Suo - Abstracts of Vol. 53, 2002

No. 1

Aber, J.S., Aaviksoo, K., Karofeld, E. and Aber, S.W.: Patterns in Estonian bogs as depicted in color kite aerial photographs (Tiivistelmä: Viron soiden pinnanmuodot värillisten leijailmakuvien valossa). Suo 53(1): 1-15.

Kite aerial photography (KAP) was conducted at three bogs in east-central and southwestern Estonia to further investigate the possibilities of this technique for mire research. Color-visible and color-infrared photographs were acquired in all orientations with film and digital cameras. Individual objects can be identified in vertical photographs in the size range 10 to 30 cm, which allows for microstructural investigations. Color-visible photographs reveal distinct color and texture zones in the vegetation cover of bogs, and water pools form a strong contrast with emergent vegetation. The intricate patterns of emergent, floating and submerged vegetation are portrayed clearly, and the boundary is defined sharply between emergent and floating moss at pool margins. Distinct color and texture zones of plant cover represent specific vegetation communities. Color-infrared photographs depict active photosynthesis of floating and emergent moss (Sphagnum sp.) in narrow zones (1–2 m wide) at pool margins. The high level of photosynthesis in such narrow zones may have significant implications for development of bog morphology, biomass accumulation, methane emission, and other environmental factors. Numerous small water bodies are more abundant than anticipated and may be more common than is generally recognized on conventional airphotos or satellite images. Multi-view angle imagery displays considerable variations in reflectivity of bog cover materials for different viewing directions. Special lighting effects, such as sun glint and the hot spot, are more prominent in color-infrared pictures, because of darker shadows. Our field experience demonstrates that kite aerial photographs may provide a basis for microstructural mapping and analysis of complex bogs within a multi-scale approach to mire investigations.

Key words: Aerial photography, kite, infrared, Estonia, bog

James S. Aber and Susan W. Aber, Earth Science Department, Emporia State University, Emporia, Kansas 66801 U.S.A. (e-mail
Kiira Aaviksoo, Remote Sensing and GIS, Estonian Environment Information Centre, Akadeemia 4, 51003 Tartu, Estonia (e-mail
Edgar Karofeld, Department of Landscape Ecology, Institute of Ecology at TPU, Kevade St. 2, 10137 Tallinn, Estonia (e-mail

Kaunisto, S & Sarjala, T: Estimating potassium nutrition of Norway spruce with needle analysis during different seasons (Tiivistelmä: Kuusen neulasanalyyttinen kaliumravitsemuksen arvionti eri vuodenaikoina). Suo 53(1): 17-26.

The aims of this study were 1) to get a better background for estimating limit values of potassium nutrition for Norway spruce (Picea abies L. Karst.) and 2) to find out if the needle potassium nutrition during dormancy could be estimated by analysing needles collected before the dormant period. Five groups of trees with different nutritional backgrounds were selected. One was on a shallow-peat (5–30 cm) mineral soil slope and four on a deep-peat site next to it. Needles were collected four times during the autumn months and twice during dormancy. The needle K concentration of a severe potassium deficiency limit indicated by the exponential accumulation of putrescine, was about 4.5 mg g–1. However, trees suffered from potassium shortage already at the potassium concentrations of about 5 mg g–1. The needle potassium concentrations during the autumn months from late August to early October were in very close correlation with the concentration during dormancy, y = 0.869x – 0.208 (r2 = 0.92), where y is the potassium concentration in the winter months and x that during the autumn months.

Key words: Deficiency, deficiency limit, mire, peatland, potassium, putrescine

Seppo Kaunisto & Tytti Sarjala, The Finnish Forest Research Institute, Parkano Research Station, Kaironiementie 54, 39700 Parkano, Finland (e-mail

No. 2

Saarinen, M.: Kasvillisuuden ja maanmuokkauksen vaikutus männyn ja koivun taimettumiseen varpu- ja puolukkaturvekankailla. (Summary: Effect of vegetation and site preparation on the restocking of Scots pine and birch in dwarf-schrub and Vaccinium vitis-idaea type peatland forests). Suo 53(2): 41-60.

The study deals with the natural regeneration of Scots pine (Pinus sylvestris) and birch (Betula pendula & B. pubescens) on ten experimental fields on peatland sites drained for forestry, mainly during the 1930s. The principal goal of the study was to investigate the effect of different types of natural ground vegetation on the restocking of pine and birch following site preparation (rotavation and mounding) on old drainage areas. Rotavation, which corresponds to disc trenching on upland forest soils, is capable of producing fully-stocked pine stands. The effect of surface treatments such as rotavation depends, however, on the predominant ground vegetation. Sphagnum moss patches are often well restocked even when not prepared, which means that site preparation often only has an effect on transformed Pleurozium and Dicranum vegetation. The success of rotavation has also encouraged forest owners to use other alternative methods of surface treatment such as mounding. The tree seedlings tend to be concentrated on the surface of the furrows produced by rotavation, which means that restricting digger-scarification to the topmost surface of the soil on well-drained regeneration sites can produce the same result; the required machinery is usually already present at the site for ditch network maintenance.

Key words: drainage areas, natural regeneration, peatlands

Markku Saarinen, The Finnish Forest Research Institute, Parkano Research Station, Kaironiementie 54, FIN-39700 Parkano, Finland (e-mail:

Kaffke, A., Matchutadze, I., Couwenberg, J. & Joosten, H.: Early 20th century Russian peat scientists as possible vectors for the establishment of Calluna vulgaris in Georgian Sphagnum bogs. Suo 53(2): 61-66.

In the summer of 2000, a stand of Calluna vulgaris (L.) Hull was found in the Ispani 2 bog near Kobuleti, being the first known occurrence of this species in Georgia (Transcaucasia). Pollen analysis of a peat core from the Calluna vulgaris stand shows that the species established itself there around 1920/1930. Dispersal by migrating birds, deliberate introduction as a garden plant, and unintentional introduction with cultural products are shown to have been improbable vectors for introduction far from the species’ main distribution area. It is concluded that Calluna vulgaris may have been accidentally introduced by Russian peat scientists and prospectors that were active in the area around the time of establishment.

Keywords: Calluna vulgaris, Colchis (Transcaucasia), bog, plant introduction, pollen analysis

Andreas Kaffke, John Couwenberg and Hans Joosten, Botanical Institute, Grimmer Straße 88, D-17487 Greifswald, Germany. Fax: + 49 3834 – 864114; email
Izolda Matchutadze, Batumi Botanical Gardens, Mtsvane Kontshi, Mahindjauri 384535 GE-Georgia. e-mail

No. 3-4

Groeneveld, E.V.G. & Rochefort, L.*: Nursing plants in peatland restoration: on their potential use to alleviate frost heaving problems. Suo 53(3-4): 73-85.

Peatland restoration measures usually require the rewetting of the disturbed ecosystem. In northern latitudes, the increase in wetness of the bare peat substrate causes frost heaving. In this paper, we described the problem of frost heaving in cutover peatlands and an array of means whereby it can be diminished. Several avenues of research should be pursued with the use of nursing plants to reduce frost heaving and promote Sphagnum establishment and growth. For large scale restoration of peatland ecosystems, Polytrichum strictum appears to be a good potential nursing plant to Sphagnum. However the importance of competition between polytric and Sphagnum is unknown and we do not know under which conditions the association is beneficial or not.

Key words: colonisation, degraded mire, peat erosion, regeneration, rehabilitation, revegetation, Sphagnum.

Elisabeth V. G. Groeneveld and Line Rochefort, Groupe Recherche en Écologie des Tourbières and Centre d’Études Nordiques, Pavillon Paul-Comtois, Université Laval, Québec, Canada G1K 7P4. *Corresponding author, email:

Huttunen, J.T., Nykänen, H., Turunen, J., Nenonen, O & Martikainen, P.J.: Fluxes of nitrous oxide on natural peatlands in Vuotos, an area projected for a hydroelectric reservoir in northern Finland. Suo 53(3-4): 87-96.

Nitrous oxide (N2O) fluxes were measured on ten natural minerotrophic peatlands in an area planned for a hydroelectric reservoir (Vuotos) in northern Finland. The mean N2O fluxes from the sites with mean water tables from –25 to 3.4 cm (negative below the peat surface) ranged from –30 to 230 µg m–2 d–1 during summer 1994. At the driest site, the herb-grass spruce mire with the mean water table at –38 cm, the mean summertime N2O emission was 940 µg m-2 d-1 in 1994, attributable to the increased N2O release at low peat temperatures in autumn. A similar increase in the N2O emissions was not found in 1995, as the measurements were finished before the peat started to freeze. The mean N2O fluxes at the sites correlated negatively with the mean water table levels. The peatlands in the northern boreal zone are unlikely important sources of atmospheric N2O in their natural state. The planned reservoir would barely have large long-term N2O emissions from the pelagic zone, but the importance of temporally flooded areas in the postflood N2O release is uncertain similar to the short-term emissions following the flooding.

Keywords: Northern boreal peatlands, climate warming, flooding, global change, greenhouse gas emission, hydro dam

Jari T. Huttunen, Hannu Nykänen and Pertti J. Martikainen: Research and Development Unit of Environmental Health, Department of Environmental Sciences, Bioteknia 2, University of Kuopio, PO Box 1627, FIN-70211 Kuopio, Finland. email:
Jukka Turunen: Department of Geography, McGill University, 805 Sherbrooke Street West, Montreal, Quebec, H3A 2K6 Canada.
Olli Nenonen: Kemijoki Ltd., Valtakatu 9-11, FIN-96101 Rovaniemi, Finland.