scholarly journals Mapping Riparian Habitats of Natura 2000 Network (91E0*, 3240) at Individual Tree Level Using UAV Multi-Temporal and Multi-Spectral Data

2021 ◽  
Vol 13 (9) ◽  
pp. 1756
Author(s):  
Elena Belcore ◽  
Marco Pittarello ◽  
Andrea Maria Lingua ◽  
Michele Lonati
Keyword(s):  
Optical Sensors ◽  
Conservation Status ◽  
Natura 2000 ◽  
Optical Data ◽  
Training Dataset ◽  
Tree Level ◽  
Natura 2000 Network ◽  
Individual Tree ◽  
Multi Temporal ◽  
Riparian Habitats

Riparian habitats provide a series of ecological services vital for the balance of the environment, and are niches and resources for a wide variety of species. Monitoring riparian environments at the intra-habitat level is crucial for assessing and preserving their conservation status, although it is challenging due to their landscape complexity. Unmanned aerial vehicles (UAV) and multi-spectral optical sensors can be used for very high resolution (VHR) monitoring in terms of spectral, spatial, and temporal resolutions. In this contribution, the vegetation species of the riparian habitat (91E0*, 3240 of Natura 2000 network) of North-West Italy were mapped at individual tree (ITD) level using machine learning and a multi-temporal phenology-based approach. Three UAV flights were conducted at the phenological-relevant time of the year (epochs). The data were analyzed using a structure from motion (SfM) approach. The resulting orthomosaics were segmented and classified using a random forest (RF) algorithm. The training dataset was composed of field-collected data, and was oversampled to reduce the effects of unbalancing and size. Three-hundred features were computed considering spectral, textural, and geometric information. Finally, the RF model was cross-validated (leave-one-out). This model was applied to eight scenarios that differed in temporal resolution to assess the role of multi-temporality over the UAV’s VHR optical data. Results showed better performances in multi-epoch phenology-based classification than single-epochs ones, with 0.71 overall accuracy compared to 0.61. Some classes, such as Pinus sylvestris and Betula pendula, are remarkably influenced by the phenology-based multi-temporality: the F1-score increased by 0.3 points by considering three epochs instead of two.

scholarly journals Landscape Changes in Protected Areas in Poland

2022 ◽  
Vol 14 (2) ◽  
pp. 753
Author(s):  
Anna Zbierska
Keyword(s):  
Land Cover ◽  
Protected Areas ◽  
Conservation Status ◽  
Coniferous Forest ◽  
Ecological Integrity ◽  
Natura 2000 ◽  
Nature Protection ◽  
Natura 2000 Network ◽  
Buffer Zones ◽  
Legal Forms

Land-Use Cover Changes (LUCCs) are one of the main problems for the preservation of landscapes and natural biodiversity. Protected Areas (PAs) do not escape this threat. Poland is among the European leaders in terms of the variety of landscapes and the share of an area designated as a protected area. However, as many as 78% of the habitats have poor or bad conservation status based on EEA reports. This article analyzes the LUCCs between 2000 and 2018 in various types of the Polish legal forms of nature protection areas and the European Natura 2000 network within the country. The research material was: the data of Corine Land Cover (CLC), the Central Register of Nature Protection Forms, and high-resolution layers, such as HRL and orthophotos. The results were compiled according to the CLC class and forms of protection. The matrix of transformations showed that the most frequently transformed CLC class was 312 (coniferous forest). It was transformed into class 324 (transitional woodland shrubs). The changes in PAs were usually smaller than in the surrounding buffer zones, which may indicate their effectiveness. The exception was the areas of the European Natura 2000 network. The scale of land-cover flows (LCFs) changed within particular forms of protected areas, though afforestation and deforestation predominating in all area types. National reserves and parks were the most stable in terms of land cover structures. However, human settlements increased around the protected areas, potentially increasing threats to their ecological integrity.

scholarly journals Habitats with Large Bitter Cress (Cardamine amara L.) in the Spring Area of Nera River (Semenic Mountains, Romania)

2017 ◽  
Vol 19 (1) ◽  
pp. 19-28
Author(s):  
Erika Schneider-Binder
Keyword(s):  
Nature Reserve ◽  
Conservation Status ◽  
Natura 2000 ◽  
Beech Forest ◽  
Light Conditions ◽  
Habitat Conditions ◽  
Low Light ◽  
Natura 2000 Network ◽  
Spring Area ◽  
Strong Relation

Abstract The paper presents the spring habitats and their communities edified by the Large Bitter Cress (Cardamine amara L.) in the area of Nergăniţa, a headwater stream of the Nera River included in the “Nature Reserve Semenic Mountains and springs of Nera River”. The communities of Large Bitter Cress are situated in and on the springs and spring streamlets situated in the beech forest area, being well adapted to the special site conditions with low water temperatures, low light conditions and humus rich soils. The species composition of the Large Bitter Cress communities and their habitats are presented in strong relation with the habitat conditions and the interrelation with other communities. Finally, the conservation status of the streamlets habitats is analyzed in the context of their importance for the European Natura 2000 network.

scholarly journals Prunus lusitanica L.: An Endangered Plant Species Relict in the Central Region of Mainland Portugal

Diversity ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 359
Author(s):  
Mauro A. M. Raposo ◽  
Leonel J. R. Nunes ◽  
Ricardo Quinto-Canas ◽  
Sara del Río ◽  
Francisco M. Vázquez Pardo ◽  
...  
Keyword(s):  
Central Region ◽  
Conservation Status ◽  
Natura 2000 ◽  
Natura 2000 Network ◽  
Current Conservation ◽  
Acacia Dealbata ◽  
Mainland Portugal ◽  
Priority Habitat ◽  
Number Of Individuals

Prunus lusitanica L. is a paleotropical relic species with an Ibero-Maghrebian distribution, which is presently considered as an endangered species, recognized by the Natura 2000 Network (92/43/EEC) as a priority habitat for conservation in Europe. The mountains in the Portuguese mainland central region offer the best location for this species to occur. The main objective of this study is to measure the current conservation status of the communities of P. lusitanica, through the collection of field data, such as the number of existing individuals of each population and their location, which will then be comparatively analyzed based on the previous literature, published at least 15 years ago. Soil characterization analysis was carried out and the main threats to conservation were identified. As a result, a decline of approximately 40% was observed in the number of individuals and in the quality of their habitat. The main threats to their conservation were found to be the seasonal occurrence of rural fires and the expansion of invasive species, such as Acacia dealbata Link and Ailanthus altissima (Mill.) Swingle. Finally, we present the main management methodologies that should be considered for the valorization of this important vegetational relic in the central region of mainland Portugal.

scholarly journals Riparian Vegetation on the Left Tributaries of the Danube Along the “Clisura” Cross Valley

2016 ◽  
Vol 18 (3) ◽  
pp. 15-30
Author(s):  
Erika Schneider-Binder
Keyword(s):  
Riparian Vegetation ◽  
Conservation Status ◽  
Natura 2000 ◽  
Alnus Glutinosa ◽  
Point Of View ◽  
Habitat Types ◽  
Natura 2000 Network ◽  
Alluvial Forests ◽  
Iron Gate ◽  
Fringe Communities

Abstract The author presents the riparian vegetation of the left tributaries of the Danube in the “Clisura” area including the habitat types 91E0* Alluvial forests with Alnus glutinosa and Fraxinus excelsior (Alno-Padion, Alnion incanae, Salicion albae), 6430 Hydrophilous tall herb fringe communities and other interlocking habitats. They are analysed from the ecological and the phytocoenological point of view. Discussed are also their phytogeographical particularities. Furthermore are emphasized the changes of the vegetation on the lower part of the tributaries as a consequence of the construction of the Iron Gate power plant and the backwater situation. Finally the conservation status of the riparian habitats is analysed in the context of their importance for the European Natura 2000 network.

scholarly journals Occurrence of the Green Shield-Moss Buxbaumia viridis (Moug.) Brid. in the Bieszczady Mountains of Poland

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 374
Author(s):  
Piotr Brewczyński ◽  
Kamil Grałek ◽  
Piotr Bilański
Keyword(s):  
National Park ◽  
Large Scale ◽  
Conservation Status ◽  
Natura 2000 ◽  
Field Work ◽  
Managed Forests ◽  
Moss Species ◽  
Microhabitat Preferences ◽  
Natura 2000 Site ◽  
Forest District

The small-sized gametophytes and sporophytes of the green shield-moss Buxbaumia viridis (Moug.) Brid. make it difficult to study. However, in Europe, there has been increasing interest in this species in the past few years, mostly as a result of the implementation of the Natura 2000 network. In Poland, B. viridis has only been reported in isolated studies that have been limited in terms of area and the number of participating workers. One of the Polish regions where B. viridis was recently recorded is the Bieszczady Mountains, but there have been no large-scale surveys of that region to date. The objective of the current work was to describe the B. viridis population in the Bieszczady Mountains in terms of its spatial distribution and abundance, investigate its selected microhabitat preferences, and evaluate the conservation status of this moss species within the Natura 2000 site Bieszczady PLC180001. The studied region encompassed 93,490.44 ha, including 69,056.23 ha of managed forests and 24,434.21 ha of forests belonging to the Bieszczady National Park. A preliminary survey was conducted in the Cisna Forest District (forest area of 19,555.82 ha) on 15–17 November 2017, while the main survey was performed in selected forest subcompartments of four forest districts—Baligród, Komańcza, Lutowiska, and Stuposiany—as well as the Bieszczady National Park from 5 to 16 November 2018. The field work consisted of searching for B. viridis sporophytes and setae and recording selected population and locality characteristics. The study led to the discovery of 353 new B. viridis localities in 202 study areas, with 9197 diploid individuals (sporophytes or setae only) growing in 545 microhabitats. The number of B. viridis localities discovered in the Bieszczady Mountains during 17 days of survey in 2017 and 2018 was two times higher than the combined number of localities previously found in Poland over more than 150 years (159 localities). Additionally, the number of sporophytes and setae identified was two times greater than their overall number in previous records. In addition, this study provides information about selected microhabitat preferences and the conservation status of this moss in the Bieszczady Natura 2000 site.

scholarly journals Structural and optical properties of amorphous Si–Ge–Te thin films prepared by combinatorial sputtering

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
C. Mihai ◽  
F. Sava ◽  
I. D. Simandan ◽  
A. C. Galca ◽  
I. Burducea ◽  
...  
Keyword(s):  
Optical Properties ◽  
Data Storage ◽  
Optical Sensors ◽  
Material Selection ◽  
Functional Materials ◽  
Stability Study ◽  
Optical Data Storage ◽  
Optical Data ◽  
Structural And Optical Properties ◽  
Topological Constraint

AbstractThe lack of order in amorphous chalcogenides offers them novel properties but also adds increased challenges in the discovery and design of advanced functional materials. The amorphous compositions in the Si–Ge–Te system are of interest for many applications such as optical data storage, optical sensors and Ovonic threshold switches. But an extended exploration of this system is still missing. In this study, magnetron co-sputtering is used for the combinatorial synthesis of thin film libraries, outside the glass formation domain. Compositional, structural and optical properties are investigated and discussed in the framework of topological constraint theory. The materials in the library are classified as stressed-rigid amorphous networks. The bandgap is heavily influenced by the Te content while the near-IR refractive index dependence on Ge concentration shows a minimum, which could be exploited in applications. A transition from a disordered to a more ordered amorphous network at 60 at% Te, is observed. The thermal stability study shows that the formed crystalline phases are dictated by the concentration of Ge and Te. New amorphous compositions in the Si–Ge–Te system were found and their properties explored, thus enabling an informed and rapid material selection and design for applications.

scholarly journals Twenty-Three Years of Land-Use Changes Induced Considerable Threats to the Main Wetlands of Sardinia and Sicily (Italy) along the Mediterranean Bird Flyways

Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 240
Author(s):  
Alessandro Ferrarini ◽  
Marco Gustin ◽  
Claudio Celada
Keyword(s):  
Land Use ◽  
Habitat Degradation ◽  
Land Use Changes ◽  
Biodiversity Loss ◽  
Natura 2000 ◽  
Global Level ◽  
Natura 2000 Network ◽  
Stopover Sites ◽  
The Mediterranean ◽  
Agricultural Areas

Biodiversity loss has multiple causes, but habitat degradation through land-use change is the predominant driver. We investigated the effectiveness of the Natura 2000 network in preserving the main wetlands of the two largest islands of the Mediterranean region, whose conservation is critical for many avian species at European and global level, in a 23-year period (1990–2012). In Sardinia, the surroundings of 22 wetlands were affected by an increase in artificial areas (+64 ha/year) and decrease in agricultural (−54 ha/year) and natural (−17 ha/year) ones. In Sicily, the surroundings of 16 wetlands were impacted by an increase in agricultural areas (+50 ha/year) and decrease in natural and semi-natural ones (−62 ha/year). Results show that the Natura 2000 policies were effective in preserving wetlands (no shrinkages detected in both regions), but their surroundings experienced intense processes of degradation and artificialization in all the sub-periods considered (1990–2000, 2000–2006, 2006–2012), whose effects are now threatening waterbirds and wetland integrity. The enlargement of the existing Natura 2000 sites, the creation of new ones and the speedup of the application of the rules of the Habitats and Birds Directives seem necessary to counteract the rapid land-use changes around these important stopover sites.

scholarly journals Development and Performance Evaluation of a Very Low-Cost UAV-Lidar System for Forestry Applications

2020 ◽  
Vol 13 (1) ◽  
pp. 77
Author(s):  
Tianyu Hu ◽  
Xiliang Sun ◽  
Yanjun Su ◽  
Hongcan Guan ◽  
Qianhui Sun ◽  
...  
Keyword(s):  
Forest Inventory ◽  
Low Cost ◽  
Canopy Cover ◽  
Tree Height ◽  
Flying Height ◽  
Tree Level ◽  
Forest Site ◽  
Lidar System ◽  
Individual Tree ◽  
Gap Fraction

Accurate and repeated forest inventory data are critical to understand forest ecosystem processes and manage forest resources. In recent years, unmanned aerial vehicle (UAV)-borne light detection and ranging (lidar) systems have demonstrated effectiveness at deriving forest inventory attributes. However, their high cost has largely prevented them from being used in large-scale forest applications. Here, we developed a very low-cost UAV lidar system that integrates a recently emerged DJI Livox MID40 laser scanner (~$600 USD) and evaluated its capability in estimating both individual tree-level (i.e., tree height) and plot-level forest inventory attributes (i.e., canopy cover, gap fraction, and leaf area index (LAI)). Moreover, a comprehensive comparison was conducted between the developed DJI Livox system and four other UAV lidar systems equipped with high-end laser scanners (i.e., RIEGL VUX-1 UAV, RIEGL miniVUX-1 UAV, HESAI Pandar40, and Velodyne Puck LITE). Using these instruments, we surveyed a coniferous forest site and a broadleaved forest site, with tree densities ranging from 500 trees/ha to 3000 trees/ha, with 52 UAV flights at different flying height and speed combinations. The developed DJI Livox MID40 system effectively captured the upper canopy structure and terrain surface information at both forest sites. The estimated individual tree height was highly correlated with field measurements (coniferous site: R2 = 0.96, root mean squared error/RMSE = 0.59 m; broadleaved site: R2 = 0.70, RMSE = 1.63 m). The plot-level estimates of canopy cover, gap fraction, and LAI corresponded well with those derived from the high-end RIEGL VUX-1 UAV system but tended to have systematic biases in areas with medium to high canopy densities. Overall, the DJI Livox MID40 system performed comparably to the RIEGL miniVUX-1 UAV, HESAI Pandar40, and Velodyne Puck LITE systems in the coniferous site and to the Velodyne Puck LITE system in the broadleaved forest. Despite its apparent weaknesses of limited sensitivity to low-intensity returns and narrow field of view, we believe that the very low-cost system developed by this study can largely broaden the potential use of UAV lidar in forest inventory applications. This study also provides guidance for the selection of the appropriate UAV lidar system and flight specifications for forest research and management.

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