Models for Forest Ecosystem Management: A European Perspective

Background Forest management in Europe is committed to sustainability. In the face of climate change and accompanying risks, however, planning in order to achieve this aim becomes increasingly challenging, underlining the need for new and innovative methods. Models potentially integrate a wide range of system knowledge and present scenarios of variables important for any management decision. In the past, however, model development has mainly focused on specific purposes whereas today we are increasingly aware of the need for the whole range of information that can be provided by models. It is therefore assumed helpful to review the various approaches that are available for specific tasks and to discuss how they can be used for future management strategies. Scope Here we develop a concept for the role of models in forest ecosystem management based on historical analyses. Five paradigms of forest management are identified: (1) multiple uses, (2) dominant use, (3) environmentally sensitive multiple uses, (4) full ecosystem approach and (5) eco-regional perspective. An overview of model approaches is given that is dedicated to this purpose and to developments of different kinds of approaches. It is discussed how these models can contribute to goal setting, decision support and development of guidelines for forestry operations. Furthermore, it is shown how scenario analysis, including stand and landscape visualization, can be used to depict alternatives, make long-term consequences of different options transparent, and ease participation of different stakeholder groups and education. Conclusions In our opinion, the current challenge of forest ecosystem management in Europe is to integrate system knowledge from different temporal and spatial scales and from various disciplines. For this purpose, using a set of models with different focus that can be selected from a kind of toolbox according to particular needs is more promising than developing one overarching model, covering ecological, production and landscape issues equally wel

Tracing drought effects from the tree to the stand growth in temperate and Mediterranean forests: insights and consequences for forest ecology and management

How drought affects tree and stand growth is an old question, but is getting unprecedented relevance in view of climate change. Stress effects related to drought have been mostly studied at the individual tree level, mostly investigating dominant trees and using their responses as indicator for the impact at the stand level. However, findings at tree and stand level may differ, as the stand responses include interactions and feedbacks that may buffer or aggravate what is observed at the individual tree level. Here, we trace drought effects on growth and development from tree to the stand scale. Therefore, we analyse annually measured data from long-term experiments in temperate and Mediterranean forests. With this analysis, we aim to disclose how well results of dominant tree growth reflect stand-level behaviour, hypothesizing that drought resistance of dominant trees’ can strongly deviate from the overall sensitivity of the stand. First, we theoretically derive how drought responses at the stand level emerge from the tree-level behaviour, thereby considering that potential drought resistance of individual trees is modulated by acclimation and tree–tree interactions at the stand level and that the overall stress response at the stand level results from species-specific and size-dependent individual tree growth and mortality. Second, reviewing respective peer-reviewed literature (24 papers) and complementing findings by own measurements (22 experiments) from temperate and Mediterranean monospecific and mixed-species forests, we are able to reveal main causes for deviations of tree-level and stand-level findings regarding drought stress responses. Using a long-term experiment in Norway spruce (Picea abies (L.) KARST.) and European beech (Fagus sylvatica L.), we provide evidence that the species-dependent and size-dependent reactions matter and how the size–frequency distribution affects the scaling. We show by examples that tree-level derived results may overestimate growth losses by 25%. Third, we investigate the development of the growth dominance coefficient based on measurements gathered at the Bavarian forest climate stations. We show that drought changes stand biomass partitioning in favour of small trees, reduce social differentiation, and homogenize the vertical structure of forests. Finally, we discuss the drought-related consequences of the social class-specific growth reaction patterns for inventory and monitoring and highlight the importance of these findings for understanding site-specific stand dynamics, for forest modelling, and for silvicultural management

Enhanced ozone strongly reduces carbon sink strength of adult beech (Fagus sylvatica) – Resume from the free-air fumigation study at Kranzberg Forest

Ground-level ozone (O3) has gained awareness as an agent of climate change. In this respect, key results are comprehended from a unique 8-year free-air O3-fumigation experiment, conducted on adult beech (Fagus sylvatica) at Kranzberg Forest (Germany). A novel canopy O3 exposure methodology was employed that allowed whole-tree assessment in situ under twice-ambient O3 levels. Elevated O3 significantly weakened the C sink strength of the tree–soil system as evidenced by lowered photosynthesis and 44% reduction in whole-stem growth, but increased soil respiration. Associated effects in leaves and roots at the gene, cell and organ level varied from year to year, with drought being a crucial determinant of O3 responsiveness. Regarding adult individuals of a late-successional tree species, empirical proof is provided first time in relation to recent modelling predictions that enhanced ground-level O3 can substantially mitigate the C sequestration of forests in view of climate change

Modeling Tree Growth Taking into Account Carbon Source and Sink Limitations

Increasing CO2 concentrations are strongly controlled by the behavior of established forests, which are believed to be a major current sink of atmospheric CO2. There are many models which predict forest responses to environmental changes but they are almost exclusively carbon source (i.e., photosynthesis) driven. Here we present a model for an individual tree that takes into account the intrinsic limits of meristems and cellular growth rates, as well as control mechanisms within the tree that influence its diameter and height growth over time. This new framework is built on process-based understanding combined with differential equations solved by numerical method. Our aim is to construct a model framework of tree growth for replacing current formulations in Dynamic Global Vegetation Models, and so address the issue of the terrestrial carbon sink. Our approach was successfully tested for stands of beech trees in two different sites representing part of a long-term forest yield experiment in Germany. This model provides new insights into tree growth and limits to tree height, and addresses limitations of previous models with respect to sink-limited growth.PMP scheme, Cambridge Faculty of Mathematic

The southernmost beech (Fagus sylvatica) forests of Europe (Mount Etna, Italy): ecology, structural stand-type diversity and management implications

The southernmost European beech forests are located in the upper forest vegetation belt on Mount Etna volcano. Their standstructural patterns were analysed to assess the effects of the site-ecological factors and previous management practices on the forest structure. Five main structural-silvicultural types were identified among the main beech forest types: coppice, highmountain coppice (HMCo), high forest, coppice in conversion to high-forest and non-formal stand. A detailed standstructural analysis was carried out through measured dendrometric parameters and derived structural characters linked to both the horizontal and the vertical profiles. Plant regeneration processes were also assessed, and several biodiversity indicators were calculated. The collected data indicate a high variability of beech stand structures in relation to the heterogeneity of the site-ecological characteristics as well as to the effects of both natural and anthropic disturbance factors. The occurrence of particular stand structures along the altitude gradient on Mount Etna is evident. It is especially visible in the multi-stemmed HMCos in relation to the changing, and increasingly limiting, ecological factors, although at higher altitudes historical anthropic actions (felling) also have had an influence. Inside the Mediterranean area, these stands highlight their ecological marginality, in terms of both latitude and altitude, especially regarding current climate change processes

Effect of platelet inhibition with perioperative aspirin on survival in patients undergoing curative resection for pancreatic cancer: a propensity score matched analysis

BACKGROUND The importance of platelets in the pathogenesis of metastasis formation is increasingly recognized. Although evidence from epidemiologic studies suggests positive effects of aspirin on metastasis formation, there is little clinical data on the perioperative use of this drug in pancreatic cancer patients. METHODS From all patients who received curative intent surgery for pancreatic cancer between 2014 and 2016 at our institution, we identified 18 patients that took aspirin at time of admission and continued to throughout the inpatient period. Using propensity score matching, we selected a control group of 64 patients without aspirin intake from our database and assessed the effect of aspirin medication on overall, disease-free, and hematogenous metastasis-free survival intervals as endpoints. RESULTS Aspirin intake proved to be independently associated with improved mean overall survival (OS) (46.5 vs. 24.6 months, *p = 0.006), median disease-free survival (DFS) (26 vs. 10.5 months, *p = 0.001) and mean hematogenous metastasis-free survival (HMFS) (41.9 vs. 16.3 months, *p = 0.005). Three-year survival rates were 61.1% in patients with aspirin intake vs. 26.3% in patients without aspirin intake. Multivariate cox regression showed significant independent association of aspirin with all three survival endpoints with hazard ratios of 0.36 (95% CI 0.15-0.86) for OS (*p = 0.021), 0.32 (95% CI 0.16-0.63) for DFS (**p = 0.001), and 0.36 (95% CI 0.16-0.77) for HMFS (*p = 0.009). CONCLUSIONS Patients in our retrospective, propensity-score matched study showed significantly better overall survival when taking aspirin while undergoing curative surgery for pancreatic cancer. This was mainly due to a prolonged metastasis-free interval following surgery

A systems perspective on the interactions between urban green infrastructure and the built environment

This research addresses the intricate dynamics between urban green infrastructure (UGI) and the built environment, focusing on the effects of urban heat islands, building energy demand, and human health. Following the idea of the Socio-Ecological-Technological Systems framework, we investigate key indicators related to green and grey infrastructure and their interactions at the urban scale. We construct a comprehensive causal-loop diagram through an iterative approach involving literature analysis and expert consultation. The outcomes highlight the significance of urban form and green infrastructure in connecting indoor and outdoor spaces. This research enhances the understanding of systemic behavior in the urban fabric and offers insights into the complex interactions between UGI and the built environment. The approach underscores the value of iterative modeling, fostering collaborative efforts and providing a foundation for further system modeling. Future research should focus on quantitative validation of the identified connections. Additionally, connection strengths and spatial elements would be valuable extensions of the presented system model

Effects of growth rate, size, and light availability on tree survival across life stages: a demographic analysis accounting for missing values and small sample sizes.

The data set supporting the results of this article is available in the Dryad repository, http://dx.doi.org/10.5061/dryad.6f4qs. Moustakas, A. and Evans, M. R. (2015) Effects of growth rate, size, and light availability on tree survival across life stages: a demographic analysis accounting for missing values.Plant survival is a key factor in forest dynamics and survival probabilities often vary across life stages. Studies specifically aimed at assessing tree survival are unusual and so data initially designed for other purposes often need to be used; such data are more likely to contain errors than data collected for this specific purpose