Integrated approach for health status assessment of urban forests in the municipalities of Etropole  and Pravets, Bulgaria

By

Georgieva, Margarita
Georgiev, Georgi
Ivanov, Miroslav
Tyufekchiev, Konstantin
Belilov, Sevdalin
Dodev, Yonko
Glogov, Plamen
Georgieva, Mira L.
Popov, Grud
Madzhov, Svetozar

Type

Article

Date of Publication

2022-8-17

Original Publication

Silva Balcanica

Volume

23

Series / Issue

Issue: 1

Pages

89--102

Subjects

biotic agents , Bulgaria , Deterioration , health condition , urban forests

Contributed by

Pensoft Publishers

Language

English

Published by

Sofia, Bulgaria Forest Research Institute - Bulgarian Academy of Sciences (FRI-BAS) [2001]-

Identifiers

DOI: https://doi.org/10.3897/silvabalcanica.23.e91220

 

Abstract

In 2020, the health status of urban forests in Etropole and Pravets municipalities was monitored based on remote sensing data and field assessment. The study provides information for early detection and identification of pests and pathogens causing damage in different forest types. Three forest stands were assessed: Scots pine (Pinus sylvestris) plantation near the town of Etropole, European beech (Fagus sylvatica) natural stand near Etropole Monastery, and Quercus spp. coppice stands in ‘Nebesnite Pasbishta’ forest park near Osikovitsa village. In two sample plots (town of Etropole and Osikovitsa village), remote sensing data were obtained by a ‘Parrot Sequoia’ multispectral camera integrated with a specialized professional system eBee ‘Flying Wing’. Normalised difference vegetation index (NDVI) was assessed by digital mixing of imagery, captured in the red and near-infrared range. It was established that the Scots pine plantations were weakened, with NDVI values between 0.66 and 0.75. The oak stands in the area of Osikovitsa village were in better health condition (NDVI mainly 0.79-0.98). Symptoms of diseases and pest damage were found during the field verifications. Severe deterioration caused by the invasive fungal pathogen Dothistroma septosporum had destroyed the pine plantation near Etropole. The pathogen caused premature needle defoliation, resulting in loss of timber yield and, in severe cases, tree death. In oak stands, damage was caused mainly by the invasive insect pest – oak lace bug (Corythucha arcuata). In Fagus sylvatica forests damage was caused mainly by abiotic factors (snow and wind), and wood destroying fungus Fomes fomentarius.