No abstract

Monitoring the structure parameters and damage to trees plays an important role in forest management. Remote-sensing data collected by an unmanned aerial vehicle (UAV) provides valuable resources to improve the efficiency of decision making. In this work, we propose an approach to enhance algorithms for species classification and assessment of the vital status of forest stands by using automated individual tree crowns delineation (ITCD). The approach can be potentially used for inventory and identifying the health status of trees in regional-scale forest areas. The proposed ITCD algorithm goes through three stages: preprocessing (contrast enhancement), crown segmentation based on wavelet transformation and morphological operations, and boundaries detection. The performance of the ITCD algorithm was demonstrated for different test plots containing homogeneous and complex structured forest stands. For typical scenes, the crown contouring accuracy is about 95%. The pixel-by-pixel classification is based on the ensemble supervised classification method error correcting output codes with the Gaussian kernel support vector machine chosen as a binary learner. We demonstrated that pixel-by-pixel species classification of multi-spectral images can be performed with a total error of about 1%, which is significantly less than by processing RGB images. The advantage of the proposed approach lies in the combined processing of multispectral and RGB photo images.

Integrated assessment of urban green infrastructure condition in Karlovo urban area by in-situ observations and remote sensing. One Ecosystem 3: e21610.

The higher mortality rate of the older gypsy moth larval instars was reported in the forest complexes of Belgrade and Valjevo region, in the culmination phase of the new outbreak of the gypsy moth in Serbia. By field and laboratory studies of the causes of their death, the presence of conidia and resting spores of the entomopathogenic fungus Entomophaga maimaiga was reported in the dead caterpillars. This has been the first report of occurrence of this species in Serbia, that is, Serbia is the third European country in which this fungus has been reported. It showed to be a powerful reducer of the population size of the gypsy moth, and in both regions it caused the collapse of the outbreak in 2011.

The complex of longhorn beetles in Rila Mt. in Bulgaria was studied by literature data and original biological materials. As a result, 126 taxa from six subfamilies were established, as follows: Prioninae (four taxa), Lepturinae (43 taxa), Necydalinae (two taxa), Spondylidinae (seven taxa), Cerambycinae (31 taxa) and Lamiinae (39 taxa). In this study, two new records for Rila Mt. (Stenurella nigra nigra and Xylosteus spinolae) and new localities or additional information for 24 cerambycid taxa were reported. The longhorn beetles belong to 18 zoogeographical categories and seven complexes. The European complex occupies a dominant position (37.3%), followed by the Palaearctic (23.8%), Eurosiberian (13.5%), Mediterranean (11.1%), European-Iranoturanian (7.1%), Balkan endemic (4.0%) and Holarctic (3.2%) complexes.

The present article lists distributional data about 19 taxa, which are new records for the Abruzzo, Lazio and Molise National Park, respectively – 16 jewel and 3 longhorn beetles. Data about 4 Italian endemics (2 buprestids and 2 cerambycids) are listed, and the category of risk according to the Italian IUCN Red Lists is also indicated for each species (when available); among the listed species, 1 is Endangered, 1 is Near threatened and 27 are Least concern.

Pine pitch canker (PPC), caused by the pathogenic fungus Fusarium circinatum (Nirenberg and O' Donnell), is a serious threat to pine forests globally. The recent introduction of the pathogen 2 of 34 to Southern Europe and its spread in Mediterranean region is alarming considering the immense ecological and economic importance of pines in the region. Pines in forests and nurseries can be infected, resulting in severe growth losses and mortality. The pathogen is known to spread in plants for planting and in seeds, and results from recent studies have indicated that F. circinatum may also spread through phoretic associations with certain insects. With this review, we aim to expand the current understanding of the risk of insect-mediated spread of PPC in different parts of Europe. Through the joint action of a multinational researcher team, we collate the existing information about the insect species spectrum in different biogeographic conditions and scrutinize the potential of these insects to transmit F. circinatum spores in forests and nurseries. We also discuss the impact of environmental factors and forest management in this context. We present evidence for the existence of a high diversity of insects with potential to weaken pines and disseminate PPC in Europe, including several common beetle species. In many parts of Europe, temperatures are projected to rise, which may promote the activity of several insect species, supporting multivoltinism and thus, further amplifying the risk of insect-mediated dissemination of PPC. Integrated pest management (IPM) solutions that comply with forest management practices need to be developed to reduce this risk. We recommend careful monitoring of insect populations as the basis for successful IPM. Improved understanding of environmental control of the interaction between insects, the pathogen, and host trees is needed in order to support development of bio-rational strategies to safeguard European pine trees and forests against F. circinatum in future.

Studies in the Taxonomy oi Some Populations oi Apodemus sylvaticus (Linnaeus, 1758) in Bulgaria Hadauia nail taksonomiką niektórych populacji Apodemus sylvaticus (Linnaeus, 1758) z Bultjarii [W ith 11 tables and 1 map!