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745 Uppsatser om Threatened species - Sida 6 av 50
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).
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.
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.
Survey of Fusarium species on yellow onion (Allium cepa) on Öland
It has been observed by both onion producers and a plant protection advisor on Öland (an island off the east coast of Sweden) that basal rot is the largest contributory factor to reduced onion quality and yield. Basal rot is mainly caused by species of Fusarium fungi. The aim of this study was to: a) investigate which species of Fusarium that can be found in onion produced on Öland, b) describe the symptoms caused by the different Fusarium fungi found and c) explore, through interviews with the onion producers on Öland, the mechanisms that may be involved in the observed increase in basal rot.Onion bulbs (Allium cepa) were sampled on two occasions. In total 181 onions from 11 different fields were analysed. In addition, eight onion producers were interviewed.
Grodsamhällen längs vattendrag på Borneo : En identifiering av habitatkaraktärer viktiga för diversitet och abundans av grodor i tropisk regnskog
The stretch from the riparian zone of a major river, through the mouth and upstream in tributaries forms a range of differing habitats. The aim of this study was to investigate the effect of these different habitats on the riparian frog community in primary rain forest in Borneo; i.e. examine whether any gradients could be demonstrated in terms of species composition, diversity and density of frogs, as well as which environmental characteristics that seem to be of most importance in forming habitats of high conservational value. A major river, Segama, and three of its tributaries were investigated. The surveys were carried out at night by searching for frogs visually and acoustically along the streams, from the shore of the Segama river and 400 metres upstream in the tributaries.
Variation in protein precipitation and phenolic content within and among species across an elevational gradient in subarctic Sweden
This project investigated how elevation and vegetation type influences variation in plant litter phenolic content and protein precipitation capacity among and within common plant species for two different vegetation types, heath and meadow, in a subarctic ecosystem in the Abisko region of northern Sweden. As nutrient availability generally decreases with increasing elevation as a result of decreasing temperature, I hypothesised that phenolic content would increase with elevation and be higher on the heath than the meadow. To test this, the total phenolic content and protein precipitation capacity was estimated in leaf litter from 13 species in both heath and meadow vegetation across an elevational gradient ranging from 500 to 1000 meters above sea level (m.a.s.l.) in the study region. The results showed that elevation and vegetation type both had a strong impact on both variables. Total phenolic concentrations decreased with elevation for the meadow, and were greater for the heath than the meadow.
Kunskapsläge och attityder till vildsvin (Sus scrofa) och dess förvaltning i Sverige
The wild boar (Sus scrofa) is since its recent establishment and increasing density a controversial species in Sweden. But the attitudes towards the wild boar are poorly documented so far. To improve this knowledge, a questionnaire was sent out to chosen people (n=400) connected to the management and/or land use activities.
The study got 162 replies (reply frequency 40,5%) and the results show varying attitude trends among organizations and individuals, with some aspects coherent within groups and some not. Farmers and their organization showed the most negative attitudes towards wild boars, which was expected due to the practical and economic problems they suffer from this species. People involved with forestry were more positive to wild boars, probably because the species does not affect forest growth etc severely, and may even promote plant establishment by the rooting.