The effect of forest management operations on population performance of Vaccinium myrtillus on a landscape-scale

We have studied the variation in average performance of Vaccinium myrtillus L. among local populations within an intensively managed boreal forest landscape in southeast Norway. Our aim was to identify whether forest disturbance history was an important factor controlling the variation in average plant performance. We used three measures of forest maturity (maturity class, tree biomass and number of trees) as variables reflecting disturbance history. These variables were used in our analysis together with measured environmental conditions (soil moisture, pH, nitrogen, and elevation) a priori known to affect plant performance. To quantify plant performance, we used multiple measures of the local V. myrtillus populations, including percentage cover, average ramet age, height, diameter, biomass, growth, and sexual reproduction (number of fruits and number of mature seeds per fruit). Most of the explained variation in our performance variables could be related to our environmental variables, but disturbance history was also an important determinant of the performance of V. myrtillus. All performance variables were higher in younger, less mature stands, except ramet age, which was highest in mature stands. The increase in performance after clear cutting indicates that this period is of high importance for the population dynamics and persistence of V. myrtillus in intensively managed boreal forest landscapes.     

Habitat selection by capercaillie in summer and autumn: Is bilberry important?

The use of habitat by female and male adult capercaillie Tetrao urogallus during summer and autumn was studied by comparing the distribution of radio locations of birds with the availability of habitat at forest stand, home range and landscape level in an area of the Bavarian Alps, Germany. Capercaillie preferred forests with structural features typical of their main distribution range, the boreal forest: they selected large patches of old forest with moderate canopy cover of about 50%, and a well developed field layer with high proportions of bilberry Vaccinium myrtillus. Hens selected both home ranges and sites within home ranges in old forest. Ranges selected by cocks did not differ from availability in the study area, but they preferred old forest within their ranges. The size of home ranges was negatively related to bilberry cover both in hens and cocks. The distribution of bilberry also determined habitat use by capercaillie at the landscape scale. The study demonstrated that bilberry is the major determinant of the selection of habitat by capercaillie in landscapes with sparse and fragmentary cover of ericaceous shrubs, such as central Europe.     

Responses to harvesting intensity in a clonal dwarf shrub,the bilberry (Vaccinium myrtillus L.)

The effects of herbivory were simulated on stands of bilberry (Vaccinium myrtillus L.) in a boreal Empetrum-Myrtillus type forest. Five harvesting intensities were used (0% (A), 25% (B), 50% (C), 100% (D) of the bilberry ramets or all the ramets of all species (E)). Density and biomass of the stands, and growth of the ramets were monitored for five growth seasons, from 1986 to 1990. After damage new ramets emerged rapidly from dormant buds at the base of removed ramets. Between 70 and 97% of the density relative to the control level was regained by the final harvest. However, only between 11 and 64% of the biomass relative to the control level was recovered. Clipping reduced the branch growth, both in the new ramets and in the new parts of the old, unclipped ramets. Severe treatments (D and E) decreased the growth more than did light harvesting (B and C). Survival and fecundity of the ramets were not affected. The result therefore suggested that the bilberry is not able to recover totally from severe herbivory damage between the years of peak rodent population that shows a 3–4 year cycle. Nevertheless, extreme grazing pressure is rare in boreal ecosystems as alternative food is available for herbivores, and predators also limit the herbivore population. Hence the bilberry exhibits moderate tolerance of the usual level of herbivory damage.     

Structure of the Microbial Communities in Coniferous Forest Soils in Relation to Site Fertility and Stand Development Stage

Abstract The structure, biomass, and activity of the microbial community in the humus layer of boreal coniferous forest stands of different fertility were studied. The Scots pine dominated CT (Calluna vulgaris type) represented the lowest fertility, while VT (Vaccinium vitis-idaéa type), MT (Vaccinium myrtillus type), and OMT (Oxalis acetocella–Vaccinium myrtillus type) following this order, were more fertile types. The microbial community was studied more closely by sampling a succession gradient (from a treeless area to a 180-years-old Norway spruce stand) at the MT type site. The phospholipid fatty acid (PLFA) analysis revealed a gradual shift in the structure of the microbial community along the fertility gradient even though the total microbial biomass and respiration rate remained unchanged. The relative abundance of fungi decreased and that of bacteria increased with increasing fertility. The structure of the bacterial community also changed along the fertility gradient. Irrespective of a decrease in fungal biomass and change in bacterial community structure after clear-cutting, the PLFA analysis did not show strong differences in the microbial communities in the stands of different age growing on the MT type site. The spatial variation in the structure of the microbial community was studied at a MT type site. Semivariograms indicated that the bacterial biomass, the ratio between the fungal and bacterial biomasses, and the relative amount of PLFA 16:1ω5 were spatially autocorrelated within distances around 3 to 4 m. The total microbial and fungal biomasses were autocorrelated only up to 1 m. The spatial distribution of the humus microbial community was correlated mainly with the location of the trees, and consequently, with the forest floor vegetation. Received: 9 November 1998; Accepted: 26 April 1999     

森林生态系统服务价值及其补偿校准——以马尾松林为例

森林补偿资金分配与生态系统服务脱钩,是长期以来制约森林生态保护制度发挥作用的关键因素。建立森林生态保护成效与资金分配挂钩的激励约束机制,对于完善生态补偿制度、保障国家生态安全具有重要意义。以马尾松林为例,运用野外调查、实验室实验等方法,精准计量评价马尾松林的固碳、水源涵养、固土保肥、生物多样性等4种主要生态系统服务;以皮尔(R.Pearl)生长曲线为基础构建生态补偿算法,测算基于生态系统服务价值的马尾松林补偿标准。第一,马尾松林生态系统服务价值为10335.86—16358.06元hm~(-2)a~(-1),固碳价值为165.93—521.03元hm~(-2)a~(-1),水源涵养价值为5024.47—11788.30元hm~(-2)a~(-1),固土保肥价值为3597.84—6405.04元hm~(-2)a~(-1),生物多样性价值为178.57—1346.15元hm~(-2)a~(-1)。第二,固碳价值、固土保肥价值在空间上呈现出随纬度增加而减小的格局,水源涵养价值、生物多样性价值与前两者分布格局相反。植被类型、经营方式影响马尾松林生态系统服务价值,混交林生态系统服务价值大于纯林,间伐补植的马尾松林生态系统服务价值高于皆伐后营造的林分。第三,马尾松林生态系统服务补偿标准为0.15×10~3—1.43×10~3元hm~(-2)a~(-1),大小主要受生态系统服务单价影响。本研究为森林生态系统服务精确计量评价、森林生态系统服务补偿标准的确定提供科学量化的依据。     

Relative importance of factors controlling the success of Oxalis acetosella: an example of linear modelling in ecological research

An ecological hypothesis concerning the relative importance of factors governing the success of Oxalis acetosella on mesic upland forest sites in southern Finland was formulated and tested statistically by means of a multivariate linear model. The data consisted of a stratified random sample of 40 plots with biological measurements and associated observations on environmental variables. The covariance matrix between the incorporated variables was computed and the model parameters were estimated using the method of maximum likelihood provided by the computer programme LISREL V. The results supported the hypothesis based on previous observations and experiments: Oxalis acetosella benefits from a high nutrient level of the soil, but is decisively dependent on the shelter provided by the tree stand. When both spruce stands and well-lit pine stands on mesic and relatively rich forest sites were considered simultaneously, only a weak correlation was found between light availability and site fertility. Accordingly, the presumed value of Oxalis acetosella as an indicator of site fertility appears to be questionable. The adequacy of linear modelling in an ecological context is discussed. The kind of models applied in this study have only a limited application range in non-experimental ecological research. However, linear modelling may contribute to solving particular ecological problems in cases where short environmental gradients are considered so that nonlinearity is not a dominant feature.     

Soil nutrients are not responsible for arrested succession in disturbed coastal dune forest

Coastal dune forest succession frequently proceeds via the Acacia karroo pathway, but may become arrested. We examine whether soil fertility arrests forest succession in A. karroo stands in coastal dune forest in KwaZulu-Natal province, South Africa. We examined soil fertility of A. karroo stands, the adjacent forest, and forested dune slacks at Cape Vidal, and four rehabilitating A. karroo stands (13- to 28-yr-old) at Richards Bay. The effect of nitrogen supplementation on growth of three tree species (a forest pioneer, a late successional forest species, and A. karroo) was compared between A. karroo stands and adjacent dune forest at Cape Vidal. Soil fertility in A. karroo stands and the adjacent forest at Cape Vidal was similar and neither total nor readily mineralisable nitrogen were limiting in either habitat. At Richards Bay, where the dunes were previously strip-mined, total nitrogen accumulated rapidly (2.1–8.0 g N m⁻² yr⁻¹) and the oldest rehabilitating A. karroo stands (26–28 yr) had similar total nitrogen and other soil nutrient levels as stands twice their age at Cape Vidal. Seedling growth was unaffected by nitrogen supplementation. All species grew fastest in A. karroo stands demonstrating that soil nutrient levels in disturbed forest colonised by A. karroo are suitable for the growth of forest tree species. Soil fertility, including available nitrogen, is not limiting secondary succession at Cape Vidal, yet forest species are not replacing A. karroo stands at this site. Post-emergence factors, such as herbivory, are likely responsible for the arrested succession of forest in A. karroo stands.     

Seasonal changes in plasma membrane H<Superscript>+</Superscript>-ATPase activity of <Emphasis Type="Italic">Vaccinium myrtillus</Emphasis> (L.) and <Emphasis Type="Italic">Pinus sylvestris</Emphasis> (L.)

Seasonal changes in vanadate sensitive plasma membrane H⁺-ATPase activity of bilberry (Vaccinium myrtillus L.) and Scots pine (Pinus sylvestris L.) were studied in a period from February to August in northern Finland. The plasma membrane isolation was performed by sucrose gradient centrifugation, and the H⁺-ATPase activity was assayed by spectrophotometrical determination of released inorganic phosphate. The studied species showed seasonal changes from high winter to low spring activity, indicating probable physiological changes between hardened and dehardened tissue. ATPase activity of bilberry peaked up at the beginning of the growth period, obviously due to active phloem loading of photosynthates.     

The role of moose <Emphasis Type="Italic">Alces alces</Emphasis> L. in boreal forest – the effect on ground beetles (Coleoptera,Carabidae) abundance and diversity

The indirect effect of moose Alces alces browsing on ground beetle's abundance and diversity was investigated by pitfall trapping in a mixed coniferous forest in Vestfold County (59°19′ N, 9°50′ E, Norway), during the summer of 2002. Three areas with different browsing pressures, ranging from non- to medium- and heavily browsed were chosen and dry weight of bilberry Vaccinium myrtillus and humidity at ground level were measured in the three locations. As predicted, the gradient analyses showed that browsing by moose influenced the composition of carabid fauna, and that browsing intensity and humidity covaried with the most important gradient in carabid species composition found across the three locations. Species that live in light stands with rather dry soil, were more often captured in the browsed areas, whereas shade tolerant and hygrophilous species were more abundant in the non-browsed area. The carabid abundance increased significantly with increasing browsing pressure. According to our predictions, the diversity at trap level (α-diversity) was higher in the highly browsed area. Conversely, species turnover (β-diversity) decreased with browsing intensity. On the other hand, the rarefaction analysis showed that the regional species richness (γ-diversity) was considerably higher in the medium browsed area than in the heavily browsed one, which is consistent with the intermediate disturbance hypothesis. This study indicates that moose, by reducing the bilberry that constitutes the field layer in summer, affect carabid species composition and might be capable to reshape the whole ecosystem in our study area by a cascade effect.     

Environmental fluctuations facilitate species co-existence and increase decomposition in communities of wood decay fungi

Correlations between mast fruiting of bilberry Vaccinium myrtillus and peak levels of Clethrionomys-voles have been reported from both Norway and Finland, but there has been a discussion whether this is a bottom-up or a top-down relationship. In a multiple regression model, 65% of the variation in a bilberry production index calculated from game reports from southern Norway 1932–1977 could be explained by the berry index of the two preceding years and climate factors acting during key stages of the flowering cycle. High vole populations in previous years did not contribute to explain the fluctuation in berry production. I used the selected model and climate data to predict bilberry production for the period 1978–2004. Predicted berry indices of the current and previous year explained 38% and the total amount of precipitation in May–June explained 16% of the variation in a log-transformed snap-trapping index of bank vole Clethrionomys glareolus 1980–2004. The vole index was not related to any of the climate variables used to predict berry production. This pattern supports the hypothesis that vole cycles are generated by changes in plant chemistry due to climate-synchronized mast fruiting.     

Formalized classification of the vegetation of <Emphasis Type="Italic">Abies alba</Emphasis>-dominated forests in the Czech Republic

A phytosociological classification of silver fir (Abies alba) forests in the Czech Republic was carried out using the Braun-Blanquet approach. It is based on the formalized and supervised Cocktail classification method. The definitions of associations were created by combinations of sociological species groups using logical operators. Dominance of single species was included in the definitions of associations. All relevés with at least 50% cover of silver fir in tree layer available from the Czech Republic were used for analysis. Three associations within two classes were distinguished. Vaccinio vitis-idaeae-Abietetum albae (Vaccinio-Piceetea, Piceion excelsae) is an oligotrophic, species-poor spruce-pine-fir forest dominated by Vaccinium myrtillus in the herb layer occurring mostly on podzols. Luzulo-Abietetum albae (Querco-Fagetea, Luzulo-Fagion) is an oligo-mesotrophic spruce-fir forest characterized by the dominance of graminoids (Luzula luzuloides, Calamagrostis arundinacea) in the herb layer. It occurs especially on cambisols. Nutrient-demanding species are typical of the stands of herb-rich mesotrophic Galio rotundifolii-Abietetum albae (Querco-Fagetea, Fagion sylvaticae, Galio rotundifolii-Abietenion) that occurs also mostly on cambisols. Soil nutrients and soil reaction (represented by Ellenberg indicator values) were determined as the most important ecological gradients affecting the variation of the vegetation in these communities.     

不同林龄刺槐林土壤团聚体化学计量特征及其与土壤养分的关系

土壤团聚体化学计量特征分析可以为土壤养分的评价提供依据,对陕北黄土丘陵区20 a、25 a、40 a、50 a刺槐林土壤团聚体有机碳、全氮、全磷化学计量比及其与土壤有机碳、全氮、全磷化学计量比的相关性采用逐步回归分析方法进行了分析。结果表明:随着林龄的增加,刺槐林各粒径土壤团聚体有机碳、全氮含量及其有机碳、全氮、全磷化学计量比显著增加(P0.05),均表现为在0—20 cm土层高于20—40 cm土层,而刺槐林土壤团聚体全磷含量变化较小;相同林龄刺槐林在0—20 cm和20—40cm土层中0.25—2 mm粒径土壤团聚体有机碳、全氮、全磷含量及其化学计量比最高。刺槐林0.25—2 mm粒径团聚体对土壤原土有机碳、全氮含量及其有机碳、全氮、全磷化学计量比有显著影响。营造刺槐林对各粒径土壤团聚体全效养分分配及其平衡关系存在积极的影响,主要体现在0.25—2 mm粒径土壤大团聚体中,通过影响0.25—2 mm粒径团聚体提高了土壤全效养分的供应和保持能力。     

Effect of N6-isopentenyladenine concentration on growth initiation in vitro and rooting of bilberry and lingonberry microshoots

Buds and shoot tips of wild bilberry (Vaccinium myrtillus L.) and lingonberry (V. vitis-idaea L.) plants were cultured on a modified MS medium containing N⁶-isopentenyladenine (2iP), 9.8–78.4 μM, in order to study the effect of the 2iP-concentration on the initiation of growth. The experiment was first performed in the autumn and repeated in the spring to determine the influence of season on growth initiation. To optimise rooting, three different rooting treatments were tested for the bilberry and lingonberry microshoots. Shoots were rooted either in vitro with 0.49 μM IBA (indole-3-butyric acid) or ex vitro, incubating microshoots in 2.07 mM KIBA-solution (potassium salt of IBA) before planting, or microshoots were planted directly on peat without exogenous auxin. The best 2iP concentration for the initiation of the growth for bilberry was 49.2 μM and for lingonberry 24.6 μM. It was observed that increasing the 2iP concentration at the growth initiation stage increased the number of brownish explants both in bilberry and in lingonberry microcultures. Spring was a considerably better time than autumn for the initiation of new growth, for both species. The results of the rooting test showed that the KIBA-treatment before planting on peat increases rooting efficiency in both bilberry and lingonberry. This revised version was published online in June 2006 with corrections to the Cover Date.     

Response patterns of Vaccinium myrtillus and V. vitis-idaea along nutrient gradients in boreal forest

Abstract. The relationships between biomass of dwarf shrub species and nutrient gradients of forest soils was studied under field conditions in boreal forests. The biomass-response curves of Vaccinium myrtillus and V. vitis-idaea were fitted against soil nutrient gradients using Generalized Linear Models (GLM). Ecological niches of Vaccinium myrtillus and V. vitis-idaea were evaluated, and effects of nitrogen addition (manipulation of the nutrient gradient) on response function were tested. The Vaccinium species showed statistically significant Gaussian responses along soil nitrogen, phosphorus and calcium gradients, but not along other gradients (K and Mg). Furthermore, manipulation of the nitrogen gradient seemed to have a minor effect on response functions, i.e. addition of nitrogen did not change ecological niches of these species. Ecological optima of V. myrtillus and V. vitis-idaea on the nutrient gradients were about the same. This study suggests that differences in dominance between Vaccinium myrtillus and V. vitis-idaea in boreal forest is not determined by nutrient gradients, but may rather be explained by light conditions and/or moisture availability.     

Early-inbreeding depression inVaccinium myrtillus andV. vitis-idaea

Summary Fertility parameters were estimated inVaccinium myrtillus andV. vitis-idaea after self- and cross-pollinations performed in growth chamber. We showed a drastic decrease in fertility after self-pollination as compared to cross-pollination. Number of plump seeds per berry was compared with previous field data. In both species, growth room conditions improved plump seed number after cross-pollination but not after self-pollination. In addition, in order to enhance resources supply to young developing fruits, cytokinin application was tested inV. myrtillus but no effect was detected. We hypothesize that the partial self-sterility is due to inbreeding depression based on the expression of recessive lethals.     

不列颠·哥伦比亚省北部小杆松及白云杉立地指数与生态立地质量的关系

为在ＰｒｉｎｃｅＲｕｐｅｒｔ林区的“亚北方”部分建立生态立地质量与森林生产力的联系,对从９３个小杆松林分和７７个白云杉林分获得的数据进行了分析．所研究的林分处于两个气候状况、８个土壤水分状况以及５个土壤养分状况．这些气候、土壤水分和养分状况被视为等级变量用于林地分类和回归分析．小杆松和白云杉的立地指数随土壤水分和养分状况变化而变化,但不依赖于气候变化．与土壤水分相关的变化格局对两个种来说很相似,但与土壤养分相关的变化格局则全然不同．在所建立的５类回归模型中,土壤小区模型对于两个种都显示出立地指数与土壤水分和养分状况具有很强的相互关系（Ｒ２＞０．８０,ＳＥＥ≤１．６ｍ）．可以认为土壤水分和养分的等级度量在大范围内可作为小杆松和白云杉立地指数的预测预报因子．     

影响不同林型天然红松混交林林隙更新的土壤特征因子

采用野外调查、样品采集和统计分析等相结合的方法,对小兴安岭天然红松混交林3种不同林型(椴树红松混交林(TP)、枫桦红松混交林(BP)、云冷杉红松混交林(PAP))的林隙及其邻近郁闭林分的土壤特征因子和树木更新的相关性进行了研究,旨在阐明林隙土壤特征因子对树木更新的影响,从而为小兴安岭天然红松混交林植被更新、退化生态系统的恢复和可持续经营提供基础数据和实践参考。结果表明:郁闭林分土壤有机质、全氮质量分数显著高于3种不同林型的林隙。有效磷和速效钾含量在BP内与其他林型之间差异显著。3种林型林隙内p H值均略高于其郁闭林分,但与其差异均不显著。3种林型林隙内更新总密度、幼树更新密度与郁闭林分差异显著(P0.05),PAP林隙中更新总密度和幼树更新密度最高。BP林隙面积与更新密度相关不显著,乔木幼苗、幼树更新密度与有机质(r=-0.400,r=-0.475)、全氮均呈显著负相关(r=-0.519,r=-0.603)。TP林隙内全氮与乔木幼苗更新密度呈正相关(r=0.092),而与乔木幼树更新密度呈显著负相关(r=-0.585)。PAP林隙内全氮与乔木幼苗、幼树更新密度均呈负相关。郁闭林分幼苗更新密度分别与有机质、全氮、速效钾、p H值、脲酶和蛋白酶呈负相关。主成分分析表明,全氮是影响林隙和郁闭林分树木更新的关键因素。     

Classification of vegetational diversity in managed boreal forests in eastern Finland

Diversity of vegetation in managed forests is studied. A classification based on forest stand structure, the abundances of vegetation species and variations in these abundances is developed and diversity indices are calculated for the classes to describe the diversity of the vegetation within the classes. The classes were formed using detrended correspondence analysis (DCA), global nonmetric multidimensional scaling (GNMDS) and TWINSPAN classification. Discriminant analysis was used to determine the environmental variables differentiating between the classes, and Duncan's multiple range test was used to examine the ability of the diversity measures to distinguish the classes. Beta diversity was estimated with Økland's method based on DCA ordination of the sample plots. The results point to fertility and the successional stage of the stand as the main factors affecting species diversity, in addition to which soil type, the number of tree species, crown cover, basal area and certain variables describing the management of the stand were relevant to the classification. The most distinct diversity indices were the reciprocal of Simpson, Pielou's J' and species richness, while the highest alpha diversity was found in young stands with a low crown cover on herb-rich or mesic forest sites. Beta diversity was quite high, its highest values of all for the whole data being recorded along the fertility gradient.     

Dynamics of Vaccinium myrtillus patches in mountain spruce forest

Abstract. The dynamics of Vaccinium myrtillus (bilberry) patches were studied in spruce (Picea abies) forest at the higher montane and lower subalpine level in the Tarentaise valley (Savoy, France). Although aerial parts of the shrub may give some indication of age and density of the patches, the annual growth and death of rhizomes are better indicators of patch dynamics. In some cases, dead and young rhizomes may occur simultaneously in the same patch, indicating that growth and death proceed continuously on the inside of dense patches. At mountain sites, slope position of plants significantly influences rhizome growth. A theoretical model of growth of bilberry patches is proposed which takes into account the anisotropic influenceof slope and the postulated independence of different rhizome units belonging to the same individual.     

Diet and habitat selection in Cantabrian Capercaillie (Tetrao urogallus cantabricus): ecological differentiation of a rear-edge population

Cantabrian capercaillie Tetrao urogallus cantabricus is a peripheral population with distinctive phenotypic, biogeographic, and genetic characteristics. Hence, the population may also show substantial ecological differentiation associated with its habitat in purely deciduous forests. We assessed seasonal diet selection, small-scale habitat selection, and patterns of trophic niche width in Cantabrian capercaillie over two years. Diet was found to be a driver of small-scale habitat selection, a result consistent with previous studies of stand-scale habitat selection. Diet and habitat selection showed the importance of beech Fagus sylvatica, holly Ilex aquifolium, bilberry Vaccinium myrtillus, and ferns in Cantabrian capercaillie’s resource selection. Conversely, the abundant oaks Quercus petraea, birches Betula pubescens, and heaths Erica sp. were used below their availability. The reliance on bilberry appears as a unifying characteristic between central and peripheral capercaillie populations. Cantabrian capercaillie showed stronger reliance on understory resources than range-central populations. It also showed wider trophic niche and higher specialization of feeding events. Trophic niche patterns and reliance on ground resources indicated a marked ecological differentiation, which stresses the need for local data and specific conservation actions.