Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

The debate on climate change has taken a prominent role in the Belgian news the last couple of months. Nowadays most people are convinced that our Earth is warming at an unprecedented speed. This is not only affecting our society, but also the natural systems on Earth. One of the effects of climate warming is the shift of suitable habitats of many plant species towards the poles: for example, plants that find optimal climatic conditions here in Flanders will find the same climate in Denmark, Norway or Sweden within decades. Species that are not able to move fast enough to these new places will have to adapt to the new environmental conditions. The species that are not able to adapt to the warmer climate only have one option left: go extinct. We aim to study the effect of climate change on the distribution of red list species and its consequences for national conservation strategies. To do so, we chose to focus on regional red list species in Flanders, as the chance is higher that the projected range shift will result in ‘national’ extinctions. In this master thesis we investigated the effect of climate change on 881 red-listed plant species in Flanders. We made predictions for future species distributions under four different scenarios: RCP2.6 (2050), RCP2.6 (2070), RCP6 (2050) and RCP6 (2070). To make these predictions we used a MaxEnt species distribution model with climatic and soil predictor variables and occurrence data from four different databases (GBIF, iNaturalist, EcoEngine and BIEN). We specifically took a look at the magnitude and direction of the geographical shifts, the changes in the extent of the geographic ranges and the changes in the regional species richness. Here we found significant differences in the magnitude of the geographical species shifts between the different categories of the Red List of Flanders. Also a clear range shift towards the north pole was shown. On a European scale a lot of species will gain new habitat with suitable climatic conditions, while in Flanders, on the contrary, a lot of species will partially lose and some species will completely lose their habitat. This study predicted the effects of future climate change scenarios on Flemish Red list plant species. It identified species which may need a helping hand in their combat with climate change. Therefore this study is relevant for policy makers and conservation managers as it can be used to inform and prioritize conservation efforts (e.g. assisted migration). By aligning future conservation actions with the results of studies like this, it must be possible to develop climate change-robust nature conservation practices.

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Establishment of foreign plant species has been known to be a massive threat to original ecosystems and can lead to high degradation of those infested areas. This also happens in Fynbos ecosytems, which are very and only occur in South-Africa. To be able to reduce the level of these invasive species and stop them from spreading, first a lot of insight is needed into their distribution mechanisms. Several studies have already shown that humans and vehicles are a huge reason for the spread of invasive plants. However, very little research is done in Fynbos ecosystems. Therefore, the aim of this research was to study how vehicles help the spread of harmful invasive plants in Fynbos ecosystems. More concrete, this study tried to find the answer to these questions: how does the species composition change along the elevation gradient? Are there more invasive plants closer to the road? And do vehicles help spread these invasive species? For the collection of data, a protocol composed by MIREN (i.e., Mountain Invasion Research Network) was followed. The vehicle road of Matroosberg, the study region of this research, was divided in to 20 sites whose altitudes levels were equally distant from each other. At each altitude level, there were three plots of 100 m²: one parallel to the road, one perpendicular on the first one, and one after the second one in the same direction, forming a T-transect. This resulted in 60 different plots at 20 different altitudes. For each plot, every plant species was identified, and their cover was estimated. Other data such as bare ground and litter percentage were recorded as well. Additionally, to the data from South-Africa, data from other studies in Tenerife and Chile were used as well, as these countries also have Mediterranean ecosystems, which are similar to Fynbos ecosystems. Once this data was combined, the data was visualised to identify any extreme data points and remove them. Next, several models were composed to identify how much elevation and proximity to the road had an influence on the number of plant species and the area coverage they had. Because different plots are correlated to each other as they are located in the same region and along the same road, the models used were generalized linear mixed models. This was done for three different types of plant species: the native plants, the invasive species, and all plant species together. This resulted into the following findings. There were more species present at the lowest altitude levels, which was expected. The disturbance levels caused by vehicles were the highest along the road. The highest number of species could be found along the road, which supports the suspicion that vehicles help the spread of all species, both native and invasive. The higher the plots, the less plant cover they had, but due to a lack of data and an overcomplicated model, no clear conclusions could be made from the cover models. Therefore, it was hard to examine if vehicles help spread invasive species to higher elevations along the road. Recommendations for further research include monitoring more variables that could help study the reason for the distribution of invasive alien species, such as the frequency of passage of vehicles or conduct a study over a longer time period. This research was a good first step in the direction of a full understanding for native species can spread and establish in Fynbos ecosystems with the use of vehicles.

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Urban populations are growing worldwide, also in Flanders. These urban populations will suffer most from the effects of climate change and the Urban Heat Island. As one of the most urbanized regions in the world, these effects are of great concern to the people of Flanders. But increasing amounts of heat waves and dry spells will not only have an impact on the vitality of human urban inhabitants, but on urban trees as well. Trees already have a lot of challenges to overcome to be able to survive in urban areas. But trees that are planted in urban areas now or in the near future will have to be able to survive in the future urban climate of Flanders. This thesis is dedicated to evaluating the climate resilience of urban tree species. To construct a list of potentially climate resilient urban tree species and traditional urban tree species, different actors of the urban green sector in Flanders were contacted. These actors were urban green managers, tree nurseries and different research institutions. Each of these actors put forward a list of potentially climate resilient urban tree species. These lists were constructed based on experience, species ecology and natural species distribution. The results show that especially Mediterranean species with small leaves show great potential as climate resilient urban trees. Although the qualitative assessment of tree species provided a useful list of potentially climate resilient urban tree species, the quantitative analysis proved necessary. Some of the species on the potentially climate resilient species list showed not to be climate resilient after the quantitative analysis. The collaboration of the researcher with the actors in the practical field of the subject proved to be very useful to both parties. The current landscape of climate resilient trees, or “climate trees” as they are called, is going through a metamorphosis. Different institutions are working around the subject in isolation, using different techniques and terms to study and discuss the same subject. These semantic discrepancies might cause confusion and miscommunication. A unification of semantics and methodology is prompted, so that all actors can contribute efficiently to the common goal of creating liveable urban areas for present and future generations.

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Due to climate change, global species distributions show latitudinal poleward and upslope shifts, as they try to keep up with the shifting climate. Species that did not possess the ability to adapt or to migrate at sufficient speed, have already gone extinct. Biodiversity and ecosystems degrade, which causes ecosystem services to be compromised. Landscapes can harbor areas with fine-scale temperature differences, microrefugia, which can reduce the extinction of plant species. Microrefugia are local microhabitats in which the environmental conditions are favorable and to which plant species can limit their habitat, in order to decouple from their distribution area that is affected by climate change. In this study, an attempt was made to recognize microrefugia in the surroundings of the Belgian Hoge Kempen National Park, based on environmental factors and modeled microclimate temperature. Potential microrefugia can best be detected by modeled maximum temperature values, instead of by visual assessment based on elevation, aspect and vegetation cover. Furthermore, it was concluded that the use of in-situ temperature measurements, instead of using modeled temperature values, would allow for better informed conclusions. Environmental variables such as total vegetation cover showed expected relationships with modeled maximum temperatures, which indicates that the study area has potential to harbor microrefugia. Potential microrefugia were compared with surrounding habitats in terms of abiotic variables, species richness and species composition. Significant differences in mean values for heat load, total vegetation cover, light intensity and modeled mean temperature were observed. Although a lower species richness was observed for higher modeled maximum temperatures, this variable could not be used to detect potential microrefugia. Microclimate did not affect the plant community composition, so it was concluded that microrefugia were not (yet) present in the study area. By indicating which variables influence microrefugia and by providing suggestions to locate microrefugia, this study aims to contribute to development of techniques to localize microrefugia. This may be relevant for research concerning Climate Change Integrated Conservation Strategies.

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Forest microclimates are evident under European forest canopies and can be highly heterogenous in space and time depending on local features that drive the microclimate variability. Microrefugia have distinct microclimate conditions, which can provide shelters that are decoupled from the macroclimate warming and thus provide favourable environmental conditions buffered from the regional climate change. They play an important role in the long-term persistence of (cold-adapted) forest plant species under future climate warming since forest plant species generally have a lower dispersal capacity and are thus not sufficiently able to track their suitable habitats. An important often overlooked step after mapping the microrefugia is the validation of the identified microrefugia. The main goal of this thesis was the validation of microrefugia in European forests. We wanted to validate whether the identified microrefugia in European forests function as shelters for forest plant species under past macroclimate change. They were validated by comparing the difference in community composition between two time periods in a certain forest area with a given microrefugia index (MI, i.e. potential of forest areas to function as microrefugia). This community composition was characterized by the community-inferred temperature (CIT) and changes in community composition by the difference between the CIT of the baseline survey and the latest resurvey (∆CIT). We expected a negative relationship between the different MIs and the ∆CIT, which would validate the functioning of the identified microrefugia since smaller community composition changes were expected within microrefugia. Using long-term community composition data from 2985 plots in 76 regions across temperate European forests together with data from other possible drivers, we found no significant relationships between the MIs and the CIT, whereby only the plot size was significantly related to the annual CIT changes. Therefore, the five different MIs could not be validated at this moment. However, when the ∆CIT was split into different components, there were significant relationships between the ∆CIT components and the MIs with the MI based on the offset of the mean annual temperature as the best performing index, indicating that the MIs could proof useful in the microrefugia identification. The macroclimate and canopy cover changes also showed to have an impact on the ∆CIT components, especially on the ∆CIT due to species loss and gain. Validating microrefugia is of increasing importance in light of current climate change, allowing for the protection of microrefugia by adapting the forest management to maintain the local features that drive the microclimate variability.