Vaccinium Type Research Articles

Spatiotemporal dynamics of plant occurrence in an urban forest fragment

The study area is an urban forest remnant in the city of Tampere (Finland). The presence of vascular plant species were surveyed in 1980 and again in 2000 within the 5 × 5 m grid cells covering the whole forest. The forest fragment has been influenced by three types of urban pressure: general ecological conditions (such as eutrophication due to increase of nitrogen), edge effect and local human disturbance. A general and spatially even eutrophication was reflected in the frequencies of C- and S-strategists as a shift towards to the C-point in the CSR triangle. The total number of native species (83 in 1980, 89 in 2000), typical Vaccinium type (VT)-forest species (32 in 1980, 31 in 2000) and aliens (57 in 1980, 68 in 2000) did change, but only to a moderate extent. The number of typical VT-forest species and native species were more common in central parts of the fragment. In terms of the number of species, the forest has been relatively resistant to date to major changes. However, the average number of native plant species per grid cell increased from 13.7 to 14.4, the average number of aliens increased from 2.0 to 4.2 and the average number of typical VT-forest species decreased from 5.5 to 5.0. Natives were spatially concentrated in the centre in 1980, but in 2000 they were more evenly distributed. The edge has offered habitats for new species, but the typical VT-forest species of the original sub-xeric forest are slowly diminishing.

Bird communities in hemiboreal old-growth forests: The roles of food supply, stand structure, and site type

Key factors causing the difference of wildlife populations in natural and managed forests are an important field of ecosystem and biodiversity research. To explore the factors contributing to bird-community features in the poorly studied European natural hemiboreal forests, we carried out a comparative study in old-growth and mature stands of five site types in Estonia. The mature stands were of clear-cut origin and managed for timber production. Old-growth hosted both more diverse and more abundant bird communities than mature stands, which does not support the putative ‘old-growth syndrome’ (high diversity at a low density) described previously in temperate Europe. Site-type specificity of bird communities was also more pronounced in old-growth, indicating a timber-harvesting induced process of biotic homogenization. In particular, natural swamp forests had characteristic bird species and those communities may be additionally sensitive to artificial drainage. In terms of invertebrate food supply, the availability of snails, rather than of insects, was related to bird-community characteristics; however, the influence of snails was due to one snail-poor forest type ( Vaccinium type pine stands), not management. The abundance of coarse woody debris was the main structural feature affecting bird communities; tree-size variation was additionally important for species richness. A significant unexplained ‘old-growth’ effect remained even after the variables describing food supply and stand structure were taken into account. Our results imply the distinct importance of old-growth of different site types for hemiboreal bird communities. However, we did not obtain any evidence of different key factors structuring the bird communities in old-growth and mature stands.

Monitoring peatland vegetation by means of digitized aerial photographs

Drainage-driven changes in peatland ecosystems in Finland were studied, using aerial photographs taken in 1995 and 1946. The species composition of the vegetation cover was examined in one drained and one undrained mire in 1995. The data were correlated with tone and texture values of digitized colour infrared aerial photographs taken the same year, using canonical correspondence analysis. The results obtained were used to reconstruct the vegetation cover of the aerial photograph from 1946. The analysis clearly differentiated drained and undrained mire site types from each other, forming the moisture gradient in the first axis. The undrained mire site types were distributed along the nutrient gradient, but the correlation between site types and different tone values was relatively weak. The main difference between 1946 and 1995 was that the open and sparsely forested peatland vegetation types diminished and two drained mire site types (drained, pine-dominated Vaccinium type and drained, pine-dominated dwarf shrub type) became dominant. Digitized aerial photographs were unable to identify the vegetation at the mire site-type level, especially in natural habitats.

Succession of understory vegetation in managed and seminatural Scots pine forests in eastern Finland and Russian Karelia

The aim of this study was to compare the understory vegetation in chronosequences representing seminatural and managed Scots pine (Pinus sylvestris L.) forests on dryish heaths of the Vaccinium type. The data represent the middle boreal vegetation zone and were collected in eastern Finland and the Dvina area of Karelia, on both sides of the border between Finland and the Russian Federation. Species diversity and the coverage of the various life-form groups (ground lichens, mosses, liverworts, grasses, herbs, dwarf shrubs, and tree seedlings) were used to analyse the properties of the ground vegetation over the succession from open forest land to closed forest communities. The clearest differences in diversity between the seminatural forests mainly influenced by fire and managed forests occurred in the early stages of succession. Forest management appeared to increase the species richness at the beginning of succession. The seminatural stands were rich in Cladonia lichens and dwarf shrubs up until tree canopy closure; however, the abundance of mosses was lower in the seminatural stands. Forest management favoured an abundance of grasses, notably Deschampsia flexuosa, which was common after clear-cutting. The use of prescribed burning in silviculture could result in more natural vegetation succession dynamics in managed stands.

Pollen–vegetation relationships in non-arboreal moorland taxa

Pollen assemblages from moss polsters from northwest Scotland are compared with the vegetation composition around the sampling points. Presence–absence data are used to calculate association, over- and under-representation indices for the relationship between plants and the pollen assemblages, and results are found to be broadly comparable with published results from Norway. Relevant pollen source areas for individual taxa are estimated using least-squares linear regression analysis of pollen percentage against distance-weighted plant abundance. The extended R-value model is applied to estimate the relevant pollen source area for the pollen assemblages. The results indicate relevant pollen source areas on the order of 2 m or less for Calluna vulgaris, Vaccinium type, Myrica gale, Cyperaceae, Poaceae, Potentilla type and Succisa pratensis. Changes in non-arboreal components of pollen assemblages from mire communities therefore appear to reflect predominantly local patch dynamics rather than wider landscape changes.

Beyond annual budgets: carbon flux at different temporal scales in fire-prone Siberian Scots pine forests

Along four chronosequences of fire-prone Siberian Scots pine forests we compared net primary production (<em>NPP</em>) and two different mass-based estimates of net ecosystem productivity (<em>NEP</em>_C and <em>NEP</em>_S). <em>NEP</em>_C quantifies changes in carbon pools along the chronosequences, whereas <em>NEP</em>_S estimates the short-term stand-level carbon balance in intervals between fires. The chronosequences differed in the mean return interval of surface fires (unburned or moderately burned, 40 yr; heavily burned, 25 yr) and site quality (lichen versus <em>Vaccinium</em> type). Of the <em>Vaccinium</em> type (higher site quality) only a moderately burned chronosequence was studied.<em>NEP</em>_C was derived from the rate of changes of two major carbon pools along the chronosequence time axes: (1) decomposition of old coarse woody debris (CWD) left from the previous generation after stand-replacing fire, and (2) accumulation of new carbon in biomass, CWD and soil organic layer by the regenerating stand. Young stands of all chronosequences were losing carbon at rates of−4 to −19 mol C m⁻² yr⁻¹(−48 to −228 g C m⁻² yr⁻¹). Depending on initial CWD pools and site-specific accumulation rates the stands became net carbon sinks after 12 yr (Vaccinium type) to 24 yr (lichen type) following the stand-replacing fire and offset initial carbon losses after 27 and 70 yr, respectively. Highest <em>NEP</em>_C was reached in the unburned chronosequence (10.8 mol C m⁻² yr⁻¹ or 130 g C m⁻² yr⁻¹). Maximum <em>NEP</em>_C in the burned chronosequences ranged from 1.8 to 5.1 mol C m⁻² yr⁻¹ (22 to 61 g C m⁻² yr⁻¹) depending on site quality and fire regime. Around a stand age of 200 yr <em>NEP</em>_C was 1.6 ± 0.6 mol C m⁻² yr⁻¹ (19 ± 7 g C m⁻² yr⁻¹) across all chronosequences. <em>NEP</em>_S represents the current stand-level carbon accumulation in intervals between recurring surface fires and can be viewed as a mass-based analogue of net ecosystem exchange measured with flux towers. It was estimated based on measurements of current woody NPP, modelled decomposition of measured CWD pools and organic layer accumulation as a function of time since the last surface fire, but ignores carbon dynamics in the mineral soil. In burned mature lichen type stands, <em>NEP</em>_S was 6.2 ± 2.6 mol C m⁻² yr⁻¹ (74 ± 31 g C m⁻² yr⁻¹) and thus five times higher than <em>NEP</em>_C at the respective age (1.2 ± 0.6 mol C m⁻² yr⁻¹ or 14 ± 7 g C m⁻² yr⁻¹). Comparing <em>NEP</em>_S and <em>NEP</em>_C of mature stands, we estimate that 48% of NPP are consumed by heterotrophic respiration and additional 35% are consumed by recurrent surface fires. As expected, in unburned stands <em>NEP</em>_C and <em>NEP</em>_S were of similar magnitude. Exploring a site specific model of CWD production and decomposition we estimated that fire reduces the carbon pool of newly produced CWD by 70%. Direct observation revealed that surface fire events consume 50% of the soil organic layer carbon pool (excluding CWD). We conclude that surface fires strongly reduced <em>NEP</em>_C. In ecosystems with frequent fire events direct flux measurements using eddy covariance are likely to record high rates of carbon uptake, since they describe the behaviour of ecosystems recovering from fire without capturing the sporadic but substantial fire-related carbon losses.

Beyond annual budgets: carbon flux at different temporal scales in fire-prone Siberian Scots pine forests

Along four chronosequences of fire-prone Siberian Scots pine forests we compared net primary production (NPP) and two different mass-based estimates of net ecosystem productivity (NEPC and NEPS). NEPC quantifies changes in carbon pools along the chronosequences, whereas NEPS estimates the short-term stand-level carbon balance in intervals between fires. The chronosequences differed in the mean return interval of surface fires (unburned or moderately burned, 40 yr; heavily burned, 25 yr) and site quality (lichen versus Vaccinium type). Of the Vaccinium type (higher site quality) only a moderately burned chronosequence was studied.NEPC was derived from the rate of changes of two major carbon pools along the chronosequence time axes: (1) decomposition of old coarse woody debris (CWD) left from the previous generation after stand-replacing fire, and (2) accumulation of new carbon in biomass, CWD and soil organic layer by the regenerating stand. Young stands of all chronosequences were losing carbon at rates of−4 to −19 mol C m−2 yr−1(−48 to −228 g C m−2 yr−1). Depending on initial CWD pools and site-specific accumulation rates the stands became net carbon sinks after 12 yr (Vaccinium type) to 24 yr (lichen type) following the stand-replacing fire and offset initial carbon losses after 27 and 70 yr, respectively. Highest NEPC was reached in the unburned chronosequence (10.8 mol C m−2 yr−1 or 130 g C m−2 yr−1). Maximum NEPC in the burned chronosequences ranged from 1.8 to 5.1 mol C m−2 yr−1 (22 to 61 g C m−2 yr−1) depending on site quality and fire regime. Around a stand age of 200 yr NEPC was 1.6 ± 0.6 mol C m−2 yr−1 (19 ± 7 g C m−2 yr−1) across all chronosequences. NEPS represents the current stand-level carbon accumulation in intervals between recurring surface fires and can be viewed as a mass-based analogue of net ecosystem exchange measured with flux towers. It was estimated based on measurements of current woody NPP, modelled decomposition of measured CWD pools and organic layer accumulation as a function of time since the last surface fire, but ignores carbon dynamics in the mineral soil. In burned mature lichen type stands, NEPS was 6.2 ± 2.6 mol C m−2 yr−1 (74 ± 31 g C m−2 yr−1) and thus five times higher than NEPC at the respective age (1.2 ± 0.6 mol C m−2 yr−1 or 14 ± 7 g C m−2 yr−1). Comparing NEPS and NEPC of mature stands, we estimate that 48% of NPP are consumed by heterotrophic respiration and additional 35% are consumed by recurrent surface fires. As expected, in unburned stands NEPC and NEPS were of similar magnitude. Exploring a site specific model of CWD production and decomposition we estimated that fire reduces the carbon pool of newly produced CWD by 70%. Direct observation revealed that surface fire events consume 50% of the soil organic layer carbon pool (excluding CWD). We conclude that surface fires strongly reduced NEPC. In ecosystems with frequent fire events direct flux measurements using eddy covariance are likely to record high rates of carbon uptake, since they describe the behaviour of ecosystems recovering from fire without capturing the sporadic but substantial fire-related carbon losses.

Fire and site type effects on the long-term carbon and nitrogen balance in pristine Siberian Scots pine forests

Effects of fire and site type on carbon (C) and nitrogen (N) balances were determined by following the change of total and component C and N pools along four chronosequences of fire-prone Siberian Scots pine ecosystems. These differed in the mean return interval of surface fires (unburned – moderately burned, 40 years – heavily burned, 25 years) and site quality (lichen versus Vaccinium site type). Of the Vaccinium site type (higher site quality) only a moderately burned chronosequence was studied. A total of 22 even-aged stands were investigated with stand ages ranging from 2 to 383 years. The C balance was dominated by the opposing dynamics of coarse woody debris (CWD) and biomass and could be divided into three phases: (1) Young stands (up to 40 years)acted as a net source for C of 6-10 mol C m-2 year-1 because the previous generation CWD pool originating from stand-replacing crown fires decayed much faster than biomass increased. During this period the C pool in the unburned lichen type chronosequence decreased from 807 to 480 mol C m-2. (2) Middle aged stands (40-100 years) being in a stage of maximum biomass accumulation were a net sink of 8-10 mol C m-2 year-1. (3)Maturestands (100 to > 350 years) continued to sequester C at a lower rate (0.8-2.5mol C m-2 year-1). Differences in the rates of C sequestration during the two later phases could be explained by the complex interaction between surface fire regime and site type. Recurrent surface fires resulted in enhanced mortality and regularly redistributed C from the living to the CWD pool thereby lowering the rate of C sequestration. Site quality determined the potential to recover from disturbance by fire events. Differences in site type did not correlate with soil and total ecosystem N pool size. However, the N status of needles as well as the N pool of physiologically active tissue was highest in the stands of the Vaccinium type. The “woody” C pool (biomass + CWD) was sensitive to differences in surface fire regime and site type. It was lowest in the heavily burned lichen type chronosequence (297 ± 108 mol C m-2), intermediate in the unburned and moderately burned lichen type chronosequence (571 ± 179 mol C m-2) and highest in the moderately burned Vaccinium type chronosequence (810 ± 334 mol C m-2). In contrast, the total soil C pool (organic plus mineral layer down to a depth of 25 cm) was independent of stand age, surface fire regimeand site type and fluctuated around a value of 250 mol C m-2. The organic layer C pool oscillated in response to recurring surface fires and its C pool was dependent on time since fire increasing at a rate of about 1.5 mol C m-2 year-during the first 40 years and then reaching a plateau of 170 mol C m-2. The total ecosystem N pool was 7.4 ± 1.5 mol N m-2 on average of which only 25 % were stored in biomass or coarse woody debris. Total ecosystem N was independent of stand age, surface fire regime and site type. No correlation was found between total ecosystem C and N pools. Average total ecosystem C:N ratio was 114 ± 35 mol C mol N-1. A conceptual model illustrating how changes in the regime of stand-replacing crown fires and recurrent surface fires and changes in site quality interact in determining the long-term C balance in Siberian Scots pine forests is presented.

Végétation holocène et dynamique d'une forêt subalpine (Queyras, France) : étude géomorphologique et paléobotanique de formations travertineuses

In the Aigue Agnelle valley (Queyras, Hautes Alpes), several travertine deposits are described between 2200 and 2300 m of altitude. Some of them, rich in leaf imprints and cones of Pine, have been dated to the beginning of the Holocene. Others revealed different phases of travertine development during the middle of the Holocene, with intercalation of detntal deposits containing charcoal remains. The interdisciplinary study of distinct morpho-sedimentary faciès, including imprints (leaves and cones) and charcoal identifications, allowed us to reconstruct the ecological and geomorphological dynamics of the valley. Erosion processes and changes in vegetation were pinpointed. At the beginning of the Holocene, the mountain Pine (Pinus uncinata) was the most frequent tree, later replaced (c.7605 BP) by the arolla Pine (Pinus cembra) in association with birch (Betula sp.) and Ericaceae (Vaccinium type). Around 5655 BP, the arrolla Pine was replaced by larch or spruce (Larix decidua/Picea abies), as a consequence of anthropogenic and/or climatic factors. The role of these two factors concerning vegetation dynamics is discussed in order to distinguish the main forcing which was involved during the different vegetation phases. These various changes in the vegetal environment of the valley are also shown by the occurrence of thick deposits of detrital material within the travertine formations.

Above-ground biomass and structure of pristine Siberian Scots pine forests as controlled by competition and fire.

The study presents a data set of above-ground biomass (AGB), structure, spacing and fire regime, for 24 stands of pristine Siberian Scots pine (Pinus sylvestris) forests with lichens (n = 20) or Vaccinium/mosses (n = 4) as ground cover, along four chronosequences. The stands of the "lichen" site type (LT) were stratified into three chronosequences according to stand density and fire history. Allometric equations were established from 90 sample trees for stem, coarse branch, fine branch, twig and needle biomass. The LT stands exhibited a low but sustained biomass accumulation until a stand age of 383 years. AGB reached only 6-10 kgdw m-2 after 200 years depending on stand density and fire history compared to 20 kgdw m-2 in the "Vaccinium" type (VT) stands. Leaf area index (LAI) in the LT stands remained at 0.5-1.5 and crown cover was 30-60%, whereas LAI reached 2.5 and crown cover was >100% in the VT stands. Although nearest-neighbour analyses suggested the existence of density-dependent mortality, fire impact turned out to have a much stronger effect on density dynamics. Fire scar dating and calculation of mean and initial fire return intervals revealed that within the LT stands differences in structure and biomass were related to the severity of fire regimes, which in turn was related to the degree of landscape fragmentation by wetlands. Self-thinning analysis was used to define the local carrying capacity for biomass. A series of undisturbed LT stands was used to characterise the upper self-thinning boundary. Stands that had experienced a moderate fire regime were positioned well below the self-thinning boundary in a distinct fire-thinning band of reduced major axis regression slope -0.26. We discuss how this downward shift resulted from alternating phases of density reduction by fire and subsequent regrowth. We conclude that biomass in Siberian Scots pine forests is strongly influenced by fire and that climate change will affect ecosystem functions predominantly via changes in fire regimes.

Time-restricted seed regeneration of Scots pine in sites dominated by feather moss after clear-cutting

Scots pine (Pinussylvestris L.) were selectively seeded in 1990, 1991, 1992, and 1994 in bottom layer vegetation of Pleuroziumschreberi (Bird.) Mitt, in a clearcut created in 1989 and in an adjacent undisturbed Scots pine forest of Vaccinium type, in northern Sweden. Seedlings from the 1990 seeding established considerably better on the clearcut than in the forest. In contrast, seeding done in 1991, 1992, and 1994 gave no significant difference in seedling establishment between the two sites. Seedlings that established in the clearcut in 1990 grew significantly larger and had a higher content of macro- and micro-nutrients than those in the forest. For seedlings that established in 1992, biomass and nutrient content of seedlings in the clearcut did not differ from those in the forest. Seedlings established in the clearcut in 1990 increased their nutrient content in relation to seed supply, while seedlings established in the clearcut in 1992 and those in the forest had in general gained less or even lost nutrients (especially P) in relation to seed reserve. These results indicate that Pleuroziumschreberi-dominated microsites can constitute a favourable microhabitat for pine regeneration following stand disturbance, although the positive effect quickly diminishes with time after disturbance. The higher establishment and growth of emerging seedlings the 1st year after cutting compared with later established cohorts in the clearcut may be caused by changes in nutrient availability. We propose that environmental stress after cutting temporarily diminishes the effect of the nutrient barrier formed by Pleuroziumschreberi, ericoid mycorrhiza, and ericaceous dwarfshrubs. We conclude that successful natural pine regeneration in Pleuroziumschreberi-dominnted vegetation induced by clear-cutting can be severely time restricted. This is an important consideration when dealing with forestry methods that depend on natural regeneration.

The distribution of some heathland plant species along a microtopographic gradient at Dinnet, Scotland, and their dehydration resistances

Along a microtopographic gradient in a heathland, five types of plant distribution were recognized: (i) Pyrola type, restricted to the crest of the rise; (ii) Vaccinium type, mainly on the steeper slopes and thin soil; (iii) Arctostaphylos type, ranging widely from the top to the bottom of the slope; (iv) Erica tetralix type, in the waterlogged wet places; and (v) Calluna type, showing the most extensive occurrence across the ranges of all the foregoing types. A clear separation of habitat was found between Erica cinerea and Erica tetralix. The stomatal transpiration of Calluna was the most active among five species studied. However, the cuticular transpiration rate is rather low. These facts all have a bearing on the widely dominant occurrence of Calluna in heathland. Vaccinium vitis-idaea and Arctostaphylos uva-ursi showed the lowest transpiration rates in the present study. Their cuticular transpiration rates are also low. These facts may be in accord with their inability to overcome Calluna under conditions of adequate water supply. However, they may become dominant in some sites, such as the terrace of thin soil. The buds of Erica tetralix are very susceptible to drought, because their lethal water deficit is very small. It may be a main cause of the restriction of this species to very wet places.

Small Rodent Abundance in Relation to Reforestation Measures and Natural Habitat Variables in Northern Sweden1

ABSTRACTResults of an extensive survey, 1972–1975, aimed at establishing the influence of forest management practices and other environmental variables on small rodent abundance are discussed. The study area included several habitat types and, in total, 1,878 small quadrats were marked out in 47 regeneration areas. Most areas were sampled twice a year, in the spring and autumn, and more than 5,000 voles were trapped; the species Clethrionomys glareolus (Schreber) and Microtus agrestis (L.) were trapped in about equal numbers, while C. rufocanus (Sundevall) was rather sporadic. The cycle increase started earlier in C. glareolus than in M. agrestis and C. rufocanus.Data on environmental variables were collected partly by means of field observations and pardy from the literature. An analysis of the effect of environmental variables revealed considerable interaction making identification of primary factors difficult. The populations of C. glareolus and C. rufocanus generally decreased with an increase in time since clear‐cutting. For M. agrestis, highest numbers were found on sites in which clear‐cutting had been carried out 5–15 years previously. The influence of surface treatment, in particular, was found to be dependent on the population cycle. During increase and early peak phases, C. glareolus was found in smaller numbers in regenerated areas treated by burning or ploughing, compared with those where only normal patch scarification had been carried out. During the very gradual decline in numbers, conditions were the reverse. During increase and early peak phases, the highest catches of M. agrestis were made in scarified areas. This inverse relationship between the 2 species was also found in connection with many of the other environmental variables studied. M. agrestis was the most typical “regeneration phase” species, positively influenced by environmental factors such as moderately coarse grained soil texture, low soil acidity, moderate humus thickness, increasing moisture up to a certain level and a vegetation type with forbs predominating as opposed to the Vaccinium type. The pattern of displacement indicates that competition occurs between M. agrertis and C. glareolus.

Metsätyypin määräytyminen maalajin ja maaperän kemiallisten ominaisuuksien perusteella

This study consists of 1228 profiles taken from forest soils mainly situated in South and Central Finland. Nine per cent of the soils are located in the Oxalis-Myrtillus type (OMT), 56 percent in the Myrtillus type (MT), 28 percent in the Vaccinium type (VT), 5 per cent in the Calluna type (CT), and 2 per cent in the Cladina type (CIT). Four layers of each profile were analyzed. In the podsolized soils (80 per cent of all cases) the layers investigated were the litter layer (A0 horizon), the leaching layer (A2), the enrichment layer (B1—2), and the subsoil (C). In the clay, silt and sand soils, in which the podsolization was weak, the uppermost sample was taken from the litter horizon (A0), the second one down to 20 cm, the third from a depth of 20—40 cm., and the fourth at a depth of 40—60 cm. The types OMT, MT and VT are found in all soil types. There are no clay, silt or finer fines and samples taken from CT and CIT, while 57 per cent of all cases were in OMT. On the other hand, only 3 per cent of the sand samples came from OMT, while 54 per cent of the CT samples and 42 per cent of the CIT samples were sand. In general, the uppermost layers of forest soils are the most acid ones. The average pH-value of the litter layers in each forest type is about one pH-unit lower than that of the subsoil of the same type. The mean values of pH(H2O) in the litter layers decrease from pH 4.7 in OMT to pH 4.0 in CIT. According to this study, the litter layer is the richest layer in nutrients in forest soils. The differences between the mineral soil layers are small in each nutrient in the same forest type. The average exchangeable calcium and potassium contents in the surface soil increase with better forest types. The average Ca contents of the mineral soil layers in OMT vary from 366 to 1 060 mg/l soil while the corresponding numbers of CIT, CT and VT are 36-117mg/l. The litter layer of OMT has the highest potassium mean value (177 mg/l) while the lowest value (7 mg/l) is found in the subsoil of CIT. The content of readily soluble phosphorus in the humus layer is 4-10 times as high as that in the deeper mineral soil layers. This is the only regularity to be found in the P contents between the different forest and soil types. Dividing the samples into soil type groups, we can say that the higher the mean values of calcium, potassium and pH, the richer the forest type they represent. Carbon and nitrogen determinations were made from surface soil samples only. The C/N ratio decreases quite regularly from 42 (CIT) to 24 (OMT).