Belova, O. 2005. Foraging Character of Deer Cervidae and Brown Hare Lepus europaeus on the Littoral Area of Pure Pine Forests in Lithuania. Baltic Forestry, 11 (2): 94-108

The main herbivorous mammals as Cervidae go in with hares Leporidae into general trophic chain as primary consumers. The basic interaction between these animals and forest woody vegetation mostly evidences in the feeding relations. Therefore the feeding character in herbivorous animals is the important item of this study. Limited factors could come drivers of the animal impact to forest. On the other hand, the interaction between animals and forest woody plants requires not only elements of this interaction but also an environment where this interaction comes to pass. Therefore, the habitat preference should be considered. We aimed to reveal the foraging character of deer and hares, and assess the animal - forest woody plants’ interaction by considering the above-mentioned notes. We employed the integrated method of belt transects (sample unit is 100 x 4 metres) and sample plots (50 x 2 metres, or 100m²). The method of pellet group count has been used to assess the number and distribution of the local populations of investigated animal species, the age structure and sex ratio of local populations of moose and red deer, and age structure of roe deer local population. We identified animal age and sex by pellet groups. Woody plants and their shoots within the feeding space of animals (that is from h = 0,1 to 2,2 m) were counted dividing damaged and untouched shoots. Browsing intensity I, and the share of woody species in animal diet P, were calculated by the consumption of all species of forest woody vegetation. Habitat preference of stands of the different age classes, composition and forest site types were estimated. The total number of sample plots is 504, and the total length of the route is 79.9 km on the study area of 2,736 hectares. The specific climatic and geomorphologic diversity of landscape and local conditions as well as the absence of agricultural landed property determine the low carrying capacity and specific structure of the local fauna and their adaptations, as the mixed forest-forest edge ecotype in hares and forest ecotype in roe deer. The coexistence of forest plants and animals is directly and indirectly influenced not only by the determined abiotic and biotic factors but also by human factors including forest management, hunting and its restrictions, supplemental feeding in winter, picking of mushrooms and berries, and other recreational activities. The mentioned activities are particularly obvious on the study territory while the forests are managed by the separate regime that is approved by the legal acts for protected areas. The animal density is less than the permissible density in pure pine forests while there is the aberrant sex ratio and age structure in local populations. That is the indicator of disfavour in living conditions. Habitat preference values and plant consumption intensity varied temporally depending on the stand composition, forest site type and forest age as well as variability of the main weather parameters. The main criteria of the animal-plant interaction are the consumption of shoots and the browsing intensity of the main woody species. The shoot consumption in conifers more than 40-50% and more than 20-30% in deciduous species is the criterion of the irreversible decline in the certain species (e.g. Populus tremula, Frangula alnus).

Key words: herbivores, pure pine forests, protected area, population parameters, habitat preference, browsing intensity, level of shoot consumption.

Grigaliūnas,V. and Ruseckas, J. 2005. The Effect of Soil Properties on Natural Forest Regeneration on Drained Fens. Baltic Forestry, 11 (2): 75-83

The objective of this study was to assess the success of natural regeneration in cutovers on drained fens (eutrophic peatland) depending on the soil properties and the depth to the water table in the forests of Birzai and Panevezys state forest enterprises in Lithuania. The assessments were carried out in 100-300 m long transects allocated perpendicularly to the drainage ditches. 131 water wells were drilled to measure the depth to the water table and 131 sample plots of 10 × 10 m were established. The soil properties were assessed in the soil chemistry laboratory. The results showed that natural forest regeneration on drained cutblocks in fens was affected by the following factors: the depth to the water table (H_V.01) (measured at the beginning of the growth period), the pH level, the potential hydrolytic soil acidity (HA), the base saturation and the thickness of the peat layer. Multiple regression analysis was used to assess the dependence of the number of regenerating trees (N) on the main factors (H_V.01 and HA): N = 168059.7 – 3446.5 H_V.01 – 35.180 HA; (R² = 0.8, F = 7.51, p < 0.0007). The maximum critical depth to the water table (allowing sufficient number of regenerating trees) was mainly affected by the subsoil texture of the shallow peat soils (HS_s– ph) and was 18.0 ± 3.7 cm, 26.5 ± 6.6 cm, 26.6 ± 3.9 cm, 29.6 ± 6.6 cm and 42.2 ± 9.6 cm in the soils with subsoil of gravel, sand, sandy loam, light loam and medium loam, respectively. The mean hydrolytic acidity of the soil in the cutblocks with sufficient regeneration was 820.99 ± 56.05 mekv/kg, which was significantly lower than in the cutblocks with insufficient forest regeneration (ΔHA = 212.29 ± 94.99 mekv/kg, t = 2.23, p = 0.038). In conclusion, to improve the natural regeneration of forests in the clear-cuttings on low peatland soils, the soil water regime should be improved by the technical means to maintain the optimum soil moisture (mainly by damming the ditches) and, in soils of very high acidity (HA <1100 mekv/kg), alkaline enrichment may be needed.

Key words: cutovers, drainage, natural regeneration, peat soils, water table.

Augustaitis, A., Augustaitienė, I., Kliučius, A., Bartkevičius, E., Mozgeris, G., Šopauskienė, D., Eitminavičiūtė, I., Arbačiauskas, K., Mažeikytė, R. and Baužienė, I. 2005. Forest Biota under Changing Concentration in Acidifying Compounds in the Air and Their Deposition. Baltic Forestry 11 (2): 84-93

Effects of acid deposition on forest ecosystems despite a drastic decrease in sulphur emission and deposition at the end of the 1990s are still among the most significant ecological issues. The key reason for this is that atmospheric concentrations of ammonium and nitrate which have a tendency to increase in the last period became the main acidifying compounds of precipitation. These changes in acid deposition resulted in main objectives of the presented study which were to estimate the effect of rain acidity and atmospheric deposition of pollutants on crown defoliation and diversity of soil microarthropods, stream macrobenthos and small mammals (rodents) on territories under changing regional pollution level. Investigation was carried out in 3 Lithuanian Integrated Monitoring Stations over the period 1994-2004. The obtained data indicated that lower life forms were more affected than higher. Acid deposition was shown to have the most significant effect on pine tree defoliation as well as on the diversity of soil microarthropods and diversity of stream macroinvertebrates and least on the diversity of small mammals. These results have indicated that regional pollution level which is below critical level for forest ecosystem has a significant effect on the biota.

Keywords: acid deposition, crown defoliation, small mammals, soil microathropodes, stream macroinvertebrates, correlation analysis.

Hytönen, J. 2005. Effects of Liming on the Growth of Birch and Willow on cut-away Peat Substrates in Greenhouse. Baltic Forestry, 11 (2): 68-74

The effects of liming (doses 0, 6, 12, 24, 48 tonnes/ha of dolomite lime) on the growth and nutrition of birch (Betula pendula Roth, Betula pubescens Ehr.) and short-rotation willows (Salix x dasyclados, Salix viminalis) were studied in a greenhouse on peat obtained from two cut-away peatland areas. Peat was NPK-fertilized using either raw phosphate or superphosphate as phosphorus source. An increase in liming dose up to 48 tonnes/ha increased peat pH asymptotically from 3.5 to 6.0 and from 3.9 to 6.7 in the two peats. The substrate’s pH did not affect the biomass production of silver and downy birch. Willows did not grow at all in the acidic Aitoneva peat without the substrate being limed. Willow growth was best when substrate pH was higher than 5.0. Liming decreased the foliar phosphorus and boron concentrations in birch and boron concentrations in willow. Rock phosphate and superphosphate gave almost equal results in birch growth, but willows grew significantly better when fertilized with superphosphate. Downy birch had significantly higher foliar potassium, calcium, magnesium and boron concentrations than silver birch. Salix viminalis had significantly higher foliar concentrations of phosphorus, potassium and boron than S. x dasyclados.

 Key words: Cut-away peatland, liming, downy birch, silver birch, willow, Salix, phosphorus