Do wind turbines impact plant community properties in mountain region?

International audienceThe emergence of renewable energy infrastructures calls for a better understanding of their impact on biodiversity. The aim of the present study was to investigate in a mountain region the impact of a wind turbine on plant communities in their vicinity. A field survey was conducted in a wind farm situated in the Southern Romanian Carpathians, five years after the turbines were installed. We tested for the effects of the presence of the turbine and the distance to the turbine on plant species richness, on five plant ecological indicators and on the quality of the pastures. Overall, 33 plant species belonging to 16 families were recorded, and among them 21 were recorded in both the presence and the absence of wind turbine. The presence of a turbine did not affect the structure of the plant community, as the majority of the plots exhibited similar plant species richness and composition. Finally, the values of the ecological indicators and the pasture quality were not altered by the presence of the turbine. Such analyses could be extended over longer time periods so as to capture potential long-term effects and by integrating other environmental factors such as microclimatic conditions or soil properties

An application of triangle mesh models in detecting patterns of vegetation

This contribution presents the results of a work in progress, attempting to use discrete curvature for triangle meshes in order to automatically identify specific structures in remote sensing data. Specifically, the focus was on determining isolated trees, on the basis of data acquired through airborne laser scanning. Five methods for discrete curvatures were tested and compared for a triangle mesh derived from a high density point cloud. The best performance was obtained for the mean curvature computed by using the shape operator

Filtrations, weights and quiver problems

AbstractWe prove the relationship between stability of (generalized) linear dynamical systems and their reachability by using tools of linear algebra

A Method for Tree Detection Based on Similarity with Geometric Shapes of 3D Geospatial Data

This paper presents an approach to detecting patterns in a three-dimensional context, emphasizing the role played by the local geometry of the surface model. The core of the associated algorithm is represented by the cosine similarity computed to sub-matrices of regularly gridded digital surface/canopy models. We developed an accompanying software instrument compatible with a GIS environment which allows, as inputs, locations in the surface/canopy model based on field data, pre-defined geometric shapes, or their combination. We exemplified the approach for a study case dealing with the locations of scattered trees and shrubs previously identified in the field in two study sites. We found that the variation in the pairwise similarities between the trees is better explained by the computation of slopes. Furthermore, we considered a pre-defined shape, the Mexican Hat wavelet. Its geometry is controlled by a single number, for which we found ranges of best fit between the shapes and the actual trees. Finally, a suitable combination of parameters made it possible to determine the potential locations of scattered trees. The accuracy of detection was equal to 77.9% and 89.5% in the two study sites considered. Moreover, a visual check based on orthophotomaps confirmed the reliability of the outcomes

Landscape persistence and stakeholder perspectives: The case of Romania's Carpathians

The traditional use of land for food, fuel and wood created cultural landscapes, which are threatened across Europe. The factors which contributed to their endangerment need to be identified to achieve effective preservation of such landscapes. The aim of our study was to identify landscapes with historical persistence in a GIS-based comparative analysis of historical and contemporary maps and the most prominent causes of the past landscape changes, based on stakeholders' perspective. We considered a case study in Romania's Carpathians. Three major land cover types were extracted from maps dating from 1912, 1980 and 2009: built-up, pastures and forests. The historical persistence of all land cover types was poor (<20%) and profound changes were quantitatively confirmed. Large, compact patches of unchanged forests were located in the neighbourhood of a national park. The persistent pastures were situated close to human settlements, and their preservation can be related to local traditional agro-silvo-pastoral management. Although the built-up area has increased over time, the corresponding surfaces are small and consist of scattered patches located around historical monuments. Semi-structured interviews were conducted to investigate stakeholders' perspective. Using cluster analysis five prominent causes of past landscape changes are identified: 'increasing tourism', 'land tenure and social changes', 'land-use intensification', 'post-communist transition', and 'foreign investments'. We join the results of the GIS analysis with those from stakeholders' perspective to gain more insights into the landscape changes. This research offers important information that could be used for the further planning of these valuable cultural landscapes in order to avoid potential conflicts and degradation. (C) 2015 Elsevier Ltd. All rights reserved

Landscape-scale simulation experiments test Romanian and Swiss management guidelines for mountain pasture-woodland habitat diversity

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