Knowledge of the ecology of species and communities is becoming increasingly important in this age of great global change. If you want to contribute to the conservation of biodiversity and the organization of its protection, consider doing a bachelor's and master's thesis in the UT Landscape Biodiversity workgroup. We are looking for active students interested in ecology, who would be inspired by summer fieldwork in eye-catching meadow communities and/or molecular analyzes that shed light on the genetic component of biodiversity in the laboratory. Our workgroup combines the so-called "green" and "white" biology in the best possible way. Please contact Assoc. Prof. Tsipe Aavik or Prof. Aveliina Helm, if you are interested in the activities of our workgroup.
TOPICS FOR BACHELOR AND MASTER THESES IN 2022/2023 ACADEMIC YEAR
If you are interested in a topic that our workgroup is working on but it is not listed below, you are welcome to contact us and we will find a solution together.
Effects of landscape structure on the network of interactions between plants and pollinators
Landscapes that become more monotonous and intensive agricultural practices reduce the biodiversity of agricultural landscapes. In addition to the species diversity and abundance of different groups of organisms, these factors have a significant impact on the interactions between different organisms, including the relationship between plants and the insects that pollinate them. Within the framework of the bachelor's thesis, an overview is given based on the literature of how changes in the landscape structure have affected the networks of relationships between pollinated plants and pollinating insects. The supervisors of the thesis are plant ecologist Tsipe Aavik and pollination ecologist Virve Sõber.
Effects of declining pollinator diversity and abundance on plant reproductive traits
Abrupt anthropogenic environmental changes can cause various evolutionary changes in plant populations. For insect-pollinated plants, a changed environment can manifest itself in shrinking and more uniform pollinator communities. The bachelor's thesis provides an overview of the scientific literature, where the influence of changes in the diversity and abundance of pollinating insects on the pollination-related traits of insect-pollinated plants has been discussed. Plant ecologist Tsipe Aavik and pollination ecologist Virve Sõber supervise the preparation of the thesis.
Impact of agri-environment measures on the network of interactions between plants and pollinators
In order to mitigate the impact of intensive agricultural techniques and impoverished landscapes on biodiversity, a number of environmental measures have been implemented within the framework of agricultural policy. Based on individual studies, the bachelor's thesis provides an overview of how different management techniques applied within the framework of environmental measures affect wild bees and other pollinating insects, the plant communities that depend on them, and plant-pollinator networks. The supervisors of the work are pollination ecologist Virve Sõber and plant ecologist Tsipe Aavik.
Effects of urbanization on plant-pollinator interactions
Increasing urbanization has a significant impact on both pollinators and the flowering plants that depend on them. The impact of urbanization on biodiversity can be both favorable and unfavorable, depending on both the degree of urbanization and the characteristics of the organisms. The bachelor's thesis provides an overview of the scientific literature, which have discussed the relationship between changes in the diversity and abundance of pollinating insects and pollinating plants with the rate of urbanization. The preparation of the thesis will be supervised by pollination ecologist Virve Sõber and plant ecologist Tsipe Aavik.
Genetic monitoring of plants in response to ecosystem restoration
Genetic diversity is an important component of biodiversity securing the resilience of populations in an era of environmental change. However, despite its increasing relevance in the light of ongoing climate change, the recovery of genetic diversity is rarely assessed in monitoring programs. The bachelor's thesis will give an overview of the different aspects of restoration success, which can be monitored with the help of plant genetic data. It will also provide an overview of the known monitoring programs relying on temporal assessment of genetic diversity and gene flow of plants. The thesis is part of the international collaboration activities COST G-BiKE (Genomic BIodiversity Knowledge for Resilient Ecosystems) and ConservePlants (An integrated approach to conservation of threatened plants for the 21st Century). The preparation of the thesis will be supervised by Tsipe Aavik.
Macrogenetics of plants
Genetic diversity of organisms is one of the main components of biodiversity alongside species and ecosystem diversity. Although the assessment of genetic diversity has become increasingly common in recent years, most research continues to be limited to assessing the fate of one or a few species. Therefore, it is difficult to make generalizations about regional and global patterns of genetic diversity and their determinants. It is also almost impossible to assess whether and to what extent global change, including climate change and the loss of natural habitats, has affected this important component of biodiversity. Macrogenetics is a new discipline that brings together existing research on the genetic diversity of organisms to assess the patterns of this important component of biodiversity and to identify the patterns that determine it. The aim of the bachelor's thesis is to provide a literature-based overview of macrogenetics as a field of science, plant-focused macrogenetic research and the main research results in this field. The supervisor of the work is Tsipe Aavik.
Methods benefiting integrated plant disease management
Using the natural enemies of crop pests is a very important method in environmental-friendly agriculture. For the most efficient use of natural enemies we need to know, which factors benefit those species both in small and landscape scale. Do their numbers depend more on the width of the field edges, the species growing there or the structure of the surrounding landscape? The study is associated with the project “ForEst&Farmland” and and the student can get involved in finding the most suitable solutions for Estonian agricultural landscapes. Supervisor of the bachelor’s thesis is Aveliina Helm.
History, future and ecological effects of grassland afforestation
In the 1960s, Soviet campaigns decided to afforest and thus make a large number of rich meadow communities "economically viable". Half a century later, the same solution is being proposed for afforesting the few remaining meadows in order to achieve climate goals. Is this an effective method or are there significant shortcomings in afforestation plans? The aim of the bachelor's thesis is to gather knowledge about the history and current state of afforestation of open landscapes and to describe the ecological consequences of afforestation, including the impact on pollinators, soil biota and meadow biodiversity and nature's benefits as a whole. The supervisors of the work are Aveliina Helm and Elisabeth Prangel.
Afforestation campaigns in the 1960s created monotonous "tree fields" on the once species-rich meadows. Forest created on an alvar in Saaremaa.
Effects of urbanization on plant-pollinator interactions
Increasing urbanization has a significant impact on both pollinators and the flowering plants that depend on them. The impact of urbanization on biodiversity can be both favorable and unfavorable, depending on both the degree of urbanization and the characteristics of the organisms. As part of the master's thesis, the impact of different management techniques on pollinator and plant communities in the green areas of the city of Tartu can be compared. The supervisors of the work are pollination ecologist Virve Sõber and plant ecologist Tsipe Aavik.
The effect of the structure of contemporary and historical landscape on the heterostyly of Primula veris
As part of the citizen science campaign “Looking for Cowslips” launched in 2019, data on cowslips (Primula veris) were collected across Estonia also in the spring of 2020. Participants were asked to find out how many flowers of two different types of cowslip are in one place. One type has anthers lower and the style higher (L-type), the other has anthers higher and the style lower (S-type). Plants with such flowers are called heterostylous, and this is one way for plants to prevent self-fertilization, because only pollen from the other type of flower is able to fertilize. In good conditions, both types of flowers are usually about equal, but this balance may be lost due to the loss of habitats suitable for cowslips. Biodiversity patterns usually respond to such landscape changes with a time lag. In the framework of the master's thesis, it will be studied whether we can immediately see an answer to the decline of habitats in patterns of heterostyly. As part of the work, spatial data must be collected using various modern as well as historical maps. The results of the master's thesis are also planned to be formalized as a research article. The supervisors of the work are Tsipe Aavik, Marianne Kaldra and Iris Reinula.
Effect of heterostyly on the gene flow of Primula veris
Landscape genetics is a discipline that combines the methods of population genetics and landscape ecology, with the help of which we can assess how environmental conditions and landscape structure affect genetic diversity and the exchange of genetic information, i.e gene flow. In addition to the nature of the landscape between plant populations, gene flow may also depend on other factors. There are two types of flowers of cowslip (Primula veris) studied in our group. One type has anthers lower and the style higher (L-type), another has anthers higher and the style lower (S-type). Plants with such flowers are called heterostylous, and this is one way in which plants prevent self-fertilization, because only pollen from the other type of flower is fertile. But the exception confirms the rule - in some cases, successful reproduction can also occur when pollen is exchanged between two L-type cowslips. This in turn can lead to differences in the gene flow and genetic diversity of S- and L-type flowers. In the face of habitat fragmentation, the pressure of natural selection may eventually favor "less precautionary" L-type grass dolls. The master's thesis examines whether and to what extent the gene flow patterns of S- and L-type individuals differ and how they are affected by the surrounding landscape. The nature of the work is diverse and includes laboratory, map and field work. The supervisors of the work are Tsipe Aavik and Iris Reinula.
Plant genetic diversity-species diversity relationships in Estonian alvar grasslands
The majority of conservation activities are focused on maintaining species diversity, because species diversity is often expected to also reflect other components of biodiversity, like genetic diversity. However, it has been found that interactions between the different mechanisms can result in positive or negative correlations between genetic and species diversity or sometimes no correlation at all. The aim of the master's thesis is to study on the basis of already collected data, what is the relationship between the genetic diversity of cowslip (Primula veris) populations and the species diversity of alvar grasslands, and what nature conservation conclusions can be drawn from it. The supervisors of the thesis are Tsipe Aavik and Iris Reinula.
Connectivity of Estonian landscapes and achievement of the 30% protection target
There are many challenges and needs for research in nature conservation today. A sustainable future depends on how well we manage today to lay the foundations for the well-being of biodiversity and nature. The European Green Agreement stipulates that effectively protected nature reserves must cover 30% of the land area, while ensuring connectivity between protected areas and the well-being of wildlife in the area between protected areas. The aim of the master's thesis is to quantify the connectivity of Estonian natural landscapes and make proposals for its restoration. The focus will be on existing protected areas and proposals will be made to achieve connected protected areas outside today's protected areas. In the course of the work, shortcomings and opportunities are identified, including the identification of barriers and proposals for the creation of possible step boards and the good functioning of the green network. The thesis is waiting for a master's student who is interested in GIS analyzes and the future of Estonian nature conservation. The work will be carried out as part of the RESTFUNC project and will use current and historical map data, nature conservation databases and remote sensing applications. Not much field work is planned, but the master's student can be involved in the field work of the Landscape Biodiversity work group planned for the summer of 2022 on wooded meadows, agricultural landscapes and roadside. The work is exciting and very necessary for applicational side. Supervisors are Associate Professor of Botany Aveliina Helm, and Associate Professor of Geoinformatics Evelyn Uuemaa.
The importance of road edges in maintaining biodiversity
In a situation where the meadow communities found in Estonian traditional landscapes have drastically decreased, the road edges offer important habitats for Estonian meadow species. Road edges can also be ecological corridors between fragmented meadow habitats. In the work group, we have previously prepared an overview for the Estonian Road Administration of more environmentally friendly maintenance of road edges, but the condition and role of Estonian road edges in maintaining biodiversity needs more specific attention. The aim of the master's thesis is to map the road edges that support species richness in Estonia, to find out which factors influence the occurrence of high nature value road edges and to identify the role of road edges in ensuring the coherence of meadow communities. The work will also identify areas where nature-friendly roadside maintenance contributes to the creation of habitat corridors and to ensuring the connectivity of landscapes. The work will be carried out as part of the RESTFUNC project and will use both existing map data and fieldwork data collected by the Master's student in the summer of 2022. The supervisors of the work are Aveliina Helm and Triin Reitalu.
Dry grassland species in a road verge in Saaremaa. Photo: T. Reitalu
Time lags in the recovery of populations and species interactions
Recovery of populations and species interactions after the restoration of communities occurs always with a time lag. In a Master’s thesis we test, how the recovery of populations and species interactions depends on landscape history and structure, and the characteristics of species and their interactions. This important work creates new scientific knowledge, looking at systems and processes that have been studied very little in the past. In our work we use data collected from plants, bees and butterflies in the restored alvar grasslands. The work is carried out as part of the RESTFUNC project. Thesis supervisors are researcher Krista Takkis and pollination specialist Jelle Devalez.
The importance of Estonian meadows as carbon sinks and stores
People often look to forests for finding ways to mitigate climate change and see the rather one-sided tree planting and plantations as a solution. However, ecosystems and well-functioning landscapes are the best mitigators of climate change and, at the same time, biodiversity. In the context of climate change, Estonian meadows have remained a bit orphaned and their importance as carbon sinks has been underestimated. In the master's thesis, we describe the role of Estonian heritage meadows as carbon sinks and stores. As part of our work, we use data collected from previous meadows, collect new data and perform some GIS analyzes. The result of the work is very important as it provides an opportunity to talk about the sustainable and smart management of Estonian landscapes. The supervisors of the work are Aveliina Helm and the doctoral student Elvi Liiv.
Restoration of natural benefits in the restoration of communities
The United Nations Decade of Ecosystem Restoration is under way, and there is a strong global focus on restoring functioning ecosystems that ensure the sustainability and preservation of essential nature's benefits, or ecosystem services. However, the recovery of ecosystem services can take some time, causing a significant time lag between restoration activities and the full functioning of ecosystems. The master's thesis answers the question of how quickly the bnature's benefits recover and to what extent the recovery of various ecosystem services depends on the landscape composition, the techniques chosen for restoration and the degree of ecosystem degradation. As a model system, we use Estonian alvar grasslands, where the large-scale restoration activities are just coming to an end. Much of the data already exists, but there is also scope for fieldwork and data collection. The supervisors of the work are Aveliina Helm and Elisabeth Prangel.
Restoration of biodiversity and nature's benefits of Estonian and Latvian wooded meadows
A large-scale nature protection project will begin this year (2021), during which 500 hectares of wooded meadows will be restored in Estonia and 200 hectares in Latvia. Wooded meadows are extremely species-rich and rare ecosystems, but their area has decreased more than 1000 times in the last 100 years. Prior to restoration work, we carry out monitoring on non-restored wooded meadows to determine the impact of restoration on different species groups and other important characteristics of wooded meadows. During the fieldwork in the summer of 2022, we will collect data on plants, insects, soil fungi as well as old trees and traditional ways of working. The aim of the master's thesis is to describe the biodiversity of so far little-known groups in wooded meadows and to give recommendations for restoration work. The work will be carried out as part of the WoodMeadowLIFE project. The supervisors are Triin Reitalu and Aveliina Helm.