Natural Beech Forests Research Articles

Remote sensing of Japanese beech forest decline using an improved Temperature Vegetation Dryness Index (iTVDI)

The Tanzawa Mountains, which cover parts of Kanagawa, Yamanashi and Shizuoka prefectures in Japan, are known for their natural beech forests. Since the 1980s, decline of the beech forests, probably caused by air pollution, water stress and insect infestation, has become a serious problem. We estimated the natural beech forest mortality rate in the mountains by using multi-temporal 8-day composite data recorded at the MODIS instrument aboard the Terra satellite, daily air temperature data at meteorological stations (AMeDAS) in 2007, and a global digital elevation model obtained from ASTER aboard the Terra satellite. For the estimation, we used a Normalized Difference Vegetation Index (NDVI) indicating the vegetation density, a Temperature Vegetation Dryness Index (TVDI), and an improved TVDI (iTVDI) indicating the differences in transpiration rates between areas of similar vegetation density. We compared the NDVI, TVDI, and iTVDI maps with an existing mortality map of beech forests in the study area to verify their accuracy. To produce iTVDI maps, we calculated maps of air temperature by using ambient air temperature and elevation data. By interpolation using an environmental lapse rate, we calibrated air temperature maps with good accuracy (RMSE = 0.49 °C). The iTVDI map could detect mortality more accurately than the NDVI and TVDI maps in both spring and summer. Use of iTVDI enabled us to detect forest decline caused by air pollution and water deficits, inducing a reduction in transpiration rates. This index should be useful for monitoring vegetation decline.

Assessment of yeast diversity in soils under different management regimes

Human activities, land management and climate change all have great impact on soil biology, but our knowledge of biodiversity of soil organisms is still very limited. Therefore, we assessed responses of soil yeasts to land management, and analysed 57 soils showing different land use from three distinct localities. We isolated and identified molecularly a total of 40 yeasts including several new species. Overall, species composition of different localities was very heterogeneous and nearly half of the species were found in a single site only. The analysis of species abundance and community composition revealed a strong long-term effect of forest replacement by grassland vegetation. Unlike forests, grasslands harbour predominantly ascomycetous yeasts and their proportion increases with management intensity. In forests, evenness of yeast communities followed the gradient of land management intensity and natural beech forests harboured the most unevenly structured community, thereby mirroring the evenness of plant communities.

Soil respiration rates and in natural beech forest (Fagus sylvatica L.) in relation to stand structure

Soil respiration rates were studied as a function of soil type, texture and light intensity at five selected natural beech forest stands with contrasting geology: stands on silicate bedrock at Kladje and Brička in Pohorje, a stand on quartz sandstone at Vrhovo and two stands on a carbonate bedrock in the Karstic-Dinaric area in Kočevski Rog, Snežna jama and Rajhenav, Slovenia, during the growing season in 2005–2006. Soil respiration exhibited pronounced seasonal and spatial variations in the studied forest ecosystem plots. The CO2 flux rates ranged from minimum averages of 2.3 μmol CO2 m−2 s−1 (winter) to maximum averages of about 7 μmol CO2 m−2 s−1 (summer) at all the investigated locations. An empirical model describing the relationship between soil respiration and soil temperature predicted seasonal variations in soil respiration reasonably well during 2006. Nevertheless, there were also some indications that soil moisture in relation to soil texture could influence the soil CO2 efflux rates in both sampling seasons. It was shown that spatial variability of mean soil respiration at the investigated sites was high and strongly related to root biomass. Based on the data, it was shown that new photoassimilates could account for a major part of the total soil respiration under canopy conditions in forest ecosystems where no carbonate rocks are present, indicating that microbial respiration could not always dominate bulk soil CO2 fluxes. At Snežna jama and Rajhenav, the abiotic CO2 derived from carbonate dissolution had a pronounced influence on CO2 efflux accounting, on average, to ∼17%. Further spatial heterogeneity of soil respiration was clearly affected by management practice. Higher respiration rates as well as higher variability in respiration rates were observed in the virgin forest (Rajhenav) than in the management forest (Snežna jama) and could be related to a higher amount of detritus and consequently to less pronounced influence of inorganic pool to CO2 efflux, lower mixing with atmospheric CO2 and higher sensitivity to environmental changes. Major differences in soil carbon dynamics among these five forest ecosystems can be explained by the influence of bedrock geology (particularly, the presence or absence of carbonate minerals) and soil texture (affecting gas exchange with overlying air and soil moisture).

Seasonal dynamics of soil microbial biomass C shows close correlation with environmental factors in natural Fagus crenata forests

Soil microbial biomass (Cmic) is an important factor regulating a number of ecosystem processes. In this study, we investigated seasonal variations in soil microbial biomass in natural climax beech (Fagus crenata) forests in a typical cold-temperate mountain region of Japan. Four permanent tower sites along an altitudinal gradient were selected and soil samples were collected once every month during the growing season of 2007. Soil microbial biomass (by fumigation-extraction method) and soil properties were later measured in the laboratory, while environmental factors (soil temperature, soil moisture) were continuously recorded in the field. Our results indicated large seasonal variations (130.4 ~ 5558.0 µg g−1) in soil microbial biomass in beech forests – a range that is much larger than previously reported. Statistically significant correlations are noted between soil properties with Cmic, but largely due to spatial linkages. On the other hand, the environmental factors of soil temperature and especially soil moisture largely control seasonal variations in Cmic. Furthermore, pH could be an important factor influencing seasonal change in Cmic at the 20–30 cm deep soil layer. The study suggests no direct correlation between plant eco-physiology and soil microbial biomass in seasonal courses of the forests.

Specific features of electrical properties of porous biocarbons prepared from beech wood and wood artificial fiberboards

This paper reports on comparative investigations of the structural and electrical properties of biomorphic carbons prepared from natural beech wood, as well as medium-density and high-density fiberboards, by means of carbonization at different temperatures Tcarb in the range 650–1000°C. It has been demonstrated using X-ray diffraction analysis that biocarbons prepared from medium-density and high-density fiberboards at all temperatures Tcarb contain a nanocrystalline graphite component, namely, three-dimensional crystallites 11–14 A in size. An increase in the carbonization temperature Tcarb to 1000°C leads to the appearance of a noticeable fraction of two-dimensional graphene particles with the same sizes. The temperature dependences of the electrical resistivity ρ of the biomorphic carbons have been measured and analyzed in the temperature range 1.8–300 K. For all types of carbons under investigation, an increase in the carbonization temperature Tcarb from 600 to 900°C leads to a change in the electrical resistivity at T = 300 K by five or six orders of magnitude. The dependences ρ(T) for these materials are adequately described by the Mott law for the variable-range hopping conduction. It has been revealed that the temperature dependence of the electrical resistivity exhibits a hysteresis, which has been attributed to thermomechanical stresses in an inhomogeneous structure of the biocarbon prepared at a low carbonization temperature Tcarb. The crossover to the conductivity characteristic of disordered metal systems is observed at Tcarb ≳ 1000°C.

The composition and structure of a natural beech forest in the "Zamkowa Góra" reserve near Kartuzy

Budowa i struktura naturalnego drzewostanu bukowego w rezerwacie "Zamkowa Góra" kolo Kartuz

Long-term trends in vegetation changes of managed versus unmanaged Eastern Carpathian beech forests

A vegetation survey of semi-permanent plots was conducted between years 1955–1962 and 2005–2009, and aimed to determine floristic changes occurring in beech forests located on a scarcely populated, dense forest area. The survey encompassed all natural beech forest types within the Polish part of the “Eastern Carpathians” International Reserve of Biosphere. A comparison of trends in changes between unmanaged (Bieszczady National Park) and managed (the remaining part of the Biosphere Reserve) forests was attempted. DCA analysis was used for the determination of changes on the community level. The density of vegetation, species richness, frequency of occurrence and cover, and functional groups of species were determined. Much more profound community changes were determined to have occurred in managed beech forests. However, a similar direction in vegetation changes within both managed and unmanaged forests verifies the existence of a regional pattern of changes in beech forests. This regional pattern involves (1) a decrease in the shares of arborescent species within the shrub layer, (2) disturbance of the canopy layer, (3) acidification of the top layer of the soil, (4) change of light conditions, (5) increase in shares of generalist species and decrease in shares of specialist species. A decreasing anthropogenic pressure, aging of forest stands, functioning of large, dense forest areas and sustainable forest management strategies forestry management system mimicking natural deciduous forest disturbance regime constitute factors shaping the regional changes of the forest vegetation. The undergoing changes can lead to biotic and spatial homogenization of the Eastern Carpathian beech forests.

Modelling dead wood islands in European beech forests: how much and how reliably would they provide dead wood?

Dead wood is an important element of forests both for biodiversity and ecosystem functions. Due to intensive silviculture, however, dead wood usually is strongly underrepresented in European forests. Forest reserves cannot fully compensate for this because they comprise only a small proportion of forested areas and are often isolated. Retaining a certain number of dead trees in managed forests is important, but may cause safety problems for lumbermen and visitors and still does not necessarily lead to an amount and incidence (i.e., probability of occurrence) of dead wood that might be required for many species and certain ecosystem functions. Our studies concentrate on a third and complimentary dead wood management strategy: dead wood islands, i.e. small unmanaged islands distributed throughout managed forests. As an example, we focus on European beech forests (Fagus sylvatica). An important question related to this strategy is: how do amount, quality, and incidence of dead wood depend on the island’s size? To provide an answer, we use the spatially explicit, rule-based simulation model BEFORE-CWD that was developed to analyse dead wood dynamics in natural beech forests. This model and its predecessor, BEFORE, are well-verified and validated. They reproduce a suite of observed patterns and generate valid secondary and independent predictions. We found that islands that are too small, i.e. smaller than 0.33 and 0.08 ha for standing and lying dead wood, respectively, can fail to provide dead wood for several decades. The shape of the islands has only a minor effect. Extreme storm events temporarily increase and then decrease the amount of standing dead wood. In terms of the amount and incidence of dead wood, it makes no difference if one big or several small islands are set aside from management, unless the islands are not too small. We conclude that even relatively small unmanaged islands within managed forests can reliably provide dead wood and therefore should be considered as a management option. Our results can be used, for example by using metapopulation models of species of interest, to develop management plans for creating networks of dead wood islands.

Characteristics of coarse woody debris in successional stages of natural beech (Fagus orientalis) forests of Northern Iran

Coarse woody debris (CWD) is an important structural and functional component in forests in Northern Iran. In this study we determine the temporal patterns of CWD in Kheyroud Forests by examining the CWD volume in different decay classes and size classes along a chronosequence of secondary forest succession. The volume of CWD followed the general “U-shaped” temporal trend: the highest in the late successional forest (51.25 m<sup>3</sup>.ha<sup>–1</sup>), lowest in the middle successional forest (25.95 m<sup>3</sup>.ha<sup>–1</sup>) and intermediate in the early successional forest (37.05 m<sup>3</sup>.ha<sup>–1</sup>). The late successional forest had a larger amount of logs, snags and stumps than the other two forests. In contrast, the snag volume did not differ between the late and middle successional forest. CWD in decay classes III and V was greater in the late successional forest than that in the other two forests, while CWD in decay classes II and I did not differ among the three successional forests. CWD in class II and I was significantly higher in the early successional forest than that in the middle successional forest. In the early and middle successional forests, CWD in early decay class was dominated by <I>Carpinus betulus</I> L. followed by <I>Fagus orientalis</I> Lipsky. In the late successional forest, CWD in early decay class was dominated by <I>Fagus orientalis</I> while CWD in the late decay class was dominated by <I>Carpinus betulus</I>. While forest succession had a large influence on the amount of CWD in different decay classes, it had no effect on CWD distribution among the different size classes. Our results suggest that both anthropogenic and natural disturbances have had a long-term effect on the distribution of CWD among three forests.

The hypothesis of the pulsed dynamics of virgin beech forests

As a result of studies in natural beech forests of the Ukrainian Carpathians and review of published data, a scheme of their asynchronous mosaic decline, natural regeneration, age-related regeneration dynamics, and centennial dynamics has been formulated on a population-ecological basis.

Forty years of natural dynamics in Swiss beech forests: structure, composition, and the influence of former management

We investigated forest development after the cessation of management based on inventory data from six beech forest reserves in Switzerland covering nearly 40 years, using observed changes to assess the textbook understanding of natural beech forest dynamics. Specifically, we evaluated the importance of light as a driver of tree species composition, and we aimed to disentangle the role of site characteristics and past management regimes for shaping today's forest properties. Forest dynamics in the reserves showed a clear trend toward a broadening of the diameter distribution, an increase in basal area and standing dead wood, an increase in beech dominance, and a reduction of tree species diversity over time, conforming to expectations. However, the expected development of specific structural features, such as significant amounts of large living trees and snags or a small-scale mosaic of various developmental phases, appears to take longer than the time elapsed since the cessation of management. The observed loss in species richness can be attributed to decreasing light availability, as almost all species that disappeared were shade intolerant. Additionally, the shade-intolerant tree species had a characteristic bell-shaped diameter distribution in all reserves, indicating a lack of recruits, whereas shade-tolerant species had an irregular to monotonically decreasing diameter distribution, demonstrating sustained regeneration. Along the environmental gradient covered by the six reserves, abiotic factors are sufficient to explain tree species distribution, with management history not contributing additional information. This suggests that at larger scales, tree species composition is determined by abiotic factors, but historical management strategies were obviously adapted well to the species' autecological requirements. Analyses such as ours provide the foundation for refining forest management systems as well as for developing effective and target-oriented conservation strategies.

Effect of Light Conditions on the Resistance of Current-year Fagus Crenata Seedlings Against Fungal Pathogens Causing Damping-off in a Natural Beech Forest: Fungus Isolation and Histological and Chemical Resistance

Forest gap dynamics affects light intensity on the forest floor, which in turn may influence defense and survival of tree seedlings. Current-year Fagus crenata seedlings show high mortality under the canopy caused by damping-off. In contrast, they survive pathogen attacks in gaps. However, defense mechanisms against damping-off have not been fully understood. In order to determine the resistance factors that affect mortality in current-year seedlings, we compared seedling survival and chemical and histological characteristics of the hypocotyls of seedlings from closed-stand and forest-edge plots. Damping-off occurred in the current-year seedlings mainly from the end of June to July; survival rate of the seedlings was higher in the forest-edge plot than in the closed-stand plot. By performing an inoculation test on the seedling hypocotyls, we identified Colletotrichum dematium and Cylindrocarpon sp. as the causative pathogens under low illumination only. In the beginning of July, only seedling hypocotyls from the forest-edge plot exhibited periderm formation. From mid-June to July, seedling hypocotyls from the forest-edge plot accumulated approximately twice the amount of total phenols as those accumulated by seedling hypocotyls from the closed-stand plot. The ethyl acetate phase of methanol extracts of hypocotyls showed antifungal activity. We conclude that seedlings from the forest-edge plot may resist pathogenic attack via periderm formation and increased phenol synthesis. Plant defense mechanisms that are controlled by light intensity may be important for promoting seedling regeneration in forest gap dynamics.

Soc stock in different forest-related land-uses in central Stara planina mountain, Bulgaria

Forest conversions may lead to an accumulation of carbon in vegetation, but little is known about changes in soil C storage with establishment of plantation forests. Understanding these effects is important to addressing issues relevant to ecosystem function and productivity, and to global balance of carbon. The study investigated the effects of the created coniferous plantations on former beech and pasture sites on the soil organic carbon storage. The major forest-related land-uses in the high mountainous regions of central Stara Planina Mountain were investigated: mountainous pasture, coniferous plantations (planted on previous pasture and beech forests between four and five decades ago) and natural beech forests. The experimental data of soil properties, conducted in 2005, 2006 and 2007, were used in determining the variations in organic carbon storage in forest litter and in mineral soil under different land-use patterns. At each site five representative soil profiles were opened and described giving a total 75 soil samples from the soil layers respectively at 0-10, 10-30 and 30-50 cm depth. A total of 55 samples from forest floor layers (Aol, Aof, Aoh and greensward) were collected with 25:25 cm plastic frame. The main soil properties were determined in accordance with the standardized methods in the Laboratory of soil science at the Forest Research Institute - BAS. The IPCC Good Practice Guidance for Land Use, Land Use Change and Forestry was used to estimate the soil organic carbon stock in soil and litter. The results obtained showed that the SOC stock was quite similar among forest land-uses. The conversion of natural beech forests to coniferous plantations in studied region is related with slightly expressed decrease in soil carbon storage. The values of SOC stocks in 0-50 cm soil layer in these sites were 8.5 (?2.1) tones/ha for pine and 11.0 (?1.4) tones/ha for spruce, while under the natural beech forest it was 14.8 (?1.0) tones/ha. The SOC stock in mountainous pasture was 20.7 (? 6.5) tones/ha, while in spruce plantation created on previous pasture it was 13.5 (?2.7) tones/ha. Our finding showed that forest conversions effect in central Stara Planina Mountain is expressed by decrease in SOC stock related with losses of carbon from the upper mineral soil decades after creation of coniferous plantations. Nevertheless the relatively large organic carbon storage in forest litter in the spruce plantations compensated C lost from mineral soil after the land-use change. The overall carbon stock both in forest litter and soil under plantations ranged from 56 tones/ha (pine) to 77 tones/ha (spruce), while under natural beech forest and pasture the values were 70 and 81 tones/ha respectively. But in terms of stability C sequestrated in mineral soil is more desirable than C sequestrated in forest floor which are more vulnerable to decomposition following disturbances. The application of silvicultural activities in coniferous plantations created by conversion of forest lands or grasslands in the region of central Balkan is desirable to improve the carbon sequestration in soils.

Potential use of pine plantations to restore native forests in a highly fragmented river basin

• In forests, the substitution of broadleaf species by conifers can reduce biodiversity because coniferous forests generally provide less diverse vascular understories than broadleaf forests. However, in some cases, former pine plantations might be useful for restoring native forests. We compared plant species composition on the plot scale in natural beech and mixed oak forests with that in plantations of Pinus radiata. Links between plant diversity and landscape parameters (patch size, fractal dimension and distance to the nearest patch of the same type) were investigated. • The objective of this study was to evaluate the use of pine plantations for restoring native diversity in a zone where native forests are very fragmented. • Similar to oak forests, plant diversity in pine plantations was high, mainly due to the presence of generalist species. Some species characteristic of oak forests also appeared in pine plantations, suggesting the onset of natural forest regeneration. • These results suggest that pine plantations could be used to promote natural regeneration of original oak forests. Moreover, residual native stands should be conserved as important sources of native species and their seeds. Mots-cles : hetre / diversite biologique / paysage / chene / plantation de pins / gestion durable

Ecological studies on a natural beech forest (XXXVI)

Ecological studies on a natural beech forest (XXXVI)

Primary Productivity Changes for a Fifteen-Year Period in a Natural Beech(Fagus crenata)Forest in the Naeba Mountains

Primary Productivity Changes for a Fifteen-Year Period in a Natural Beech(Fagus crenata)Forest in the Naeba Mountains

Měkkýši NPR Voděradské bučiny [Molluscs of the Voděradské Bučiny national reserve

This paper brings a research of molluscan fauna of the Voděradské Bučiny, an important Nature Reserve near Jevany (Central Bohemia, Czech Republic). Altogether, 38 mollusc species have been recorded in the large complex of natural beech forest on the granite background. Rare woodland species Daudebradia rufa and Vertigo substriata were recorded here. Voděradské Bučiny reserve can be used as a model example of natural molluscan assemblage of acidic beech forest.

THE STRUCTURE AND VOLUME PARAMETERS OF UNEVEN-AGED ORIENTAL BEECH (FAGUS ORIENTALIS LIPSKY) FORESTS IN TURKEY

Summary This paper describes stand structure and growth in natural oriental beech forests of northern Turkey. All sample plots showed uneven-aged stand structure at 0.01 significance levels. This was confirmed by Z- test results where Zmin: 1.58 and Zmax: 33.30 values were determined. The total volume of uneven-aged oriental beech stands ranged between 289.8–1481.9m3/ha in pure stands, and 172.2–924.2m3/ha in mixed stands, giving a mean volume for all stands of 500m3/ha. Correlation and regression analyses were carried out to test site indexes, and typical increase of stand volumes in line with site indexes were established (F= 118.452 *** > F0.001; 1; 83 = 11.7439). Stand volume and its distribution into diameter classes in site indexes (F= 409.78 *** > F0.001. 5; 1372 = 3.743) was highly significant. The acquired basal area values ranged between 91.6–17.4 (42.9)m2/ha and stand volume ranged between 3.8–23.4 (11.8)m3/ha/year. This study into oriental beech forests, may guide managers in Turkey, in south-eastern Europe, the northern Caucasus, northern Iran and Syria. The implications of the results for forest management are discussed.

Proceedings of the IUFRO Working Party 2.02.15 “Breeding and Genetic Resources of Five-Needle Pines” Conference held from September 19 to 23, 2006, Valiug, Romania

An international IUFRO WP 2.02.15 conference was held from 19-23 September, 2006, at Valiug, namely at the Claris Hotel placed just in the heart of an outstanding multi-age natural beech forest from south-western Carpathians. The conference was attended by 46 delegates representing nine countries. A total of 21 oral and eight poster presentations were given. Reports were presented on variety of research topics, all of them connected to the five needle-pines.

Evaluating the impact of a biological control parasitoid on invasive Vespula wasps in a natural forest ecosystem

The overall impact of the parasitoid Sphecophaga vesparum vesparum on invasive Vespula wasps in New Zealand native beech forest was evaluated by assessing the levels of parasitism achieved and the parasitoid’s effect at nest level and population level. The maximum proportion of nests parasitised was 17%, but there was no significant increase with time ( r 2 = 0.139; p = 0.115). However, there was an exponential reduction in the number of parasitoids produced per parasitised nest from a peak of 570 ( SE = 143) parasitoids per nest in 1990, declining to only 15 ( SE = 6) parasitoids per nest in 2004. Even when parasitoid density was high, the parasitoid had no detectable impact on the number of small cells or the total host nest size, but it halved the number of large (reproductive) cells produced. This may have resulted in fewer queens produced per parasitised nest. Wasp nest density was highly variable from year to year, but there was no evidence that the wasp population density at the parasitised site (Pelorus Bridge) had declined relative to the five sites where the parasitoid had not established. We conclude that the parasitoid is unlikely to have had any significant effect on wasp populations hitherto, nor is it likely to impact host populations in the future. We recommend other biological control programs adopt pre-release assessment of per capita impact as a way of identifying agents that are more likely to be successful and hence minimising economic and potential ecological costs of biocontrol.