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Browsing by master's degree program "Ekologian ja evoluutiobiologian maisteriohjelma"

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  • Englund, Mikael (2022)
    I present a case study demonstrating how an integrative approach can be applied in systematics to describe a new lepidopteran species and genus. I apply several imaging techniques to provide unambiguous illustrations of diagnostic morphological characters with an emphasis in experimenting non-destructive imaging methods, especially the Micro CT scanning. We establish the taxonomic position and molecular phylogeny of the study species using a multigenetic dataset comprising the study species and 272 other terminal taxa from the superfamily Geometroidea. My study taxon is a largish and conspicuous geometrid moth from South Africa, which we classify to the looper moth family Geometridae, the subfamily Larentiinae of the tribe Xanthorhoini sensu lato. Based on the inspection of the study specimens and all other available information, we conclude that the study specimens belong to a yet undescribed genus and species. During the study, we found out that the species has been present in collections for at least 128 years but has not been formally described. Micro CT scanning was found to be a useful imaging method, particularly when the target structure is flat such as arthropod wing venation, and I recommend it to be applied when dealing with rare specimens. We provide images and description of the known distribution, habitat, host plant, adult and immature stages, and parasitoids of a new species, Chloecolora vergetaria sp. n. Englund & Staude. We intend to publish the formal description of the new genus and species in a separate forthcoming article. Tutkielmassani selitän tieteelle uuden perhossuvun ja -lajin soveltaen useita kuvantamis- ja muita menetelmiä, joiden avulla esitän uudelle lajille tunnusomaiset ulkoiset tuntomerkit. Erityisesti tutkin Micro CT skannauksen ja muiden näytteitä rikkomattomien kuvantamismenetelmien soveltamista integratiivisessa taksonomisessa tutkimuksessa. Selvitämme uuden lajin sukulaisuussuhteet ja taksonomisen paikan käyttäen uuden lajin ja 272 muun mittarimaisten perhosten (Geometroidea) yläheimoon kuuluvan lajin useista geenisekvensseistä koostettua tietokantaa. Tutkimuslajini on suurehko Etelä-Afrikkalainen yöperhonen, jonka luokittelemme kuuluvaksi heimoon mittarit (Geometridae), alaheimoon Larentiinae ja sukukuntaan Xanthorhoini sensu lato. Näyteyksilöiden tutkimuksiin ja kaikkeen muuhun käytössämme olleeseen aineistoon perustuen päättelemme, että näyteyksilöt kuuluvat aiemmin kuvaamattomaan sukuun ja lajiin. Tutkimuksen aikana selvisi, että lajin yksilöitä on ollut tieteellisissä kokoelmissa jo ainakin 128 vuoden ajan, mutta laji on jäänyt vaille muodollista kuvausta. Micro CT skannaus osoittautui käyttökelpoiseksi kuvantamismenetelmäksi erityisesti, kun kuvattava kohde on tasomainen, kuten esimerkiksi niveljalkaisen siipisuonitus - suosittelen sen käyttöä, kun kuvauksen kohteena on harvinainen näyteyksilö. Esitämme uuden lajin, Chloecolora vergetaria sp. n. Englund & Staude, aikuisten sekä sen tunnetun levinneisyyden, elinympäristön, ravintokasvin, kehitysasteiden sekä tunnettujen loisten kuvaukset. Aiomme julkaista uuden suvun ja lajin muodolliset kuvaukset erillisessä artikkelissa.
  • Palonen, Aura (2020)
    Early life conditions have long-term effects on the fitness and survival of individuals. Foetal development is an especially crucial period and even small changes may have large impacts on the development of individuals. Mammal foetuses may be exposed to additional testosterone either from their male littermates or their mother. This additional prenatal androgen exposure leads to masculinization of female features and behavior. In males the effects of additional prenatal androgen exposure are less drastic due to their own testosterone production. The anogenital distance, defined as the distance between the anus and genitalia, has been used to determine the sex of young mammals since males have longer anogenital distances than females. An elongated anogenital distance is an indicator of additional prenatal androgen exposure in females, and in some species also in males. It correlates with for example increased aggressiveness in both females and males. In females a longer anogenital distance has also been connected to delayed puberty and decreased fertility. I studied the effects of additional prenatal androgen exposure on weight and important life-history traits in banded mongooses (Mungos mungo) with data from a long-term study. Banded mongooses are small co-operatively breeding mammals living in family groups of 10-30 individuals across sub-Saharan Africa. Breeding is extremely synchronized within groups and in most cases all pregnant females give birth on the same day. The resulting communal litter is cared for by most adults in the group regardless of relatedness. Adults escort the pups until three months of age, providing the pup with food, grooming and protection. This early life care has long-term fitness benefits for the pups. Pregnant females may change the phenotype of their offspring via maternal effects. When the competition faced by breeding females is more intense, they compensate by investing more resources to their foetuses, making them bigger. Using the anogenital distance as a proxy for additional prenatal androgen exposure, I measured its effects on weight at early life and maturity, the amount of care received as pups and whether the individual reproduced in its lifetime or not. I hypothesized that a longer anogenital distance may be an indicator of increased competitiveness in the banded mongoose. It could lead to a cumulative advantage since more aggressive individuals may be able to access more food and care, which leads to higher maturity weight and lifetime reproductive success. I also measured the effects of resource abundance and intensity of competition during gestation on the anogenital distance of the pups. I hypothesized that mothers may prepare their offspring for future competitive environment by exposing them to androgens during gestation. In males a longer anogenital distance predicted higher weight both at early life and maturity. Higher weight at the beginning of the escorting increased the amount of care received, which in turn increased weight at maturity. A longer anogenital distance therefore has both direct and indirect fitness benefits in male banded mongooses. In females, a longer anogenital distance predicted lighter weight at maturity, suggesting that it may have negative effects on female growth and development. This study offers evidence that additional prenatal androgen exposure has long-term fitness consequences on banded mongooses and that these consequences are sex specific. Future research should focus on confirming the connection between additional prenatal androgen exposure and longer anogenital distance in this species, as well as assessing the effects of prenatal androgen exposure on survival, puberty and growth of especially female individuals.
  • Zavattoni, Giorgio (2022)
    Populations of forest grouse – capercaillie (Tetrao urogallus), black grouse (Lyurus tetrix) and hazel grouse (Tetrastes bonasia) - have been declining through all of Europe. Habitat loss, fragmentation and degradation are recognized to be the most important ultimate causes behind this trend. In Fennoscandia, there is a general consensus that forestry practices have a primary role, even though the mechanisms are still not fully understood. Nest predation is generally thought to be an important proximate cause of the declines, but how nest predation relates to habitat changes remains poorly understood. I combined long-term data provided by the Natural Resources Institute Finland (LUKE) from inventory studies, both for grouses and predators, with an artificial nest experiment. I investigated a) how predation rate varies with forest age and landscape structure; b) what is the possible role of non-native mesopredator species as predators; c) how nest predation rate relates to larger scale reproductive success. In spring 2021, I placed 141 nests with two hen eggs each, in the regions of Kainuu and North Karelia for 14 days with camera traps. The nests were equally divided between mature forests (>80 years), young forests (<40 years) and edges of mature forests (in a mature forest 5m from a clearcut or a field). I found that the overall predation rate was low (~13 %) and similar in the three sites, but predation time was faster in mature forests, suggesting that when these are scarce, they can act as an ecological trap by increasing nest detectability. However, nest predation decreased with the increasing of mature forests in the landscape around the nest, supporting the hypothesis that on a larger scale forestry may increase generalist predator densities. Areas with higher predator densities suffered higher nest losses. The main predators were pine martens, badgers and magpies, followed by bears and ravens. No nests were predated by raccoon dogs or American minks. There was no correlation between areas with higher nest predation and areas where grouse had lower reproductive success which may result from other factors, e.g., chick predation. My results add to the diverse outcomes of several studies of grouse nest predation in Europe, which together indicate large variation in nest predation, no consistency in predatory species, and weak effects of landscape composition on nest predation.
  • Pääkkö, Henna (2021)
    Animal personality is described as consistent behavioural variation between individuals over long periods of time. Behaviours often connected to animal personality are such as boldness, aggressiveness, and anxiety. In this thesis, the focus was on the behaviours along the shy-bold axis, containing various degrees of boldness expressing behaviour. The study was conducted by using long-term data from the past 30 years on the banded mongoose (Mungos mungo) population in the Mweya Peninsula in the Queen Elizabeth National Park in Uganda. In particular, I used the data on regular weighing events done within the population. As the weighing is not forced on these individuals, the participation percentage on these events can be used to describe an individual’s boldness. I used the participation percentage as a boldness index (values between 0 and 1) for each individual to describe their position on the shy-bold axis. This index was then used to analyse the differences between sexes, and the fitness effects boldness had on the individuals of this population by using proxies of survival, weight at sexual maturity and lifetime reproductive success (LRS). To determine long-term consistency between individuals, I analysed the repeatability of the boldness index. The repeatability of these values showed we can consider this behaviour as an animal personality. From the fitness analyses, it was concluded that boldness had significant positive effects on the fitness proxies used, proposing that bold individuals have higher fitness in this population. While sex did not affect an individual’s boldness, it had significant interactions with boldness, affecting the strength of fitness effects on individuals in weight at sexual maturity and LRS.
  • Korvenkontio, Pekka (2024)
    Työssä kuvataan eri puolilta Suomea toukokuussa 1976 eläinsuojista kerättyjen talvehtineiden hibernaatiossa olleiden naaraiden insektaariossa munimien munien morfologiaa. Valomikroskoopilla munista määritettiin yläpinnan kirjailu, mitattiin munan kokonaispituus, yläpinnan leveys,kellukkeiden pituus sekä laskettiin kellukkeiden kaarien määrä. Munan yläpinnan kirjailuun ja yläpinnan leveyden - munan kokonaispituuden väliseen suhteeseen perustuvien määritysten avulla aineistosta oli todettavissa kaksi lajia: Anopheles messeae messeae Falleroni sekä Anopheles beklemishevi beklemishevi Stegnii & Kabanova. A. b. beklemishevi määritetään Suomesta ensimmäistä kertaa. SEM- ja TEM-kuvauksissa tutkitaan Hintonin (1968) mainitsemia piirteitä, joiden hän katsoo eroavan eri Anopheles lajeilla. Lajinmäärityksen kannalta SEM-tarkastelu ei ole tarpeellinen, sillä mainittavia eroja ei löytynyt kuin yläpintaa ympäröivän reunuksen ja kellukkeiden liittymäkohdasta. Lisäksi työssä esitetään em. lajien levinneisyys ja vertaillaan saatuja levinneisyyskarttoja vanhoihin malarian levinneisyyttä Suomessa ja muualla Pohjoismaissa käsitteleviin tietoihin.
  • Haapalainen, Samuli (2021)
    Biodiversity is decreasing globally due to human activity. At times, on-time monitoring of the state of habitats and biodiversity is challenging. One useful way to study these is to use certain species as indicators for the state of habitats and biodiversity. One group that are often used, are birds. They are easy to detect and they have specialized to most terrestrial ecosystems. Changes in the population sizes of different bird species can reflect changes in different habitats and their biodiversity. Therefore, it is essential that different bird monitoring practices produce reliable and comparable results. I compared datasets produced by two different Finnish bird census programs in my thesis. The census programs were national breeding bird survey program and Hanko Bird Observatory´s migratory bird census program. Both programs produce data on population abundances and changes in population sizes. Because methods between these programs differ greatly, their data may differ for some species. I compared the datasets by comparing population change indexes of the same species. I also tested whether species traits would be associated with the comparability of the datasets. These traits were mean body size, migratory behavior, favored habitats, and number of sightings for each species. I made models for all combinations of traits. I used a generalized linear model in my analysis. I compared the models by using Akaike´s information criterion (AIC) with correction for small sample sizes (AICc). My results showed that both national breeding bird survey program and Hanko Bird Observatory´s migratory bird census program produce parallel population trends for species. From the tested species traits, only migratory behavior was associated with comparability of the datasets. The datasets were highly comparable for long- and short-distance migratory birds but only moderately comparable for resident birds. This is likely due to migratory bird census program recording the local population dynamics of resident birds of Hanko peninsula. These local population trends may differ from the national trends of the same species. The breeding bird survey program should better reflect the national population trends. My results also showed that more numerous common bird species are declining faster than uncommon species. This is an alarming scenario because it points at extensive habitat degradation and biodiversity loss. Also, population trends of species favoring mires and mountains were clearly declining compared to species favoring other environments. This may be due to endangering of mire and mountain habitats due to climate change and human land use such as peatland drainage. Strong declines of species may also be explained by changes in the wintering areas of these species. Finnish breeding bird survey program and Hanko Bird Observatory´s migratory bird census program both produce overall comparable data on population trends of birds. They could be used to complement one another and to provide supporting evidence on the validity of bird population trends. Producing quality bird census data is highly important in tracking the state of biodiversity and when deciding on conservation acts. The data on the census programs provide support for the research on state of Finnish and European habitats and biodiversity.
  • Saarinen, Ronja (2023)
    Monen eri eläinryhmän edustajat käyttävät sosiaalista informaatiota sekä lajinsisäisesti, että lajienvälisesti erilaisten kelpoisuuteen vaikuttavien päätösten tekemisessä. Sosiaalinen informaatio voidaan jakaa tahallisiin ja tahattomiin signaaleihin ja informaation havainnoija voi käyttää tahattomia signaaleja hyväkseen johtaen siihen, että signaalin tuottaja kärsii huonommasta kelpoisuudesta. Tästä johtuvat valintapaineet voivat luoda informaation peittämisstrategioita signaalin tuottajassa. Tämä voi puolestaan johtaa osapuolten väliseen adaptaatioiden sykliin, jota kutsutaan myös koevolutiiviseksi kilpavarusteluksi. Pesäloiset ja niiden isäntälajit ovat klassinen esimerkki tällaisesta vuorovaikutussuhteesta. Leppälintu (Phoenicurus phoenicurus) on ainoa käen (Cuculus canorus) isäntälaji, joka pesii pelkästään koloissa. Kolopesintä tekee leppälinnusta erityisen isännän, eikä sen puolustautumiskäyttäytymistä ole laajalti tutkittu. Tutkimukseni päähypoteesi on, että leppälinnut piilottavat sosiaalista informaatiota käeltä puolustamalla niiltä pesäänsä vähemmän munintavaiheessa verrattuna haudontavaiheeseen. Aiemmissa tutkimuksissa näitä kahta vaihetta ei olla juurikaan vertailtu, vaikka käki loisii pesän pelkästään isännän munintavaiheessa. Testasin päähypoteesiani kenttäkokeilla, joissa ensin vertailin sitä, miten usein leppälinnut ovat läsnä pesillään muninnan ja haudonnan aikana sekä sitä, miten ne puolustavat molemmissa vaiheissa eri uhkia vastaan: pesäloinen, saalistaja ja kontrolli. Leppälinnut olivat enemmän pesillään haudonnan aikana ja tämä johtuu luultavasti siitä, että silloin linnut ovat panostaneet enemmän pesintäyritykseensä ja siitä, että naaraan täytyy pysyä pesällä pidempiä aikoja. Kaiken kaikkiaan, linnut puolustivat pesiään enemmän haudontavaiheessa, mutta niiden reaktio käkeä vastaan oli alhainen molemmissa vaiheissa. Jos siis leppälinnut peittävät informaatiota käiltä, ne eivät muuta tätä käyttäytymistä muninnan ja haudonnan välillä. Lintujen varoittelu lisääntyi saalistajan läsnä ollessa, mutta muu puolustautuminen ei vaihdellut uhkien mukaan. Tulokseni osoittavat, että saalistus saattaa olla pesäloisintaa suurempi uhka leppälinnuille tai että leppälinnut eivät tunnista käkeä uhkaksi. Kolopesintä vaikuttaa olevan leppälinnun paras puolustus käkeä vastaan, mutta lisää tutkimusta tarvitaan näiden kahden välisen dynamiikan tarkastelemiseksi.
  • Heikkilä, Sofi (2020)
    Conservation actions towards large carnivores have been successful in Europe, and the formerly lawfully persecuted species have started to reclaim their historical range. Coexistence with the predators is needed if their conservation should continue to succeed, as Europe does not host wilderness areas large enough to separate large carnivores from humans. As the importance of top-down regulation in ecosystems is recognized, the protection of these predators becomes essential. In Finland, all four large carnivore species, brown bear, grey wolf, Eurasian lynx and wolverine, have established populations, though their presence is not easily accepted by some. Large carnivores pose a threat to livestock and cause fear in the locals living in their territories. Wolf – hunting dog conflict is especially prominent in Finland south of reindeer husbandry area and the poaching of wolves hinders the population’s management. Attitudes towards large carnivores are often influenced by personal background, such as education level, ecological knowledge and respondent’s position in possible human – wildlife conflict. Residence can have an effect, as well, since conditions between living in urban or rural areas often differ. Hypothesis for this study are 1) attitudes towards large carnivores get worse while getting closer to protected areas, 2) attitudes towards large carnivores differ between eastern and western study areas, and 3) a higher education level increases positive attitudes towards large carnivores. The effect of ecological knowledge, prior experiences with large carnivores, age, sex and position in conflict was also explored. Study was conducted as a questionnaire, with face-to-face interviews and web survey distribution targeting two areas in Finland with large carnivore occupancy, one in the West and one in the East. A link between negatively perceived personal experiences and negative opinions towards large carnivores and their management was found. Living in the western area, where large carnivores have resided for a shorter time, predicted attitudes towards stricter management of the species. Third level education influenced attitudes positively. By understanding local attitudes towards large carnivores, it is possible to better understand the conflict between humans and predators, and so, find more likely solutions. Conservation actions where locals have been included, have been documented as successes. Regional differences in attitudes should be further studied and included in future decision making.
  • Witting, Ossian (2023)
    Urbanisation threatens species and biodiversity globally. Consequent habitat loss and habitat fragmentation force species upon one another, inevitably also increasing human-wildlife conflicts. Despite the situation growing dire for many organisms, studies also show species from a variety of taxa being able to adapt to urban environments. Most studies of primates’ ability to adapt to urban environments have been done on diurnal species. To my knowledge, the African lesser bushbaby (Galago moholi) is the only nocturnal primate in which this has been studied. To assess urban adaptability in another nocturnal primate, I present transect and recording data on the abundance of the white-tailed small-eared greater galago (Otolemur garnettii lasiotis) in an urban and rural environment in the biodiversity hotspot Taita Hills, Kenya. Sampling was done in Wundanyi town and Ngangao forest and the two locations were then compared by fitting a negative binomial as well as a Poisson model for recording and transect count data. Additionally, preliminary observations are made regarding behavioural and spectral acoustic adaptation, increased sociality, and colouration coupled traits. My results indicate O. g. lasiotis to be significantly more abundant in the town than in the forest. In the town, I observed a two-fold increase in total number of vocalizations and mean vocalization rate, and a seven-fold increase in total number of sightings and mean encounter rate, as indicated by recordings and transects respectively. This discrepancy in estimated abundance differences in location from transect and recording data (two-fold versus seven-fold) suggest that urban individuals vocalize less than rural individuals. The spectral profile of three vocalization types were studied and urban individuals exhibited significantly higher high frequencies in the clustered squawk vocalization. I found town dwelling individuals to be a part of a larger group or pair considerably more often than forest dwelling individuals. A dark morph, as opposed to a light morph, was significantly more frequently encountered in the urban location, whereas both morphs were encountered almost equally often in the rural location. In summary, O. g. lasiotis seems to be capable of adapting to an urban environment, as indicated by its’ greater abundance in the town than in the forest. My data suggest decreased vocalization rate, increased sociality, and colouration coupled traits being possible adaptations affecting O. g. lasiotis’ capability to inhabit an urban environment. Further research is required to draw conclusions on what factors and adaptations might allow for the high abundance of O. g. lasiotis in the town.
  • Koskinen, Elisabeth (2023)
    Three-dimensional (3D) cellular cultures have been shown to represent tissue formations and functions more accurately than two-dimensional (2D) cultures and have been successfully utilized more accurately in model organisms, e.g., to understand cellular modular functions. However, the applications in non-model organisms are limited, and to our knowledge have not been implemented in ectotherms. At an ecological scale, the technique can enhance our understanding by providing insights on cellular and tissue level molecular mechanisms. A potential implementation of this method in Atlantic salmon is to elucidate the molecular function of the vestigial-like 3 (vgll3) gene, which plays a central role in salmonid maturity, potentially by regulating energy allocation via regulating adipogenesis. In this thesis, a proof of principle study was implemented, where the feasibility of obtaining and maintaining a suspension 3D adipose tissue culture in Atlantic salmon (Salmo salar) was assessed. The harvested visceral white adipose tissue from around the intestinal tissue of mature Atlantic salmon (salmon past smolt stage) was first separated into stromal vascular fraction (SVFs) and mature adipose fraction (MAFs). SVFs contain preadipocytes (precursors of adipocyte cells) in addition to a variety of other cell types. MAFs are mature adipocytes. Both MAFs and SVFs were successfully maintained in-vitro for over four weeks. SVFs were then successfully differentiated into mature adipocytes, demonstrating the feasibility of studying adipogenesis in Atlantic salmon. Proof of this methodology and its further implications may help us to understand the cellular functions of vgll3 and may subsequently help to better understand its causal relation to the maturation process in Atlantic salmon.
  • Schwenk, Cindy Emilia (2022)
    Breeding-dispersal and philopatry are important life-history traits when it comes to the ecology of animals. A number of factors such as sex, age, habitat stability, population density, predation and various environmental factors influence the movement patterns of species. Philopatry, in general, can be used by organisms as a predator avoidance strategy and to improve feeding efficiency. Dispersal on the other hand has been shown to help avoid inbreeding and competition within groups or between kin. Among the different types of dispersal and philopatry, breeding dispersal and site fidelity to breeding sites have been studied in many vertebrates. Many birds and some ungulate species have been the focus of these studies and have shown that breeding success influences site fidelity. Among ungulates, the reindeer genus (Rangifer tarandus spp.) however, has received little attention for this topic. A species of special conservational value is the wild forest reindeer (Rangifer tarandus fennicus), which is a rare, and near-threatened subspecies of reindeer living in Finland. Knowledge of factors influencing the dispersal and site fidelity for this species is lacking but has important implications for the conservation and management of this and other vulnerable species. In my thesis I investigated the philopatry of wild forest reindeer females from eastern Finland and tested if the calving site fidelity was influenced by breeding success, predator pressure and the female’s age. Given the high densities of predators in the study area (Kainuu) and thus high predator pressure on reindeer, I expected (i) the philopatry of the wild forest reindeer female’s to be stronger in areas with higher predator pressure but (ii) higher dispersal movement when wild forest reindeer females had no breeding success the previous year. Additionally, I expected (iii) the dispersal distances of wild forest reindeer females to be negatively correlated with their age. For this study I used long-term GPS monitoring data of 53 collared wild forest reindeer females, which were followed for varying periods (2-6 years) between 2010-2021 from Eastern Finland. I found that the inter-year distances between calving sites per female had a median distance of 2.84 km, confirming that female wild forest reindeer show philopatry to calving sites, as do other reindeer subspecies. Even though the movement ranged from 4.8 m to 36.99 km, showing substantially longer dispersal for some individuals. The model outcomes indicate some association between predation pressure and site fidelity, and reduced philopatry following calf mortality, although none of these associations were significant. The age of the mother did also not show any significant influence on a female’s site fidelity. Nonetheless, these results would suggest that a mother's choice to leave or return to the same calving site might be influenced by the previous year's calf mortality but more complex variables like anthropogenic disturbances, environmental factors, as well as intrinsic factors and the physical condition of the mother most likely also play a role in this.
  • Lindholm, Tanja (2015)
    Suomesta tavataan kaksi majavalajia: alkuperäinen euroopanmajava (Castor fiber) ja vieraslaji amerikanmajava (Castor canadensis). Euroopanmajava metsästettiin sukupuuttoon 1800–luvulla ja viimeinen euroopanmajava ammuttiin tiettävästi Sallan Eniönjoesta vuonna 1868. Vuonna 1935 aloitettiin majavien uudelleenistutukset 17 Norjasta tuodulla euroopanmajavalla. Vuonna 1937 Suomen majavakantaa vahvistettiin seitsemällä Amerikasta tuodulla amerikanmajavalla. Tahallisesta vieraslajin tuomisesta ei kuitenkaan ollut kyse, vaan vasta vuonna 1973 todettiin Castor-suvun koostuvan kahdesta eri lajista. Alueilla, joille istutettiin molempia lajeja, on jäljellä ainoastaan amerikanmajava. Syyt ovat edelleen epäselviä. Molempien lajien kannat ovat edelleen keskittyneet alkuperäisten istutusalueiden läheisyyteen, ja amerikanmajavakanta on muutamia poikkeuksia lukuun ottamatta saanut kasvaa ilman euroopanmajavan kilpailun vaikutusta. Jos lajien elinympäristövaatimukset ovat samat, eivät lajit voi esiintyä rinnakkain. Näin ollen on tärkeää tuntea molempien lajien elinympäristön käyttö mahdollisemman tarkkaan aluekohtaisesti ja ennakoida, johtaako majavalajien kohtaaminen kahden lajin rauhaisaan yhteiseloon vai mahdollisesti euroopanmajavan häviämiseen läntisestä Suomesta. Tutkimuksen tarkoituksena oli vertailla lajien elinympäristön vaatimuksia ja sitä kautta tuoda lisätietoa euroopanmajavan suojeluun. Tutkimusalueeksi valikoitui keskinen Pirkanmaan alue, missä lajien välinen etäisyys on ainoastaan 11 kilometriä linnuntietä. Aineisto koostuu vuoden 2013 Luonnonvarakeskuksen koordinoimista valtakunnallisten majavalaskentojen pesätiedoista sekä erilaisista paikkatietoaineistoista. Elinympäristönkäytön mallin muuttujat on tuotettu CORINE Land Cover 2012 (CLC2012), vuoden 2011 Valtakunnallisen Metsien Inventoinnin (VMI) ja Maanmittauslaitoksen maastotietokannan digitaalisiin paikkatietoaineistojen avulla. Alueelle luotiin 60 satunnaispistettä, jotka kuvaavat tarjolla olevaa elinympäristöä. Lajien elinympäristöjen käyttöä analysoitiin kahden logistisen regressioanalyysimallin avulla, joista ensimmäisessä tarkastellaan ydinaluetta (50m) ja toisessa elinpiiriä (1km). Analyyseissä verrattiin lajeja keskenään sekä satunnaispisteisiin. Ennen regressioanalyysejä tarkasteltiin muuttujien kolineaarisuutta Variance Inflation Factor:in (VIF) avulla, jonka jälkeen tarkasteltiin aineiston yhteensopivuuttaa mallin kanssa Akaiken informaatiokriteerin (AIC) avulla. Pienin AIC ilmaisee parhaan mallin korkeimman selitysasteen ja mallin yksinkertaisuuden (parsimonisuuden) kompromissina. Ydinalueella ei havaittu merkitseviä eroja elinympäristön vaatimuksissa lajien välillä. Majavien elinympäristönkäyttö ei kuitenkaan ollut satunnaista. Kuusen tilavuudella oli positiivinen vaikutus euroopanmajavan esiintymiseen ja lehtipuiden tilavuudella oli positiivinen vaikutus amerikanmajavan esiintymiseen verrattuna tarjolla olevaan ympäristöön. Elinpiirianalyyseissä lajien välillä havaittiin merkitseviä eroja, joissa euroopanmajava esiintyi alueilla, missä kuusen tilavuus ja sekametsän osuus oli suurempi verrattuna amerikanmajavan elinpiiriin. Kasvavalla kuusen tilavuudella, sekametsän osuudella sekä vesistöjen määrällä oli positiivinen vaikutus euroopanmajavan esiintymiseen ja rakennetuilla alueilla negatiivinen vaikutus euroopanmajavan esiintymiseen verrattaessa tarjolla olevaan ympäristöön. Amerikanmajavan elinympäristön käyttö ei poikennut satunnaisesta. Tulokset saattavat heijastaa rantavyöhykkeen metsäsukkession eri vaiheita, mutta on huomattava, että lajien välillä oli merkittäviä eroja. Elinympäristön muuttujat selittivät huomattavasti enemmän euroopanmajavan esiintymistä alueella verrattuna amerikanmajavaan. Toisin sanoen euroopanmajavan elinympäristön vaatimukset ovat spesifimmät/tarkemmat/ominaisemmat. Tulosten avulla on mahdollista ennustaa niin amerikanmajavan leviämistä alueella kuin hyödyntää tietoja euroopanmajavalle tärkeiden elinympäristöjen suojelussa.
  • Malmsten, Annina Maria (2023)
    Promoting carbon sequestration and storage is an important part of climate change mitigation. Soils play a prominent role in this, as they contain the largest terrestrial carbon pools. Urban soils have been shown to contain significant amounts of carbon, and thus, urban green spaces have the potential to contribute to climate regulation through soil carbon sequestration and storage. Many green spaces in cities consist of managed lawns containing significant amounts of soil organic carbon, although management activities such as mowing can also be a source of carbon emissions. A low-maintenance alternative to lawns is urban meadows. The benefits in terms of soil carbon sequestration in urban meadows, however, are still poorly documented. This study aims to contribute to an increased understanding of the ecosystem services urban meadows provide, which is valuable in the planning of urban green infrastructure. I quantified soil organic carbon content in 140 urban meadows of different land use types in the Helsinki Metropolitan Area to determine their value in terms of carbon storage and to compare this with the soil carbon storage in highly managed urban lawns. The meadow types explored included valuable grasslands, which have special nature or cultural values, landscape meadows, road verge grasslands, and rocky outcrops. Soil samples were taken from a depth of 0–10 cm using a soil corer. The soil organic matter content and bulk density were measured. Existing data from the soils of city park lawns in Helsinki were used for comparison in the analysis. The soil organic carbon content in the different meadows, as well as in the lawns, was then analysed using land use type and site productivity as explanatory variables. Results show that park lawn soils have a significantly higher carbon density (kg C per square meter) than any of the meadow types. Out of the meadow sites, valuable grasslands had the highest carbon density. The higher carbon content in park lawn soils may be due to increased productivity due to frequent mowing, as well as the fact that these lawns were likely established on nutrient-rich soil. Interestingly, the highest %C was detected in rocky sites. However, the total carbon stocks of rocky sites are lower due to the soil cover being shallow and large portions of the sites not having soil cover at all. To answer the question of whether a lawn should be converted into a meadow in hopes of increasing carbon sequestration and storage, future studies should focus on meadows that were formerly lawns, and that had the same or similar initial conditions as a typical lawn.
  • Yrjölä, Veikko (2023)
    While the effects of agricultural land use on biodiversity are beginning to unravel in Europe and North America, Africa remains poorly studied. Biodiversity in a broad sense provides ecosystem functioning and services, whose importance has become obvious to humankind in the quickly changing modern world. In Ghana, the practice of mango farming continues to grow in popularity due to suitable climate and potential source of livelihood. With increased demand and production of mango, natural habitats, namely savannahs, are being converted to plantations. The effects of such habitat conversion on local biodiversity are unknown for most taxa, thus providing an interesting study system for biodiversity research. Given the direct relation between functional diversity and ecosystem services, in this work I compare the taxonomic and functional diversity of ground-living spiders between mango orchards and savannah. I chose spiders (Arthropoda; Araneae) as model organisms as they critically contribute to several ecosystem services, such as biological pest control and nitrogen cycling, while being ubiquitous and abundant, thus easy to collect in the field. Spiders were captured with pitfall traps from six mango and four savannah areas in the Northern region of Ghana. A total of 424 individuals and 53 (morpho)species were identified and counted. Additionally, six morphological and four ecological traits were quantified for each (morpho)species. With these data, I calculated taxonomic richness and evenness, functional richness, dispersion, and evenness, and beta diversity of the different assemblages in the R environment. These metrics were then compared between spiders collected from mango orchards and savannah. Mango orchards showed lower taxonomic and functional evenness than savannah, contrary to all other alpha diversity measures. The two habitat types share many of the same diversity of ground-living spiders, but species and traits are distributed less evenly in mango orchards due to incomplete niche differentiation between species. Both taxonomic and functional beta diversity were significantly different between habitat types indicating that mango orchards sustain a similar richness of species as savannah, but the species composition is different. In conclusion, mango orchards have the potential to conserve some aspects of the original diversity, but species composition and the way species interact are substantially different. We should strive to find the best practices to produce mango without radically changing the natural biodiversity patterns.
  • Gonzaga Roa, Amaia (2023)
    Deforestation is the main threat to biodiversity, ecological integrity and socio-ecological resilience of the of the Amazon biome, one of the most biodiverse places on Earth and home to at least 2 million people. A complex network of diverse protection strategies exists across the Amazon as key component of the global strategy to halt biodiversity loss. Biosphere reserves are a part of this network that aims to create spaces to learn how human communities can develop sustainably, while the protecting the environment, by implementing a zonation system with different degrees of protection We consider that it is necessary to produce relevant efficiency assessments on area-based conservation strategies in this region, and to understand how different protection strategies affect conservation outcomes. We used state-of-the-art matching methods to create a counterfactual deforestation avoidance measure of seven Biosphere reserves the western Amazon: Yasuní, Podocarpus-El Cóndor, Sumaco, Manu, BIOAY, Pilón Lajas and Beni. We obtained diverse efficiency results, some of the studied reserves avoiding large quantities of deforestation to reserves that were attracting deforestation. We found that more strictly protected zones were subjected to significatively lower relative pressure levels and did not have higher deforestation avoidance values. Representativity of the matched treatment area was also lower for these zones, meaning that the matching analysis was more difficult to perform in these areas. These research findings add to growing evidence about the important role of biosphere reserves in buffering against deforestation in one of the world’s most important biodiversity hotspots.
  • Myllylä, Heidi (2024)
    Korkeasaari Zoo has several large ruminants adapted to distinct climates and habitats. It is well known, that ensuring the possibility of the animals to live in captivity, that resemble their natural habitat, is important for their welfare. However, thermal environment of zoo-housed animals is not often studied, even though it can have major impact on animal welfare. Especially for cold-adapted species the shade availability during hot, sunny days is essential and therefore needs high attention. In my thesis, I monitored the shade use and behaviour of musk ox (Ovibos moschatus), yak (Bos grunniens), takin (Budorcas taxicolor), wisent (Bison bonasus), Przewalski’s wild horse (Equus przewalskii) and kulan (Equus hemionus kulan) in their enclosures in Korkeasaari zoo by using ZooMonitor application. Species were chosen by their different level of warm adaption for comparison. I found out the shade availability in each enclosure during different times of the day with aerial photographs. The purpose was to find out if there is a need to enhance the shaded areas to ensure animal welfare. Research questions were 1) How much shade is available in each enclosure? 2) Is shade use dependent on a) temperature b) time of the day? 3) Are less warm adapted species (musk ox, yak, takin) seeking shade more obviously than more warm adapted species (wisent, kulan, wild horse)? To analyse, behavioural space use data was assessed in the form of a heat map with aerial photographs to evaluate location preferences for each animal in each enclosure. Behaviour Budget reports were used to display the percent of time engaged in behaviours. In conclusion, musk ox has shade in their enclosure 43% in the morning, 18% in the noon and 36% in the afternoon. Its shade use is dependent on time. Yak, kulan and wild horse has shade 33% in the morning, 18% in the noon and 21% in the afternoon. Shade use of yak and kulan is dependent on temperature. Shade use of wild horse is dependent on time. Takin has shade 93% in the morning, 73% in the noon and 77% in the afternoon. Its shade use is dependent on temperature and time. Wisent has shade 57% in the morning, 43% in the noon and 14% in the afternoon. Its shade use is dependent on time. Less warm adapted species are seeking shade more frequently than more warm adapted species, but surprisingly kulan stronger than wisent and almost equally as yak. Combined, shaded areas are important for zoo-housed animals to thermoregulate. The least warm adapted musk ox needs more shaded areas as they are scarce in their enclosure. Providing more shaded areas increases the space available for the animals.
  • Putkiranta, Pauli (2023)
    Arctic ecosystems face drastic changes in community structure due to warming, shrubification, permafrost loss, and other environmental changes. Due to the spatial heterogeneity of these ecosystems, understanding such changes on a local scale requires high-resolution data. Earth observation using satellite imagery and aerial photography has become a staple in mapping large areas and general patterns. Advances in sensor technology, the proliferation of unmanned aerial vehicles (UAVs), and increases in processing capacity enable the use of higher spatial and spectral resolutions. As a result, more detailed ecological observations can be made using remote sensing methods. In this thesis, I assess how increased spectral resolution affects the remote-sensing based modelling of plant communities in low-growth oroarctic tundra heaths. Based on a large field observation dataset, I estimate biomass, leaf area index, species richness, Shannon's biodiversity index, and fuzzy community clusters. I then build random forest models of these with image data of varying spectral, spatial, and temporal specifications and topographical data. Finally, I create maps of the vegetation. Leaf area index and biomass are best estimated of the response variables, with R2 values of 0.64 and 0.59, respectively, with multispectral data proving the most important explanatory dataset. Biodiversity metrics are best estimated with R2 values of 0.40–0.50 with the most important explanatory variables being topographical and hyperspectral, and community cluster with R2 values of 0.27–0.53, with the importance of various explanatory variables depending on the cluster being estimated. These results can help choose a suitable high-resolution remote sensing approach for modelling plant communities in similar conditions.
  • Loponen, Laura (2020)
    The Miocene epoch (c. 23-5 million years ago) was a noteworthy geological time period in which significant changes took place both in the climate regimes as well as in vegetation characteristics, bringing about novel adaptations in many herbivorous lineages. These adaptations constituted morphological, dietary, and ecological factors in a relatively short period of evolutionary time. Among these herbivores were the proboscideans, the living and extinct elephants, which were among the most dominant and largest herbivores at the time. Despite that proboscideans were diverse and large group of hundreds of species, yet the understanding of dietary and ecological patterns of majority of Miocene sympatric species is still limited. The aim of this study was to analyse the molar surfaces of Miocene proboscideans (e.g. Deinotherium and Gomphotherium) from Eurasia to provide a reconstruction of the feeding preferences of the study species based on observed dental wear. The dental wear indicates the abrasiveness of the diet, thus allowing broad categorization to either browser (<10% grass in the diet), mixed-feeder (10-90% grass in the diet) or grazer (>90% grass in the diet). Secondly, this study aimed for providing estimation of the environmental characteristic and vegetation patterns of the study localities by comparing to the previous studies and to hypsodonty value (proxy of general openness and aridity of the environment). Proboscidean dietary signals from the key localities of Maragheh (Iran) and Pannonian basin (Austria) were compared with the paleobotanical studies. Thus, the general estimation of spatial and temporal variation of the environment characteristics in the study localities were based on these parameters. The materials of fossilized molars were analysed by mesowear angle method, in which the measured angles show the diet abrasiveness due the nutritional targets’ differences. The results allowed the reconstruction of the feeding preferences which suggested that majority of Miocene proboscideans were browsers and browse-dominated mixed feeders or pure mixed-feeders. Instead, Choerolophodon pentelici was found grass-dominant mixed-feeder. The wide spectrum of feeding preferences allowed diet flexibility according available vegetation and also these sympatric species to co-exist by niche partitioning. Thus, demonstrating clearly the connection between diets and environments thought the diet. As a conclusion, in the diet of the paleocommunities of proboscideans had, on average, more grass-dominant components in open and dry environment likely due the presence of grass-dominant vegetation. Instead, in the wet conditions the closed-canopy forest environments enhanced browsing. Further, the results indicated shift in feeding preferences of proboscideans prior to Miocene climate and environment changes. These results are in line with the findings of the previous studies of modern elephants’ diet- environment relationships. The further studies would provide insight to the relative amounts of the grass in the diet of Miocene proboscideans.
  • Kökkö, Juho (2024)
    Dispersal is a vital life-history trait in terms of species survival, reproduction, and persistence, among others. We know that temporal and spatial differences in the environment alter the risks and rewards involved in dispersal, thus influencing dispersal behaviour and ability. Less known, however, is how exactly seasonal shifts and land use together affect dispersal ability. Butterflies are a well-known and ecologically important study group whose traits are majorly influenced by environmental conditions. Here, I study how the dispersal ability of the green veined white butterfly (Pieris napi) is influenced by when they fly, as well as land use in their local habitat. I collected butterflies of two subsequent generations during the late spring and summer of 2023 in the Åland archipelago (Finland). I then measured the flight metabolic rates and forewing lengths of these butterflies to estimate their dispersal ability. The results described here indicate that P. napi females flying in late spring and early summer are more capable of dispersing than those flying later in the summer. Land use had seemingly no effect on P. napi dispersal ability. Identifying the factors that influence dispersal is key in understanding and securing the future for species in a changing world.
  • Lunde, Andreas (2023)
    Macrozooplankton is an understudied size class of plankton in the Arctic, but even though species composition is similar around the Svalbard archipelago, the relative composition can act as a proxy for climate change. This study investigated if the fjords around Svalbard are similar in species composition and if any differences could be explained. 11 fjords were sampled with a focus on common and indicator species in terms of abundance, relative composition and length distribution. I found low presence of T.libellula and high abundances of T.abyssorum and T.inermis. T.abyssorum was the only species whos abundance was significantly correlated to water mass (Atlantic water), but T.libellula, T.abyssorum, T.inermis, T.longicaudata and A.digitale all showed significant differences in length distribution. This study provides further understanding of species composition in the different high Arctic fjords around Svalbard.