Search results for "boreal"
showing 10 items of 232 documents
Bacterial community response to changes in a tri-trophic cascade during a whole-lake fish manipulation
2015
Microbial communities play a key role in biogeochemical processes by degrading organic material and recycling nutrients, but can also be important food sources for upper trophic levels. Trophic cascades might modify microbial communities either directly via grazing or indirectly by inducing changes in other biotic or in abiotic factors (e.g., nutrients). We studied the effects of a tri-trophic cascade on microbial communities during a whole-lake manipulation in which European perch (Perca fluviatilis) were added to a naturally fishless lake divided experimentally into two basins. We measured environmental parameters (oxygen, temperature, and nutrients) and zooplankton biomass and studied th…
Data from: Effects of undergrowth removal and edge proximity on ground beetles and vascular plants in urban boreal forests
2019
Urban forests are regularly managed for human safety and aesthetic reasons, but they are crucial habitat for many species. Removals of undergrowth occur commonly in these forests, yet the ecological consequences of these operations are poorly understood. We sampled ground beetles (Coleoptera, Carabidae) and vascular plants along 20-m edge gradients in Finnish urban forests, in five stands treated 0.5−2.5 years earlier with undergrowth removal and in five untreated stands. We hypothesized that undergrowth removal and edge proximity would benefit opportunistic and open-habitat species, whereas shady-habitat species would be affected negatively. (1) Regarding carabids, diversity and evenness i…
The relationship between stocking eggs in boreal spawning rivers and the abundance of brown trout parr
2015
Abstract Stocking with eggs has been widely used as a management measure to support degraded salmonid stocks. In Finland, Atlantic salmon and both sea-migrating and lake-migrating brown trout are stocked as eggs, alevins, fry, parr, and smolt, whereas trout are also stocked as mature fish. The aim of this stocking is to improve catches and to support collapsed spawning stocks. We assessed the success of stocking with brown trout eggs in a study of 17 Finnish boreal forest rivers, of which 9 were subject to egg stocking. All rivers contained some naturally spawning trout. In 16 rivers, including non-stocking years and unstocked rivers, egg stocking did not increase the total (wild and stocke…
Proposal for the Thuoux section as a candidate for the GSSP of the base of the Oxfordian stage.
2012
20 pages; International audience; The Thuoux section, located in South-Eastern Basin of France (coordinates: 44°30'55"E; 5°42'25"N), is a section that satisfies numerous demanding criteria as reference section (GSSP) for the base of the Oxfordian stage. Sedimentation was continuous in that the abundant ammonitic fauna yields no detectable hiatuses. The stratigraphic boundary is located between the Lamberti Zone and the Mariae Zone or more precisely between the Paucicostatum horizon (MARCHAND, 1979) and the Thuouxensis horizon (FORTWENGLER & MARCHAND, 1994a). In this section, there is a perfect mixing bet-ween Boreal ammonites (Cardioceratinae) whose species are used as stratigraphic markers…
A record of the Jurassic/Cretaceous boundary climatic variation on the southern margin of the Tethys : clay minerals and palynofacies of the early Cr…
2005
Abstract In order to precise the paleogeographic extension of the climatic variation known at the Jurassic/Cretaceous boundary, the sedimentary organic matter (palynofacies and Rock-Eval) and the clay minerals content of Berriasian sediments of the Sidi Kralif Formation are studied on the Jebel Meloussi section, central Tunisia. Standard sedimentological and palynofacies analysis allow to reconstruct the bathymetric curve and the sequence stratigraphic scheme. Using existing biostratigraphy based on calpionellids and ammonite zonation, the sequence stratigraphic interpretation can be correlated with the established eustatic chart. Clay mineral assemblages are characterized by a shift in the…
The effects of forest management on wood-inhabiting fungi occupying dead wood of different diameter fractions
2014
Forest management has caused severe ecological degradation throughout the Globe. One of its most prominent consequences is the drastic change in dead wood profile and consequently in the dead wood dependent biota. Wood-inhabiting fungi are, considering ecosystem functions, the most important species group utilizing dead wood, because they take care of majority of the decaying process. The earlier research focusing on the effects of forest management on wood-inhabiting fungi has strongly focused on large dead wood pieces (i.e. coarse woody debris, CWD), even though it has been shown that a major part of fungal diversity utilizes (also) small dead wood pieces (i.e. [very] fine woody debris, […
The use of artificial nest-boxes by Apodemus sylvaticus dichrurus in Sicily
2008
Reports of wood mouse arboreality are rather scarce outside Britain. I reviewed and analysed 267 visits and 16.456 checks of glirids artificial nest-boxes mounted on trees, in twelve sample areas of Meso- and Supra-Mediterranean woodlands (Sicily, 1995-2005). The wood mouse was recorded only 65 times (0.395%) using the artificial nest-boxes in nine sample areas, and based on this low frequency, the wood mouse can be considered as an occasional dweller of artificial nest-boxes. The resource selection index allowed checking the use respect to the availability of nest-boxes placed at different heights. These were likely reached by climbing the dense understorey and low tree branches up to 5 m,…
Transitions in Herd Management of Semi-Domesticated Reindeer in Northern Finland
2008
In northern Finland, reindeer-herd management has experienced two major transitions: extensification of intensive herding, and development of supplementary/corral feeding in winter. The transitions were studied in six herding associations in different parts of the Finnish reindeer management area. It was suggested that intensive herding turns into more extensive forms as the reasons for intensive herding (predation, reindeer disappearing to foreign areas, protection of agricultural fields) gradually ceased to exist. The results of the study, based on interviews of elderly reindeer herders, were variable. In the three southern areas intensive herding changed to the free ranging system at the…
Guenon Radiation is Enriched by a New Species that Demonstrates an Evolutionary Complexity with Which we are yet to Become Familiar
2012
th September described this discovery to the scientific community (1). As is becoming increasingly frequent these days, given the high number of scientific articles, the media news reached us faster than the scientific information. The area known as TL2, a few hundred km as the crow flies south- west from the city of Kisangani, famous for its manufacturing, and important port on the Zaire river, is still uncontaminated and houses several important endemisms. This new species, studied in the area since 2007, on the basis of first sightings by the inhabitants of the zone and local hunters, has been named Cercopithecus lomamiensis. C.lomamiensis (CLO) is a tree-dweller and has been described i…
Factors influencing the distribution, abundance and nest-site selection of an endangered Egyptian vulture (Neophron percnopterus) population in Sicily
2003
Egyptian vulture (Neophrom percnopterus) breeds in Sicily and, in 22 years of monitoring, has shown a decline followed by a slight recovery. We used Generalised Linear Models to predict: (1) the distribution range, (2) the habitat selection within the range, (3) the quality (i.e., occupation rate, breeding success) of breeding sites. Some 60% of Sicily proved to be unsuitable, being either too densely forested and without cliffs for nesting, or too densely populated, along with intensive agriculture. The models converged, indicating that the pairs select a precise upland habitat where low cliffs, distant from urban areas, are surrounded by arboreal crops and Mediterranean vegetation. The va…