South Patagonian ombrotrophic bog vegetation reflects biogeochemical gradients at the landscape level

Question: Which environmental variables affect the floristic composition of south Patagonian bog vegetation along a gradient of climate and biogeochemical changes with increasing distance from the Pacific ocean? Location: Trans‐Andean transect (53° S), southern Patagonia Material and Methods: Floristic composition, peat characteristics (water level, decomposition, pH, total nitrogen, total carbon, ash content and plant available P, K, Na, Ca, Mg, Fe, Mn, Zn, and Al) and climatic constraints of ombrotrophic peat‐lands were measured at 82 plots along a gradient of increasing distance from the Pacific Ocean. Results: Climatic constraints and biogeochemical peat characteristics significantly change with increasing distance from the Pacific. Peatland vegetation shifted from hyperoceanic blanket bogs dominated by cushion forming vascular plants to the west to Sphagnum bogs to the east. Climatic and biogeochemical variables explained a large proportion of the floristic variation along the first DCA axis. The second axis represented a water level gradient. When ‘distance to the Pacific’ was defined as a covariable in partial CCA, the proportion of variance explained declined for most other variables, especially in the case of annual precipitation and exchangeable base cations and related traits. The differences in biogeochemical characteristics related to peat were mainly attributed to the input of sea‐borne cations. Conclusions: While variation in vegetation composition along a longitudinal gradient crossing the southern Andes was attributed to climatic constraints as expected, vegetation composition was also strongly affected by the biogeochemical characteristics of peat. Sea spray was of high ecological importance to peat chemistry and, consequently, to floristic composition. Presumably, south Patagonian peat bogs represent a glimpse of pre‐industrial environments, so that these peat bogs may act as reference systems with respect to atmospheric inputs in mire ecology research.     

Changes in nitrogen and base cation concentrations in soil water due to the tree cutting in a wetland alder forest in the Kushiro Wetland, northern Japan

As part of the Kushiro Wetland Restoration Project, we evaluated the effect of the tree-cutting (February 2003) on soil water chemistry for 3 years in an alder (Alnus japonica) shrubland on the peat soil in the Kushiro Wetland, the largest wetland in Japan. The alder stand was divided into two types; low stature and high stature stands, mean heights being 1.5 and 2.6 m, respectively. The treatment plot with tree cutting and the reference plot measuring 25 m × 25 m each were established in both stands, and a soil incubation experiment was also conducted by trenching the root zone of wetland vegetation in the treatment plots in both stands in the summer of 2004. The tree cutting did not substantially increase the concentrations of ammonium ion (NH₄ ⁺) and nitrate ion (NO₃ ⁻) in the soil water, although a gradual and slight increase of NO₃ ⁻ concentration was found after the tree-cutting only in the high stature stand (<10 μmol/l). This increase in the NO₃ ⁻ concentration in the high stature stand was probably due to the rhizosphere oxidation of wetland herbaceous vegetation, and was accompanied by the increase of Ca²⁺ concentration. The soil incubation experiment showed no significant change of the nitrogen concentration, suggesting that inorganic nitrogen was immobilized and NO₃ ⁻ was denitrified intensively in this wetland peat soil. The results of this study suggested that this wetland ecosystem had a high potential to stabilize the soil water chemistry.     

Implications of floristic and environmental variation for carbon cycle dynamics in boreal forest ecosystems of central Canada

Abstract. Species composition, detritus, and soil data from 97 boreal forest stands along a transect in central Canada were analysed using Correspondence Analysis to determine the dominant environmental/site variables that differentiate these forest stands. Picea mariana stands were densely clustered together on the understorey DCA plot, suggesting a consistent understorey species composition (feather mosses and Ericaceae), whereas Populus tremuloides stands had the most diverse understorey species composition (ca. 30 species, mostly shrubs and herbs). Pinus banksiana stands had several characteristic species of reindeer lichens (Cladina spp.), but saplings and Pinus seedlings were rare. Although climatic variables showed large variation along the transect, the CCA results indicated that site conditions are more important in determining species composition and differentiating the stand types. Forest floor characteristics (litter and humus layer, woody debris, and drainage) appear to be among the most important site variables. Stands of Picea had significantly higher average carbon (C) densities in the combined litter and humus layer (43530 kg‐C.ha^‐1) than either Populus (25 500 kg‐C.ha^‐1) or Pinus (19 400 kg‐C.ha^‐1). The thick surface organic layer in lowland Picea stands plays an important role in regulating soil temperature and moisture, and organic‐matter decomposition, which in turn affect the ecosystem C‐dynamics. During forest succession after a stand‐replacing disturbance (e.g. fires), tree biomass and surface organic layer thickness increase in all stand types as forests recover; however, woody biomass detritus first decreases and then increases after ca. 80 yr. Soil C densities show slight decrease with ages in Populus stands, but increase in other stand types. These results indicate the complex C‐transfer processes among different components (tree biomass, detritus, forest floor, and soil) of boreal ecosystems at various stages of succession.     

黄河三角洲植被空间分布特征及其环境解释

为了解黄河三角洲地区植被空间分布与环境因子之间的关系,通过局地植被样方调查、区域遥感影像提取归一化植被指数(NDVI)及地形高度、地下水位埋深、表层土壤Cl~-含量等环境数据采集,综合样地植被与环境数据进行了除趋势对应分析(DCA)和除趋势典范对应分析(DCCA),并对区域NDVI与主要环境变量进行了单因子相关性分析和多元逐步回归分析。结果显示:DCA排序可将黄河三角洲植被分为翅碱蓬、柽柳-翅碱蓬、芦苇-柽柳、芦苇4个主要群落类型(群丛),DCCA与DCA排序图总体相似,但DCCA更清晰地表明其第一轴主要代表的是潜水Cl~-浓度等关键水盐因子,且随着水土环境系统盐分含量的减小,群落由翅碱蓬逐渐向芦苇演变。区域典型植被群落和NDVI分布格局与变化趋势受地下水位埋深和潜水Cl~-浓度2个环境因素影响较大(NDVI与2个环境变量间建立的二元回归方程R~2=0.57),而土壤Cl~-含量的植被效应实际上受地下水位埋深和潜水Cl~-浓度的影响。在区域地下水普遍浅埋条件下,地下水成为影响植被生长与分布的生态环境最敏感要素,而地下水位埋深和潜水Cl~-浓度是这一要素中的2个关键因子,尤其是后者梯度变化对天然植被分布格局起重要的控制作用。     

Vegetation-environment relations of a Middle Zambezi floodplain

Detrended correspondence analysis was used to study the relationships between environmental factors and the species composition of vegetation on Zambezi River alluvium downstream of the Kariba hydroelectric dam. Grass, sedge and woody species were recorded in 73 stands in Mana Pools National Park, Zimbabwe. Grass and sedge species composition was related to the soil moisture regime, as indexed by soil texture and flooding frequency. The first woody plant ordination axis was related to a stand development gradient; Acacia albida was a pioneer species on lowlying sandbanks and the woody species richness of stands increased with their height above the Zambezi River. Two-way indicator species analysis identified 7 vegetation types which could be separated on the basis of their topsoil texture and flooding frequency. The types were: sandbanks; young A. albida woodland; A. albida woodland; A. albida dominated mixed woodland; mixed riverine woodland with understory; mixed riverine woodland; and grassland on clay soils.     

The Finnish forest site type approach: ordination and classification studies of mesic forest sites in southern Finland

A.K. Cajander's forest site type classification system is based on definition of plant communities typical to certain climatical and edaphical site conditions, but the structure and composition of the tree stands in Finland are considered sensitive to random variation and are therefore not used as primary classification criteria. The system has often received criticism, usually that the effects of the tree stand and successional stage of the stand have been underestimated. Most of the present-day forest stands in Finland represent young successional stages and are subjected to intensive management. This should result in an additional difficulty in the application of the forest site types in the field.The present study is based on three independent data sets representing forests on mineral soil in southern part of Finland. TWINSPAN classification, DCA ordination and canonical correspondence analysis (CCA) techniques were applied in successive stages of the data analysis. It was found that the definition of the intermediately fertile, mesic site types was clearly confused by the effects of the tree species and age of the stand. The analyses also revealed that the succession pathways on mesic forest sites are largely determined by the tree species composition. In stands dominated by Pinus sylvestris, the succession follows the competitive hierarchy model, whereas in stands dominated by Picea abies, severe shading of the tree canopy governs the development of understorey vegetation.Abbreviations CCA Canonical correspondence Analysis - DCA Detrended correspondence Analysis - TWINSPAN Two-way indicator species analysis     

Understorey vegetation development in North Finnish Picea forests after disturbance: re‐analysis of Sirén's data

Abstract. Sirén (1955) studied understorey species composition, tree stand properties and humus‐layer thickness in 64 unlogged forest stands on topographically and pedologically comparable sites. The stands were of even age (6 – 300 yr), stocked with the first or second tree generation after wildfire. The view of Sirén and several authors after him, that the vegetation of old‐growth boreal Picea forests is homogeneous on a broad scale, was examined by applying, in parallel, the partial variants of two ordination methods (DCA and PCA) to Sirén's vegetation data. Two main vegetation gradients were found: a major gradient running from recently burnt plots with prominence of pioneer species to plots with stand age > 100 yr, a well stocked tree layer and a thick humus layer, dominance of feather‐mosses and ample occurrence of shade‐tolerant as well as light‐preferring vascular plant species, and a second gradient along which first‐ and second‐generation plots segregate. The more prominent element of Betula trees in first‐ than in second‐generation stands < 100 yr contributed to the latter. A minor third gradient related to humus‐layer thickness was recovered by partial DCA only. The main vegetation gradient reappeared in separate ordinations of data from 47 mature forest stands (> 100 yr), but without being correlated with forest age. Variation among mature‐forest stands in the importance of pioneer species is considered mainly to be brought about by fine‐scale disturbance processes such as tree uprooting. Increasing importance of factors operating on within‐stand scales [development of a varied gap structure and stronger gradients in tree influence (radiation at ground level), soil moisture, soil depth and nutrient availability] with time is also reflected in the second and third mature‐forest ordination axes. Possible implications of the results for conservation of biological diversity and monitoring of changes in boreal forests are discussed.     

Growth Response of Coyote Willow (Salix exigua) Cuttings in Relation to Alluvial Soil Texture and Water Availability

A common approach to re‐establishing cottonwood–willow habitat along regulated rivers is through installing dormant, rootless cuttings, yet there is little published information exploring floodplain characteristics that optimize growth of southwestern riparian willows planted in this manner. The goal of this project was to evaluate relationships between growth attributes of Salix exigua and soil texture and soil water availability. Monitoring plots were established in five willow swales planted with dormant S. exigua cuttings along the banks of the Middle Rio Grande in central New Mexico. Data analysis revealed significantly higher aerial cover, height, and stem density for S. exigua plants installed in plots with intermediate levels (15–25%) of fine textured soils distributed through the soil profile. Similar relationships were found in relation to soil water availability. Regression analysis of percent fines and available water at different depth increments provided limited explanation of variability in willow growth attributes at different plots. Findings indicate that S. exigua plants established from cuttings can achieve heights and aerial cover values similar to naturally established willow bars if the floodplain soil profile contains intermediate levels of fine textured soils and the maximum depth to groundwater is within 1.5 m of the ground surface. Where sites are dominated by coarse sand, S. exigua growth may be improved if maximum depth to groundwater is within 1 m of the ground surface.     

Do understorey or overstorey traits drive tree encroachment on a drained raised bog?

• One of the most important threats to peatland ecosystems is drainage, resulting in encroachment of woody species. Our main aim was to check which features – overstorey or understorey vegetation – are more important for shaping the seedling bank of pioneer trees colonising peatlands (Pinus sylvestris and Betula pubescens). We hypothesised that tree stand parameters will be more important predictors of natural regeneration density than understorey vegetation parameters, and the former will be negatively correlated with species diversity and richness and also with functional richness and functional dispersion, which indicate a high level of habitat filtering.
• The study was conducted in the ‘Zielone Bagna’ nature reserve (NW Poland). We assessed the structure of tree stands and natural regeneration (of B. pubescens and P. sylvestris) and vegetation species composition. Random forest and DCA were applied to assess relationships between variables studied.
• Understorey vegetation traits affected tree seedling density (up to 0.5‐m height) more than tree stand traits. Density of older seedlings depended more on tree stand traits. We did not find statistically significant relationships between natural regeneration densities and functional diversity components, except for functional richness, which was positively correlated with density of the youngest tree seedlings.
• Seedling densities were higher in plots with lower functional dispersion and functional divergence, which indicated that habitat filtering is more important than competition. Presence of an abundant seedling bank is crucial for the process of woody species encroachment on drained peatlands, thus its dynamics should be monitored in protected areas.

     

Relations between understorey vegetation,site productivity,and environmental factors in Pinus sylvestris L. stands in southern Finland

Relations between understorey vegetation, site productivity, and environmental factors in mature stands of Pinus sylvestris L. in southern Finland were studied using data from 234 sample plots. The (weighted) Pearson product-moment correlation between site index and the first ordination axis of detrended correspondence analysis (DCA) was 0.83. The correlation was clearly better where site index was above 21 m (r=0.83) than where it was less (r=0.33). Partial canonical correspondence analysis (CCA) indicated that the residual compositional variation, not related to site fertility as expressed by site index, can be partly ascribed to high moisture regime with poor drainage (paludification), soil deposit type, soil stoniness, and macroclimate, and in part to unexplained sources. The unique influence of canopy cover on the vegetation composition was non-significant (p<0.05) and that of stand age too small to be detected in the vegetation data. The results support Cajander's forest site type theory according to which there exists a dominant relationship between understorey vegetation and site productivity in boreal forest ecosystems. Cladonia sectio Cladonia lichens, exluding Cladonia uncialis, were treated collectively, and abbreviated as Cladonia spp. The most frequent of these species were C. gracilis, C. cornuta, C. fimbriata, C. deformis, C. cenotea, C. botrytes, C. crispata, C. pyxidata, C. cornuta, and C. furcata.     

Classification and ordination of plant communities in Abune Yosef mountain range,Ethiopia

Understanding how topography-soil-disturbance drives spatial distribution of vegetation is the interest of ecologists. This study was, conducted to investigate the topography-soil-disturbance and vegetation relationships in Abune Yosef mountain range, Ethiopia. A total of 85 nested sample plots measuring 400 m², 25 m² and 1 m² were established for trees, shrubs and herbs respectively. Topographic, soil and disturbance variables were also assessed from each plot. Plant community classification was described and identified by agglomerative hierarchical clustering using Ward's minimum variance clustering methods. Shannon diversity index was employed to determine community diversity. After detecting the length of the first Detrended Correspondence Analysis (DCA) axis, Canonical Correspondence Analysis (CCA) forward and backward stepwise selection of environmental variables was performed based on their p-value by running permutation tests. The first axis explained 43.63% of the overall inertia and is correlated with Elevation, pH, slope aspect, total Nitrogen, soil organic Carbon & Clay. On the other hand, the second axis explained 32.06% of the total inertia and is correlated with bulk density, slope, logging, & available Phosphorus. The present study revealed that topographic variables have a profound influence on vegetation spatial distribution than soil and disturbance factors.     

Floristics and environmental relations in two extreme desert zones of western Egypt

• 1 The present study provides quantitative estimates of soil, vegetation structure and species distribution in 144 stands along two transects in two extreme desert zones of western Egypt. This study had two aims: (1) to describe the floristic composition of the accidental type of vegetation growing in parts of the Western Desert of Egypt; and (2) to analyse the distribution of species in relation to certain environmental factors by multivariate data analysis.
• 2 Eight environmental variables were recorded: salinity, pH, calcium carbonate, soil moisture, organic matter content, and percentages of sand, silt and clay. A total of 60 species belonging to 19 families of the angiosperms and Ephedra alata was recorded. Chamaephytes and therophytes were the most frequent, denoting a typical desert life‐form spectrum, mainly of Saharo‐Arabian distribution.
• 3 The samples were classified into eight twinspan groups. Detrended correspondence analysis (DCA) showed that these groups could be distinguished by the first two DCA axes. They could also be effectively interpreted and explained with canonical correspondence analysis (CCA). Based on forward regression, salinity, fine sediments, organic matter and soil moisture content related closely to the first three canonical axes, and accounted for 84.1% of the species–environment relationship among the stands.
• 4 Both classification and ordination resulted in a clear demonstration of the vegetation pattern in the study area. Other twinspan groups were characterized in addition to those identified previously. In conclusion, the study area has a transitional character where the Nubian Desert and the Northern Mediterranean vegetation meet.

     

Overstory vegetation and successional trends of Land Between The Lakes,USA

133 stands from the uplands of Land Between The Lakes (LBL) were sampled. Stand data were ordinated to identify clinal patterns in the overstory vegetation. A coeno-cline, accounting for 52% of the species variance, was developed from the first ordination axis. Classification of stands identified nine dominance types: Pinus echinata-Quercus spp., Q. prinus, Q. prinus-Q. alba, Q. stellata-Q. alba, Q. velutina-Q. alba, Q. alba, Q. alba-Q. rubra, Acer saccharum-Q. alba-Fagus grandifolia sadF. grandifolia-A. saccharum. Compositionally-stable (climax) and unstable (successional) stands were analyzed separately. Trajectories of unstable stands include the succession of P. echinata to Quercus-dominated communities on xeric sites and of Quercus types to more mesophytic communities (e.g. A. saccharum and F. grandifolia) onmesic sites. These shifts indicate the nature of the future climax overstory composition at LBL. The first axis DCCA ordination for climax stands accounted for 45% of the vegetation variance. Factor Analysis identified two significant suites of variables related to vegetation: soil chemistry/soil moisture and soil texture. Specific variables related to variation in the climax vegetation include soil pH, calcium and magnesium, effective soil depth, available water capacity, percent rock in the soil, slope position, aspect, elevation and distance to the opposing slope. Modal positions of species along the direct gradient ordination were similar in rank order to those derived from the indirect gradient ordination of all stands. The latter ordination represents the present forest vegetation pattern at LBL. Climax stands showed a shift in modes of Quercus spp. toward the xeric end of the gradient and increases in habitat width of mesophytic species. Following a reduction in disturbance, species appear to adjust to changes in competition and available habitat. That is, the dimensions of realized niches (i.e. habitat widths) change with succession. The climax vegetation at LBL appears to show centrifugal organization.     

黄土区露天煤矿排土场土壤与地形因子对植被恢复的影响

在脆弱的生态环境改善和恢复过程中,植被恢复与重建扮演着重要的角色。黄土露天煤矿区生态环境极其脆弱,认识矿区损毁土地植被恢复与地形、土壤因子之间的作用规律对矿区土地复垦与生态恢复改善至关重要。为此,选择山西平朔安太堡露天煤矿南排土场对2条样带27个复垦样地的土壤、地形、植被参数进行了采集与测定,并应用单因素方差分析与CANOCO4.5软件的降趋势对应分析和冗余分析研究了地形与土壤因子对植被恢复的影响。结果表明:植被与土壤变量之间呈显著相关,与地形变量之间相关性不明显;坡度主要影响草本覆盖度,坡向与有机质和速效磷之间具有线性相关性;速效钾对植被的变化起着重要的作用;土壤容重与砾石含量对土壤养分含量具有明显的指示作用;有机质与全氮呈显著正相关,各土壤养分指标之间存在明显的相关关系。为了改善和恢复黄土区露天煤矿排土场脆弱的生态系统,应该考虑植被和土壤的联合演替。在当地的生态环境状况下土地复垦与生态恢复的关键是改善土壤状况和增加人工植被,同时加强对排土场人工和自然植被的保护。     

Potential of Salix as phytoextractor for Cd on moderately contaminated soils

Biomass production and Cd uptake in Salix (willow) is generally high. The aim of this study was to quantify the amounts of Cd in different plant and soil compartments in commercial Salix stands grown on different soil types and to use these data for estimation of the long-term effects of Cd removal by Salix at stem harvest on the soil Cd content by calculating Cd balances. Ten commercial short rotation willow coppice stands, planted with clone 78183 of Salix viminalis (L.) were investigated in order to include three different soil types with respect to pH. Stands with high stem biomass production generally had lower Cd concentrations in the plant and grew on more alkaline soils with low Cd availability when compared to stands with low stem biomass production. The highest output of Cd by Salix is therefore not necessarily achieved by stands with the highest yields or the highest Cd concentrations, as both these parameters have to be considered. The net removal of Cd from the plough layer by the Salix crop under different conditions varied between 2.6 and 16.5 g Cd ha^–1 year^–1. The long-term effects of Salix cultivation on soil Cd content, i.e. after 6–7 cutting cycles (25 years), were calculated and we reached the conclusion that there is a high potential in Salix to remove significant amounts of Cd at stem harvest. Salix can therefore presumably be used to counteract Cd pollution of agricultural soils in Sweden provided that the Cd in furnace ashes is taken care of.     

Patterns of clonal diversity in three species of sub-arctic willow (Salix lanata, Salix lapponum and Salix herbacea)

Sub-arctic willow scrub is an endangered habitat in Britain, and typically occurs on steep crags inaccessible to grazing animals. These willows can reproduce both sexually and asexually, although the relative importance of each is unknown. Knowledge of reproductive mode is important for the design of grazing management and restoration programmes. Accordingly, clonality was assessed in the largest stand of sub-arctic willow scrub in the UK, focusing on Salix lanata and S. lapponum. Little evidence of clonal growth was detected; most individuals possessed distinct multi-locus genotypes. Thus despite the capacity for vegetative reproduction, and seedlings being rarely observed, sexual reproduction is the predominant means of perpetuation and dispersal at this site. We also examined clonal growth in a common willow species (Salix herbacea) that occupies a different habitat type (exposed mountain tops and ridges). Multiple individuals shared identical genotypes up to 7 m apart, suggesting an important role for clonal growth in local patch formation in this species.     

Influence of soil nutrients on ectomycorrhizal communities in a chronosequence of mixed temperate forests

Many factors associated with forests are collectively responsible for controlling ectomycorrhizal (ECM) fungal community structure, including plant species composition, forest structure, stand age, and soil nutrients. The objective of this study was to examine relationships among ECM fungal community measures, local soil nutrients, and stand age along a chronosequence of mixed forest stands that were similar in vegetation composition and site quality. Six combinations of age class (5-, 26-, 65-, and 100-year-old) and stand initiation type (wildfire and clearcut) were replicated on four sites, each representing critical seral stages of stand development in Interior Cedar-Hemlock (ICH) forests of southern British Columbia. We found significant relationships between ECM fungal diversity and both available and organic P; available P was also positively correlated with the abundance of two ECM taxa (Rhizopogon vinicolor group and Cenoccocum geophilum). By contrast, ECM fungal diversity varied unpredictably with total and mineralizable N or C to N ratio. We also found that soil C, N, available P, and forest floor depth did not exhibit strong patterns across stand ages. Overall, ECM fungal community structure was more strongly influenced by stand age than specific soil nutrients, but better correlations with soil nutrients may occur at broader spatial scales covering a wider range of site qualities.     

Within‐stand spatial structure and relation of boreal canopy and understorey vegetation

Question: How do spatial patterns and associations of canopy and understorey vegetation vary with spatial scale along a gradient of canopy composition in boreal mixed‐wood forests, from younger Aspen stands dominated by Populus tremuloides and P. balsamifera to older Mixed and Conifer stands dominated by Picea glauca? Do canopy evergreen conifers and broad‐leaved deciduous trees differ in their spatial relationships with understorey vegetation? Location: EMEND experimental site, Alberta, Canada. Methods: Canopy and understorey vegetation were sampled in 28 transects of 100 contiguous 0.5 m × 0.5 m quadrats in three forest stand types. Vegetation spatial patterns and relationships were analysed using wavelets. Results: Boreal mixed‐wood canopy and understorey vegetation are patchily distributed at a range of small spatial scales. The scale of canopy and understorey spatial patterns generally increased with increasing conifer presence in the canopy. Associations between canopy and understorey were highly variable among stand types, transects and spatial scales. Understorey vascular plant cover was generally positively associated with canopy deciduous tree cover and negatively associated with canopy conifer tree cover at spatial scales from 5–15 m. Understorey non‐vascular plant cover and community composition were more variable in their relationships with canopy cover, showing both positive and negative associations at a range of spatial scales. Conclusions: The spatial structure and relation of boreal mixed‐wood canopy and understorey vegetation varied with spatial scale. Differences in understorey spatial structure among stand types were consistent with a nucleation model of patch dynamics during succession in boreal mixed‐wood forests.     

Ectomycorrhizal development on Scots pine (Pinus sylvestris L.) seedlings in different soils

In the present study ectomycorrhizal development of Laccaria bicolor, Rhizopogon luteolus and Suillus bovinus associated with Scots pine (Pinus sylvestris) seedings was studied as affected by primary stand humus, secondary stand humus, podsolic sandy soil or peat in perspex growth chambers. After 9 weeks, ectomycorrhizal development with S. bovinus was significantly greater in peat and primary stand humus than in secondary stand humus or podsolic sandy soil. Ectomycorrhizal development with R. luteolus in secondary stand humus was higher than in primary stand humus. Degree of ectomycorrhizal development of L. bicolor, R. lutuelus and S. bovinus on Scots pine was related to potassium concentration, organic matter content and pH of the soils suggesting that chemical composition of the soils affects ectomycorrhizal development.