Search results for "populaatioekologia"

The effect of variation in developmental mode on the population dynamics of a spionid polychaete (Pygospio elegans) in a heterogeneous environment

2018

Shared socioeconomic pathways for climate change research in Finland: co-developing extended SSP narratives for agriculture

2021

AbstractShared socioeconomic pathways (SSPs), developed at global scale, comprise narrative descriptions and quantifications of future world developments that are intended for climate change scenario analysis. However, their extension to national and regional scales can be challenging. Here, we present SSP narratives co-developed with stakeholders for the agriculture and food sector in Finland. These are derived from intensive discussions at a workshop attended by approximately 39 participants offering a range of sectoral perspectives. Using general background descriptions of the SSPs for Europe, facilitated discussions were held in parallel for each of four SSPs reflecting very different c…

Reproductive success, local adaptation and genetic diversity in small plant populations

1999

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 …

Thinhorn sheep evolution and behaviour

2006

Miksi kaikki ohutsarvilampaat Kanadan Yukonjoen itäpuolella ovat tummia, mutta joen toisella puolella valkoisia? Minkä vuoksi tummissa populaatioissa lampaiden väri vaihtelee niin paljon? Näitä kysymyksiä John Loehr valotti väitöskirjassaan.Ohutsarvilammas on pohjoisamerikkalainen villilammaslaji, joka elää Alaskan ja Pohjois-Kanadan vuoristoissa. Laji on mielenkiintoinen värivaihtelunsa takia. Suurin osa populaatioista on täysin valkoisia, mutta kolmesta vuoristosta löytyy harmaita ja mustia lampaita. Näissä vuoristoissa lammasyksilöiden tummuusaste vaihtelee niin paljon, että Loehr pystyi tunnistamaan yksilöitä värikuvioiden avulla. Loehr tutki myös ihmisten mahdollista vaikutusta ohutsar…

Eco-epidemiology of tick- and rodent-borne pathogens in boreal forests

2017

Infectious diseases are amongst the ten major causes of human mortality worldwide, 60% of them being animal-borne. Variations of abiotic and biotic conditions are likely to modify the transmission of parasites and pathogens within reservoir species, and, as a consequence, alter the zoonotic risk for human. My thesis aims at elucidating the dynamics and mechanisms of the maintenance of ticks, tick-borne pathogens (TBPs) and the Puumala hantavirus (PUUV) in the reservoir host, the bank vole (Myodes glareolus, BV). In Northern Europe, tick-borne diseases are growing in importance to human because of the latitudinal expansion of the tick Ixodes ricinus. Field monitoring revealed that I. ricinus…

Lotic life stages of the European river lamprey (Lampetra fluviatilis) : anthropogenic detriment and rehabilitation

2015

Verifying the predicted risk of extinction based on ecological characteristics

2021

Red List status of species should reflect species extinction risk. Because data are limited and species response has a time lag, species may be threatened by extinction even if they are not Red‐Listed. The ability to predict species risk of extinction from ecological characteristics holds promises for proactively targeting conservation measures to species at high risk. In 2005, the risk of extinction from ecological characteristics was predicted for 81 species of Finnish butterflies. Now, after 15 years and two additional national Red List assessments, these predictions are verified. Species with a higher risk of extinction according to the original ecological extinction risk rank (EERR) ha…

Complex plant quality—microbiota–population interactions modulate the response of a specialist herbivore to the defence of its host plant

2022

Many specialist herbivores have evolved strategies to cope with plant defences, with gut microbiota potentially participating to such adaptations. In this study, we assessed whether the history of plant use (population origin) and microbiota may interact with plant defence adaptation. We tested whether microbiota enhance the performance of Melitaea cinxia larvae on their host plant, Plantago lanceolata and increase their ability to cope the defensive compounds, iridoid glycosides (IGs). The gut microbiota were significantly affected by both larval population origin and host plant IG level. Contrary to our prediction, impoverishing the microbiota with antibiotic treatment did not reduce larv…