Comparison of Pruning Regimes for Stone Pine (Pinus pinea L.) Using a Functional- Structural Plant Model

Functional-Structural Plant Models (FSPM) are becoming important tools for modeling the structure and growth of plants, including complex organisms like trees. These models combine the advantages of empirical, mechanistic, and structural models to simulate the growth of individual plant structures (branches, buds, leaves, etc.). This approach enables realistic evaluation of the plant’s response– including changes in structure and growth to different environmental conditions. We demonstrate the potential use of these models to evaluate individual tree growth under different management regimes (pruning). The data used in this study was obtained from 3-D measurements taken with a FASTRAK Polhemus digitizer, with specific attention given to bud creation and branching. Each branch segment was analyzed to estimate its age, enabling us to document annual structural changes. We use the XL programming language and a GroIMP environment to simulate and compare different pruning scenarios

Optimal Regeneration Regime under Continuous Crown Cover Requirements in Cork Oak Woodlands

In the present work the cork oak tree spatial growth simulator CORKFITS is used to create candidate scenarios for generating a large set of regeneration regimes combining both time and intensity factors with the individual tree spatial information. An optimal regeneration regime under continuous crown cover requirements is sought by applying a dynamic programming algorithm. It is shown that the crown cover constraint influences the total cork production potential in a negative way. The target cover constraint of 50% decreases the cork production by 66% from the potential in 40 years in our mature plot, and approximately 43% in our young plot. Higher crown cover constraint of 70% decreases the potential cork production approximately by 54% in the mature plot and does not have any influence on the younger plot. The observed losses in cork production in relation with the potential with the crown cover constrains need to be compensated economically by the higher availability of growing space for the grazing and livestock part of the montado/dehesa production system

Growth modeling in complex forest systems: CORKFITS a tree spatial growth model for cork oak woodlands

Cork oak (Quercus suber L.) woodlands (montado) consist of a multifunctional forest system that covers about 713,000 ha in Portugal. Today, its importance stems from cork production, with Portugal producing half of the cork in the world. As the main economic objectives may change with changes in markets and environment conservation concerns (e.g. biodiversity, water, carbon) there is a need for improved management tools. Spatial tree growth simulators are tools that enable the generation of tree growth scenarios dependent on site and competition status, that allow to simulate large scope management actions. In the present work it is presented a cork oak tree spatial growth simulator, CORKFITS, that was constructed with data generated by the monitoring system installed in 1995. The simulator was built assuming the potential increment modifier principle: z = zpot * modifier + ε, where zpot is the potential growth as function of site; modifier is the reduction factor as function of spatial competition index and the intensity of debark; ε is a random error. CORKFITS is composed by sub growth models (cork, stem, tree height and crown), cork production models and mortality models. Single trees are in cork oak woodlands subjected to natural (genetics and competition) and artificial (debark, crown pruning, root pruning) factors that affects their growth therefore there is a large amount of unexplained variability which creates problems in the modeling phase, the solutions for these problems will be discussed in the present work

Economic implications of different cork oak forest management systems

The agro-silvopastoral system 'montado' is mostly dominated by Mediterranean evergreen oaks such as, cork oak (Quercus suber L.) and holm oak (Quercus rotundifolia). The 'montado' production system management aims the maintenance of a balanced sustainable land use to cope with the Mediterranean climate variability. One important issue in cork oak forests is the control shrub growth in order to prevent forest fire hazard, which is of high risk in Mediterranean climate. In this article, two shrub control systems are compared and the results show that although soil disking is more profitable than shrub cutting, the results are reversed, if one considers the carbon sequestration. This means that besides the great economic sustainability of cork oak dependence on the price of cork, the profitability of different shrub control methods depend also on the way society valuates other goods and services provided by cork oak forest

Software development for forest growth models and management. CORKFITS: web based growth simulator

New methods of forest management and the study of their impact on sustainability are strongly dependent on realistic mathematical modelling. The complexity of the models however, makes the use of computational power, and thus the incorporation of knowledge from computer science and research, indispensable. In this paper we wish to demonstrate the development of a simulator for the growth and production of cork oak woodlands – montados. The software is divided into three sub-modules, sharing a common core, with functions and mathematical operations. The desktop client allows for repeated operations for more intense calculations, and statistical operations for modelling purposes. The web version is intended to be used by final users in forest practice. It permits simulation of inventory data based on individual tree measurements, and inventory data based on plot description with a reduced amount of detail (number of trees per ha, diameter structure, etc.) The last module allows the incorporation of the cork model into other software by means of SOAP protocol, via web services. It conforms to the WS-I Basic Profile 1.1, to ensure interoperability among the largest number of clients. This module allows other developers to use the cork oak growth-model in their software, and the developers from other areas of expertise (management optimisation, decision support...) have the opportunity to test their techniques on real stands, with the most recently-updated model versions

Observations on 3-dimensional crown growth of Stone pine

In this work we wish to demonstrate the possibility of a reconstruction of the 3D growth of the Stone pine (Pinus pinea L) crown. The crowns of two samples were digitized in segments corresponding with individual years, which allowed us to reconstruct length-growth and 3D shape over the last 5 years. Due to the low sample amount, we limited ourselves to observations and methodology-descriptions instead of overall conclusions. We were able to observe diminished height-growth in year 2006, which is the year after a severe drought. However, this was not observed in the total length-growth of the crown. It is possible to see that the growth of 2006 is not dominant at the top of the crown, as it would have been in normal years. The year of the drought, 2005, is visible in the annual rings, but the shoot length of 2005 is not visibly lower than expected

Economic implications of different cork oak forest management systems

The agro-silvopastoral system “montado” dominates the landscape of the south-western Iberian Peninsula, occupies approximately 3.1 million hectares of woodland in Spain and 1.2 million hectares in Portugal. The forest system “montado” is mostly dominated by Mediterranean evergreen oaks such as cork oak (Quercus suber L.) and holm oak (Quercus rotundifolia). The “montado” production system management aims the maintenance of a balanced sustainable land use to cope with the Mediterranean climate variability. One important issue in cork oak forests is the control shrub growth in order to prevent forest fire hazard, which is of high risk in Mediterranean climate. The two most common ways of controlling the shrub component is by mechanical destruction with soil disking (that implicates soil mobilization) or by shrub cutting (that is done with minimum impact on soil). The two referred techniques have different costs and different impacts on cork production and other goods and services (multifunctionality) of cork oak forests. In this paper, the two shrub control systems are compared and the results show that, although soil disking is more profitable than shrub cutting, the results are reversed, if one considers the carbon sequestration. This means that besides the great economic sustainability of cork oak dependence on the price of cork, the profitability of different shrub control methods depend also on the way society valuates other goods and services provided by cork oak forest

Integrating differentiated landscape preferences in a decision support model for the multifunctional management of the Montado

A great part of the Alentejo region in Southern Portugal is covered by an agro-silvo pastoral system, the Montado. This traditional landuse system is specific, inter alia, in its ability to join production with favorable conditions for non-production functions. At the present time, as society positively evaluates and even demands cultural and amenity functions from the countryside, the Montado management faces the challenge of integrating production with non-production functions in a way which will result in suitable multifunctionality, and a more sound viability of the whole system. The decision support tool (DST) for the cork oak Montado management, the CORKFITS, based on the singletree growth model and working at the stand level, is oriented primarily to the management of the production functions, but it is able to integrate also other data that can contribute for a more multifunctionality oriented management. In this exploratory study, the integration in the DST, of the preference distribution, as expressed by landscape users is investigated. The aim was to test a more comprehensive functioning of this tool, where non-production functions are also integrated. The described integration intended to communicate to decision-makers how the change in management practices at tree and under cover level, might alter the satisfaction of expectations of different user groups, as such changes affect the composition of the Montado, at both levels. The users considered are those practicing non-production functions in the Montado. Preferences were assessed through a questionnaire survey applied in the region of Alentejo, in the area of dominance of the cork oak, in the Montado system. The non-production functions are, in this context, related particularly to hunting, aesthetic appreciation related to walking and other leisure activities, to life quality, and to tradition and identity, as well as bee-keeping and mushroom picking. This paper focuses on the description of the specific methodological steps applied for the successful integration of the landscape preferences of different user groups into the DST for the cork oak Montado. Integration has proved to be possible, even if some methodological challenges still need to be faced for a more consistent use of the proposed tool

FOR-instance: a UAV laser scanning benchmark dataset for semantic and instance segmentation of individual trees

The FOR-instance dataset (available at https://doi.org/10.5281/zenodo.8287792) addresses the challenge of accurate individual tree segmentation from laser scanning data, crucial for understanding forest ecosystems and sustainable management. Despite the growing need for detailed tree data, automating segmentation and tracking scientific progress remains difficult. Existing methodologies often overfit small datasets and lack comparability, limiting their applicability. Amid the progress triggered by the emergence of deep learning methodologies, standardized benchmarking assumes paramount importance in these research domains. This data paper introduces a benchmarking dataset for dense airborne laser scanning data, aimed at advancing instance and semantic segmentation techniques and promoting progress in 3D forest scene segmentation. The FOR-instance dataset comprises five curated and ML-ready UAV-based laser scanning data collections from diverse global locations, representing various forest types. The laser scanning data were manually annotated into individual trees (instances) and different semantic classes (e.g. stem, woody branches, live branches, terrain, low vegetation). The dataset is divided into development and test subsets, enabling method advancement and evaluation, with specific guidelines for utilization. It supports instance and semantic segmentation, offering adaptability to deep learning frameworks and diverse segmentation strategies, while the inclusion of diameter at breast height data expands its utility to the measurement of a classic tree variable. In conclusion, the FOR-instance dataset contributes to filling a gap in the 3D forest research, enhancing the development and benchmarking of segmentation algorithms for dense airborne laser scanning data

Cork influenced by a specific water regime—macro and microstructure characterization: the first approach

Cork is the most valuable non-wood product of the cork oak (Quercus suber L.). However, the cork oak sector may be at risk due to climatic and economic pressures on cork oak forests, affecting both the quantity and technological quality of products. At some sites, irrigation may present a solution for stimulating cork growth and thereby increasing production. This study presents an initial approach to characterizing cork grown in a forest stand associated with a specific water regime, by comparing cork growth on two plots—irrigated and a traditional rainfed—over an initial five-year period. Samples of cork tissue were analysed and several parameters were set: cell area, diameter, cell-wall thickness, number of cells, porosity, growth, and density. Irrigation plot samples showed on average: 25.83 ± 3.74 mm thickness, 5.17 ± 1.49 mm cork-ring width, 0.149 ± 0.041 g.cm−3 density, 13 ± 3.4% porosity coefficient in the tangential plane, 407.58 ± 268.22 µm2 cell area in the tangential plane and 887.80 ± 449.14 µm2 in the transverse plane, a total number of cells of 1232 ± 147 per mm2, and 1.03 ± 0.30 µm cell-wall thickness; whereas traditional rainfed plot samples presented: 21.33 ± 5.48 mm thickness, 3.08 ± 1.44 mm cork-ring width, 0.167 ± 0.068 g.cm−3 density, 10 ± 3.5% porosity coefficient in the tangential plane, 304.31 ± 205.83 µm2 cell area in the tangential plane and 752.45 ± 398.94 µm2 in the transverse plane, a total number of cells of 1481 ± 153 per mm2, and 1.204 ± 0.327 µm cell-wall thickness. As regards irrigation, two parameters, ring width and porosity coefficient, proved to be statistically significant, in contrast to density. Access provided by Universidade de Évora, member of B-on Consortium Portuga