Search results for "BOREAL"

Caracterización, Inventariación y aplicación del método de Valoración Biogeográfica de paisajes vegetales (LANBIOEVA) a la comarca de Collsacabra (Gi…

2018

The study presented in this paper takes part of a research project (LANBIOEVA: Landscape Biogeographic Evaluation) carried out for the past 25 years and it is, for now, its last stage. It’s a global landscape valuation method focused on vegetation as a main element of different units that can be evaluated. So far, the use of this method has resulted in numerous works: books, articles, book chapters, communications and presentations, and it has been applied in the study of different temperate and boreal regions of Europe and America. The method has been applied in the study and assessment of diverse vegetation landscapes of the Collsacabra shire (Girona). The objective is to verify its effec…

High rates of short-term dynamics of forest ecosystem services

2021

Currently, the main tools for assessing and managing ecosystem services at large scales are maps providing snapshots of their potential supply. However, many ecosystems change over short timescales; thus, such maps soon become inaccurate. Here we show high rates of short-term dynamics of three key forest ecosystem services: wood production, bilberry production and topsoil carbon storage. Almost 85% of the coldspots and 65% of the hotspots for these services had changed into a different state over a ten-year period. Wood production showed higher rates of short-term dynamics than bilberry production and carbon storage. The high rates of dynamics mean that static snapshot ecosystem service map…

Assessing physical surrogates for biodiversity: Do tributary and stream type classifications reflect macroinvertebrate assemblage diversity in runnin…

2006

Landscape classifications are increasingly being used in conservation planning and biodiversity management, although there is a dearth of studies actually showing concordant patterns between such classifications and biodiversity. We studied the utility of tributary and stream type classifications in accounting for the variability of invertebrate biodiversity in a boreal drainage system. We found that only weak, although significant, differences existed between the studied three tributaries and four stream types in macroinvertebrate assemblage structure, species distributions, and taxonomic richness. Further, the classification strengths, calculated as mean within-group-similarity minus mean…

Has the Northern Hemisphere been warming or cooling during the boreal winter of the last few decades?

2013

Abstract The Intergovernmental Panel on Climate Change (IPCC) reported a significant rise of the global mean surface temperature over the last 100 years, with a rate of warming over the last few decades almost double that over the last 100 years. The rate of warming is higher at land surfaces over the Northern Hemisphere (NH), and particularly extreme warming is occurring over the Arctic. In spite of the global warming trend, some asymmetries have been observed. In a recent study, a widespread cooling over the NH during the boreal winter season was reported, although other previous studies observed a warming during this season. In this paper we report trends in winter air temperatures over …

How dry was the Younger Dryas? Evidence from a coupled <i>δ</i><sup>2</sup>H–<i&gt…

2019

Abstract. Causes of the Late Glacial to Early Holocene transition phase and particularly the Younger Dryas period, i.e. the major last cold spell in central Europe during the Late Glacial, are considered to be keys for understanding rapid natural climate change in the past. The sediments from maar lakes in the Eifel, Germany, have turned out to be valuable archives for recording such paleoenvironmental changes. For this study, we investigated a Late Glacial to Early Holocene sediment core that was retrieved from the Gemündener Maar in the Western Eifel, Germany. We analysed the hydrogen (δ2H) and oxygen (δ18O) stable isotope composition of leaf-wax-derived lipid biomarkers (n-alkanes C27 an…

L’IMPIEGO DELLA MORFOMETRIA GEOMETRICA E IL CONTRIBUTO DELLA CITOGENETICA NELLO STUDIO DELLA TRIBÙ CERCOPITHECINI (ORDINE PRIMATES)

The tribe Cercopithecini is a large and colourful taxon of African primates. Together with the tribe Papionini, it belongs to the subfamily Cercopithecinae (Gray, 1821). Despite several studies carried on the present species of Cercopithecini (guenons and sister genera), up to date a strong and clear systematics is missing. The evolutionary relationships inside the tribe are controversial, as are the numbers of genera and species. This lack prevents our full comprehension of the evolution of the tribe. We decided to investigate the tribe Cercopithecini through the use of two methodologies: geometric morphometrics and cytogenetics. The geometric morphometric survey was conducted on 1126 cran…

Water mites of small boreal forest lakes (Central Finland)

1999

The water mite fauna of 10 small forest lakes in close proximity to each other was studied in 1979–1985. In total approximately 62 species of water mites belonging to 22 genera were detected in the lakes. The most diverse genera were Piona (14 species), Arrenurus (11), Unionicola (4) and Limnesia (4). Widely spread and abundant species were Piona variabilis and Limnesia maculata. Locally abundant were Unionicola crassipes, U. minor, Piona carnea and P. paucipora. Zoogeographically interesting though accidental species were Arrenurus werestschagini, Limnesia polonica, Momonia karelica, Piona gyrophora and Unionicola parvipora. Considerable spatial and seasonal differences were observed in th…

Effect of Stem Snapping on Aspen Timber Assortment Recovery in Hemiboreal Forests

2020

Post-disturbance salvage logging mitigates economic loss after windthrow, and the value of salvaged timber is strongly linked to its quality and dimensions. We studied the occurrence of wind-induced damage of aspen in the hemiboreal forests of Latvia based on data from the National Forest Inventory and additional measurements. Individual tree data from three re-measurement periods were linked to follow a tree condition (live, broken, uprooted) and to link tree characteristics to a respective snag. Three linear models were developed to assess factors affecting the snapping height. An assortment outcome was calculated for undamaged and salvaged trees using the bucking algorithm, and timber va…

Modelling the impact of higher temperature on the phytoplankton of a boreal lake

2014

We linked the models PROTECH and MyLake to test potential impacts of climate-changeinduced warming on the phytoplankton community of Pyhäjärvi, a lake in southwest Finland. First, we calibrated the models for the present conditions, which revealed an apparent high significance of internal nutrient loading for Pyhäjärvi. We then estimated the effect of two climate change scenarios on lake water temperatures and ice cover duration with MyLake. Finally, we used those outputs to drive PROTECH to predict the resultant phytoplankton community. It was evident that cyanobacteria will grow significantly better in warmer water, especially in the summer. Even if phosphorus and nitrogen loads to the la…

Data from: Exposing the structure of an Arctic food web

2016

How food webs are structured has major implications for their stability and dynamics. While poorly studied to date, arctic food webs are commonly assumed to be simple in structure, with few links per species. If this is the case, then different parts of the web may be weakly connected to each other, with populations and species united by only a low number of links. We provide the first highly resolved description of trophic link structure for a large part of a high-arctic food web. For this purpose, we apply a combination of recent techniques to describing the links between three predator guilds (insectivorous birds, spiders, and lepidopteran parasitoids) and their two dominant prey orders …