Projects / Programmes
Mortality of lowland oak forests - consequence of lowering underground water or climate change?
| Code |
Science |
Field |
Subfield |
| 4.01.01 |
Biotechnical sciences |
Forestry, wood and paper technology |
Forest - forestry |
| Code |
Science |
Field |
| B430 |
Biomedical sciences |
Sylviculture, forestry, forestry technology |
| Code |
Science |
Field |
| 4.01 |
Agricultural and Veterinary Sciences |
Agriculture, Forestry and Fisheries |
pedunculate oak, mortality, floodplain forest, climate change, forestry, oak decline
Researchers (19)
Organisations (4)
Abstract
Increasingly frequent droughts and hot summers are significantly changing both the society and nature. In Central and Western Europe, the problems with drought are detectable yet manageable, however in the Mediterranean and the South-west Europe, extreme droughts are becoming both an economic and social problem which is, together with a changed water regime of main watercourses, starting to seriously impact the agriculture, forestry, economy and natural ecosystems in the region.
The Pannonian Basin is one of the potentially most affected landscape by the climate change. Different climate change scenarios report that air temperatures will continue to increase, while the precipitation amount will decrease. Lowland forests in the region heavily depend on three key environmental factors: (1) level and quality of ground water, (2) river flow and groundwater recharge and (3) the amount of precipitation. Not only the Pannonian Basin receives small amount of precipitation (800 mm and less) but also all ground- and surface waters are heavily influenced by the agricultural activities and industrial use of groundwater. With a downward trend of water sources availability in the area, the survival of the lowland forests is questioned. Due to climatic change in the last 30-years, the number of hot and dry summers has increased, while the river water (due to less snowfall during the winters) and the groundwater levels have decreased resulting in an increased oak stand mortality throughout the Pannonian Basin. Once optimal sites for oak growth are now becoming marginal and oaks, in particular pedunculate oak, are experiencing high mortality, which questions future existence of the species in this region.
With the proposed research project, we want to investigate how the changes in the precipitation regime and in groundwater levels influence the growth of oak stands in the Pannonian Basin and to define the trigger point at which oaks start to die. As this is a complex task we will focus on various methods and approaches to address oak mortality. We will study the growth of the oaks and past climatic and environmental factors that have been affecting oak growth, as well as physiological response of trees to climate and environment in the present time. We will combine tree ring proxies with meteorological data and stable isotope data in precipitation and ground water to see which water is actually used for the growth of the oaks. Newly gained knowledge will be used for prediction of future development of oak forest in the Pannonian Basin and to help foresters to better tackle with consequences of climate change. Research objectives are the following:
Analysis of dendrometric, anatomical and physiological parameters of declining and vital oaks, and identification of reasons for the degradation at the tree and stand levels within the Pannonian Basin area (an area with the most productive oak stands in Europe)
Analysis of the environment in which such degradation is taking place in the light of changes such as decreasing groundwater, river flow and precipitation levels, and global warming
Study correlation between changing environmental conditions and oak stand degradation
Modelling of expected oak mortality in a wider area (based on a chosen number of plots)
Silvicultural guidelines based on scientific expertise
Significance for science
The main advantages of the proposed project in comparison to research work already done in the field of oak decline in Europe are its multi-layered analyses and large-scale approach. This multi-layered approach is key to understanding oak responses and their plasticity in severe environmental and climatic conditions. This project shall not be limited to just a few stands in Slovenia, it shall strive to gain a wholesome image of the degradation of lowland oak stands in an area which presents an important share of lowland oak forests in Europe. This large-scale approach is missing in most of the research known to us. According to accessible data, isotope studies in oak tree-rings in this area do not exist or are extremely rare. Quantitative wood-anatomical analyses of oak tree-rings are also very rare (and spatially limited). Similarly, long-term oak chronologies do not presently exist or are only now being constructed, while a large portion of these chronologies was formed in the dendrochronological laboratory of the institution proposing this project (SFI), and in Hungarian and Romanian laboratories. Most of the rare physiological oak studies that do exist were concluded by SFI researchers in cooperation with local institutes.
Significance for the country
Slovenia has always been viewed as the country rich in water resources, where the supply of drinking water is not considered to be a problem. The almost complete absence of rainfall, which occurred between October 2011 and March 2012 showed that Slovenia could easily find themselves in serious difficulties regarding the supply of drinking water. A good example of the serious difficulties in the supply of healthy drinking water was Notranjska (winter 2011/2012), where the karst water resources almost dried up, while remaining wells were contaminated with faecal bacteria and water need to be transported from elsewhere. Similar problem is also in the eastern most part of Slovenian in Prekmurje, in particular in the summer there is always a problem with water supply. Prekmurje is part of the large Pannonian basin which is a (or used to be) the region where our most productive oak forests grow and not only in Slovenia, also in other countries of the region forests (and people) are influenced by the changing precipitation regime and sinking underground water table. This demands to change the attitude towards the healthy drinking water and requires development of proper water management strategies to response to drought occurrence. The proposed project will use innovative approaches to reconstruct the occurrence of drought in the regions considered to be more vulnerable as Slovenia (e.g. Croatia, Serbia, Hungary) and knowledge about the incidence and duration of droughts will be transferred to Slovenia. Thus we will get the information, what can happen in Slovenia, if temperature will rise and the climate conditions will become similar to those more southern from us. Project will provide important theoretical frameworks that are currently missing, in order to achieve the established guidelines in the “Adaptation of Slovenian agriculture and forestry to climate change”. The results of our study, in which we will focus on the growth of trees floodplain forest, in, so to say, the middle of the food production region, and influence of drought on growth of lowland, floodplain forest, will be a significant potential contribution to greater awareness to extreme weather events in particular in the lowlands. Knowledge that we gain with the proposed project will have a major impact on local communities and decision makers. The resolution of the National Security Strategy of the Republic of Slovenia says that climate change is a threat to national security, and that the state will do its utmost to prevent this, beside this we are in the middle of the process to include the right for the safe drinking water in the highest act of the R of Slovenia, the constitution. Our findings will help managers, planners and policy makers to prepare strategies and make short and medium term decisions based on deeper understanding of the drought variability in the future.
Most important scientific results
Interim report,
final report
Most important socioeconomically and culturally relevant results
Interim report,
final report
