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The aim of the study was to compare the feeding activity of soil fauna in seven temperate forests with the application of the bait-lamina method. Seven types of temperate forests located throughout Poland (East-Central Europe) were tested, ranging from dry pine forest with a typical poor quality soil to eutrophic riparian fresh deciduous forest. Each forest type was represented by five stands and all stands altogether represented natural gradient of soil fertility, texture and vegetation diversity. Despite clear diversification between the studied forest types according to a range of soil physicochemical properties and vegetation characteristics in addition to applying recommended measurement conditions for the method, we determined that the feeding activity of soil fauna did not differ between forest types. The activity of soil fauna did not depend on site botanical characteristics or any soil physical or chemical features, indicating that the bait lamina method was useless in measuring the feeding activity of soil fauna in temperate forest soils. Differences in the feeding activity of soil fauna might result from other environmental factors that influence soil fauna feeding activity in forest stands that were not measured here, i.e., soil temperature and humidity. The differences could also be attributable to the attractiveness of the bait substrate to soil fauna, which may be different in various soil conditions.
Forest vegetation is a key factor in the maintenance of global carbon cycle balance under the present climate change conditions. Forest ecosystems are both buffers against extreme climatic events accompanying climate change and carbon sinks diminishing the environmental impact of anthropogenic greenhouse gas emissions. We investigated the influence of stand structure and site characteristics on the productivity and carbon storage capacity of temperate forest types. Predictors of species productivity were parameters such as stand density, age, height, average diameter and wood density. Morus alba (L.) was more productive than average both in terms of annual volume increment and annual biomass gain, while Quercus sessiliflora (Matt.) Lieb. and Quercus frainetto (Ten.) were significantly less productive than average. Differences in stand productivity were explained by stand density, age, height, altitude, type of regeneration and species composition. Statistically significant differences were measured between the productivity of stands dominated by different woody species, with low productive stands dominated by slow growing species with high wood density like Quercus or Fagus, and highly productive stands rich in fast growing species with low wood density like Populus or Salix. Stands with different plant communities in the underlying herbaceous layer also tended to have different levels of productivity.
The effectiveness of dispersers on seeds of Korean pine (Pinus koraiensis Siebold et Zuccarini) was investigated in three fragmented stands and one primary stand. The proportion of Korean pine trees was less than 7% in the fragmented stands but more than 90% in primary stand. Five estimates related seed dispersal (proportion of removed seeds, scatter-hoarded seeds, cache dynamics, dispersal distance and microhabitat) were assessed to see the effect of forest fragmentation on the probability of seed dispersal of Korean pine seeds. Our results indicated fast seed harvest of Korean pine by small rodents at the seed stations and no difference among the four stands. Scatter-hoarding rodents were potentially important in promoting natural regeneration of Korean pine as revealed by high proportion of seed removal (up to 50%), short seed lifetime from the seed release locations and lower proportion of seeds remained on the ground surface. Although a proportion of seeds were scatter-hoarded in fragmented stands, no seedling successfully established due to heavy predation. Dispersal distances were strongly left-skewed in fragmented stands, indicating that fragmentation is likely to be disadvantageous for longer distance dispersal. The effective dispersal was suffered from a very heavy cost as accompanied by a great portion of seed predation and lower level of scatter-hoarded seeds. Failing to see seedling establishment in fragmented stands rather than in primary stand indicated that fragmentation and deforestation have negative effects on dispersal behavior and consequently seed destination. Artificial tree plantation and pinecone protection are highly recommended for Korean pine regeneration.
We studied the relationship between tree-species diversity and the above-ground biomass on an example of two natural Polish forest with different altitiudinal range, plant species pool, vegetation and climatic conditions. The study sought to determine whether: (1) above-ground biomass in natural forests correlates with tree-species diversity irrespective of the kind of forest (montane or lowland), and (2) the relationship in question is negative, (3) the above-ground biomass is greater in montane forests than in lowland ones. Natural forests present in 1º Polish Gorce Mountains (montane forest) alongside comparable data for the 2º world-renowned lowland forest that is present in the Białowieża National Park. Data were collected within 558 sample plots (á 200-square-metre). The diameter at breast height of all trees with girths of or exceeding 12 cm was measured. To compute above-ground biomass we calculated dry masses for each tree on the basis of values for dbh and height, next we summed these values for all species present within each plot. The number of tree species on a plot ranged from only one (mainly in spruce stands) to six (in mixed deciduous lowland forest stands). The above-ground accumulated biomass ranged from 6 to 1155 (average 251±13) t ha–1 within the lowland forest, and from 2 to 849 (average 242±8) t ha–1 within the montane forest. We concluded that there was a humped-back shaped relationship between tree-species diversity and above-ground biomass in both lowland and montane natural forests.
As the main predator and disperser of seeds, rodents play an important role in the process of vegetation regeneration by adopting different foraging and hoarding strategies in forest ecosystems. Infrared automated detection cameras and seed-tagging methods were used to understand the effects of rodents on seeds in natural environments. We chose the dominant species Apodemus peninsulae (Korean field mouse) as the focus of this study, and seeds of the three species Pinus koraiensis, Corylus mandshurica and Quercus mongolica were released and tracked in a temperate forest in northeast China. The results showed that approximately 80% of the seeds were manipulated by A. peninsulae, 15.1% of the seeds were used as food, 20.4% of the seeds were handled after feeding, 41.3% of the seeds were handled during storage, and 23.3% of the seeds remained intact. In addition, A. peninsulae preferred Q. mongolica (85.3%) and P. koraiensis (85.6%) over C. mandshurica (59.2%). The rodents frequently hoarded seeds from every species in many small, close-range, widely dispersed, single scatter-hoarded caches around the seed station. Most caches were dispersed approximately 2–4 m from the seed station. The results indicated that A. peninsulae adopted significant discriminatory processing strategies for predation, consumption, dispersal and hoarding of the different seeds of sympatric species. Seed size, proportion of kernel mass, nutrient content, and hull thickness characteristics affected the scatter-hoarding decision processes.
Great Spotted Woodpecker is the most abundant and widespread European woodpecker species, and it thus contributes the most to the number of excavated tree holes – an important habitat resource for secondary hole users. However, majority of nest site characteristics data comes from boreal and temperate forests, with lack of information from Southern Europe. In this article, nest sites of the Great Spotted Woodpecker have been investigated in the continental forests of Croatia – a previously understudied area of this species’ range. A total of 41 active nest-holes found in the breeding seasons 2003 and 2004 are described. Nest-holes were mainly positioned below the crowns, in injuries of branch abscission. Nesting tree species were not used randomly: wild cherry Prunus avium in hill and pedunculate oak Quercus robur in riverine forests were preferred while hornbeam Carpinus betulus and maples Acer sp. were avoided. While tree species used for nesting vary across the Great Spotted Woodpecker range, and thus cannot be used as a uniform nest site predictor, defected wood spots on a tree, like scars of branch abscission, are identified as an important nest site clue and a habitat feature that is spatially more consistent. Nest-holes’ dimensions acquired in this research could not be clearly differentiated from those given for the other parts of the continent.
Dispersal distance and burial mode of acorns are two of the most important characteristics in renewal processes of oaks that result from the food hoarding ecology of the Eurasian Jay Garrulus glandarius. To obtain the dispersal distance and to locate precisely the caches with scattered acorns we used radio-tracked transmitters with flexible 13 cm long sticking out antennae injected into drilled acorns. From mid-September to mid-October acorns of Pedunculate Oak Quercus robur with transmitters were mixed with untagged acorns and exhibited on five feeders distributed from each other at a distance of at least 1.3 km (max. 3.8). We obtained information on 121 tagged acorns scattered by Jays in two consecutive years (2014 - 42 records, 2015 - 79 records). For both seasons, mean dispersal distance was 115.7 metres (SE = 9.2). The maximum detected distance was 456 m, the minimum was 3 m. Most of the acorns (52.6%) were deposited by Jays up to 100 m from the source. Dispersal distance differed significantly between the two years of research and between feeders. Mean dispersal distance was much higher in 2014 (166 m, N = 42) than in 2015 (86 m, N = 72) and differed between seasons while the seed crop was similar and low. Only four acorns (3.5%) were found on the litter with no signs of hiding, which suggests accidental loss during transport (dyszoochory). Most of the cached acorns (44.6%) were deposited in the Scots Pine Pinus silvestris litter or moss cushions no deeper than 0.5 cm. The additional covering of caches with pieces of bark or leaves were noted accidentally in nine cases (9.8%).
Cyclic population dynamics of small mammals are not restricted to the boreal and arctic zones of Eurasia and North America, but long-term data series from lower latitudes are still less common. We demonstrated here the presence of periodic oscillations in small mammal populations in eastern Poland using 22-year (1986–2007) trapping data from marginal meadow and river valley grasslands located in the extensive temperate woodland of Białowieża Primeval Forest. The two most common species inhabiting meadows and river valleys, root vole Microtus oeconomus and common shrew Sorex araneus, exhibited synchronous periodic changes, characterised by a 3-year time lag as indicated by an autocorrelation function. Moreover, the cycles of these two species were synchronous within both habitats. Population dynamics of the striped field mouse Apodemus agrarius was not cyclic. However, this species regularly reached maximum density 1 year before the synchronized peak of root voles and common shrews, which may suggest the existence of interspecific competition. Dynamics of all three species was dominated by direct density-dependent process, whereas delayed density dependent feedback was significant only in the root vole and common shrew. Climatic factors acting in winter and spring (affecting mainly survival and initial reproduction rates) were more important than those acting in summer and autumn and affected significantly only the common shrew. High temperatures in winter and spring had positive effects on autumn-to-autumn changes in abundance of this species, whereas deep snow in combination with high rainfall in spring negatively affected population increase rates in common shrew.
We studied an old growth deciduous forest seed bank to examine how its potential role in regeneration is shaped by natural forest environment. Our research questions were: is the spatial pattern of seed bank influenced by local variation in elevation, soil moisture and light intensity, and what is the impact of herb layer characteristics on seed bank pattern. We recorded species composition of the herb layer and seed bank on a 2 × 40 m study plot divided into 20 quadrates, situated in a natural oak-hornbeam forest, in the Białowieża Primeval Forest, (NE Poland). Soil cores were sampled from two soil layers (0–5 cm and 5–10 cm) yielding altogether 40 samples of a total 15.9 dm3 and 0.159 m². Seeds were extracted from soil samples under a microscope. Ellenberg indicator values were used to characterize light (L) and moisture (F) conditions. Relative quadrate elevation was averaged for nine points. There were 6.65 × 10³ seeds m⁻² in upper soil layer and 3.00 × 10³ seeds m⁻² in lower soil layer. Seed bank structure constituted of patches 6 m diameter in the upper soil layer and 4 m in the lower soil layer. Aggregated pattern of the seed bank was influenced by clumped distribution of plants in the herb layer. Seed bank species richness in the upper soil layer was correlated with moisture (r = 0.485, P =0.03) and light (r = 0.526, P = 0.0172) values. Seed densities were correlated with moisture (r = 0.848 P <0.0001 upper and r = 0.491 P = 0.0278 lower soil layer) and light (r = 0.803 P <0.0001 upper and r = 0.751 P = 0.0001 lower soil layer). Seed density in upper soil layer was negatively correlated with elevation (r =–0.485 P = 0.0422). Higher seed density and species richness of the seed bank associated with better light conditions and higher moisture is probably caused by higher seed production in favourable conditions, and factors promoting seed persistence in soil. Our results indicate, that even subtle changes in light, moisture and mean relative elevation can shape seed bank spatial pattern on a fine local scale, differentiating the response of this community to small scale disturbances present in natural forests.
In temperate forest ecosystems, management is one of the most relevant factors that can drive the temporal pattern of species. As species in an ecosystem show susceptibility to stress and disturbance, it is useful to take into account the plant community “compositional dimension”, which derives from species behaviour and ecological attributes and provides information on the mechanisms underlying species assemblages. Taking into account the influence of environmental factors on species diversity and composition, in order to determine the most suitable ecological behaviour type of each species, the research aim was to generate a model for Ostrya carpinifolia coppiced woods (central Italy) that describes forest ecosystem regeneration after coppicing by the assessment of change in the composition of ecological behaviour types. Vascular species cover percentage, field data, soil data, light intensity at the undergrowth, dominant tree layer cover and time since last logging were recorded for 63 plots covering 400 m2 each (20 x 20 m), randomly selected within a set of homogeneous macro-environmental conditions. Low species richness is related to stressing factors (acid soil, high soil skeleton percentage), while high species richness is linked to high light intensity at the undergrowth level due to scarce canopy cover soon after coppicing. The driving forces affecting floristic composition, highlighted through multi-response permutation procedures (MRPP) were light intensity at the undergrowth, regenerative phase, dominant tree layer cover, acidity, presence/absence of outcropping rock or rock fragments and total nitrogen content. Six species groups, each one characterized by homogeneous ecological behaviour, were defined by indicator species analysis (ISA) and tested using bioindication values analysis. Floristic successional change, related to time since last coppicing, turned out to follow an ecological cycling process characterized by cyclical occurrence/disappearance of species belonging to the six groups.
Population dynamics of ungulates (European bison Bison bonasus, elk Alces alces, red deer Ceruus ela.ph.us, roe deer Capreolus capreolus, wild boar Sus scrofa, non-native fallow deer Dama dama, and cattle) were analysed in the Białowieża Primeval Forest (BPF, 1250 km2), one of the largest remaining tracts of ancient mixed and deciduous forests in the lowlands of Europe. Forty percent of BPF belongs to Poland, and 60% to the Belarus Republic. Polish and Betarussian game departments inventories of ungulate numbers (1946-1993) and archival data on censuses and hunting statistics (1798-1940) are presented. The recorded ranges of densities of native wild ungutates were: European bison 0-1.5 inds/km2, elk 0-0.6, red deer 0-5.4, roe deer 0.6-4.8, and wild boar 0.2-3.8 inds/km2. Fallow deer were introduced in 1890 (maximum density reached in 1914 was 1.2 inds/km2) and were eradicated by 1920. Cattle were traditionally pastured in the Forest, and its grazing impact was heaviest in 1880-1914 (maximum recorded density 6.7 inds/km2). In 1798-1993, the community of wild ungulates consisted of three to six species, with total densities varying from < 2 to 14.4 inds/km2 (65 to 1180 kg of crude biomass per 1 km2). Roe deer, wild boar, and red deer were usually the dominants. However, in 1860-1971, cattle constituted from 15% to 80% by numbers and from 37% to 87% by biomass of all ungulates in Białowieża Forest. Data on population trends within a five-species assemblage of native wild ungu­lates were subject to multiple regression analysis to determine the roles of predation (by wolves Canis lupus and lynxes Lynx lynx), competition, food, weather variables, and humans in shaping population densities and increase rates of ungulates. Growth of the mean annual temperature had positive effect on densities of all ungulates, probably through improving food supply and feeding conditions. Bison and elk were shaped by intra- and interspecific competition for food. Bison numbers have heen significantly limited by humans, due to both uncontrolled exploitation in years of political instability and deliberate culling in years of protection. Red deer and roe deer were primarily shaped by predation from wolves and lynx, respectively. Compe­tition for food influenced red and roe deer when they had erupted after predator extermination. Wild boar was influenced predominantly by food availability, especially the highly variable crops of oak seeds.
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