5x0.15 cm) of cellulose (bleached sulphite pulp) were dried, weighed, and fastened in a row into a nylon bag. The bags were placed into the soil at a slant so that the upmost piece of cellulose was in the depth of 0–1.5 cm and the bottom one 6–7.5 cm. The weight losses of the pieces were measured after periods ranging from 6 to 12 months.

The results show that even within the same forest type, decomposition is much more rapid in birch stands than in spruce stands. In all the stands the decomposition rate decreased rapidly with increasing depth. The difference between birch and spruce stand, as well as the decrease with increasing depth, was probably mainly due to different thermal conditions.

The PDF includes a summary in English.

  • Lähde, ORCID ID:E-mail:

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