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1.
2.
We sampled the wood beetle fauna in 1) living hollow, 2) standing dead and 3) downed dead beech Fagus svlvatica logs in fragmented old–growth forests in southern Sweden In nearly primaeval stands, species richness was similar in the three types of microhabitat, but m previously (50–100 yr ago) managed stands species richness was lower in living hollow trees The number of red–listed beetle species per sample was higher in living hollow beeches in nearly primaeval stands than in formerly managed stands, but there was no difference in downed dead beeches This agrees with our expectation, based on the relative stability of the microhabitats, that species living in hollow trees would have a lower dispersal propensity than those that depend on dead, downed logs Among 55 red–listed species found, 69% had a higher frequency in nearly primaeval stands than in previously managed stands For 22 endangered plus vulnerable species the figure was 77% Most red–listed species had occurrence frequencies of 5%, or less  相似文献   

3.
Precipitation as a key determinant of forest productivity influences forest ecosystems also indirectly through alteration of the nutrient status of the soil, but this interaction is not well understood. Along a steep precipitation gradient, we studied the consequences of reduced precipitation for the soil and biomass nutrient pools and dynamics in 14 mature European beech (Fagus sylvatica L.) forests on Triassic sandstone. We tested the hypotheses that lowered summer precipitation (1) is associated with less acid soils and (2) a reduced accumulation of organic matter on the forest floor, and (3) reduces nutrient supply from the soil and leads to decreasing foliar and root nutrient concentrations. Soil acidity, the amount of forest floor organic matter, and the associated organic matter N and P pools decreased to about a half from wet to dry sites; the C/P and N/P ratios, but not the C/N ratio, of forest floor organic matter were reduced as well. Net N mineralization and P and K pools in the mineral soil did not change with decreasing precipitation. Foliar P and K concentrations (beech sun leaves) increased while N remained constant, resulting in decreasing foliar N/P and N/K ratios. Estimated N resorption efficiency increased toward the dry sites. We conclude that a reduction in summer rainfall significantly reduces the soil C, N and P pools but does not result in decreasing foliar N and P contents in beech. However, the decreasing foliar N/P ratios towards the dry stands indicate that the importance of P limitation for tree growth declines with decreasing precipitation.  相似文献   

4.
Schipka F  Heimann J  Leuschner C 《Oecologia》2005,143(2):260-270
Forest hydrologists have hypothesised that canopy transpiration (Ec) of European temperate forests occurs at rather similar rates in stands with different tree species and hydrologic regimes. We tested this hypothesis by synchronously measuring xylem sap flow in four mature stands of Fagus sylvatica along a precipitation gradient with the aim (1) of exploring the regional variability of annual canopy transpiration (Ec(t)) in this species, and (2) of analysing the relationship between precipitation (P) and Ec(t). Ec(t) rates of 216, 225, 272 and 303 mm year–1 corresponded to precipitation averages of 520, 710, 801 and 1,040 mm year–1 in the four stands. We explored the regional variability of Ec(t) in Central European colline to sub-montane beech stands in two meta-analyses based on (1) existing sap flow data on beech (n=5 observations), or (2) all canopy transpiration data on beech obtained by different techniques (sap flow, micrometeorological or soil water budget approaches, n=25). With a coefficient of variation (CV) of 20%, the regional variability of Ec(t) (213–421 mm year–1) was smaller than the variation in corresponding precipitation (550–1,480 mm year–1). The mean Ec(t) for beech was 289 (±58) mm year–1 (n=25). A humped-shaped relationship between Ec(t) and P, with a broad transpiration maximum in the precipitation range from ca. 700 to 1,000 mm year–1, was found which may indicate soil moisture limitation of transpiration for P –1, and reduced transpiration by increased cloudiness or leaf wetness for P>1,000 mm year–1. Thus, the precipitation level significantly influences canopy transpiration of humid temperate forests; however, the size of the P influence on Ec(t) and, in part, the direction of its effect differ from forests in semi-arid or arid climates. European beech has the capacity to maintain high Ec rates in both humid and partly dry summer climates (P<550 mm year–1).  相似文献   

5.
It is important to conserve bryophyte diversity in fragmented forests, due to the vulnerability of this group to environmental change. In this study, the utility of bryophyte functional groups (taxonomic classes, substrate classes, and life-forms) was examined as indicators for planning urban area conservation of bryophyte diversity. The study sites comprised 27 fragmented forests in Kyoto City, Japan. Using linear regression models, it was found that the species richness of almost all functional groups was positively correlated with patch size. Furthermore, two types of bryophyte life-form (fans and thalloid mats) were significantly correlated with environmental factors considered important for conservation planning. The species richness of fan bryophytes was positively correlated with the presence of natural forest patches and was negatively correlated with distance from mountainous areas. Similarly, the species richness of thalloid mat bryophytes was negatively correlated with maintenance practices. These results may be explained by the vulnerability of these two bryophyte groups to environmentally caused drought stress, accompanied by decreasing patch size, maintenance practices, disturbance, and/or loss of natural vegetation. Considering that drought stress represents a major threat to bryophyte diversity in fragmented forests, the species richness of hygrophilous life-forms (e.g., fans and thalloid mats) may be used as an indicator of fragmented forests that are less affected by drought stress, and these species should be preferentially conserved to maintain high levels of bryophyte diversity.  相似文献   

6.
The beetle Osmoderma eremita has received much attention in the last few years, as it is among those species with the highest priority in the European Union's Habitat Directive. In this paper the species is evaluated as a potential indicator and umbrella species for the endangered beetle fauna in tree hollows. To be useful as an indicator of a species-rich fauna it should be easy to inventory and be strongly correlated with the presence of other species. An umbrella species is a species which is so demanding that the protection of this species will automatically save many others. The species richness of saproxylic beetles and occupancy of O. eremita were surveyed in tree hollows in an area in southeastern Sweden by assessing the presence/absence of living and dead adults (including fragments) and larvae. The species richness was higher when O. eremita was present, both at tree and stand level. Several threatened species were associated with the presence of O. eremita, whereas others did not correlate with the occurrence of O. eremita. As O. eremita is easy to find and identify, it is useful as an indicator of stands with a rich beetle fauna in tree hollows. Osmoderma eremita can be used as an umbrella species, because if measures are taken to conserve O. eremita, many other species in the same habitat are also conserved. However, there are some beetles in tree hollows which seem to be more sensitive to habitat fragmentation than O. eremita, and may go extinct if only O. eremita is taken into consideration.  相似文献   

7.
Although Tuber aestivum is widely distributed across Europe, little is known about its biology and ecology. We assess the vegetation composition of wild T. aestivum sites and use this information to characterise suitable habitats in Fagus sylvatica, Carpinus betulus and Ostrya carpinifolia (FCO) forests. Plant species composition at 16 naturally colonised T. aestivum sites in southwestern Germany and Switzerland was compared with that of 232 reference sites in Swiss FCO forest communities. The vegetation composition of truffle sites exhibits a high proportion of herb and shrub species that are indicators of a warm and dry climate, alkaline soil, and open tree canopy and thus typically occur in thermophilous FCO communities on calcareous bedrock. We conclude that T. aestivum is associated with a set of key species in addition to known host species. Based on their floristic composition, we identified FCO forest communities with high and low suitability for T. aestivum.  相似文献   

8.
Whilst forest policy promotes cultivation and regeneration of beech dominated forest ecosystems, beech itself is a highly drought sensitive tree species likely to suffer from the climatic conditions prognosticated for the current century. Taking advantage of model ecosystems with cool-moist and warm-dry local climate, the latter assumed to be representative for future climatic conditions, the effects of climate and silvicultural treatment (different thinning regimes) on water status, nitrogen balance and growth parameters of adult beech trees and beech regeneration in the understorey were assessed. In addition, validation experiments with beech seedlings were carried out under controlled conditions, mainly in order to assess the effect of drought on the competitive abilities of beech. As measures of water availability xylem flow, shoot water potential, stomatal conductance as well as delta (13)C and delta (18)O in different tissues (leaves, phloem, wood) were analysed. For the assessment of nitrogen balance we determined the uptake of inorganic nitrogen by the roots as well as total N content and soluble N compounds in different tissues of adult and young trees. Retrospective and current analysis of delta (13)C, growth and meteorological parameters revealed that beech growing under warm-dry climatic conditions were impaired in growth and water balance during periods with low rain-fall. Thinning affected water, N balance and growth mostly of young beech, but in a different way under different local climatic conditions. Under cool, moist conditions, representative for the current climatic and edaphic conditions in beech forests of Central Europe, thinning improves nutrient and water status consistent to published literature and long-term experience of forest practitioners. However, beech regeneration was impaired as a result of thinning at higher temperatures and under reduced water availability, as expected in future climate.  相似文献   

9.
Monitoring restoration effectiveness implies that restoration measures should be evaluated using multiscale analysis and modelling approaches. In this way, the scale-dependent nature of ecosystem processes and dynamics can be adequately described. Here, we evaluated how grain size (i.e. the dimension of sampling units) and type of data (abundance vs. presence/absence) impact the analysis of the response to restoration management activities aiming at halting the loss of European beech forests with Abies alba in the central Apennines (Italy). The proposed analysis relies on forests sampled in three Sites of Community Importance (SCIs) located in central Italy. For each treatment (reference, control and impact), randomly located multi-scale plots were selected. Vascular plant occurrences were recorded twice in every plot during summer 2010 or 2011 (before restoration) and in 2013 or 2014 (after restoration). Analysis of species abundances, recorded at the largest grain size available (20 X 20 m plot), showed a significant change in plant species composition in restored sites just after two years from the restoration management. When presence/absence data were used previous results were less visible, for all the examined grains, in two out of the three sites, suggesting a site-dependent response.  相似文献   

10.
Heavy natural disturbance in large protected areas of former commercial forests increasingly evokes European parliaments to call for management intervention because a loss of habitats and species is feared. In contrast, natural early successional habitats have recently been recognised as important for conservation. Current knowledge in this field mostly results from studies dealing only with selected taxa. Here we analyse the success of species across 24 lineages of three kingdoms in the Bavarian Forest National Park (Germany) after 15 years of a European spruce bark beetle (Ips typographus L.) outbreak that led to rapid canopy opening. Using indicator species analysis, we found 257 species with a significant preference for open forests and 149 species with a preference for closed forests, but only 82 species with a preference for the stand conditions transitional between open and closed forests. The large number of species with a preference for open forests across lineages supports the role of this bark beetle as a keystone species for a broad array of species. The slowdown of the outbreak after 15 years in the core zone of the national park resulted in less than half of the area being affected, due to variability in stand ages and tree species mixtures. Our case study is representative of the tree species composition and size of many large protected montane areas in Central European countries and illustrates that (1) natural disturbances increase biodiversity in formerly managed forests and (2) a montane protected area spanning 10,000 ha of low range mountains is likely sufficient to allow natural disturbances without a biased loss of closed-forest species.  相似文献   

11.
Trapping approaches developed for the emerald ash borer (EAB), Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), were adapted for trapping several European oak buprestid species. These approaches included the use of natural leaf surfaces as well as green and purple plastic in sticky trap designs. Plastic surfaces were incorporated into novel ‘branch‐trap’ designs that each presented two 5 × 9‐cm2 rectangular surfaces on a cardboard structure wrapped around the leaves of a branch. We used visual adult Agrilus decoys in an attempt to evoke male mating approaches toward the traps. Our first experiment compared the attractiveness of visual characteristics of the surfaces of branch‐traps. The second looked at the effect on trap captures of adding semiochemical lures, including manuka oil, (Z)‐3‐hexen‐1‐ol, and (Z)‐9‐tricosene. In total, 1 962 buprestid specimens including 14 species from the genus Agrilus were caught on 178 traps in a 22‐day time‐span. Overall, the green plastic‐covered branch‐traps significantly out‐performed the other trap designs. We further found that the presence of an EAB visual decoy placed on the trap surface often increased captures on these green traps, but this effect was stronger for certain Agrilus species than for others. The visual decoy was particularly important for the most serious pest detected, Agrilus biguttatus Fabricius, which was captured 13 times on traps with decoys, but only once without a decoy. There were some small but significant effects of odor treatment on the capture of buprestids of two common species, Agrilus angustulus Illiger and Agrilus sulcicollis Lacordaire. There were also 141 Elateridae specimens on these traps, which were not influenced by trap type or decoys. The results suggest that small branch‐traps of this nature can provide a useful new tool for monitoring of buprestids, which have the potential to be further optimized with respect to visual and olfactory cues.  相似文献   

12.
Question: What role does air humidity play as an environmental factor for the abundance and distribution of temperate woodland herbs? Location: Beech forests on calcareous soils in southern lower Saxony, central Germany. Methods: The abundance of woodland herb species and total herb cover were investigated in 60 plots with contrasting exposure, slope angle and relief type. On all plots, air humidity, air temperature, soil moisture, photosynthetically active radiation, pH (H2O) and concentration of salt‐exchangeable Ca, Mg and K were measured. Species‐environment relationships were analysed with multiple regression analysis and CCA. Results: Air humidity (RH), soil moisture and the concentration of exchangeable Ca and K, but not light, C/N ratio and the concentration of exchangeable Mg were identified as the most important abiotic factors influencing the cover of the most abundant plant species and total herb cover. RH varied substantially across the different forest floor site types and influenced species abundance independent of soil moisture. In several species (including Mercurialis perennis and Impatiens noli‐tangere), RH was found to be a key environmental factor. Other species such as Aegopodium podagraria and Lamiastrum galeobdolon depended more on elevated soil moisture, while RH was less important. Conclusions: This study showed that the distribution of widespread temperate woodland herb species depends on high air humidity, and that certain sensitive species do not occur at sites with reduced air humidity even though soil moisture is high. Thus, high air humidity and ample soil moisture are key abiotic factors in beech forests on calcareous soils. Shade level (PAR) was found to be of secondary importance.  相似文献   

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14.
Atmospheric deposition is an important nutrient input to forests. The chemical composition of the rainfall is altered by the forest canopy due to interception and canopy exchange. Bulk deposition and stand deposition (throughfall plus stemflow) of Na+, Cl?, K+, Ca2+, Mg2+, PO 4 3? , SO 4 2? , H+, Mn2+, Al3+, Fe2+, NH 4 + , NO 3 ? and Norg were measured in nine deciduous forest plots with different tree species diversity in central Germany. Interception deposition and canopy exchange rates were calculated with a canopy budget model. The investigated forest plots were pure beech (Fagus sylvatica L.) plots, three-species plots (Fagus sylvatica, Tilia cordata Mill. or T. platyphyllos Scop. and Fraxinus excelsior L.) and five-species plots (Fagus sylvatica, T. cordata or T. platyphyllos, Fraxinus excelsior, Acer platanoides L., A. pseudoplatanus L. or A. campestre L. and Carpinus betulus L.). The interception deposition of all ions was highest in pure beech plots and was negatively related to the Shannon index. The stand deposition of K+, Ca2+, Mg2+ and PO 4 3? was higher in mixed species plots than in pure beech plots due to higher canopy leaching rates in the mixed species plots. The acid input to the canopy and to the soil was higher in pure beech plots than in mixed species plots. The high canopy leaching rates of Mn2+ in pure beech plots indicated differences in soil properties between the plot types. Indeed, pH, effective cation exchange capacity and base saturation were lower in pure beech plots. This may have contributed to the lower leaching rates of K+, Ca2+ and Mg2+ compared to the mixed species plots. However, foliar analyses indicated differences in the ion status among the tree species, which may additionally have influenced canopy exchange. In conclusion, the nutrient input to the soil resulting from deposition and canopy leaching was higher in mixed species plots than in pure beech plots, whereas the acid input was highest in pure beech plots.  相似文献   

15.
16.

Key message

Fine root ingrowth and mortality of European beech are related to evapotranspiration, cumulative forest floor precipitation, soil temperature and water content, which are affected by forest management and gap creation.

Abstract

The ingrowth and mortality of European beech (Fagus sylvatica L.) fine roots (diameters <2 mm) were studied in relation to environmental variables describing temperature and water availability at four sites, covering a range in environmental conditions likely to be encountered in Slovenian beech forests. Minirhizotron images were used to determine fine root dynamics in a stand and gap in each of the sites for 12 periods during the 2007–2009 growing seasons. The environmental variables included air and soil temperatures, precipitation, forest floor precipitation, evapotranspiration and soil water contents. For data analysis, the daily mean values for each period for all variables were used. Fine root ingrowth and mortality were higher in the managed stand and gap compared to the old-growth stand and gap, but only significantly correlated with each other in the case of the managed stand. Forest floor precipitation and soil temperature were significant in explaining fine root ingrowth, whereas maximal evapotranspiration, soil temperature and soil water content were more important for fine root mortality. However, the correlations were weak and inconsistent among the four sites. By including site as predictor as well as environmental variables, R 2 values of 0.49 and 0.55 for ingrowth and mortality, respectively, were achieved. Despite this, the relationships between the fine root dynamics and selected environmental factors appeared relatively weak and complex, especially for fine root ingrowth and might be partially related also to differences in successional stages of the forests under study.
  相似文献   

17.
Andrés Baselga 《Ecography》2008,31(2):263-271
This study assessed the diversity patterns of a large family of beetles, Cerambycidae, in Europe and tested the following hypotheses: 1) richness gradients of this hyperdiverse taxon are driven by water and energy variables; 2) endemism is explained by the same factors, but variation between areas also reflects post‐glacial re‐colonization processes; and 3) faunal composition is determined by the same climatic variables and, therefore, beta diversity (species turnover) is related to richness gradients. Species richness, endemism and beta diversity were modelled using inventories of 37 European territories, built from a database containing the distributions of 609 species. Area, spatial position, and nine topographical and climatic variables were used as predictors in regression and constrained analysis of principal coordinates modelling. Species richness was mostly explained by a temperature gradient, which produced a south‐to‐north decreasing richness gradient. Endemism followed the same pattern, but was also determined by longitudinal variation, peaking in the southwestern and southeastern corners of the continent. Faunal turnover was explained by an important purely spatial pattern and a spatially structured environmental gradient. Thus, contrary to other groups, cerambycid richness was mostly explained by environmental energy, but not by water availability. Endemism was concentrated in the Iberian and Greek peninsulas, but not in Italy. Thus, the latter area may have been the major source of post‐glacial re‐colonization for European longhorn beetles or, otherwise, a poor refuge during glaciations. Turnover patterns were independent of the richness gradient, because northern faunas are nested in southern ones. Turnover, in contrast to richness, was driven by both the independent effects of climate and geographic constraints that might reflect dispersal limitation or stochastic colonization events, suggesting that richness gradients are more environmentally deterministic phenomena than turnover patterns.  相似文献   

18.
Population sizes of many birds are declining alarmingly and methods for estimating fluctuations in species’ abundances at a large spatial scale are needed. The possibility to derive indicators from the tendency of specific species to co‐occur with others has been overlooked. Here, we tested whether the abundance of resident titmice can act as a general ecological indicator of forest bird density in European forests. Titmice species are easily identifiable and have a wide distribution, which makes them potentially useful ecological indicators. Migratory birds often use information on the density of resident birds, such as titmice, as a cue for habitat selection. Thus, the density of residents may potentially affect community dynamics. We examined spatio‐temporal variation in titmouse abundance and total bird abundance, each measured as biomass, by using long‐term citizen science data on breeding forest birds in Finland and France. We analyzed the variation in observed forest bird density (excluding titmice) in relation to titmouse abundance. In Finland, forest bird density linearly increased with titmouse abundance. In France, forest bird density nonlinearly increased with titmouse abundance, the association weakening toward high titmouse abundance. We then analyzed whether the abundance (measured as biomass) of random species sets could predict forest bird density better than titmouse abundance. Random species sets outperformed titmice as an indicator of forest bird density only in 4.4% and 24.2% of the random draws, in Finland and France, respectively. Overall, the results suggest that titmice could act as an indicator of bird density in Northern European forest bird communities, encouraging the use of titmice observations by even less‐experienced observers in citizen science monitoring of general forest bird density.  相似文献   

19.

Questions

We aim for a better understanding of the different modes of intra‐ and inter‐specific competition in two‐ and three‐species mixed‐forests. How can the effect of different modes of competitive interactions be detected and integrated into individual tree growth models? Are species interactions in spruce–fir–beech forests more associated with size‐symmetric or size‐asymmetric competition? Do competitive interactions between two of these species change from two‐ to three‐species mixtures?

Location

Temperate mixed‐species forests in Central Europe (Switzerland).

Methods

We used data from the Swiss National Forest Inventory to fit basal area increment models at the individual tree level, including the effect of ecological site conditions and indices of size‐symmetric and size‐asymmetric competition. Interaction terms between species‐specific competition indices were used to disentangle significant differences in species interactions from two‐ to three‐species mixtures.

Results

The growth of spruce and fir was positively affected by increasing proportions of the other species in spruce–fir mixtures, but negative effects were detected with increasing presence of beech. We found that competitive interactions for spruce and fir were more related to size‐symmetric competition, indicating that species interactions might be more associated with competition for below‐ground resources. Under constant amounts of stand basal area, the growth of beech clearly benefited from the increasing admixture of spruce and fir. For this species, patterns of size‐symmetric and size‐asymmetric competitive interactions were similar, indicating that beech is a strong self‐competitor for both above‐ground and below‐ground resources. Only for silver fir and beech, we found significant changes in species interactions from two‐ to three‐species mixtures, but these were not as prominent as the effects due to differences between intra‐ and inter‐specific competition.

Conclusions

Species interactions in spruce–fir–beech, or other mixed forests, can be characterized depending on the mode of competition, allowing interpretations of whether they occur mainly above or below ground level. Our outcomes illustrate that species‐specific competition indices can be integrated in individual tree growth functions to express the different modes of competition between species, and highlight the importance of considering the symmetry of competition alongside competitive interactions in models aimed at depicting growth in mixed‐species forests.
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