Decision support tools and strategies to simulate forest landscape evolutions integrating forest owner behaviour: a review from the case studies of the European Project, INTEGRAL

For forest sustainability and vulnerability assessment, the landscape scale is considered to be more and more relevant as the stand level approaches its known limitations. This review, which describes the main forest landscape simulation tools used in the 20 European case studies of the European project “Future-oriented integrated management of European forest landscapes” (INTEGRAL), gives an update on existing decision support tools to run landscape simulation from Mediterranean to boreal ecosystems. The main growth models and software available in Europe are described, and the strengths and weaknesses of different approaches are discussed. Trades-offs between input efforts and output are illustrated. Recommendations for the selection of a forest landscape simulator are given. The paper concludes by describing the need to have tools that are able to cope with climate change and the need to build more robust indicators for assessment of forest landscape sustainability and vulnerability.The INTEGRAL project has received funding from the European Union’s Seventh Programme for research, technological development and demonstration under grant agreement No. 282887. http://www. integral-project.eu/. Moreover, financial support by the Transnational Access to Research Infrastructures activity in the 7th Framework Programme of the EC under the Trees4Future project (No. 284181) for conducting the research is gratefully acknowledged. This research has also received funding from the European Union H2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 691149 (SuFoRun). Researcher Jordi Garcia-Gonzalo was supported by a “Ramon y Cajal” research contract from the MINECO (Ref. RYC-2013-14262) and has received funding from CERCA Programme/Generalitat de Catalunya. This paper could be achieved thanks to support of EFIATLANTIC donors: Conseil regional d’Aquitaine, Ministère de l’agriculture et de la forêt

How sensitive are ecosystem services in European forest landscapes to silvicultural treatment?

While sustainable forestry in Europe is characterized by the provision of a multitude of forest ecosystem services, there exists no comprehensive study that scrutinizes their sensitivity to forest management on a pan-European scale, so far. We compile scenario runs from regionally tailored forest growth models and Decision Support Systems (DSS) from 20 case studies throughout Europe and analyze whether the ecosystem service provision depends on management intensity and other co-variables, comprising regional affiliation, social environment, and tree species composition. The simulation runs provide information about the case-specifically most important ecosystem services in terms of appropriate indicators. We found a strong positive correlation between management intensity and wood production, but only weak correlation with protective and socioeconomic forest functions. Interestingly, depending on the forest region, we found that biodiversity can react in both ways, positively and negatively, to increased management intensity. Thus, it may be in tradeoff or in synergy with wood production and forest resource maintenance. The covariables species composition and social environment are of punctual interest only, while the affiliation to a certain region often makes an important difference in terms of an ecosystem service’s treatment sensitivityinfo:eu-repo/semantics/publishedVersio

An Improved Weise’s Rule for Efficient Estimation of Stand Quadratic Mean Diameter

The main objective of this study was to explore the accuracy of Weise’s rule of thumb applied to an estimation of the quadratic mean diameter of a forest stand. Virtual stands of European beech (Fagus sylvatica L.) across a range of structure types were stochastically generated and random sampling was simulated. We compared the bias and accuracy of stand quadratic mean diameter estimates, employing different ranks of measured stems from a set of the 10 trees nearest to the sampling point. We proposed several modifications of the original Weise’s rule based on the measurement and averaging of two different ranks centered to a target rank. In accordance with the original formulation of the empirical rule, we recommend the application of the measurement of the 6th stem in rank corresponding to the 55% sample percentile of diameter distribution, irrespective of mean diameter size and degree of diameter dispersion. The study also revealed that the application of appropriate two-measurement modifications of Weise’s method, the 4th and 8th ranks or 3rd and 9th ranks averaged to the 6th central rank, should be preferred over the classic one-measurement estimation. The modified versions are characterised by an improved accuracy (about 25%) without statistically significant bias and measurement costs comparable to the classic Weise method

Siltation of Small Water Reservoir under Climate Change: A Case Study from Forested Mountain Landscape of Western Carpathians, Slovakia

The effectiveness of small reservoirs in a mountain landscape continuously decreases over time due to the gradual siltation. We examined two hypotheses about the enhanced siltation rate and the constant relative contribution of unpaved roads to the siltation of a small water reservoir in the period 1990–2014, with pronounced climate change, compared to the reference period 1970–1989. Analysis was based on deposit volumes extracted from the reservoir in 1989 and detected at the reservoir bottom in 2014. The geographical information systems, image analysis and universal soil loss equation were applied to model the soil erosion according to the two sources—catchment area and roads—to study siltation processes in depth. Despite expectations, rates of siltation were almost unchanged in compared periods. The positive changes in vegetation cover (the forest expansion and changes in forest management practices) offset the enlarged rain erosivity. On the other hand, road erosion increased by 41% from 1990 and became twice as much a contributor to sediments compared to 1970–1989. The intensity of erosion from roads was from 13 to 29 times greater than from other areas. Therefore, proper maintenance of road networks could rapidly decrease reservoir siltation. Moreover, we recommend continuous cover forestry as a critical measure for central Europe’s forested regions to prevent growing erosion pressures

Forest management scenarios modelling with morphological analysis – examples taken from Podpoľanie and Kysuce

Scenarios modelling offers to forest management an option how to envision complex future associated with various natural, social, or economic uncertainties. The challenge is what modelling method to choose as many methodological approaches to scenario building exists. Morphological analysis is a basic modelling method for structuring and analysing a whole set of relationships existing in multi-dimensional, non-quantifiable, and complex topics. Especially, its application is relevant when abstract policy or market-driven challenges need to be investigated. In this study, we demonstrated the usefulness of the morphological analysis with an example case taken from forest management in Slovakia. The use of the method has enabled, from a number of uncertain futures, to identify three possible, plausible and consistent future scenarios of possible forest management direction in the regions of Podpoľanie and Kysuce. Additionally, the future scenario modelling as prognostic method of qualitative research supported by quantitative models or forestry DSS could introduce participation and more dimensions into forest management modelling. Thus, the future scenarios modelling offers new methodological possibilities to how to deal with increasing uncertainties associated with increasing demands for various ecosystem services or negative impacts of climate change, that forest management in Slovakia will face in the near future

Siltation of Small Water Reservoir under Climate Change: A Case Study from Forested Mountain Landscape of Western Carpathians, Slovakia

The effectiveness of small reservoirs in a mountain landscape continuously decreases over time due to the gradual siltation. We examined two hypotheses about the enhanced siltation rate and the constant relative contribution of unpaved roads to the siltation of a small water reservoir in the period 1990–2014, with pronounced climate change, compared to the reference period 1970–1989. Analysis was based on deposit volumes extracted from the reservoir in 1989 and detected at the reservoir bottom in 2014. The geographical information systems, image analysis and universal soil loss equation were applied to model the soil erosion according to the two sources—catchment area and roads—to study siltation processes in depth. Despite expectations, rates of siltation were almost unchanged in compared periods. The positive changes in vegetation cover (the forest expansion and changes in forest management practices) offset the enlarged rain erosivity. On the other hand, road erosion increased by 41% from 1990 and became twice as much a contributor to sediments compared to 1970–1989. The intensity of erosion from roads was from 13 to 29 times greater than from other areas. Therefore, proper maintenance of road networks could rapidly decrease reservoir siltation. Moreover, we recommend continuous cover forestry as a critical measure for central Europe’s forested regions to prevent growing erosion pressures

Evaluation of tree stump measurement methods for estimating diameter at breast height and tree height

The estimation of diameter at breast height (DBH) and tree height from stump dimensions plays a crucial role in assessing the economic and environmental impacts resulting from illegal logging or natural disasters. In this study, we assessed tree stump dimension measurements using a tape measure, nadir color photographs, and the UAV orthophoto. We explored challenges in stump measurement and evaluated the effectiveness of these measurement methods in predicting DBH and tree height from stump dimensions. The study was conducted on 93 stumps of European beech (Fagus sylvatica L.) in a 100-year-old forest with a planned timber harvest. In the first part of the study, we compared the smallest and largest diameter, circumference, and area of the stumps measured by the methods studied. The best correlation was found between the stump measurements on the UAV orthophoto and the nadir color photographs. The tape measurements were statistically significantly different from the measurements on the UAV orthophoto. Most of the outliers in the measurements were found in the pairs of UAV orthophoto and nadir photographs. An incorrect determination of the shape of the tree stump in the UAV orthophoto mainly caused the outliers. The visibility of the tree stumps in the orthophoto was affected by nearby vegetation, logging residues, and light conditions. In the second part of the study, we derived linear regression models for one, two, and three independent variables of DBH and measured tree stump sizes and linear regression models for tree height and measured stump sizes. The performance of the linear regression models for DBH was similar for all stump measurement methods examined. For the linear regression models for tree height, the best accuracy was obtained for models based on measurements on nadir photographs. Increasing the number of independent variables only slightly improved the accuracy of the linear regression models. We also tested whether using the average distance to the three nearest tree stumps measured on a UAV orthophoto could improve the accuracy of linear regression models. Including the average distance to the three nearest stumps did not improve the accuracy of the linear regression models for DBH but did help improve the accuracy of the distance-dependent linear regression models for tree height. The performance of the linear regression models for tree height for two and three independent variables was similar for all stump measurement methods examined. Given the accuracy of DBH and tree height estimates and the error distribution, top-down photography appears to be the most appropriate method for measuring stump size. Stump accessibility, forest regeneration, obstacles, time required for data collection, complexity of data processing, and expected accuracy of stump measurements must all be considered when selecting an appropriate method for stump surveying. The influence of the surveyor's skills on the field measurements and the orthophoto interpretation must also be considered