Carbon allocation in woodlands using a multi-data approach

The project entitled Carbon allocation in woodlands using a multi-data approach aims to enhance our knowledge base on the carbon dynamics of open woodlands, a vegetation type frequent world- wide exhibiting a lower tree cover as compared to closed forests. While forests generally exist under less extreme climatic conditions with sufficient rainfall, woodlands are frequently found under very cold or very hot conditions such as in the far North, at high elevations in the mountains or in the South if it is dry and hot. Woodlands are nonetheless important for the global climate, for the livelihood of local communities and for biodiversity. While we know a lot about forests, our knowledge on woodlands is rather scarce, potentially due to their often remote locations and traditionally low economic value. By combining several data sources and novel methodologies we will advance our understanding of woodlands in Oceania, a continent of about the same size as Europe. The key objective is to provide reliable information on carbon allocations and growth rates of woodlands across large areas. Such information will provide novel insights into carbon fixation rates and biomass produced by woodlands, which are important for global climate change and potentially also for a bio-based economy. We will combine direct measurements on for instance tree diameters with maps derived from satellite data, which will give us spatial information on vegetation properties across large areas. Reliable and solid information is important for reporting systems such as those under the Kyoto protocols, which tell us how much carbon dioxide we are emitting and how much carbon is sequestered. This project will provide such information to societies and policy makers alike to facilitate taking good and informed decisions. Joining forces with the oldest University of Australia, the University of Sydney, and one Australias largest forest agencies (Forestry Corporation New South Wales), the research team led by Dr. Mathias Neumann from the University of Natural Resources and Life Sciences, Vienna, will tackle these challenging tasks. Local contact points are Prof. Mark Adams from the University of Sydney and Dr. Chris Eastaugh from the Forestry Corporation. Together the research team will contribute to solve one of the major future challenges worldwide, shifting our societies towards a green bio-based economy.

The carbon cycle, that is the balance of carbon uptake and release by plants, is critical for the global atmospheric carbon dioxide concentration (CO2). Widespread worldwide and thus important vegetation types include forests (composed of in general faster growing taller trees) and woodlands (short-statured, low-productive, tree-dominated ecosystems). This project help achieve a better understanding of the processes governing the carbon cycle of forests and woodlands. The study region was Australia and the used tools were a combination of field measurements, remote sensing information and simulation and modelling tools. Analysis of data from across Australia showed that forests have higher carbon uptake than woodlands and this difference can be mostly attributed to more carbon allocated into wood by forests. Litterfall, that is the amount of dead matter being shed annually, is high for both forests and woodlands. This litterfall transfers not only large amounts of carbon to the ground surface, but also creates important fuel load pools, that can be burnt during a fire. A continental meta-analysis of litterfall and standing litter revealed that climate determined the speed of litter accumulation while time since and stand structure is important for standing litter. This information is important to understand fuel load accumulation, which had particular relevance in the intense Australian wildfire season of 2019/2020. Over 10 Million hectares forests were burnt, releasing large amount of carbon to the atmosphere and negatively affecting wildlife and societies alike. These fires affected both forests, woodlands, grasslands and agricultural areas, which underscores the importance to consider all vegetation types in comprehensive studies of fire risk as well as for carbon assessments. The available data were combined with models and permit now calculating the fuel accumulation based on climate and time since fire. This concept can now be applied in Europe, where fire risk is important regionally (such as Southern Europe and Scandinavia) and is expected to become more relevant in Central Europe, as climate change is increasing air temperature and thus evaporation. Soil carbon is the major carbon pools worldwide accounting for often more than two third of total carbon storage. Apart from litterfall, fine roots are the other major carbon flux into soil. By linking fine root production, litterfall and litter decomposition a process-based quantification of soil carbon is possible, that is currently missing in many global climate models. Europe can further benefit from the Australian knowledge on managing fire-prone ecosystems, such as prescribed burning and fire control. This is of particular importance for Eucalypts, the dominant tree species in Australia, which are now widely used in plantations worldwide.