Search results for "forest"

Adaptive plasticity of blue tits(Parus caeruleus)and great tits(Parus major)breeding in natural and semi‐natural insular habitats

2004

The breeding performance and foraging of blue and great tits, and the abundance of arthropods living on the trees of an oak-wood and of a coniferous reafforestation were studied in Sicily, in order to: 1) compare breeding parameters in natural and semi-natural habitats within the same area; 2) estimate the degree of overlap in peak resource and peak demand of young tits, and the overlap of nestling diet of the two species in the two habitats. Both species had earlier laying dates, laid more eggs and raised more fledglings in the oakwood than in the reafforestation; they achieved the same fledging success within the same habitat type. These differences are probably due to the earlier and hig…

Great tit (Parus major) breeding in fire-prone oak woods: differential effects of post-fire conditions on reproductive stages

2011

Wildfires negatively affect the overall reproductive success of several woodland avian species, but there is scarce information about which stages of the nesting cycle are specifically affected. We conducted a 3-year study to identify the effects of fire on the reproductive parameters of the great tit (Parus major) and the survival of its nests at different stages of the nesting cycle. We recorded the occupancy rate, clutch and brood size, hatching, fledging and nesting success in nest boxes placed on study plots with different post-fire age. By examining the post-fire succession, we analysed the survival of eggs and nestlings under predation risks. As the forest matured after a wildfire, …

Natural nest-sites of Great Tits (Parus major) in a primeval temperate forest (Białowieża National Park, Poland)

2015

Knowledge of the breeding ecology of the Great Tit Parus major is vast, but almost exclusively concerns birds using nest-boxes. Information on birds nesting in natural conditions is scant. Here, we present the results of the first thorough study on natural nest-sites of the Great Tit. The data, including descriptions of nest-cavity location and dimensions, were collected during 39 breeding seasons in the primeval forest of Bialowieza National Park (BNP), Poland. With an excess of available tree-cavities providing a diverse choice of nesting options, Great Tits nested mainly in non-excavated, very deep and spacious cavities with elongated, narrow openings, placed at intermediate heights in l…

Disappearance rates of old nest material from tree cavities : an experimental study

2013

Numerous forest organisms critically depend on availability of tree cavities. Some birds and rodents fill their cavities with bulky nests, which – if not removed – could accumulate and render cavities unusable, as recorded in nest-box studies. Data from earlier studies indicate that old nests can disappear from tree cavities so fast that practically no remnants are detectable the following spring. Rapid decomposition of nests in situ, augmented by physical removal of nest material by the cavity-users have been proposed as possible causative mechanisms. We tested these hypotheses in cavities used by tits (Parus major L., Poecile palustris L.) in the Białowieża National Park (E Poland). To mi…

Quantification of the heterogeneity of prognostic cellular biomarkers in ewing sarcoma using automated image and random survival forest analysis

2014

Driven by genomic somatic variation, tumour tissues are typically heterogeneous, yet unbiased quantitative methods are rarely used to analyse heterogeneity at the protein level. Motivated by this problem, we developed automated image segmentation of images of multiple biomarkers in Ewing sarcoma to generate distributions of biomarkers between and within tumour cells. We further integrate high dimensional data with patient clinical outcomes utilising random survival forest (RSF) machine learning. Using material from cohorts of genetically diagnosed Ewing sarcoma with EWSR1 chromosomal translocations, confocal images of tissue microarrays were segmented with level sets and watershed algorithm…

Ģeogrāfija. Ģeoloģija. Vides zinātne: referātu tēzes

2008

Landowners’ willingness to promote bioenergy production on wasteland − future impact on land use of cutaway peatlands

2017

Landowners are the key players in bioenergy production on wasteland; such as cutaway peatlands. In this study, the landowner's interest to use cutaway peatlands for bioenergy production was investigated using a survey and GIS (Geographic Information Systems) methods in an area in South Ostrobothnia, Finland. The focus was to identify which different bioenergy production chains are preferred by the respondents: combustion, gasification or biogas production from agriculture, energy-willow short-rotation forestry or forestry based energy crops. Also, the influence of personal environmental values on the selection was measured and the future impacts and barriers for the land use were assessed. …

The role ofSphagnummosses in the methane cycling of a boreal mire

2010

Peatlands are a major natural source of atmospheric methane (CH4). Emissions from Sphagnum-dominated mires are lower than those measured from other mire types. This observation may partly be due to methanotrophic (i.e., methane-consuming) bacteria associated with Sphagnum. Twenty-three of the 41 Sphagnum species in Finland can be found in the peatland at Lakkasuo. To better understand the Sphagnum-methanotroph system, we tested the following hypotheses: (1) all these Sphagnum species support methanotrophic bacteria; (2) water level is the key environmental determinant for differences in methanotrophy across habitats; (3) under dry conditions, Sphagnum species will not host methanotrophic ba…

The impact of long-term water level draw-down on microbial biomass : A comparative study from two peatland sites with different nutrient status

2017

We examined the effects of long-term (51 years) drainage on peat microbial communities using phospholipid fatty acid (PLFA) analysis. We analysed the peat profiles of natural and adjacent drained fen and bog sites. Viable microbes (i.e. microbial PLFA) were present in relatively large amounts even in the deepest peat layers of both peatland sites, a finding that warrants further investigation. Microbial biomass was generally higher in the fen than in the bog. Microbial community structure (indexed from PLFA) differed between the fen and bog sites and among depths. Although we did not exclude other factors, the effect of drainage on the total microbial biomass and community structure was not…

Stable carbon isotopic composition of peat columns, subsoil and vegetation on natural and forestry-drained boreal peatlands.

2018

We studied natural and forestry-drained peatlands to examine the effect of over 34 years lowered water table on the δ13C values of vegetation, bulk peat and subsoil. In the seven studied sites, δ13C in the basal peat layer was 1.1 and 1.2 ‰ lower than that of the middle-layer and surface layer, respectively. Furthermore, there was a positive correlation between the δ13C values of the basal and surface peat layers, possibly due to carbon (C) recycling within the peat column. In the same mire complex, natural fen peat δ13C values were lower than those of the nearby bog, possibly due to the dominance of vascular plants on fen and the generally larger share of recycled C in the fens than in the…