Search results for " SITE"
showing 10 items of 1641 documents
Breeding success of the Great Tit Parus major in relation to attributes of natural nest cavities in a primeval forest
2015
An overlap in attributes of nest cavities used by Great Tit Parus major across Eurasia suggests similar nest site preferences within the geographical range, although the drivers of these preferences are unclear. To determine whether preferred cavities provide conditions enhancing successful reproduction, we investigated the breeding performance of Great Tits in relation to tree cavity characteristics using data collected during 2008–2011 in primeval conditions (Białowieża National Park, Poland). Here, tree cavities are diverse and superabundant but nesting birds are at risk from a variety of predators. According to expectations, nest losses were high (60 % of Great Tit nests failed), mostly…
Molecular Bases for Sensitivity to Acetyl-Coenzyme A Carboxylase Inhibitors in Black-Grass
2005
Abstract In grasses, residues homologous to residues Ile-1,781 and Ile-2,041 in the carboxyl-transferase (CT) domain of the chloroplastic acetyl-coenzyme A (CoA) carboxylase (ACCase) from the grass weed black-grass (Alopecurus myosuroides [Huds.]) are critical determinants for sensitivity to two classes of ACCase inhibitors, aryloxyphenoxypropionates (APPs) and cyclohexanediones. Using natural mutants of black-grass, we demonstrated through a molecular, biological, and biochemical approach that residues Trp-2,027, Asp-2,078, and Gly-2,096 are also involved in sensitivity to ACCase inhibitors. In addition, residues Trp-2,027 and Asp-2,078 are very likely involved in CT activity. Using three-…
Comparison of binding properties and early biological effects of elicitins in tobacco cells
1998
Abstract Elicitins are a family of small proteins secreted by Phytophthora species that have a high degree of homology and elicit defense reactions in tobacco (Nicotiana tabacum). They display acidic or basic characteristics, the acidic elicitins being less efficient in inducing plant necrosis. In this study we compared the binding properties of four elicitins (two basic and two acidic) and early-induced signal transduction events (Ca2+ influx, extracellular medium alkalinization, and active oxygen species production). The affinity for tobacco plasma membrane-binding sites and the number of binding sites were similar for all four elicitins. Furthermore, elicitins compete with one another fo…
Elicitins, proteinaceous elicitors of plant defense, are a new class of sterol carrier proteins
1998
Some phytopathogenic fungi within Phytophthora species are unable to synthesize sterols and therefore must pick them up from the membranes of their host-plant, using an unknown mechanism. These pseudo-fungi secrete elicitins which are small hydrophilic cystein-rich proteins. The results show that elicitins studied interact with dehydroergosterol in the same way, but with some time-dependent differences. Elicitins have one binding site with a similar strong affinity for dehydroergosterol. Using a non-steroid hydrophobic fluorescent probe, we showed that phytosterols are able to similarly bind to elicitins. Moreover, elicitins catalyze sterol transfer between phospholipidic artificial membran…
Co-Designing Urban Carbon Sink Parks: Case Carbon Lane in Helsinki
2021
In order to achieve the goals of carbon (C) neutrality within next 20 year, municipalities worldwide need to increasingly apply negative emission technologies. We focus on the main principles of urban demonstration areas using biochars for C sequestration and explore the lessons learned from a co-creation process of one such park, Hyväntoivonpuisto in Helsinki, Finland. Demonstration sites of urban C sinks in public parks must be safe, visible and scientifically sound for reliable and cost-effective verification of carbon sequestration. We find that different interests can be arbitrated and that synergy that emerges from co-creation of urban C sink parks between stakeholders (scientists, ci…
Effects of traditional coppice practices and microsite conditions on tree health in a European beech forest at its southernmost range
2016
Abstract: European beech (Fagus sylvatica) grows at the southern limit of its range in the mountain-Mediterranean vegetation belt up to the timberline. The southernmost beech forests of Sicily (southern Italy) show peculiar ecological, structural and silvicultural characteristics, growing in fragmented and isolated stands near the timberline and in topographically marginal unfavorable habitats. Past silvicultural practices increased the heterogeneity of stand structure at these sites. We compared stand structural characteristics and tree health in coppice-cut and control beech stands with respect to the local topographic gradient (bottom, slope and ridge) and canopy cover (clearing/border v…
Decomposition of nest material in tree holes and nest-boxes occupied by European Starlings Sturnus vulgaris: an experimental study
2017
Numerous bird species depend on the availability of tree cavities, and most non-excavators fill their cavities with considerable amounts of nest material. If not removed, this material can accumulate and render cavities unusable, as recorded in some nest-box studies. Data from earlier studies of tree cavities, however, showed that nest material can decrease mostly due to in situ decomposition, but the relative difference between nest decomposition in tree holes and nest-boxes is still unknown. We undertook parallel studies of decay in tree holes and nest-boxes used by European Starlings Sturnus vulgaris in oak-hornbeam stands (SW Poland). We inserted into its tree holes and nest-boxes litte…
Age structure in a newly established and increasing population: initially high proportion of young birds among nesting Great Grey Owls
2020
AbstractThe mechanisms behind expansions of the distribution of a bird species and the ensuing establishment of new populations are poorly known. The distribution of Great Grey Owl (Strix nebulosa) in the western Palearctic has generally expanded towards southwest during the past fifty years, and particularly so in Fennoscandia. In the past decade, the recorded breeding population in Norway, confined to Hedmark county bordering Sweden, increased from 1 pair in 2009 to > 100 pairs in 2017–2018, extending the southwestern border of the distribution > 100 km. We studied the age structure of this expanding population based on the molting pattern of the wing feathers of birds captured at t…
Are sacred caves still safe havens for the endemic bats of Madagascar?
2018
AbstractDespite conservation discourses in Madagascar increasingly emphasizing the role of customary institutions for wildlife management, we know relatively little about their effectiveness. Here, we used semi-structured interviews with 54 adults in eight villages to investigate whether sacred caves and taboos offer conservation benefits for cave-dwelling bats in and around Tsimanampetsotsa National Park, south-west Madagascar. Although some caves were described as sites of spiritual significance for the local communities, most interviewees (c. 76%) did not recognize their present-day sacred status. Similarly, only 22% of the interviewees recognized taboos inhibiting bat hunting and consum…
How to escape from insect egg parasitoids : a review of potential factors explaining parasitoid absence across the Insecta
2020
The egg is the first life stage directly exposed to the environment in oviparous animals, including many vertebrates and most arthropods. Eggs are vulnerable and prone to mortality risks. In arthropods, one of the most common egg mortality factors is attack from parasitoids. Yet, parasitoids that attack the egg stage are absent in more than half of all insect (sub)orders. In this review, we explore possible causes explaining why eggs of some insect taxa are not parasitized. Many insect (sub)orders that are not attacked by egg parasitoids lack herbivorous species, with some notable exceptions. Factors we consider to have led to escape from egg parasitism are parental egg care, rapid egg deve…