Search results for "metsäekosysteemit"

A bark beetle infestation predictive model based on satellite data in the frame of decision support system TANABBO

2020

The European spruce bark beetle Ips typographus L. causes significant economic losses in managed coniferous forests in Central and Northern Europe. New infestations either occur in previously undisturbed forest stands (i.e., spot initiation) or depend on proximity to previous years’ infestations (i.e., spot spreading). Early identification of newly infested trees over the forested landscape limits the effective control measures. Accurate forecasting of the spread of bark beetle infestation is crucial to plan efficient sanitation felling of infested trees and prevent further propagation of beetle-induced tree mortality. We created a predictive model of subsequent year spot initiation and spo…

Ecological mechanisms can modify radiation effects in a key forest mammal of Chernobyl

2019

International audience; Nuclear accidents underpin the need to quantify the ecological mechanisms which determine injury to ecosystems from chronic low-dose radiation. Here, we tested the hypothesis that ecological mechanisms interact with ionizing radiation to affect natural populations in unexpected ways. We used large-scale replicated experiments and food manipulations in wild populations of the rodent, Myodes glareolus, inhabiting the region near the site of the Chernobyl disaster of 1986. We show linear decreases in breeding success with increasing ambient radiation levels with no evidence of any threshold below which effects are not seen. Food supplementation of experimental populatio…

Choosy beetles : How host trees and southern boreal forest naturalness may determine dead wood beetle communities

2021

Wood-living beetles make up a large proportion of forest biodiversity and contribute to important ecosystem services, including decomposition. Beetle communities in managed southern boreal forests are less species rich than in natural and near-natural forest stands. In addition, many beetle species rely primarily on specific tree species. Yet, the associations between individual beetle species, forest management category, and tree species are seldom quantified, even for red-listed beetles. We compiled a beetle capture dataset from flight intercept traps placed on Norway spruce (Picea abies), oak (Quercus sp.), and Eurasian aspen (Populus tremulae) trees in 413 sites in mature managed forest…

Growth form matters – Crustose lichens on dead wood are sensitive to forest management

2022

Lichens have a vital role in forest ecosystems and they are a threatened group in boreal forests. However, the conservation ecology of the total lichen community has very rarely been studied. Here we studied lichen species and communities, including macrolichens (=foliose and fruticose growth forms) and rarely studied crustose li-chens, on decaying wood in boreal spruce-dominated forests in Finland. We also studied obligate lignicoles that grow only on dead wood and are mostly crustose in growth form. Species richness and community composition were examined on decaying logs and natural or cut stumps of Picea abies at different decay stages (2-5) in 14 stands, half of which were natural or s…

Titmice are a better indicator of bird density in Northern European than in Western European forests

2022

Publisher Copyright: © 2022 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. Population sizes of many birds are declining alarmingly and methods for estimating fluctuations in species’ abundances at a large spatial scale are needed. The possibility to derive indicators from the tendency of specific species to co-occur with others has been overlooked. Here, we tested whether the abundance of resident titmice can act as a general ecological indicator of forest bird density in European forests. Titmice species are easily identifiable and have a wide distribution, which makes them potentially useful ecological indicators. Migratory birds often use information on the densit…

Global warming, forest biodiversity and conservation strategies in boreal landscapes

2014

Ecology, environmental requirements and conservation of corticioid fungi occupying small diameter dead wood

2016

The increasing human impact upon the biosphere of earth is causing profound changes across all spatial scales. The ability to cope with human-induced disturbance varies among organisms; specialist species are more negatively affected than generalist species. Forests are among the most heavily affected ecosystems; especially the dead wood associated organisms are in peril. The earlier research has strongly focused on large diameter dead wood and associated species. The aim of this thesis was to investigate small diameter dead wood and collect systematic information about species richness and abundance as well as habitat and substrate preferences of associated corticioid fungi. Fungal data wa…

Short-term effects of forest restoration on beetle diversity

2007

Toivanen tutki väitöskirjassaan ennallistamisen, erityisesti luontaisten metsäpalojen jäljittelyn ja lahopuun tuoton, lyhyen aikavälin vaikutuksia havumetsien kovakuoriaislajistoon. Ennallistamisella pyritään luontaisten rakenteiden, toimintojen ja lajikoostumuksen palauttamiseen ihmisen muuttamiin ekosysteemeihin. Ennallistamisen tarve on suuri erityisesti Etelä-Suomessa, missä suuri osa suojelluistakaan alueista ei täytä luonnontilaisen metsän vaatimuksia pitkän metsien käytön historian johdosta. Toivasen tulokset ovat näin suoraan sovellettavissa käytännön suojelutyöhön.Toivanen havaitsi, että poltetuilla ennallistamiskohteilla kovakuoriaisten laji- ja yksilömäärät olivat merkittävästi s…

Functional structure of European forest beetle communities is enhanced by rare species

2022

Biodiverse communities have been shown to sustain high levels of multifunctionality and thus a loss of species likely negatively impacts ecosystem functions. For most taxa, however, roles of individual species are poorly known. Rare species, often most likely to go extinct, may have unique traits and functional roles. Alternatively, rare species may be functionally redundant, such that their loss would not disrupt ecosystem functions. We quantified the functional role of rare species by using captures of wood-living (saproxylic) beetle species, combined with recent databases of morphological and ecological traits, from three regions in central and northern Europe. Using a rarity index based…

Effects of interspecific relationships in forested landscapes on breeding success in Eurasian treecreeper

2005

Jatkuvat vanhoihin metsiin kohdistuvat metsänhakkuut kaventavat puukiipijöiden ja kekomuurahaisten elinmahdollisuuksia. Havaitsin tämän väitöstyössäni, jonka teemoina olivat puukiipijän ja kekomuurahaisten välinen ravintokilpailu puiden rungoilla ja petojen, lähinnä kärpän, lumikon ja käpytikan vaikutus puukiipijän pesintämenestykseen pesäpönttöpopulaatiossa. Tutkimus on toteutettu Keski-Suomen metsissä Konneveden, Hankasalmen ja Laukaan kunnan alueella vuosina 1990-2003. T his study is focused on the effects of predation to the breeding success of Eurasian treecreeper and resource competition between red wood ants, Formica rufa -group and treecreepers. One of the most important factors in …