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19 Uppsatser om Quercus - Sida 1 av 2
Mortalitet och skottskjutningsförmåga hos ek (Quercus robur) efter brand :
In this study I analysed how burning affects sprouting ability and survival of oak (Quercus robur) during the first season after a burn in southern Sweden. The study
consisted of two separate field tests; in the first, two 300 m2- plots in western oak
dominated forest were burned to analyze the fire behavior and the immediate mortality of oak and beech seedlings defined as individuals (> 20cm of height). At the end of the season almost 50% of the oak seedlings had resprouted while the beech seedlings had 100% mortality. An attempt to investigate the effect of the burn of artificially sown acorns was totally ruined by wild boar grouting before any conclusive results could be seen.
In the second test the resprouting ability of oaks of varying diameters (average BHD 7-9 cm, range 2-42 cm) was examined one season after a prescribed burn in southeastern Sweden.
Betydelsen av taggbuskar, ljus och hävd vid föryngring av ek (Quercus robur)
Many species and hence biodiversity depend on old, large oaks (Quercus robur) with hollow trunks. The populations of oak-living organisms have to migrate to a nearby old oak in order to survive the death of the host. The oak district south of Linköping, Sweden, is unique in area and the number of old oaks. It is anyway doubtful whether regeneration of oak will secure future continuity. Oaks are light-demanding and thrive in open pastures.
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).
Större och mindre växtätares samexistens : Möjlig interaktion och effekt på lokal biodiversitet
The purpose of this report was to investigate to which extent local presence of large herbivore mammals (Alces alces, Cervus elaphus, Capreolus capreolus, Dama dama and Sus scrofa) covaries with small rodents (Myodes glaerolus, Apodemus flavicollis and Apodemus sylvaticus? The hypothesis was that high abundance of wild ungulates would inhibit the density of small forest rodents. The data was collected during field work within FoMA (Environmental Monitoring Assessment)/SLU (Swedish University of Agricultural Science). The Ungulate dropping inventory and rodent trappings, which is the base in this report, where performed 2012 ? 2014 in Gnesta/Nyköping municipalities (G/N) with a relatively high density of wild ungulates and Vetlanda/Växjö municipalities (V/V) with relatively lower wild ungulate density.
Ekens förekomst i Ludvikatrakten
Ekens (Quercus robur) nordgräns sägs gå vid Dalälven, Limes Norrlandicus ? den biologiska Norrlandsgränsen. Ludvikabygden skiljer sig naturgeografiskt och topografiskt från övriga Dalarna och tillhör Mälarens avrinningsområde. Trakten runt sjön Väsman har ett varmare klimat och fler soltimmar än den övriga bygden.
För mellan 5.000-8.000 år sedan vandrade eken in i Sverige efter den senaste istiden.
Omvandling av granskog till ädellöv i södra Sverige ? fallstudier från Söderåsens nationalpark och Raslångens ekopark
I Sverige och stora delar av Europa har det planterats gran, Picea abies, på marker som tidigare varit lövdominerade. Idag restaureras ädellövskog på dessa marker i ökad omfattning, bland annat för att gynna skogens biologiska mångfald och rekreationsvärden. Syftet med detta arbete var att undersöka överlevnad och tillväxt av ek, Quercus robur, och bok, Fagus sylvatica, som planterats efter gran i Söderåsens nationalpark och i Raslångens ekopark i södra Sverige. I Söderåsens nationalpark undersöktes plantutvecklingen tio år efter plantering på öppna hyggen (ek och bok) eller under björkskärm (bok). För Raslångens ekopark var syftet att undersöka om inversmarkberedning och hägn påverkar initial etablering och överlevnad hos bokplantor på öppna hyggen.
Resultaten från Söderåsen visar att ek och bok tio år efter plantering kan nå en hög överlevnad och god tillväxt med hjälp av fungerande hägn och regelbundna röjningar.
Olika strategier vid val av alléträd : vilka faktorer påverkar valet av alléträd? hur kan vi skapa bra förutsättningar för att kunna bibehålla alléträds livskvalitet?
Arbetet handlar om träd i stadsmiljön, främst alléträd. Arbetet visar på problematiken kring träden och hur viktigt det är att anpassa rätt art till rätt plats, både gällande ståndort men också gällande de andra förhållandena som spelar roll på en växtplats som utrymme både ovan och under mark. Vegetation i städerna spelar en mycket stor roll. Vegetationen är årstids-speglande vilket medför att utan vegetation skulle staden se likadan ut året om.
Syftet är att visa på vilka faktorer som påverkar valet av alléträd i stadsmiljö samt vilka arter som kan vara relevanta för framtida bruk. Studien skall även beskriva hur vi kan skapa bra förutsättningar för att kunna bibehålla alléträds livskvalitet.
Arbetet visar på mindre inventeringar av tolv alléer i Motala kommun som utfördes sommaren 2012.
Identifiering av lek- och övervintringsområden för lax (Salmo salar) och öring (Salmo trutta) i Klarälven
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).
Kan hårdare gallring kring huvudstammarna gynna dimensionsutvecklingen och därmed minska omloppstiden för den svenska eken?
Ett problem med ekproduktion i Sverige är att trädslaget har en förhållandevis lång omloppstid i jämförelse med övriga trädslag. Spekulationer har funnits om man genom en hårdare gallring kan påskynda ekarnas tillväxt och skapa en effektivare ekskogsskötsel. Dessa aspekter, tillsammans med behovet av ett gallringsförsök inom landets gränser, medförde att forskare vid institutionen för sydsvenskt skogsbruk i Alnarp anlade försöket.
I det här arbetet analyserar vi hur och om en alternativ skötsel av ek påskyndar diametertillväxten och därmed förkortar omloppstiden, samt vilka effekter det får för volymproduktionen. Genom regressionsanalys skapades tillväxtfunktioner för diametertillväxten av huvudstammarna för de olika skötselmetoderna som använts.
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).
Hybridlärkens tillväxt i Snogeholm : hur påverkas produktionen i blandbestånd jämfört med trädslagsrena bestånd?
The hybrid larch (Larix x eurolepis Henry) is a fast growing tree species and was introduced in Sweden for about 50 years ago. The high growth and expected resistance to diseases are probably the main reasons of introducing the tree species into the Swedish forests.
The purpose of this thesis was to document the production of hybrid larch planted in the Snogeholm landscape laboratory and to compare the production in the pure hybrid larch stand with the mixture together with pedunculate oak (Quercus robur).
The data collection in Snogeholm since the establishment has been carried out by the Swedish University of Agricultural Science (SLU). The fieldwork for the thesis was carried out in 3 stands, containing hybrid larch, pedunculate oak and a mixture of hybrid larch and pedunculate oak, in order to be able to compare the total stand production of the areas.
The results show that the total production of hybrid larch in the mixed stand only is 35 % compared with the total production of hybrid larch in the pure stand. Therefore, the hypothesis that the total production of hybrid larch is equal to the planted mixture with pedunculate oak was rejected.
The other hypothesis that the total production of a 2 hectare large stand containing a mixture of hybrid larch and pedunculate oak would be greater than the total production of two pure stands of 1 hectare containing hybrid larch and oak each was also rejected. In the studied case the total production was 45 % greater if hybrid larch and pedunculate oak was planted in pure stands.
The results from the case-study only indicate that the total production of hybrid larch and oak under the investigated conditions can be higher when planting the two species in pure stands compared with a mixture of the two species.
En inventering av säregna trädformer funna i Sverige
In Sweden and in Scandinavia the amount of tree species are rather few. However many different forms of trees arise due to mutations and gives rare appearances like cut-leaved and hanging forms. In some cases these trees are interesting as cultivars and a few of them have become popular garden trees. The knowledge of the original trees and early propagation is meagre.In this study a selected group of trees were found through search of literature. Eight tree forms were chosen and investigated in situ.
Träd och buskar i kantzoner : en undersökning av kanteffekter i några av östersjöregionens skogar
Around the world, forests are generally being fragmented and as plant populations decline in both sizeand number of individuals, the genetic variation will also decrease whitch in the end leads to totalextinction of the plant. In this paper, I wanted to investigate what specific species of trees and shrubsyou usually find in the edge and core habitats in some of the forests in the Baltic Sea region. I alsowanted to identify the edge effects and their sources and finally compare the results between thedifferent regions.The data sources used are derived from the ongoining research project Landscape structures, patterns ofbiodiversity and conservation strategies in the Baltic Sea region by Kari Lehtilä, Patrik Dinnétz ochTiina Vinter who have made a record of all herbaceous plant species in four randomly chosen forestregions situated around the Baltic Sea: Estonia, Skåne, Södermanland and Germany. I made statisticalanalyses, using the computer program R, concerning the distribution of species in the edge habitats ofthe forests as well as in the core habitats. I performed generalized linear models and then variationanalyses with the factors light and biomass in order to investigate wether edge effects might appear dueto these factors.
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.