Papers by beatriz fidalgo
The majority of forested area in Portugal was planted in 20th century. Extended plantations were ... more The majority of forested area in Portugal was planted in 20th century. Extended plantations were performed with maritime pine and with the fast-growing exotic species Eucalyptus globulus make up a large proportion of the forest land (60%). Opinions differ as to the value of the new forests for biodiversity, but numerous studies have highlighted the positive value of planted forests for wildlife. This study was performed in order to carry out a comparison of biodiversity in planted areas on a range of varied sites, similarly attempts to compare biodiversity in planted areas with remnant native forests. In other words, our research aimed at obtaining information on the type/levels of biodiversity in planted forests; evaluating the contribution of planted areas to conservation of native flora through the comparison with native broadleaved stands; identifying indicators by relating the diversity to vegetation and stand structure variables. This study was carried out in Centro Region in ...
In Europe traditional mosaic landscapes have been experienced dramatic changes through either int... more In Europe traditional mosaic landscapes have been experienced dramatic changes through either intensification or abandonment of land use. Both trends are thought to affect plant diversity in forest areas. To evaluate the sustainability of specific forest systems we need approaches for 1) assessment of the contribution of different land use systems for plant species diversity and 2) identification of habitat and landscape features that lead to patterns of biodiversity. Despite good theoretical knowledge about determinants of plant species richness in mosaic landscapes, validations based on surveys are scarce. We conducted a case study in a forested landscape in Central Portugal, with an area of 130 km 2 , were the already referred drivers of change have been shaping the landscape in the past decades. We used aerial photo-interpretation to identify land cover/use types; and a multi-scale field inventory to assess plant species diversity. Diversity measures were calculated at patch, ha...
Visibility analysis and visual diversity assessment in rural landscapes
Analysing the visibility of landscape features is usually based on methods which calculate the nu... more Analysing the visibility of landscape features is usually based on methods which calculate the number of locations from which such features are visible. However, visibility analysis using Geographic Information Systems (GIS) suffers from several limitations which can significantly influence the results. In this study the authors have tested the differences in visibility through time, and used a Digital Elevation Model which includes the heights of land cover features. The results provided information about the visibility of each land cover type, at each of three dates: 1954, 1974 and 1995. The derived maps of visibility were used as inputs to analysis of the visual content of the landscape, which were then used to evaluate the visual diversity at each date, and to provide an input to the derivation of information on landscape visual quality. The results show significant differences in both visual content and diversity through time, and illustrate a difference between the potential p...
Changes in the Landscape Protected Area of Serra do Açor, occurred as a consequence of the intera... more Changes in the Landscape Protected Area of Serra do Açor, occurred as a consequence of the interaction of environmental factors such as climate and geomorphology, with cultural social and economic driven forces. This work studied the extent of the changes in land use that occurred in the area during a thirty year period and proposes an operational way of computing an amenity index for the area, based on spatial attributes such as visibility, accessibility and visual diversity, and other intrinsic attributes of the different patches. We came to the conclusion that the studied area has high dynamics in what concerns land use changes. The main evidence is the fact that the area of broadleaved increased whereas the area of pine forests and agricultural areas decreased dramatically. That index, with a quantitative and spatial dimension, allowed the discrimination of areas with different recreation and landscape potential values, as well as the identification of the sensitive areas from t...
Governo da República Portuguesa, 2018
Geografia, Riscos e Proteção Civil. Homenagem ao Professor Doutor Luciano Lourenço. Volume 2, 2021
Os danos causados por distúrbios provocados por pragas e doenças ou fenómenos climatéricos extrem... more Os danos causados por distúrbios provocados por pragas e doenças ou fenómenos climatéricos extremos, têm vindo a intensificar-se nas florestas de toda a Europa e também em Portugal, fruto das alterações climáticas em curso e da gestão florestal aplicada. Neste trabalho estuda-se o efeito destes distúrbios na estrutura e composição de povoamentos de pinheiro bravo e estimam-se os impactos na produção de serviços de produção lenhosa, captura de carbono e biodiversidade. Conclui-se que a ação continuada dos distúrbios produz alterações estruturais nos povoamentos que conduzem a uma diminuição importante na sua capacidade de fornecimento dos serviços dos ecossistemas estudados e que indicam a necessidade de aplicar novos modelos de silvicultura na gestão destes povoamentos.
Symmetry
Measuring biometric tree characteristics to estimate the volume of wood in a forest area is a tim... more Measuring biometric tree characteristics to estimate the volume of wood in a forest area is a time consuming task. It is usually performed by a team of two or more people, who measure the diameter and height of several trees in sampling plots. The results are then extrapolated for the forest stand. The present paper describes a method which facilitates estimating tree biometric parameters using computational techniques. A camera takes two pictures of each sample tree, with an especially designed target placed close to the tree, to facilitate image processing and camera calibration steps. Taking advantage of the trees’ natural shape and assuming a symmetric stem, the diameter and height of the tree stems are estimated from the images and the volumes of the tree stems are calculated. Experimental trials show promising results, exhibiting errors similar to the traditional methods used currently, in the range of 10%, showing that the method is suitable for forest inventory.
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Papers by beatriz fidalgo