Deciduous Forest

In this study, we compared the soil seed bank and current vegetation under coniferous plantations and adjacent native deciduous forests. The objective was to assess how much of the initial plant diversity is retained in such plantations, and the potential to restore this initial plant community from seed bank in case of reversion to broadleave stands. Four stands growing side by side and with different dominant species were selected at two locations (site of Haye: Quercus petraea, Pseudotsuga menziesii, Pinus sylvestris and Picea abies; site of La Petite-Pierre: Quercus petraea, Fagus sylvatica, Pinus sylvestris and Picea abies). In each stand, ground vegetation was surveyed and soil seed bank was sampled. Composition of ground flora and seed bank of stands were quite different: only 11 to 30 % of the species were in both the ground flora and the seed bank. Composition of the seed bank was mainly influenced by site location and sylvicultural practices such as the type of afforestation or the tree cover. Species richness of seed banks and vegetation were higher in the site of Haye than in the site of La Petite-Pierre. Seedling density strongly decreased with stand age. Whereas between 65 and 86 % of species found in the ground vegetation of native deciduous stand were also present in the understory or the seed bank of mature coniferous stands, this was only about 50 % in young coniferous stands. Species of deciduous stands which were absent from coniferous stands were typical of old forests. In contrast, species mainly found in the coniferous stands were often ruderal. In the studied areas, it would be possible to restore up to 86 % of the native deciduous forest vegetation, but some plant species typical of ancient forests may have disappeared during the coniferous stage.

Species in the genus Castanea are widely distributed in the deciduous forests of the Northern Hemisphere from Asia to Europe and North America. They show floristic similarity but differences in chestnut blight resistance especially among eastern Asian and eastern North American species. Phylogenetic analyses were conducted in this study using sequences of three chloroplast noncoding trnT-L-F regions. The trnT-L region was found to be the most variable and informative region. The highest proportion of parsimony informative sites, more and larger indels, and higher pairwise distances between taxa were obtained at trnT-L than at the other two regions. The high A+T values (74.5%) in the Castanea trnT-L region may explain the high proportion of transversions found in this region where as comparatively lower A+T values were found in the trnL intron (68.35%) and trnL-F spacer (70.07%) with relatively balanced numbers of transitions and transversions. The genus Castanea is supported as a monophyletic clade, while the section Eucastanon is paraphyletic. C. crenata is the most basal clade and sister to the remainder of the genus. The three Chinese species of Castanea are supported as a single monophyletic clade, whose sister group contains the North American and European species. There is consistent but weak support for a sister–group relationship between the North American species and European species.

The aim of this paper is to present the non-target species caught in the traps baited with synthetic pheromones of the species Cydia pomonella, Grapholita funebrana, Grapholita molesta, Archips podana, Adoxophyes orana, Tortrix viridana and Gravitarmata margarotana, in the frame of some experiments conducted during the years 1989-1990 in order to identify sexual attractants for the main conophagous Lepidoptera in Romania. At the same time we assessed the selectivity of these products and identified the compounds which could be used as sexual attractants for different tortricid species. Deploying pheromone traps in coniferous mature tree stands or seed orchards having in their neighbourhood fruit trees or deciduous forests, only 5 reference species and 30 non-target species have been caught , 23 of them being tortricid moths. The selectivity (specificity) of the used synthetic pheromones was rather low. However, this should not be a problem in the current works accomplished with atra...

Surface water and soil samples were collected from a series of small catchments on granitic gneiss in the Canton of Ticino in southern Switzerland. Elevations of the sampling points ranged from 220 to 2400 m; vegetation varied correspondingly from deciduous forest through coniferous forest to alpine pasture and essentially unvegetated rock and talus. Annual precipitation averaged 1.9 to 2.4 m. The concentrations of the major cations and silica in surface waters decreased more or less exponentially with elevation. The cationic denudation rate decreased from about 500 meq/m 2 · y at the lower elevations to about 20 meq/m 2 · y at the highest. Alkalinity decreased from 250 to about -7 μeq/1. Although total concentrations decreased with elevation, there were no clear systematic trends in the ratios of the concentrations of the major cations and silica. This suggests that the nature of the secondary minerals formed during weathering in the area does not change with elevation, despite great changes in soil type and environmental conditions. The clay mineralogy of the soils is dominated by unweathered and slightly weathered bedrock minerals: mica and chlorite, hydrobiotite, and poorly characterized mixed-layer material. Small amounts of kaolinite and smectite were observed in a few samples, but there do not appear to be any systematic trends in clay mineralogy with elevation. Mass-balance arguments suggest that the major (in terms of solute generation) weathering product is either kaolinite or a mixture of A1(OH) 3 and 2:1 clays. The lack of dependence of weathering stoichiometry on elevation (a surrogate for several environmental variables) or solute concentrations perhaps reflects the importance of local relief, which did not vary systematically with elevation.

... Sidney A. Gauthreaux Jr, Patricia Heglund, Keith A. Hobson, Alex E. Jahn, Douglas H. Johnson, Steven C. Latta, Douglas J. Levey, Peter P. Marra, Christopher L. Merkord, Erica Nol, Stephen I. Rothstein, Thomas W. Sherry, T. Scott Sillett, Frank R. Thompson III, Nils Warnock. ...

The Białowieża Primeval Forest (BPF) is the only forest area in temperate Europe where forest communities have developed a natural stand structure and a natural distribution of coarse woody debris ((CWD)=standing dead trees (SDT)+down woody material (DWM)). Stand and dead wood characteristics are influenced by ancient and recent historical factors and current processes, such as fires, competitive exclusion, storms, insect outbreaks, and forest management. The aim of the present study was to relate CWD to stand characteristics in mesic deciduous forest (Tilio–Carpinetum (TC)) and riparian forest (Circaeo–Alnetum (CA)). Direct comparison of managed forest to protected forest provides information about the impact of the forestry practices on TC stand and CWD characteristics. Approximately two-fold larger volume of trees was found in the Białowieża National Park (BNP) TC stands (from 336 to 555 m3 ha−1) than in the commercial forest ((CF), from 239 to 279 m3 ha−1). Irregular distribution of “legacy trees” (DBH>90 cm) accounted for most of the variability among the TC BNP stands. Even stronger differences within TC stands were revealed among the various developmental phases (from 147 m3 ha−1 in degradation phase to 630 m3 ha−1 in biostatic-optimal phase). Difference in rate of stand development was responsible for the variability of tree volume within CA (338 m3 ha−1 in early succession stand versus 634 m3 ha−1 in close-to-climax stand). CWD (mostly DWM) contributed about one-quarter of the total above ground wood biomass in BNP TC and CA ecosystems, ranging from 87 to 160 m3 ha−1. Higher relative abundance of spruce in DWM than in living stand volume and more spruce in old debris than in fresh debris suggests that the end of the spruce mortality wave was imminent. As a consequence, structural and dynamic changes in favour of smaller regeneration units are expected. A mere vestige of CWD was found in the CF ecosystem. Both stand and CWD data show a negative impact of former management on the forest ecosystems. In conclusion, special measures aimed at the restoration of ecological capacity of forest communities, including legacy retention and management for decadence, have been recommended. There is an urgent need for complementary studies to supply information necessary for successful adaptive management of the Białowieża Primeval Forest.

Wooded meadows are seminatural plant communities that support high diversity of various taxa. Due to changes in land use, wooded meadows have severely declined during the last century. The dominant trees in wooded meadows acquire mineral nutrients via ectomycorrhizal fungi. Using anatomotyping and sequencing of root tips, interpolation and extrapolation methods, we studied the diversity and community structure of ectomycorrhizal fungi in two soil horizons of both managed and forested parts of a wooded meadow in Estonia. Species of Thelephoraceae, Sebacinaceae and the genus Inocybe dominated the whole ectomycorrhizal fungal community of 172 observed species. Forested and managed parts of the wooded meadow harboured different communities of ectomycorrhizal fungi, whereas soil horizon had a negligible effect on the fungal community composition. Diverse soil conditions and host trees likely support the high richness of ectomycorrhizal fungi in the wooded meadow ecosystem. Direct sequencing integrated with interpolation and extrapolation methods are promising to identify the fungi at the species level and to compare species richness between communities of ectomycorrhizal fungi.

ON PATAGONIAN PHYTOGEOGRAPHY. The character of the vegetation of the southernmost South America (Patagonia s. lat.) is notably dualistic. Eastern parts are characterized by open spaces of the treeless Patagonian steppe while areas on the western side of the Andes are in natural condition covered by dense forests. This is due to the climate and particu­ larly clear differences in

Multidisciplinary investigations of the sequence at Beeches Pit, West Stow (Suffolk, UK), have a direct bearing the age of the Hoxnian Interglacial and its correlation with the continental Holsteinian and with the global marine record. At this site, glacial deposits (till and outwash gravels) ...

The aim of this study was to investigate the effects of habitat loss, fragmentation and habitat quality on sedentary forest birds in an urban and suburban environment. The study area was situated in Stockholm, the capital of Sweden, embracing the city centre, suburbs and parts of the rural surroundings. Breeding forest birds were surveyed in 51 forested sample sites (2-700 ha) and five species of resident birds were selected for further studies: willow tit (Parus montanus), crested tit (P. cristatus) and coal tit (P. ater) representing coniferous forest and marsh tit (P. palustris) and nuthatch (Sitta europaea) representing deciduous forest. A spatial landscape analysis was made using a geographical information system (GIS). In 21 of the smaller sites (2-200 ha), a field study was conducted to examine habitat quality parameters like vegetation age, structure and composition, and human-induced disturbance. The probability of occurrence (breeding) of bird species as functions of landscape and habitat descriptors was tested using logistic regression. All investigated species of the Parus guild showed high probabilities of occurrence only in forest patches larger than 200-400 ha, and was not present in patches smaller than 10-30 ha. This meant that patches of presumably suitable habitat (coniferous vs. moist deciduous forest) were left unoccupied. The amount of standing dead and decaying trees provided additional explanation for the distribution of the willow tit. Large areas of urban open land, industrial land use and large bodies of water had a negative influence on the probability of occurrence of several species, which indicate that they were sensitive to isolation. The probability of occurrence of the marsh tit was also influenced by distance to other sample sites with marsh tits. Unlike the Parus species, the nuthatch was breeding in most of the parks and forest remnants. This species prefers mature deciduous forest, mainly oak, which habitat was common in the urban environment. The nuthatch was only absent in some of the smallest (a few ha) forest fragments, with a mean distance between forest patches in the surroundings of over 100 m. The study showed that large forest areas and a high amount of forest in the landscape are important for the investigated resident birds that are not adapted to the urban environment. Vast areas without tree-cover seemed to be poor habitat and/or restrict dispersal. Strips of high-quality habitats, including standing trees with nest-holes, were not entirely absent in the urban and suburban environment.

A detailed analysis of the location and composition of Iberian vegetation types during the whole Pleistocene and Holocene periods shows a complex patched landscape with persistence of different types of ecosystems, even during glacial times. In addition, recent, high-resolution palaeoecological records are changing the traditional picture of post-glacial vegetation succession in the Iberian Peninsula. The main available charcoal and pollen sequences include, coniferous and deciduous forest, steppes, shrublands, savannahs and glacial refugia during the Pleistocene for Meso-thermophytes (phytodiversity reservoirs), in different proportions. This panorama suggests an environmental complexity that relates biotic responses to climate changes forced by Milankovitch cycles, suborbital forcings and by the latitudinal and physiographic particularities of the Iberian Peninsula. Thus, many factors are critical in the course of vegetational developments and strong regional differences are obser...