Search results for "40"

Colonisation of newly established habitats by soil decomposer organisms: the effect of habitat corridors in relation to colonisation distance and hab…

2005

Abstract The aim of the present 2.5-year-long field experiment was to explore the ability of various members of the detrital food web to colonise newly established habitat patches in field conditions, either in the presence or absence of habitat corridors. Patch size and distance to the “mainland” (colonisation source) were manipulated to explore the scale dependency of the corridor effects. Sterilised humus patches, embedded in mineral soil regarded as uninhabitable (or non-preferred) matrix for the soil organisms, functioned as newly established habitats. Intact forest soil served as the source of colonisers. Three kinds of patches were established: large ones situated at relatively long …

Onset of natal dispersal in Peregrine Falcon from Mediterranean islands (Italy)

2018

Abstract Basic information on natal dispersal of Peregrine Falcons is virtually lacking in Europe, despite increased attention on this species, and the sensitivity of this stage in the Peregrines’ life history. In this study, we collected satellite telemetry data during the onset of natal dispersal of 19 Peregrine Falcons tagged in Sicily and the Aeolian archipelago (Italy). We divided the onset of dispersal into the following 3 periods: post-fledging dependence period (PFDP), wandering, and wintering. PFDP lasted on average 47±16 days, during which young peregrines moved very little (0.167 km), and explored small areas (0.226 km2) far from the nest cliff, and showed no sex differences. The…

Eight decades of adaptive changes in herring reproductive investment: the joint effect of environment and exploitation

2021

Abstract Reproductive investment is a central trait for population dynamics and productivity. Fishing and environmental variations are major drivers affecting population structure, dynamics, and adaptation of life-history and behavioural traits. However, those factors are often considered independently, and few studies take into account their joint effect. In this study, we investigate the contribution of environment, fishing pressure, and intra-specific competition to variation in the reproductive investment of the Norwegian spring-spawning herring (Clupea harengus), a stock that has been fished for centuries, and monitored for decades. Reproductive investment and post-spawning weight were…

Genetic variability in Peregrine falcon populations of the Western Palaearctic region

2018

We analyzed variation in ten polymorphic microsatellites and a portion of cytochrome b mitochondrial DNA in 4 populations of the Peregrine falcon (Falco peregrinus). living in northern and southern Italy. Spain and Czech Republic to assess species diversity in the poorly investigated Western Palearctic region. The Spanish population lives in the contact zone between F. peregrinus peregrinus and F. p. brookei. both the northern Italian and the Czech populations live within the range of F. p. peregrinus and the southern Italian is within the F. p. brookei. We added to our cytochrome b sequence dataset comprising 81 samples. previously published mitochondrial DNA sequences (n = 31) of English …

Do enchytraeid worms and habitat corridors facilitate the colonisation of habitat patches by soil microbes?

2004

Due to their high abundance and ubiquitous existence, microbes are considered to be efficient colonisers of newly established habitats. To shed light on the dispersal mechanisms of soil microbes, a controlled microcosm experiment was established. In these microcosms, the dispersal of microbes from a source humus patch to originally sterile humus patches (embedded in a mineral soil matrix) was followed for 16 months, applying 16S and 18S ribosomal DNA-based PCR-DGGE molecular methods. Specifically, the role of enchytraeid worms and habitat (humus) corridors as possible facilitators of microbe dispersal was studied. The results showed that enchytraeid worms function efficiently as vectors for…

Afforested fields benefit nutrient-demanding fungi

2015

Impaired ecosystems are converted back to natural ecosystems or some other target stage by means of restoration and management. Due to their agricultural legacy, afforested fields might be valuable compensatory habitats for rare fungal species that require nutrient-rich forest soils. Using a large-scale field experiment in Finland, we studied community composition of macrofungi (agarics and boletes) on former fields, which had been afforested as monocultures 20 years ago using native spruce Picea abies, pine Pinus sylvestris, and birch Betula pendula. We studied the effect of soil quality, tree species, and site on community composition and structure. Many nutrient-demanding as well as rare…

2021

Without insights into the threats affecting species across their distributions and throughout their annual cycles, effective conservation management cannot be applied. The Whenua Hou diving petrel Pelecanoides whenuahouensis (WHDP) is a Critically Endangered small seabird whose offshore habits and threats are poorly understood. We tracked WHDPs year-round in 2015/16, 2017/18, and 2018/19 using global location-sensing immersion loggers to identify offshore distribution, movements, behaviour, and overlap with commercial fishing effort. During the breeding period, WHDPs ranged from southern Aotearoa (New Zealand) to Maukahuka (Auckland Islands). After breeding, WHDPs migrated southwest towards…

Control of off-flavor compounds in a full-scale recirculating aquaculture system rearing rainbow trout Oncorhynchus mykiss

2020

Fish is increasingly produced in recirculating aquaculture systems (RAS), which can offer some production and environmental benefits. Unfortunately, there is a tendency to develop off-flavors in RA...

Proposing a Technical Solution for Restoring Longitudinal Connectivity in the Brădeni/Retiş Accumulation Area on Hârtibaciu River

2016

Abstract The fish fauna of the Hârtibaciu River has experienced a disrupted connectivity due to the hydrotechnical works and the Brădeni/Retiş Dam located across the Hârtibaciu watercourse being one of this significant obstacles. The newly proposed constructed wetlands can improve the habitat quality for the fish species of conservative interest sampled in the Brădeni/Retiş Dam proximity Rhodeus amarus, and can increase the individuals’ number of this population. Also can benefit the local populations of Phoxinus phoxinus and Gobio obtusirostris. Using gravitational force and also the underground layout, a proposed technical solution gives maximum safety regarding the water supply for the n…

The use of a spatial model of economic efficiency to predict the most likely outcomes under different fishing strategy scenarios

2021

The current European Union has been progressively implementing since January 2014 a discard ban which includes the obligation to land unwanted catch for certain regulated species and sizes. Although a full enforcement of the landing obligation has a direct impact on discard reduction through more responsible and selective fishing, fishers argue that it will prompt both a decrease in incomes and an increase in working time onboard. Thus, the measure is in a hold in south-western waters due to the difficulties to implement the ban in mixed fisheries This paper analyzes some possible scenarios which fishers could face under the landing obligation. It is shown the construction of a spatial bio-…