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751 Uppsatser om Threatened species - Sida 6 av 51

Gamla tallars betydelse för biologisk mångfald på Gotland

Modern methods for managing pine (Pinus sylvestris) create homogenized forests. This decreases nature?s potential for biodiversity and might threaten species in need of different types of milieu. The main purpose of this study was to investigate how important older pine trees are for biodiversity. In the Hall-Hangvar Reserve in the north-west part of Gotland, insects collected from traps showed that more species were found in old or dead trees compared to younger pine trees.

Vindfällning i naturliga och skapade bryn och kanter :

The aim of this work was to study if the edge of the forest is more resistant to heavy winds than the trees located further in from the edge, and how this edge effect changes between different types of tree species and site types. The data was collected from an electric power line going from the north to the south of Sweden. The mean value of the clearcutted area around the power line was 120 meters. The main direction of the storm in January 2005 was west-southwest and thus the power line was a perfect place for gathering a large data set. The main parameter studied was the damage frequency at the edge of the forest compared to the trees located further in from the edge (up to 100 m from the power line). Tree species mixture, soil moisture class, soil type, topography, stand height, stand height of the stand on the other side of the power line and wind exposition was estimated. The results showed a distinct edge effect. The edge of the forest had clearly lower damage frequency for all tree species. A marked difference was observed between tree species and damage frequency.

Skillnader i mulmvolymer mellan fem trädslag i Östergötlands eklandskap

Old hollow trees of oak contain a large amount of wood mould. Unfortunately, these trees have in the last century been greatly reduced in numbers. It has resulted in that species that depend on these habitats, saproxylic species, have become at risk to decrease in numbers or die out regionally. Previous studies have shown that the volume of wood mould is an important factor for occurrence and population size of saproxylic organisms. The aim of the present study was to examine how the volume of wood mould varies among ash (Fraxinus excelsior), lime (Tilia sp.), maple (Acer platanoides), aspen (Populus tremula) and oak (Quercus robur).

Evaluation of an ectomycorrhizal macrofungi as an indicator species of high conservation value pine-heath forests in northern Sweden

Since the 1950s, the development of modern rotation forestry in boreal Fennoscandia has resulted in a severe reduction of older forests, and a high degree of fragmentation among the small patches that remains of old forest. In Sweden, when performing conservation value assessments in order to identify and preserve the remaining forest habitats, the government authorities use to a significant extent a set of indicator species that indicate habitats of high biological conservation value. One species considered to indicate high conservation values in pine-heath forests is the red-listed ectomycorrhizal (EM) macrofungi Sarcodon scabrosus (Fr.) P. Karst. In the present study, the validity of using S.

Upptryck : En jämförelse mellan RIDAS och internationella riktlinjer

Old hollow trees of oak contain a large amount of wood mould. Unfortunately, these trees have in the last century been greatly reduced in numbers. It has resulted in that species that depend on these habitats, saproxylic species, have become at risk to decrease in numbers or die out regionally. Previous studies have shown that the volume of wood mould is an important factor for occurrence and population size of saproxylic organisms. The aim of the present study was to examine how the volume of wood mould varies among ash (Fraxinus excelsior), lime (Tilia sp.), maple (Acer platanoides), aspen (Populus tremula) and oak (Quercus robur).

F?gelv?gen och f?gels?gen. En multi-proxy analys av m?nniskans relation till f?glar under den yngre j?rn?ldern i Mellansverige

Prior research in human bird relations is relatively small and discussion about bird ecology in relation to humans is largely not discussed. The study means to understand how a difference in usage of birds and symbolization of a bird occurs. This will be answered through analysis of two bird species. The study uses three different sources of material to conclude its answers. The sources are graves with bones of predatory birds, material culture representing bird motifs and historical sources discussing mythology.

Lövsuccessioner i sluttningar längs nedre Umeälven :

Secondary deciduous forests, which have their origin in earlier pasture- and meadow-land in slopes along the lower reaches of the Ume river, are thought to contain high nature conservation values, in spite of a relatively low age. The aim of this study was to clarify how factors as historical use, exposition, disturbance dynamics and successional age influences the conservation values in these types of riparian forests and how this can be implicated in the practical work with conservation and management at Umeå municipality. Sample plots were placed in seven stands with a variation of their historical use, exposition, disturbance dynamics and age of succession. Conservation values as structure, tree-regeneration, abundance and composition of vascular plants, amount of dead wood and the abundance of signal-species were measured and registered. The species composition and especially the composition of tree species, differed between forests with different exposition and different historical use.

Får är får och get är get : utvärdering av osteologisk metod med stöd av arkeogenetik

The difficullty to distinguish between sheep and goats is a well-known problem in archaeology and osteology. Distinguishing sheep and goats in archaeological animal remains takes time and time is often limited for osteologists. Because of this difficulty osteologists and archaeozoologists often use the term sheep/goat or ?ovicaprids? in their analytical reports. But even if the term sheep/goat comprise both species, this is often not the case when archaeologists and osteologists interpret and present archaeological findings.

Potentiella arealer för ökad virkesproduktion i norra Sverige genom skogsodling med Pinus contorta var. latifolia, Larix sukaczewii, Abies lasiocarpa, Populus × wettsteinii och Picea mariana

Sweden is a country with few native tree species. According to Govt. 2007/08: 108, exotic tree species may be seen as an opportunity to increase the growth of tree volume in Sweden. Potential areas where explored In this work for cultivation with Pinus contorta var. latifolia Engelm., Larix sukaczewii Dylis, Abies lasiocarpa (Hook.) Nutt., Populus × wettsteinii Hämet-Ahti (tremula x tremuloides) and Picea mariana (Mill.) Britton et.al.

The influence of active bomas on habitat choice of the common warthog (Phacochoerus africanus)

The common warthog (Phachocoerus africanus) is a relatively long-legged pig with noticeable curved tusks, a short neck and three pairs of facial warts. It has four recognized subspecies. The common warthog is a non-migratory ungulate living on the African savannah. It is a hindgut fermenter and predominantly dependent on high-quality foods. It prefers open areas for grazing but use bushes for cover.

Optimization and validation of a triplex real-time PCR assay for thermotolerant Campylobacter species associated with foodborne disease

The genus Campylobacter is globally recognised as the leading bacterial cause of human foodborne gastroenteritis. Every year around 8000 Swedes are infected by Campylobacter. Most people are infected by thermotolerant Campylobacter species, commonly C. jejuni and C. coli.

Brandrelaterade insekters lokala artrikedom i förhållande till olika miljövariabler : Fokus på betydelsen av konnektivitet på brandfält i boreal skog i Västerbottens län

The last century, forest fires have decreased in frequency due to efficient fire-suppression along with the growth of the industrial forestry. Since 1990, fire has been reintroduced under controlled forms to recreate burnt habitats. Many species that are dependent on, or benefits from, forest fires have increased since fire was reintroduced. The importance of connectivity is often addressed in ecological research. This is particularly important for species dependent on short-lived habitats such as burnt forests.

VILKEN STRANDVEGETATION BIDRAR TILL DET ORGANISKA MATERIALET I KUSTN?RA SEDIMENT? Kols?nkor/k?llor, nedbrytbarhet och eDNA sp?rning

Coastal sediments are important carbon sinks, storing organic matter and thereby helping to reduce the amount of greenhouse gases in the atmosphere. However, they can also act as carbon sources if the deposited organic matter decomposes rapidly, contributing to increased greenhouse gas emissions and global warming. Rapid decomposition partly depends on the degradability of the material itself. In this literature review, I examine which coastal plant species dominate different locations along the Swedish coast, based on coverage data from the ClimScape project (www.climscape.se). For the most dominant species, I investigated the type of organic matter they may contribute to the sediments and based on those results I qualitatively assessed which sites that may function as carbon sinks or sources.

Biologisk mångfald i små grönområden : Inventering av insekter och fåglar i bebyggda områden i Solna kommun

All over the world the urbanisation increases at the expense of green areas. Many plants and animals are endangered today because their habitats gets smaller or disappear. The green areas that are left in city centres and suburbs are often small and surrounded by roads and buildings. Despite this, several studies have shown that these small green areas may house large biological diversity.This project aims to study the biological diversity in small green patches in residential areas. The study has been carried out in Råsunda in Solna municipality (Stockholm county) during the period May?July 2006.Three equivalent areas (5000?10 000 m2) with quite many old oaks were chosen for the study and inventoried for birds and saproxylic insects.

Biologisk mångfald i små grönområden : Inventering av insekter och fåglar i bebyggda områden i Solna kommun

All over the world the urbanisation increases at the expense of green areas. Many plants and animals are endangered today because their habitats gets smaller or disappear. The green areas that are left in city centres and suburbs are often small and surrounded by roads and buildings. Despite this, several studies have shown that these small green areas may house large biological diversity.This project aims to study the biological diversity in small green patches in residential areas. The study has been carried out in Råsunda in Solna municipality (Stockholm county) during the period May?July 2006.Three equivalent areas (5000?10 000 m2) with quite many old oaks were chosen for the study and inventoried for birds and saproxylic insects.

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