Regularities of spruce-fi r and oak forests distribution over the Udyl’ State Nature Reserve (the lower Amur River region)

Influence of climatic and geographic factors on the spatial distribution of Qinghai spruce forests in the dryland Qilian Mountains of Northwest China

Forest is the largest terrestrial ecosystem on the earth. Quantitative evaluation of the impacts of the land surface slope on forest spatial distributions is of great significance for a deeper understanding of functions and stability of forest ecosystem, scientific planning and rational management of forest resources. The superposition analysis of map of vegetation and digital elevation model (DEM) is an effective method to study impacts of the land surface slope on forest spatial distributions. In the past time, the data of land surface slope was mainly obtained by field measurement which had some problems of time-consuming, labor-intensive and high investigation cost. With the development of space technology, DEM data can be used to obtain land surface slope data rapidly and efficiently which has been widely used in digital forestry construction. However, studies on the influence of land surface slope on forest spatial distribution by using DEM data are rare at home and abroad. Dali City of Yunnan Province was selected as the research area in this study. The contour line vector is used to establish DEM of this area, then collect the slope data and divide the slope grades into five groups: flat slopegentle slopemoderate slopesteep slope and sharp slope. Supervised classification and visual interpretation were executed to interpret and classify the map of vegetation of Dali. By putting map of forest distribution and DEM togetherthe relationship between forest distribution and slope was analyzed and the trend of forest spatial distribution was found out. The results showed that Dali city is relatively flat and the terrain is complex and diverse. The woodland has a large area distribution in Dali City, which is related to the monsoon climate of the subtropical plateau in Dali. The shrub forests were mainly distributed on moderate slope and steep slope, and the coniferous forests were mainly distributed on gentle slope and moderate slope. As the slope changes, the distribution of shrubberies increases and decreases sharply, indicating that shrubberies are highly dependent on slope. Coniferous forests have a large area distribution at each grade, indicating that they are less dependent on slope. In general, with the increase of slope, both forest types showed a trend of increasing first and then decreasing, indicating that the surface slope has an impact on the spatial distribution of forests. This study can offer reference to the rational and scientific management of forest resources.

Using a geographic information system (GIS), digital maps of environmental variables including geology, topography and calculated clear-sky solar radiation, were weighted and overlaid to,predict the distribution of coast live oak (Quercus agrifolia) forest in a 72 km2 region near Lompoc, California. The predicted distribution of oak forest was overlaid on a map of actual oak forest distribution produced from remotely sensed data, and residuals were analyzed to distinguish prediction errors dueto alteration of the vegetation cover from those due to defects of the statistical predictive model and due to cartographic errors. Vegetation pattern in the study area was associated most strongly with geologic substrate. Vegetation pattern was also significantly associated with slope, exposure and calculated monthly solar radiation. The proportion of observed oak forest occurring on predicted oak forest sites was 4O(rlo overall, but varied substantially between substrates and also depended strongly on forest patch size, with a much higher rate of success for larger forest patches. Only 21% of predicted oak forest sites supported oak forest, and proportions of observed vegetation on predicted oak forest sites varied significantly between substrates. The non-random patterns of disagreement between maps of predicted and observed forest indicated additional variables that could be included to improve the predictive model, as well as the possible magnitude of forest loss due to disturbances in different parts of the landscape.

Forests play an important role in maintaining ecosystem services, especially in ecologically fragile areas such as the Loess Plateau (LP) in China. However, there is still great uncertainty in the spatial extent and distribution of forests in such a fragmented region. In order to examine the advantages and disadvantages of existing forest mapping products, we conducted a thorough accuracy assessment on the eight recent, medium resolution (30–50 m) products by using the LP in 2010 as the region of interest. These mapping products include Landsat and/or PALSAR images (including the forest products from GlobeLand30), FROM-GLC, Hansen, ChinaCover, NLCD-China, GLCF VCF, OU-FDL, and JAXA. The same validation data were used to assess and rank the accuracy of each product. Additionally, the spatial consistency of the different forest products and their dependence on the terrain were analyzed. The results showed that the overall accuracies of the eight forest products on the LP in 2010 were between 0.93 ± 0.003 and 0.97 ± 0.002 with a 95% confidence interval, and GlobeLand30 presented the highest overall accuracy (0.97 ± 0.002). Among them, the PALSAR-based products (OU-FDL and JAXA) indicated relatively high accuracies, while the six Landsat-based products showed a large diversity in the accuracy. According to the eight products, the total estimated forest area of the LP varied from 7.627 ± 0.077 to 10.196 ± 0.1 million ha with a 95% confidence interval. We also found that the consistency in the spatial distribution of forests between these maps: 1) increased substantially with increasing elevation until 2000m, but then decreased at higher elevations, and 2) showed mild variation along increasing slope, but had a slight rate of increase. Our findings implied that future forest mapping studies should consider topographical attributes such as elevation and slope in their final products. Our results are fundamental in guiding future applications of these existing forest maps.

We consider data on a variety of different forest forming tree species in a unique facility of Mediterranean flora on Russian territory – State Nature Reserve "Utrish." Conifers are represented by three species of junipers (Juniperus exelsa Bieb., Juniperus foetidissima Willd., Juniperus oxycedrus L.), Rinus kochiana Klotsc, Pinus pityusa Stev., Taxus baccata L. Greek Juniper is a dominating one on the area of 563.2 hectares, followed by prickly juniper (52.8 ha) and stinking juniper (38.9 ha). Their age is ranged from 121 to 141 years. The average height of juniper woodlands, where juniper stands as forest formimg species ranges from 5.4 m, with an average diameter of 16.3 cm for forests with Juniperus oxycedrus dominance to 7.6 m with an average diameter of 27.1 cm, in the case of Juniperus foetidissima and 6.9 m with an average diameter of 26.2 cm for Juniperus exelsa. Hardwoods dominate in the composition of forests in the reserve. Oak forests cover an area of about 7500 hectares. Large areas are under European ash forests dedicated to wetter conditions in the valleys in the crevices and flattened sheltered gullies. Examples of these types are associated with forests and the dominance of the Caucasian hornbeam, field maple. Carpinus orientalis usually playing a role in the undergrowth juniper stands and oak forests with dominance of pubescent oak forms plantations in clearings. Conifers are dominant in the coastal part of the reserve, and oak forests are basic phytocenoses forming the forest reserve "Utrish".

Potential distribution of oak forests in the central Himalayas and implications for future ecosystem services supply to rural communities

Зависимость дыхания стволов дуба разных классов роста от условий окружающей среды

To provide a basis for analyzing the forest carbon cycle，carbon storage，and carbon changes，forest biomass，the main parameter for determining carbon cycle processes in terrestrial ecosystems，was estimated. Variables measured in the study site of Shangri-La，Yunnan Province，included the vegetation index，precipitation，accumulated temperature，total radiation，and elevation. Established models of regional forest biomass estimations for spruce-fir forests （Abies georgei and Picea likiangensis），oak forests （Quercus aquifolioides），Yunnan pine forests （Pinus yunnanensis），and alpine pine forests （Pinus densata） were tested by combining layers of remote sensing integrated factors，of geographic comprehensive factors，and of the above listed variables. Then，forest biomass was estimated. Results revealed a total biomass of 1.14 hundred million tons with the following forest type biomass estimates in hundred million tons：spruce fir forests was 0.71，oak forests 0.14，Yunnan pine forests 0.09，and Alpine pine forests 0.20. Also，for these forest types，altitude and slope influenced distribution of total biomass，but aspect did not.［Ch，1 fig. 7 tab. 10 ref.］

«Вестник Санкт-Петербургского университета. Науки о Земле» — научно-теоретический рецензируемый журнал, обобщающий результаты исследований в области геологии, гидрогеологии и геохимии, петрологии и экологии, ландшафтного планирования и геоморфологии, экономической и социальной географии.

Mediterranean woodland environments are characterised by high spatial and temporal heterogeneity, which means the inhabiting species face a wide variety of selective pressures. Species may respond differently to habitat heterogeneity and so distinct eco-evolutionary scenarios may be responsible for the inter-habitat variability in reproductive strategies observed in certain species. The inter-forest variability of some reproductive traits in passerines has been examined by comparing forest patches or separated fragments. However, there is still little information regarding how such highly mobile animals adjust their breeding performance across continuous and heterogeneous woodlands. Here we studied the reproductive performance of a population of Blue Tits (Cyanistes caeruleus) in an area of continuous Mediterranean woodland that included two mountain slopes and four different types of forest, ranging from deciduous oak forests to perennial non-oak forests. We studied the habitat heterogeneity and inter-forest phenotypic variation in terms of reproductive performance and adult and nestling biometry, besides also exploring the effects of ectoparasites on Blue Tit reproduction. Eggs were laid earliest in deciduous Pyrenean Oak (Quercus pyrenaica) forests, while clutch size and the number of fledglings were highest in the humid Pyrenean Oak forest, which had the greatest tree coverage and most humid climate, and lowest in the coniferous Scots Pine (Pinus sylvestris) forest. There were no inter-forest differences in hatching (percentage of nests with at least one egg hatched) and fledging (percentage of nests in which at least one nestling fledged) success. Similarly, there were no inter-forest differences in adult and nestling biometry, but adults that raised more fledglings had a lower body mass, while males whose females laid larger clutches had smaller tarsi. Most ectoparasites did not affect Blue Tit reproduction, although Culicoides had a negative impact on nestling body mass. These results suggest that Blue Tits can adjust their reproductive effort to the forest where they breed even across a very small spatial scale. Different eco-evolutionary scenarios, such as phenotypic plasticity or genetic structuring and local adaptation, might explain the phenotypic differentiation in the reproductive strategies observed over small areas in woodlands.

The sequestration of carbon in biomass of herb and moss layers of forest ecosystems is relatively less studied, than analogical processes in trees biomass and soil organic mass. The paper presents mean values of carbon concentration and mean amounts of dry mass of plant material in the herb and moss layer of phytocoenoses formed under canopy of stands of main forest-forming species of trees in Poland. The parameters were studied for beech, birch, oak, alder, pine, fir and spruce forest stands, for most of the particular age classes. The studied plots were contained in following plant associations and communities: Ribo nigri-Alnetum, Fraxino-Alnetum, Galio odorati-Fagetum, Luzulo luzuloidis-Fagetum, Molinio caeruleae-Quercetum roboris, Calamagrostio-Quercetum petraeae, Abietetum polonicum, Abieti-Piceetum montanum, Calamagrostio villosae-Piceetum, as well as anthropogenic communities: Betula pendula comm. on Leucobryo-Pinetum habitat, Larix decidua comm. on Tilio-Carpinetum habitat, Pinus sylvestris comm. on Tilio-Carpinetum habitat, Picea abies comm. on Luzulo pilosae-Fagetum habitat (in lowland) and Picea abies comm. on Luzulo luzuloidis-Fagetum habitat (in lower mountain localities). The relatively highest carbon amount was observed in oak forests, pine forests and in older age classes of lowland beech forest, where the carbon concentration in dry mass reaches from 60 to 81%. The lowest concentrations were determined for lowland spruce forests, highland fir forests and for alder forests. The carbon concentration reached in these types of ecosystems from 39 to 41%.

Overexploitation of forests to increase wood production has led to the replacement of native forest by large areas of monospecific tree plantations. In the present study, the effects of different monospecific tree cover plantations on density and composition of the indigenous soil microbial community are described. The experimental site of "Breuil-Chenue" in the Morvan (France) was the site of a comparison of a similar mineral soil under Norway spruce (Picea abies), Douglas fir (Pseudotuga menziesii), oak (Quercus sessiflora), and native forest [mixed stand dominated by oak and beech (Fagus sylvatica)]. Sampling was performed during winter (February) at three depths (0-5, 5-10, and 10-15 cm). Abundance of microorganisms was estimated via microbial biomass measurements, using the fumigation-extraction method. The genetic structure of microbial communities was investigated using the bacterial- and fungal-automated ribosomal intergenic spacer analysis (B-ARISA and F-ARISA, respectively) DNA fingerprint. Only small differences in microbial biomass were observed between tree species, the highest values being recorded under oak forest and the lowest under Douglas fir. B- and F-ARISA community profiles of the different tree covers clustered separately, but noticeable similarities were observed for soils under Douglas fir and oak. A significant stratification was revealed under each tree species by a decrease in microbial biomass with increasing depths and by distinct microbial communities for each soil layer. Differences in density and community composition according to tree species and depth were related to soil physicochemical characteristics and organic matter composition.

Environmental history and tephrostratigraphy at Carp Lake, southwestern Columbia Basin, Washington, USA

The article presents the information about the current state of the larch forests of the “Bastak”. State Nature Reserve The area, ecological and cenotic conditions of growth are determined, the classification of the studied plant communities is presented, a brief description of the forest structure is given. The current state of the larch forests of the “Bastak” State Nature Reserve can be assessed as fairly stable. Currently, larch forests occupy within 25 % of the forested area. The most widespread area is occupied by lowland larch forests (94 %). Mountain larch forests are derived plant communities formed after forest cutting in fir-spruce forests.

Oaks retained in production spruce forests help maintain saproxylic beetle diversity in southern Scandinavian landscapes