Search results for "laji"
showing 10 items of 410 documents
Haitallisen vieraslajin komealupiinin (Lupinus polyphyllus Lind.) ja alkuperäislaji hiirenvirnan (Vicia cracca L.) välinen kilpailu pölyttäjistä
2011
Kilpailu vaikuttaa usein haitallisesti yksilöiden elossa säilymiseen, lisääntymiseen ja kas-vuun ja tätä kautta myös lajien populaatiodynamiikkaan, eliöyhteisöjen rakenteeseen ja evoluutioon. Lajien välisessä resurssikilpailussa kilpailun vaikutus välittyy muihin lajeihin epäsuorasti ympäristön resurssien runsauden kautta. Lajien välinen kilpailu voi olla hel-pommin havaittavaa vieras- ja alkuperäislajien välillä kuin alkuperäislajien välillä, sillä vieras- ja alkuperäislajeilla ei ole yhteistä evolutiivista historiaa, eikä siten adaptaatioita keskinäisiin vuorovaikutuksiin, kuten kilpailun välttämiseen. Vieraslajikasvit voivat kil-pailla alkuperäislajien kanssa pölyttäjistä, jolloin alkupe…
Niche position drives interspecific variation in occupancy and abundance in a highly-connected lake system
2019
Highlights • We studied interspecific variation in occupancy and abundance of freshwater species. • Occupancy and abundance correlated positively for both diatoms and macroinvertebrates. • Niche position had clearest effects on variation in occupancy and abundance. • The more marginal the niche position, the rarer a species is. We examined how niche position, niche breadth, biological traits and taxonomic relatedness affect interspecific variation in occupancy and abundance of two commonly-used biological indicator groups, i.e. diatoms and macroinvertebrates. We studied 291 diatom and 103 macroinvertebrate species that occupied the littoral zones of a large (305 km2) highly-connected freshw…
Chimpanzees surviving in a fragmented high‐altitude forest landscape of the Congolese Albertine Rift
2021
This paper documents a community of eastern chimpanzees (Pan troglodytes schweinfurthii Giglioli, 1872) inhabiting three relict forest fragments situated on the Lake Albert escarpment, down the Ituri highlands, of eastern Democratic Republic of the Congo (DRC). The area explored had a combined forested surface of ±18.15 km2 in 2017, shrinking by 1.2% per year between 2010 and 2015. Between 2015 and 2017, we found 160 chimpanzee nests along 37.6 km of pilot walks, some up to 2,000 m altitude. Another 123 nests logged along 6.7 km transects led to an estimate of chimpanzee density of 4.62 weaned individuals per square kilometer of forest habitat. Camera‐trap images and direct observations rev…
Sehr geehrter Herr Schmidt… : Eine Analyse zu den Textproduktionsaufgaben in der Lehrbuchserie Panorama Deutsch für die gymnasiale Oberstufe
2016
Tässä kandidaatintutkielmassa tarkastellaan saksan kielen lukion B2-oppimäärän opiskeluun suunnatun kirjasarjan (Panorama Deutsch) tehtäväkirjojen tekstintuottamistehtäviä tekstilingvistiikan näkökulmasta. Tässä sekä määrällisessä että laadullisessa tutkimuksessa tarkastellaan tuotettavien tekstilajien lukumäärien lisäksi tekstilajien tyypillisiä ominaisuuksia sekä sitä, heijastuvatko valtakunnalliset opetussuunnitelman perusteet tehtävätyypeissä. Metodina tutkimuksessa on teoriaohjaava sisällönanalyysi ja taustalla vaikuttavana käsitteistönä on Brinkerin, Cölfenin ja Pappertin (2014) tekstifunktiojaottelu. Jaottelu ohjaa tehtävänannoissa tuotettavien tekstien kategorisointia, mutta tutkimu…
Development of microfluidics for sorting of carbon nanotubes
2018
Sorting of carbon nanotubes by their chirality is the current bottleneck in the way to their broad employment based on their exceptional electronic and optical properties. Despite the extensive effort, there is no known method, which would result in really pure chirality ensembles. Previously reported sorting protocols result in enrichment rather than in sorting, alter electronic structure, and suffer from low yield. This is mostly due to the statistical approach, where the nanotubes with mixed chiralities are treated as a set. In this thesis, we propose a new sorting technique based on nanotube-by-nanotube compartmelization, characterization, and sorting in a continuously running droplet-b…
Jokiravun (Astacus astacus) ja täpläravun (Pacifastacus leniusculus) sopeutuminen virtavesiin
2008
The evolution of temperature tolerance and invasiveness in a fluctuating thermal environment
2016
The consequences of the climate change on species are still uncertain, despite of intensive research. Currently, rising temperature is not the only concern, since the climate change scenarios also predict increases in the amount of disturbances, such as storms, floods, and thermal fluctuations. Disturbances have also been shown to affect species’ evolution, for example by selecting for traits that are advantageous in fluctuating environments but are also facilitating invasiveness. In this thesis, I study the consequences of evolving in a fluctuating thermal environment by utilizing bacterial microcosms. First I tested the effects of fluctuating vs. constant temperature on the evolution of t…
Population divergence in maternal investment and embryo energy use and allocation suggests adaptive responses to cool climates
2023
1. The thermal sensitivity of early life stages can play a fundamental role in constraining species distributions. For egg-laying ectotherms, cool temperatures often extend development time and exacerbate developmental energy cost. Despite these costs, egg laying is still observed at high latitudes and altitudes. How embryos overcome the developmental constraints posed by cool climates is crucial knowledge for explaining the persistence of oviparous species in such environments and for understanding thermal adaptation more broadly. 2. Here, we studied maternal investment and embryo energy use and allocation in wall lizards spanning altitudinal regions, as potential mechanisms that enable su…