Browsing by Subject "biodiversity"
Now showing items 1-12 of 12
-
(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.
-
(2020)As biodiversity is being lost worldwide at an accelerating rate due to anthropogenic activities, the frequency and severity of many infectious diseases has been observed to increase. Together these patterns have brought forth an urgent need to understand the possible linkages between biodiversity and disease risk. Two contradicting hypotheses have been proposed to explain the diversity-disease relationship. The dilution effect hypothesis suggests that increasing host community species diversity ‘dilutes’ disease risk, whereas the amplification effect hypothesis predicts disease risk to increase with increasing diversity. Even though most of the studies support the dilution effect, there remains an intensive debate regarding the generality of this effect. As most of the research efforts to understand the relationship between diversity and disease have focused on animals and crop plants or have been carried out experimentally, one of the research gaps is how relevant the dilution effect is in wild plant communities. In nature, plants and their diseases are affected simultaneously by multiple abiotic and biotic environmental factors that might confound or supersede the effects of diversity. It is also poorly understood, whether we might expect dilution effects to occur not only on diversity gradients driven by anthropogenic diversity loss, but also on natural diversity gradients. To study the possible association between host community species diversity and disease risk in the wild and to test whether this association could be detected after accounting for the effects of abiotic factors, I surveyed grassland vascular plant communities for their species diversity and foliar disease symptoms along a natural diversity gradient driven by elevation. I also recorded data on the mean soil surface temperature in the surveyed plant communities and used structural equation modelling to differentiate and compare the effects of biotic and abiotic variables on disease risk. The data were collected on Mount Calanda in the Swiss Alps during summer 2019. In this thesis I show that host community species diversity and disease risk are negatively associated with each other along a natural diversity gradient driven by elevation. Furthermore, this negative effect can be detected even after accounting for the effects of elevation and mean soil surface temperature on disease. Together the results support the occurrence and the ecological relevance of the dilution effect in wild plant communities along natural diversity gradients and suggest that diversity might protect wild plant communities from increased disease risk. Future studies should aim to identify the exact mechanisms of the association to help us better understand when and where we might expect dilution effects to occur in the wild. This knowledge can be used to predict how epidemics, that affect the well-being of ecosystems, humans and wildlife, are born in the changing world.
-
(2014)The purpose of this thesis was to examine the diversity and species composition of dung beetle (Scarabaeinae) communities in degraded rainforest landscapes in southeastern Madagascar. Several studies elsewhere in the world have revealed that forest-dwelling dung beetle communities and especially large species suffer from forest degradation and fragmentation by decreased species diversity. The most important factors affecting community structure of forest-dwelling dung beetles are habitat area, connectivity and vegetation quality i.e. microclimate. The hypothesis of this study was that the situation is the same in Madagascar. As dung beetles provide several important ecosystem services, like nutrient cycling and bioturbation, loss of dung beetle diversity imposes a secondary threat to the extraordinary nature of Madagascar by decreasing the regeneration ability of vegetation. Material for the study was collected in forest fragments of different size and quality between two areas of primary tropical rainforest – Ranomafana National Park and Vatovavy mountain – in November and December 2011 and January 2012. The sampling was conducted by transects of 30–60 fish- or carrion-baited pitfall traps which were set up in 55 localities in the study area. In each locality, several variables were measured to describe the vegetation and microclimatic conditions. The variables included temperature, humidity, estimate of vegetation quality by 6 observation-based classes, vegetation density, hights of three clearly visible vegetation layers, altitude and slope steepness. In addition, connectivities were measured for the localities using GIS and a satellite image –based vegetation classification. In order to demonstrate the differences between certain localities the study sites were divided into seven zones in terms of their distance from the Ranomafana National Park, average connectivity of the transects and elevation. Altogether 4,199 individuals belonging to 24 species were collected. Six of the species are currently under identification process in the Paris Museum of Natural History. According to the preliminary results they include two species new to science. Largest numbers of species were collected from good quality fragments between Ranomafana and Vatovavy. Also, a clear transition zone in species composition was detected a few kilometers west from Vatovavy, where altitude changes sharply. The study reveals that the species assemblages in the forest fragments and degraded forest areas are surprisingly species rich. This may, however, be partly because of extinction debt, and many of the still surviving species may soon die out due to restricted dispersal possibilities. Connectivity and vegetation quality were shown to have an effect on Canthonini species richness, with less species in less connected areas and lower vegetation quality. Vegetation quality was also shown to have an impact on the proportions of species with different body length: more small and medium-sized (< 8 mm) species were found in fragments where vegetation was more degraded. In addition to revealing how rainforest fragmentation and degradation affect local communities, the study gives interesting information about the distribution of certain species of Epilissus (Scarabaeinae: Canthonini). It has been known before that four species of Epilissus show elevational differentiation in their occurrence in Ranomafana. In this study, two more species of the same genus, E. prasinus and E. emmae obscurpennis, were shown to continue this pattern in lower elevations near Vatovavy mountain, about 50 kilometers east of Ranomafana.
-
(2023)Biodiversity has been declining over the last decades due to land-use changes. Habitat loss and fragmentation are considered the key drivers of biodiversity loss. While evidence indicates that habitat loss has a negative impact on biodiversity, the effect of fragmentation itself is debated. The Habitat Amount Hypothesis proposes that fragmentation per se –more discontinuous habitat distribution but no difference in habitat amount- has no effect or even a positive effect on biodiversity. Studies have looked at its effect on species richness, but its impact on intraspecific genetic diversity is still unknown. In this thesis, I aimed to test this hypothesis using the Glanville fritillary butterfly, which has been extensively monitored in the Åland islands since 1990, as a model system. I studied how fragmentation per se affects genetic diversity of the focal populations, while controlling for the habitat amount within the landscape in the Åland islands. For this, I used an existing dataset for which larvae were sampled during two consecutive years and genotyped for 40 neutral SNPs, and calculated four genetic diversity indices in over 200 habitat patches with relatively high population abundance. Following Martin et al. (2021) protocol, I first defined the scale of effect. Then, to reduce the correlation between total habitat amount and number of habitat fragments, I split my dataset in two sub-datasets. Finally, I assessed for each sub-dataset the differences in genetic diversity between landscapes with different level of fragmentation and total habitat amount. The number of fragments had a neutral effect on the genetic diversity, supporting the habitat amount hypothesis. Moreover, the results suggest that all habitat fragments, even the small ones, are contributing to maintain the genetic diversity of the focal population. The species’ ecology, population dynamics and specific adaptations to a fragmented landscape might have led the Glanville fritillary butterfly to be especially resistant to fragmentation.
-
(2022)Biodiversity loss and ecosystem service degradation and the related economic costs are increasingly recognized as sources of financial risks. The risks are arising through physical and transition sources of risks caused by dependencies and impacts upon biodiversity and ecosystem services. Therefore, it has become increasingly important for both individual financial institutions as well as central banks and financial supervisors to better understand and manage these risks. However, biodiversity loss is associated with unique complexity and uncertainty, making it a challenging task. The purpose of this thesis was to study the linkages between biodiversity loss and financial stability in Finland. This was done by assessing the financial exposure of Finnish credit institutions to sectors dependent on ecosystem services for their production processes. A quantitative analysis was conducted in order to combine loan data obtained from the Bank of Finland and ecosystem service data obtained from the ENCORE database. The results showed that 23% of loans provided by Finnish credit institutions are exposed to high or very high biodiversity-related financial risks. The sectors associated with most value at risks were real estate and agriculture, forestry and fishing sectors. Disruptions of ecosystem services providing surface water and climate regulation were posing the highest financial risks. The findings represent a first step towards assessing the exposure of the Finnish financial system to biodiversity-related financial risks. The results and previous literature indicate that physical biodiversity-related financial risk exposures are significant for individual financial institutions and for the whole financial system, despite the prevailing methodological challenges and gaps in knowledge. In order to complete a comprehensive biodiversity-related financial risk assessment, further research is needed.
-
(2021)This study aimed to identify conservation landscapes with potential to be mutually beneficial for people and African savanna elephants (Loxodonta africana) in South Africa through spatial conservation planning analyses that integrate ecological and socioeconomic data. The research questions were: (i) what are the most ecologically suitable areas for the reintroduction of elephants, and (ii) which of these areas provide the best opportunities for also sustaining socioeconomic development of local people. The first question was answered with an ecological model that predicts habitat suitability for elephants, developed by a combination of literature review, expert opinion, and GIS-based methods. The second question was answered by combining the ecological model with socioeconomic criteria in Zonation spatial conservation planning software. The results show that the central part of South Africa holds most potential for elephant conservation as it has the largest uniform area of high-quality habitat, while the area also meets the socioeconomic criteria. The priority areas for the conservation of elephants were classified into top priority classes of 1%, 2%, 5%, 10% and 20%. The identified areas hold an unrealized opportunity in the wildlife and ecotourism sectors, and the reintroduction of elephants to those areas could provide the foundation for long-term economic activity of local communities e.g. in the form of elephant-based ecotourism, while contributing to the conservation of elephants. Conserving just the top 5% priority areas would grow South African protected area estate by approximately three million hectares and increase the current elephant range by approximately 75%. Ideally, the results of this study could be used to inform the on-going decision-making process on where to allocate resources for elephant conservation in South Africa.
-
(2020)High Nature Value (HNV) farming systems hold significant natural values but have decreased drastically during the process of agricultural modernization. Biodiversity in Europe is dependent on these extensively farmed areas because they maintain habitats for many endangered species; e.g. 30% of Europe's butterfly species have declining populations and most live in natural and semi-natural habitats. European common agricultural policy (CAP) favour conventional agriculture, leading HNV agriculture in a foul position. HNV areas are often abandoned or replaced with intensive farming practices. Participatory agricultural innovation processes offer solutions to the distress of HNV farmlands. In these processes different actors – such as farmers, entrepreneurs, advisors, NGO and municipality representatives – are brought together to find localized solutions to the challenges of the area. HNV-Link project was active during years 2016-2019 identifying, developing and improving innovations in ten European HNV farming areas. In this thesis I examine the success of innovations in seven Learning Areas (LA) in terms of socio-economic viability, environmental conservation and cultural region. The data in this thesis is both quantitative and qualitative. I use mixed methods- approach where the statistical analysis and qualitative content analysis support each other. I carried out a survey for the LA coordinators where they responded how was the impact of the innovations to social, economic and environmental wellbeing. I complement the survey with data gathered by the project in 2016-2017. I conduct a qualitative content analysis to innovation fiches using Atlas.ti programme and a statistical analysis with IMB SPSS statistics programme with non-parametric tests. I compare the relation of socio-economic and environmental impact of the innovations, explicit aim of HNV conservation, recognition of environmental topics in the fiches and cultural region. Innovations were successful both socio-economically and environmentally. There was a possible synergy between economic and environmental impacts, which indicates economic viability of the LA’s improving HNV conservation. Innovations with explicit HNV conservation objective had more positive environmental impact than the ones without. Innovations with high recognition of environmental themes in fiches had slightly more positive environmental impact, but the difference was so weak that they fail to express the environmental outcomes reported in the survey. Congruent patterns didn’t occur inside cultural regions which might be due to the similarities of the areas or small sample size. The results display the inherent unpredictability of innovation processes, and the importance of holistic understanding and long-term monitoring of them.
-
(2023)Land-use change stands behind the current biodiversity crisis and all it entails in terms of ecosystem services. Guinea-Bissau, in West Africa, is originally characterized by a forest- savanna mosaic biome. However, while savannas have long been planted with rice, both rice paddies and forest remnants are now being converted into cashew monocultures – the only cash crop in the country – at unprecedented rates. The ecological impact of such rapid change is largely unknown. To help fill this gap, we examined how three diversity metrics – rarefied species richness, abundance and composition – varied across forest remnants, cashew orchards and rice paddies for amphibians and reptiles in northern Guinea-Bissau. To do so, visual encounter surveys were carried across 21 sampling sites, seven of each habitat type. A total of 703 amphibian and 266 reptile encounters was recorded from nine and 14 taxa, respectively. The results show class-specific responses to habitat type. Amphibians’ diversity in forest remnants and cashew orchards was similar across all metrics, but rice paddies had a higher abundance and unique composition compared to forest remnants. Reptiles’ abundance was highest in cashew orchards and this habitat had a distinct composition, when compared to forest remnants. Rice paddies sustained both lower reptile richness and abundance. Overall, our results are not in agreement with the expected detrimental impacts of cashew expansion, which might be due to the still high heterogeneity of habitat types within the landscape. Rice paddies proved particularly important for amphibians, and for open-habitat reptiles, boosting overall species diversity. In face of the eminent habitat conversion, maintaining heterogeneous landscapes, including the persistence of both forest remnants and rice paddies, will allow minimizing biodiversity loss in West Africa.
-
(2020)Iron-manganese (FeMn) concretions are found on soft sediment bottoms both in the deep sea and coastal sea areas, formed as a result of a combination of biogeochemical and microbial processes. It has been estimated that concretions occur at least in 11 % of the Finnish marine areas. Concretions form hard substrates on predominantly soft seafloors, and they are therefore suggested to increase geodiversity and habitat complexity of the seafloor. This has been found to correlate with biodiversity of the benthic fauna. Despite their widespread occurrence in the northern Baltic Sea, the ecological importance of FeMn concretions has been left unaddressed. In the recent assessment of threatened habitat types in Finland, concretion fields were classified as a data deficient habitat type. The aim of this study is to examine the role of FeMn concretions as habitats in the Baltic Sea ecosystem. Benthic biodiversity was investigated utilizing two approaches; the abundance of mobile fauna and sessile macrofauna were studied with point-dives. The data was compared to pre-existing data from similar soft bottoms where there are no observations of concretions, collected in the Finnish Inventory Programme for the Underwater Marine Environment (VELMU). Samples for sediment in-fauna were taken with a Van Veen Grab Sampler, and additional data was gathered also from Environmental Information System HERTTA (administered by Environmental Administration). The shape and quantity of concretions appear to affect the abundance of sediment in-fauna. Similarities to the invertebrate composition of soft sediment habitats depends of the soft sediment availability in the habitat, which is dependent on concretion shape and quantity. Crusts seem to affect the faunal composition more than spheroidal and discoidal concretions, as they offer the most complex habitats, significantly different from bare seafloors. Based on this study, the concretion fields should not necessarily be considered as just one habitat type, since the faunal composition appears to differ according to the shape of the concretions.
-
(2023)Agroforestry is a collective name for land-use systems and technologies where woody perennials are deliberately used on the same land-management units as agricultural crops and/or animals. Silvopasture is a type of agroforestry that integrates trees, livestock, and forage crops on the same piece of land. This topic is specifically interesting because silvopasture is already present in Finland, mostly in the form of traditional biotopes, despite these being endangered habitats. Agroforestry is also recognized by the Kyoto Protocol as an afforestation practice that has several advantages. These include environmental benefits, increased productivity, and animal welfare. However, there has been discussion on detrimental effects of animal presence to the trees as well. This research aims to explore the effects of silvopasture on trees, cattle, and the environment in South-western Finland traditional biotopes. Several individual criteria are assessed in three categories: woodland, animal performance and biodiversity. Data was collected on three farms on four pastures through field surveys and farmer interviews. The data is analyzed through multi criterium decision analysis (MCDA) with normalized values from agriculture and forestry to assess performance of silvopastures on three separate categories. Results from four pastures follow a somewhat similar pattern but variation occurs. High scores of forest indicators are reached in woodland category whereas biodiversity category results are lower. Silvopasture negatively affects forest regeneration but otherwise does not have adverse effects. Cattle performance is positive outcome whereas biodiversity category has room for improvement. To get more accurate and comprehensive results the research should be conducted during growing season and with several farms around Finland. However, silvopasture is a meaningful measure to diversify habitats, contribute to animal wellbeing and strengthen ecosystem services.
-
(2022)The ongoing growth and densification of urban areas is threatening biodiversity in cities. Previously continuous habitats are reduced and fragmented into smaller areas, which increases the edge effect and changes the qualities of the original habitat. Urban greenspaces are frequently used by people, and disturbances, such as trampling, and understorey management are increasing the similarity of habitat patches (i.e. homogenisation). In this study, I investigated the effects of small-scale homogeneity in forests produced by urbanisation on the distribution patterns and trait composition of carabid beetles. Sampling was done with pitfall traps during the summer of 2021 and altogether 21 study sites were selected in the City of Lahti, Finland. The study sites represented three different environments: 1) structurally complex (heterogenous) habitat in remnant spruce forests in the city, 2) structurally simple (homogenous) habitat in remnant spruce forests in the city, 3) structurally simple habitat under spruce trees in managed urban parks. In addition to the beetles, a set of environmental variables was collected to quantify the complexity of the three habitat types. As expected, habitat homogeneity affected carabid beetle species composition so that the proportion of generalist and open-habitat species was greater in homogenous sites, including homogenous forest remnants and highly homogenous urban parks, whereas the proportion of forest specialists was greater in heterogenous forests. Species richness was higher in the homogenous sites due to species-rich open-habitat genera in the carabid beetle family. Trait distribution at the community level showed clear differences between the three studied habitat types. As expected, the proportions of large and heavy species were higher in the forest habitats than in the parks, whereas homogenous habitats, especially highly homogenous park sites consisted of a higher proportion of flight capable species than heterogenous forests. At the species level, individual beetles were generally smaller in the parks, whereas the results between the two forest types varied and a clear difference between habitat specialists and generalists could not be detected. As cities grow, keeping the management of greenspaces moderate, selecting native vegetation, and preserving decaying woody material are ways to increase habitat heterogeneity, which according to this study, can support biodiversity and life of different organisms in urban areas.
-
(2023)Ihmistoiminnan, kuten kaupungistumisen, seurauksena syntyvät maankäytön muutokset kiihdyttävät globaalia luontokatoa. Kaupunkien maankäyttösektori vaikuttaa päätöksillään paikallisen luonnon monimuotoisuuden turvaamiseen kaupungistumisen ristipaineissa. Zonation on spatiaalisen priorisoinnin työkalu, jonka avulla tuotetaan luonnon monimuotoisuuteen liittyvää tietoa päätöksenteon tueksi. Sitä käytetään osana laajempaa systemaattisen suunnittelun prosessia. Zonationia on käytetty lähinnä suojelualueverkostojen suunnittelussa, mutta sen käytöllä on mahdollisuuksia myös laajemmin kaupunkialueiden maankäytön suunnittelussa. Tämän Pro gradun päämääränä oli tutkia maakuntatason suunnittelutarpeisiin tehtyjen Zonation analyysien hyödyntämistä käytännössä kuntatasolla. Tapaustutkimuksen kontekstina oli suomalainen hierarkkinen maankäytön suunnittelun systeemi, jossa lopulliset maankäytön muutokset toteutetaan kuntatasolla. Datankeruumenetelmänä käytettiin teemahaastatteluja. Yhteensä haastateltiin seitsemää ympäristö- ja suunnitteluvirkailijaa kunta- sekä maakuntatasolta Uudeltamaalta, Espoosta, Vantaalta. Tutkimuskysymykset olivat seuraavat: 1. Millä tavoin maakuntatason suunnittelun tueksi tuotettuja Zonation analyysejä on hyödynnetty kuntatasolla? Ja 2. Mitkä tekijät vaikuttivat analyysien tiedon hyödyntämiseen tämän tutkimuksen tapausesimerkissä? Tämän Pro gradu tutkimuksen tuloksista selvisi, että Zonation analyysejä käytettiin pääasiassa vahvistamaan tietoa jo tunnistetuista ekologisista yhteyksistä kunnissa. Lisäksi tuloksista kävi ilmi, että analyysien tiedon hyödyntämiseen vaikuttivat positiivisesti hyvin toimiva yhteistyö suunnittelutasojen välillä, sekä sidosryhmien osallistaminen analyysien suunnitteluprosessissa. Tiedon hyödyntämisen esteenä taas olivat Zonationilla tuotettujen analyysien sekä itse Zonation-ohjelman toimintalogiikan vaikeatulkintaisuus ja ajanpuute. Myös suunnittelutasojen väliset erot luontoalueiden tarkastelutasossa ja suunnittelumittakaavassa vaikuttivat analyysien hyödyntämiseen. Tuloksista selvisi myös, että analyyseistä tehtävien lopputuotteiden selkeydellä ja käyttäjäystävällisyydellä voidaan helpottaa analyysien tiedon viemistä käytäntöön. Tämän Pro gradun tulokset ovat linjassa alan tutkimuskirjallisuuden kanssa, ja vahvistavat niitä. Lisäksi tulokset lisäävät tietoa tapauksista, joissa spatiaalisen priorisoinnin analyysejä on hyödynnetty käytännössä, mitä on toivottu alan tutkimuskirjallisuudessa. Tulosten perusteella ehdotetaan, että jatkotutkimuksissa datankeruuseen kannattaisi sisällyttää pienenpiä kuntia, ja laajemmin systemaattisen suunnittelun prosessien sidosryhmäläisiä, sekä luontokonsultteja.
Now showing items 1-12 of 12