Search results for "BOREAL"
showing 10 items of 232 documents
Faunal invasions as a source of morphological constraints and innovations? The diversification of the early Cardioceratidae (Ammonoidea; Middle Juras…
2005
Abstract Multivariate analysis of shell characters and quantification of morphological diversity (morphospace occupation and disparity) are used here to investigate the modes of morphological diversification of ammonites. We define five events in early cardioceratid history that connect geographical changes causing emigration or immigration phases with biodiversity dynamics: (1) the initial colonization of the Arctic Basin by the Cardioceratidae at the end of the Bajocian, Middle Jurassic; (2) the first appearance of the Kosmoceratidae clade in the Boreal Realm during the Bathonian; (3) the ensuing expansion phase of this clade in the Boreal Realm; (4) the first phase of migration of the Ca…
Horizontal and elevational phylogeographic patterns of Himalayan and Southeast Asian forest passerines (Aves: Passeriformes)
2011
Aim Zoogeographic patterns in the Himalayas and their neighbouring Southeast Asian mountain ranges include elevational parapatry and ecological segregation, particularly among passerine bird species. We estimate timings of lineage splits among close relatives from the north Palaearctic, the Sino-Himalayan mountain forests and from adjacent Southeast Asia. We also compare phylogeographic affinities and timing of radiation among members of avian communities from different elevational belts. Location East Asia. Methods We reconstructed molecular phylogenies based on a mitochondrial marker (cytochrome b) and multilocus data sets for seven passerine groups: Aegithalidae, Certhiidae (Certhia),…
Emulating natural disturbances in boreal Norway spruce forests: Effects on ground beetles (Coleoptera, Carabidae)
2014
The disturbance regime of boreal forests has been substantially altered by human influence in northern Europe. In this context, emulations of natural disturbance have become increasingly common as management tools to minimize negative effects of forestry on biodiversity. In a large-scale habitat-restoration experiment conducted in Norway spruce stands in southern Finland, we tested the effects of controlled burning, partial harvesting, and increasing the amount of downed wood on ground beetles (carabids). We also evaluated the effects of moisture gradients within harvested sites. We collected beetles seven years after the treatments. The moisture gradient was the strongest determinant of ca…
Correspondence between regional delineations and spatial patterns in macroinvertebrate assemblages of boreal headwater streams
2002
AbstractGeographical stratification may provide a useful framework for stream management programs, yet most studies testing the utility of such stratifications have been conducted in temperate regions. We studied the correspondence between regional delineations (5 ecoregions, 11 subecoregions), environmental characteristics, and benthic macroinvertebrate assemblages in 156 boreal headwater streams in Finland, using a combination of principal components analysis, nonmetric multidimensional scaling, and discriminant function analysis (DFA). Both stream characteristics and macroinvertebrate assemblage structure showed a closer correspondence to ecoregions than to subecoregions, a pattern partl…
Spatial trade-offs between ecological and economical sustainability in the boreal production forest
2022
Economically-oriented forestry aims to sustain timber harvest revenues, while ecologically-oriented management supplies suitable habitat for species using deadwood as primary habitat. As these objectives are conflicting, planning for economic and ecological sustainability involves compromise and trade-offs. We analyze the spatial trade-offs between the economic value from timber harvesting and the volume of deadwood in the boreal forest. We assess these trade-offs from three perspectives: (1) landscape characteristics, affected by conservation strategies; (2) forest management promoting either economic or ecological values; (3) uncertainty in inventory errors undermining the estimate of the…
Lessons on Marine Protected Area Management in Northern Boreal Regions from the United States and Norway
2017
In comparison to tropical reef systems, relatively few marine protected areas (MPA’s) exist in temperate or subarctic systems (e.g., North Pacific and North Atlantic) where species diversity is lower, abundance of individual species is often higher, and many fish species exhibit large amounts of movement during one or more of their life stages, especially as adults. A review of MPA’s in three northern areas—the Northwest Atlantic, Northeast Atlantic, and the Northeast Pacific—indicates that MPA’s can be useful management tools towards fisheries management and habitat conservation. However, achieving fishery goals, such as sustainable use of the fisheries resources, will depend on population…
Trophic transfer of polychlorinated biphenyls (PCB) in a boreal lake ecosystem: Testing of bioaccumulation models
2013
Understanding the fate of persistent organic chemicals in the environment is fundamental information for the successful protection of ecosystems and humans. A common dilemma in risk assessment is that monitoring data reveals contaminant concentrations in wildlife, while the source concentrations, route of uptake and acceptable source concentrations remain unsolved. To overcome this problem, different models have been developed in order to obtain more precise risk estimates for the food webs. However, there is still an urgent need for studies combining modelled and measured data in order to verify the functionality of the models. Studies utilising field-collected data covering entire food we…
Habitat preferences of edible dormouse, Glis glis italicus: implications for the management of arboreal mammals in Mediterranean forests
2015
Research on arboreal mammals living in Mediterranean forests is poor. Molecular research assessed the existence of an evolutionary significant unit in the edible dormouse populations living in south Italy, Sicily and Sardinia, and we decided to investigate the environmental factors capable of explaining its occurrence and abundance in Sicily, for a better management of these populations. We assessed the species habitat preferences by setting 25 large and 25 small nestboxes in five sample areas along an altitudinal gradient of the Madonie Range, and recorded habitat variables, food availability, and demographic data for two years. To obtain synthetic descriptors of the dormice habitat requir…
Chromosomal Dynamics in Cercopithecini Studied by Williams-Beuren probe mapping
2010
Chromosomal evolution in the tribe Cercopithecini and in related taxa is highly debated. Uncertainty in reconstruction is mainly related to the great genetic variability and polymorphism of the taxa. Recent molecular and karyological efforts individuate a split between genetically conservative, arbitrarily defi ned, “terrestrial” guenons and vervets, and genetically variable and derived “arboreal” guenons. We performed the mapping of WS loci probe (7q11.23) in order to verify the chromosomal dynamics of the genomes of three tree-dwelling species of the tribe: C. neglectus, C. mitis mitis, C. albogularis labiatus. Data from literature for the “ground-dwelling” Chlorocebus aethiops sabaeus ha…
Un site de plein air du Mésolithique ancien à Tramoyes « Sous le Port » (Ain)
2016
Der Fundplatz wurde am heute trockengelegten Lac des Echets lokalisiert, in einem sandigen Kontext alluvialen Ursprungs, der sich den OSL-Datierungen zufolge im jüngeren Spätglazial abgelagert hatte. Die ergrabene Fläche ist zu klein, um die räumliche Organisation der durch verstreute Geröll- und Feuersteingeräte materialisierten Spuren zu erfassen. Der größte Teil der Funde wird dem Frühmesolithikum des Typs Beuronien zugeordnet, zu dem einige Elemente des älteren Sauveterrien kommen. Die 14C-Datierungen ordnen diese Belegungsphasen in das mittlere Präboreal ein. Die technotypologischen Merkmale der Steinartefakte zeigen, dass beim Abbau vorwiegend Lamellen produziert werden, daneben auch …