@article{MannGohrBlumroederetal.2023, author = {Mann, Deepika and Gohr, Charlotte and Blumr{\"o}der, Jeanette Silvin and Ibisch, Pierre L.}, title = {Does fragmentation contribute to the forest crisis in Germany?}, series = {Frontiers in Forests and Global Change}, volume = {6}, journal = {Frontiers in Forests and Global Change}, publisher = {Frontiers Media S.A.}, issn = {2624-893X}, doi = {10.3389/ffgc.2023.1099460}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:eb1-opus-3909}, pages = {12}, year = {2023}, abstract = {Intact forests contribute to the ecosystem functionality of landscapes by storing and sequestering carbon, buffering and cooling the microclimate, and providing a range of related ecosystem functions. Forest fragmentation not only poses a threat to many organisms but also reduces the resistance and resilience of the ecosystem, which is especially relevant to the ongoing climate crisis. The effects of recent extreme heat years on forests in Germany have not been studied in detail for the influence of fragmentation. We investigate the relation of forest fragmentation with temperature and vitality in Germany per ecoregion at the canopy level using satellite imagery at 1-km and 30-m resolution. We compiled and correlated forest maps for connectivity based on Thiessen polygons, canopy temperatures on the hottest days based on land surface temperature, and forest vitality based on the maximum normalized difference vegetation index per growing season. We differentiated between ecoregions and main forest types. In 2022, larger intact tree-covered areas that are less fragmented have relatively low temperatures on hot days and higher overall vitality. Nearly 98\% of the almost 1.95 million forest fragments at 30-m resolution in Germany are smaller than 1 km2, which cover nearly 30\% of the total forest area. To counteract the forest crisis, forest and landscape management should aim to reduce fragmentation and maintain tree biomass and forest cover in the landscape. Increasing the size of continuous forest fragments contributes to ecosystem-based adaptation to climate change.}, language = {en} } @article{GohrBlumroederSheiletal.2021, author = {Gohr, Charlotte and Blumr{\"o}der, Jeanette Silvin and Sheil, Douglas and Ibisch, Pierre L.}, title = {Quantifying the mitigation of temperature extremes by forests and wetlands in a temperate landscape}, series = {Ecological Informatics}, journal = {Ecological Informatics}, number = {66}, publisher = {Elsevier}, issn = {1574-9541}, doi = {10.1016/j.ecoinf.2021.101442}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:eb1-opus-4376}, year = {2021}, abstract = {As a result of ongoing climate change and more frequent heat events, the regulating services of land cover in terms of moderating and mitigating local temperatures are increasingly important. While the reduced temperatures found in forests and wetlands are recognized, their wider contribution to regional landscape cooling remains largely uncharacterized and unquantified. Herein, we propose and test a new method that estimates the temperature response and inertia of landscapes in high temperatures, based on land cover share. In order to achieve this goal, we combined the MODIS daytime land surface temperature (henceforth LST) time series and CORINE land cover data. We classified the time series in two ways, i.e. by stepwise temperature range (-10/-5 °C to +35/+40 °C) and by the occurrence of hot days (days with a mean LST ≥ 30 °C). As an explanatory variable, we developed and used a greenest pixel composite of the MODIS normalized difference vegetation index (NDVI) time series. In our study area, covering parts of northeastern Germany and western Poland, the fragmented landscape has heterogeneous temperature patterns, including urban heat islands, warm agricultural areas, cool forests and cold wetlands. We found that at high temperature ranges only forests and wetlands remained comparably cool, with LSTs up to 20.8 °C lower than the maximum LST in the study area. The analysis of land cover shares and LSTs revealed the substantial cooling effect of forests and wetlands in line with increasing land cover share in higher temperature ranges, as well as on hot days. The relation between LST and the NDVI indicated vegetation cover as the cause. We propose the corresponding metrics to quantify landscape-level temperature regulation. Equally, we advocate for management to identify these ecosystem services and their current and potential contributions, along with implications for sustaining and increasing, both tree cover and wetlands and thereby adapting landscapes to climate change.}, language = {en} }