Issues

Abstract

The hatching dynamics of larvae of early developing phenological form of pine processionary
moth (Thaumetopoea pityocampa) based on 93 egg batches was monitored under laboratory
conditions. The egg batches were collected on July 12, 2018 in a 30-year-old Pinus nigra plantation,
at an altitude of 450 m in the region of Fotinovo village, Kirkovo State Forestry, Eastern
Rhodopes. Newly hatched larvae started appearing at the beginning of July 2018, and continued
for a month, until August 8, 2018. The peak lasted for 13 days, from the 19th to 31th of July, during
which 80.6 % of the larvae hatched. Field observations conducted in parallel, showed that the
larval development in the studied habitat lasted for about three months.

Abstract

The set of reproductive parameter estimates, determined by this study, gives the first quantitative
estimates for this population. The study was conducted in the autumn during the period of
years 2010–2011. A total of 97 fish specimens were caught by electrofishing. The study found that
both sexes mature sexually in the second year. The females become sexually mature, once they
reach a length of 122 mm and 25 g weight. The males become sexually mature once they reach
a length of 90mm and 7 g weight. The fecundity of barbel population from the Chepinska River
ranges from 2000 to 17,969 eggs. The average fecundity was 5246 eggs. The absolute fecundity
was positively correlated with the growth of the length and mass of the fish. Consequently, the
five years old Maritsa barbels had the highest fecundity rate. The average values of the relative
fecundity were 115 eggs per kg.

Abstract

Craniometric characteristics and sexual dimorphism have been described for many carnivore
species in Europe. However, very few studies have focused on cranial variability of golden jackal
(Canis aureus Linnaeus, 1758) in Europe, despite its expanding distribution in recent decades.
Although numerous works have addressed sexual dimorphism in carnivore skull size, only few
studies have attempted to study dimorphism in overall cranial shape. The present study proposes
the first comprehensive analysis of golden jackal skull morphometry in Bulgaria, trying to clarify
shape and size related cranial variability and differentiation. Extensive morphometric data of jackal
skulls were analysed by applying recently developed statistical tools to answer the following
questions: (i) is there a geographic variation in skull size and shape among golden jackal population
in Bulgaria, (ii) are there age-related cranial differences, and (iii) how pronounced is the sexual
dimorphism in skull shape and size? A total of 176 skulls of golden jackals, collected all over the
country, were analysed by univariate and multivariate statistical methods. Principal component
analysis and linear discriminant analysis were applied on the standardized and log-transformed
ratios of the original measurements to clearly separate specimens by shape and size. Skulls of
golden jackal in Bulgaria show considerable individual variability but weak intrapopulation differentiation.
The differences in shape and size of the jackal skulls, as far as they exist, are age-related,
but only juveniles younger than 11 months could be easily distinguished. Subadult and
adult jackals largely overlap in skull size and shape. Sexual dimorphism in jackal skulls is weakly
pronounced, with older males a little bit larger than females. The results of the present research
are consistent with recent genetic and morphological studies and give new insights on patterns in
cranial variability and population structure of golden jackal in Bulgaria.

Abstract

Based on the processing of literary sources and our own research, we studied the features of
grafting ornamental forms of Morus alba: ′Pendula′, ′Globosa′, ′Pyramidalis′, ′Contorta′, ′Macrophylla′
and ′Tatarica′. It is proposed to distribute these ornamental forms according to the grafting
and budding dates: winter – the second or the third decade of February – the first decade of
March; spring: early spring (the second or the third decade of March); spring the average (the
first – the second decade of April); late spring (the third decade of April – the first to the second
decade of May); summer – the end of the first decade of July is the first decade of August. It is investigated
that the best period for its holding is the first and the second decade of April. It is determined
that the most effective method of winter grafting is improved copulation, which was carried
out in early March – the highest average splicing of various components after grafting of these
plants was observed in forms ′Tatarica′ (70 %) and ′Macrophylla′ (60 %). When grafting plants by
splitting in these forms, the highest average splicing is also noted – compared 61 % and 54 %.
The highest splicing results of grafted plants during their spring grafting were also obtained by
applying the improved copulation method in forms ˊTataricaˊ – (88–92 %), ˊPendulaˊ – (78–84 %)
and ˊMacrophyllaˊ – compared 65–75 %. The largest number of splices of grafted plants during
grafting by applying the method for behind the barkis noted in form ˊTataricaˊ (87–91 %, a little
lower – in ˊPendulaˊ (73–77 %) and ˊMacrophyllaˊ – compared 64–72 %. It was investigated that
the wild plant (M. alba) and its studied ornamental forms resemble their internal structure and the
grafting sites are quickly spliced and are completely covered with a protective fabric before the
onset of the rest period.

Abstract

The soil fertility of Acrisols on the territory of ‘Petrohan’ Training and Experimental Forest
Range was assessed by applying the National Classification System developed for soils in forest
territories, according to which the following 4 indicators were used – soil depth, org. C stock, total
N stock and available soil moisture. In accordance with it Acrisols were characterized from low
to moderately fertile. The growth of tree species was also assessed and it was determined as
very good for Fagus sylvatica L., Quercus petraea (Matt.) Liebl. and Betula pendula L. For Pinus
sylvestris L. and Carpinus betulus L. was established low growth. The good growth of tree stands
did not correspond to the soil fertility assessments. They were different regarding the different indicators.
It is assumed that the static examination of nutrient stock should be replaced by studies
on the balance of their use and recovery in soils through the biological nutrient cycling.

Abstract

Network Real-time kinematic mode survey technology shows really an efficient and fast improvement
within today’s technological developments. Permanent reference stations for Global
Navigation Satellite System (GNSS) have for a long time been used for positioning of rovers in
RTK (Real-Time Kinematic) mode. In this article, we examine the performance and use of Continuously
Operating Reference Station (CORS-Network RTK) as an extension of RTK technology-
based data acquisition systems near/under tree canopy. As a general rule, a clear view of the
sky is preferred when using RTK for determining location. Eight permanent reference stations
belonging to the ISKI (Istanbul Water and Sewerage Administration) in Istanbul, Turkey were
used for the test measurements. This paper presents the results of İSKİ (Istanbul Water and Sewerage
Administration) CORS satellite measurements made using Networked Transport of Radio
Technical Commission for Maritime Services via Internet Protocol (NTRIP) data transmission. As
a result of measurements taken at 17 measurement points in the obstructed and unobstructed
environments, the accuracies obtained at the points with numerous covers in the form of tree
branches and leaves ranged from several centimetres which is characteristic for GPS/GLONASS
measurements taken under conditions of limited availability of satellites.

Abstract

Releasing of hand-reared game birds is a powerful tool to increase the population size of wild
birds and to lower hunting pressure on their natural populations. Survival and adaptation in the
wild of farm game birds is crucial for assessing game farming efficiency. Survival rate of 36 Grey
partridges released in the autumn from cages in the harsh environment of Mala Mountain uplands
(850 m a.s.l.) (Central Western Bulgaria) was estimated by applying radio-telemetry. The study
area was covered mainly by hay fields and pastures, while arable land was below 10 % of the
territory. The birds stayed within an area of 70 ha (100 % maximum convex polygon) with dispersion
below 770 m from releasing points. Very few birds dispersed in such long distances, while
most of them stayed close to the cages. After releasing partridges showed preferences to scrub
near hay fields. The highest mortality rates occurred in the first week when almost 80 % of birds
died, and only one bird probably survived more than two weeks. The main factor for mortality was
predation by Red fox (66.7 %). Synthesis and application: Grey partridge population size in harsh
environments could not be increased by releasing of farm birds using traditional methods. Still
the use of farm produced birds is reliable way for wild bird populations recovery, but the correct
methods and high-quality farm birds have to be used. Habitat quality also plays an important role
in the survival of released birds and their interactions with wild populations.

Abstract

In this study, we developed allometric equations for approximating tree biomass components
in dry forests in Kupang regency, Indonesia. Biomass allocation was examined and allometric
equations were developed using tree height and DBH as variable for individual tree species
with DBH<20 cm and DBH>20 cm, respectively. Allometric equations were elaborated for leaf,
branch, stem, root biomass and overall tree biomass. Based on the results, leaf, branch, stem
and root accounted for 7 %, 16 %, 66 % and 11 % of overall tree biomass. The values of leaf,
branch, stem, root and total tree biomass (t) with DBH>20 cm was 0.033±0.016, 0.067±0.034,
0.289±0.082, 0.049±0.023 and 0.441±0.156, respectively. It was also found that the tree biomass
(t) with DBH<20 cm was 0.039±0.014. All allometric equation models of tree biomass have a high
quality-of-fit as shown by high constancy value (R2), which indicated significant linear relationships
between biomass and the predictors (DBH and tree height).

Abstract

The main objective of this study was to investigate the influence of genotype, spacing, age
and harvesting cycle on the woody biomass production from coppiced plants of the black poplar
hybrids (Populus × euramericana (Dode) Guinier) ‘Agathe F’ and ‘Guardi’. The experiment was
carried out in a Nelder wheel trial plantation with 11 nearly-square spacings, ranging from 1.0
to 11.5 m2 and data collection took place at the end of the 2nd, 4th and 5th year from plantation
establishment. Spacing significantly affected dendromass production in both clones and all harvesting
cycles considered. The individual plant biomass generally increased with spacing, but
growth approached saturation at the lowest densities for the plants of clone ‘Agathe F’. Comparable
dendromass amounts were recorded for both clones after 1 and after 3 years of shoot
growth, and marginally significant genotype effect was found for the 4-year-period of dendromass
production, when the plants of ‘Guardi’ attained higher biomass yields. No significant effect of the
harvesting cycle was distinguished within 3-year production period, the accumulated amounts of
1- and 2-year-old shoots yielding similar quantities to those of 3-year-old sprouts for both clones.
The black poplar hybrids did not differ significantly in the number of sprouts produced at any of
the investigated ages. The shoot number increased with growing space and with stump age, the
influence of age being obscured only at the highest planting densities. The plants of clone ‘Agathe
F’ showed substantial growth decline in the 5th year from plantation establishment due to
worsen environmental conditions and biotic pests, while clone ‘Guardi’ proved higher suitability
for cultivation as a short rotation crop under Mediterranean climate, because of its steady growth
even at worsen site conditions. Under unfavourable alterations in the water availability and without
additional irrigation, coppiced plantations of ‘Guardi’ would produce above 4 Mg/ha/year dry
dendromass, if cultivated on light arable Fluvisols.

Abstract

Determined that in connection with decentralization in the sphere of forest in Ukraine, the
state forest management authority needs to assess the effectiveness of the implementation of
the powers delegated to the regions. The results of the study of regulatory framework and practice
of assessing the effectiveness of forest resources use in the context of various management
entities led to the conclusion that there is no single approach to both assessing and determining
criteria and indicators of forestry management effectiveness. In this regard, the article presents
a methodological approach to assessing the effectiveness of sustainable forest management,
which involves the application of a set of evaluation criteria and indicators, unlike existing ones,
characterizing the combination of forest, forest exploitation, forest protection and reforestation
processes in the forest management system. The choice of the system of assessment indicators
for sustainable forest management in Ukraine was carried out taking into account the accumulated
national experience and pan-European criteria and indicators of sustainable forest
management. The key principle of the proposed approach is elimination of the difference in the
dimensions of reduced parameters by normalization, that is, their translation into a dimensionless
form. Application of this approach allows to determine the level of use of productive, ecosystem,
protective and socio-economic functions of forest ecosystems, and to identify problem aspects of
forest management, depending on the elements of forestry activities.

Abstract

The aim of the research was assessment of the vegetation in park Zaimov, situated in the
central part of Sofia. The used methods represent a new approach for more profound assessment
of urban green spaces vegetation in Bulgaria, in more than one aspect. Therefore, those methods
could be a subject of improvement and development in future studies. All woody vegetation
of the park was taxonomically identified and mapped. Forty-four tree species from 27 genera
were registered in the park. The individuals count 1156 trees with calculated relative effective
volume (REV) of 79,511.45 m3. This volume decreases 10 times during winter, which makes the
park vegetation inefficient during this period. The vegetation is in good condition except trees at
the south border of the park. Models of the tree crowns of four common species, well presented
in the park, were made. The aesthetic values of the presented species give well-balanced and
enough in quantity ornamental accents to the park environment in the different times of the year.
The valuable old vegetation should be preserved in future reconstructions and better care should
be provided to the new planted one. A strong suggestion for building a denser hedge barrier of
evergreen vegetation across the south border or the park was made.

Abstract

The cultivation of community forestry (Hutan Kemasyarakatan/HKm) land by planting some
crops had increased its economic value. Therefore, this study aims to identify the types of food
crop products and analyze the economic value of HKm food products. The data was obtained
through in-depth interviews and field observations. Data analysis was done by qualitative and
quantitative methods. The results showed that the products utilized in HKm consist of 28 species
dominated by coffee products. These products are mixed from agricultural crops, plantations,
and forestry planted in agroforestry on HKm land with coffee plants as the main crop. Other food
products that are also found in HKm are chili, pepper, spring onions, cocoa, cloves, avocado and
so on. Crops products other than coffee are planted spread among coffee plants with an average
number of coffee plants of 2000 to 2500 stems per ha. The economic value of HKm food products
reached 5 billion Rp. with the highest economic value being the coffee product as the main plant
(60 %). The highest economic benefit of HKm land occurs in August while the economic benefits
are low enough in December, January, February, March, and April. Farmers need to diversify food
products and take into account the harvest period in order to obtain the optimum benefits from
HKm land at all times. Therefore, farmers are advised to plant commercial crops such as bananas,
papaya, eggplant, chayote, tomatoes, spring onions, avocados, jackfruit, sugar palm, pepper,
ginger and chili with an agroforestry system because these species have high economic value
and are able to provide sustainable economic and ecological benefits, while for coffee, cacao and
cloves, although the economic value is high, it is not recommended to develop on HKm land because
it is related to the policy which only allows maintaining coffee and cocoa plants in the forest.
In this regard, the Government’s support is very much needed related to HKm’s policy based on
the economic value in order to reconcile the interests of the community and forest sustainability.

Abstract

The high radiosensitivity of woody plants and the large forest areas polluted by Chernobyl fallout
demand assessment of radiation effect on the forest ecosystems components. This research
aims to study the state of Scots pine (Pinus sylvestris L.) stands located in the far and near areas
contaminated by Chernobyl fallout, and to assess the current dose loads on the structural elements
of the trees 30 years after the Chernobyl Nuclear Power Plant (CNPP) accident. The study
was conducted in radioactively contaminated Scots pine stands, which are the near and far areas,
in the Chernobyl fallout areas. The experimental plots were established during the period from
1991 to 2006 inside Scots pine stands from the II–IV age classes. The retrospective assessment
of dose loads of the Scots pine was conducted according to the data obtained on 13 experimental
plots located in the far area of the Chernobyl fallout through the software RESRAD-BIOTA 1.5
(11/18/2009). The condition of pine stands in the near areas has significantly worsened since the
accident, compared to their condition before the accident. The changes in the state of the pine
stands after the accident were characterized by their strong weakening. Ambiguous trends were
also observed in the stability of stands depending on the type of forest and land relief. In 1986,
the radionuclide 134Cs accounted for 25 % of the total amount of soil pollution by mixture (134Сs +
137Сs) in pine stands. However, in 1995, this amount decreased to 2.5 %. The state of the Scots
pine stands after the accident were characterized by their strong weakening.

Abstract

In this article a study is described for determining the impact of the chipper power and the size
of materials on the productivity of different chippers. Machines with various engine powers have
been used in the range of 21 to 70 kW, being equipped with disc or drum chipping mechanism
propelled by either self-engine or PTO. The experiments have been carried out with fresh, scots
pine small-size wood, grouped into nine groups of materials. The results indicate that the greatest
impact on the productivity of the chipping machines has their power, then is the diameter of the
materials and least is the influence is the length of the materials.

Abstract

Rock partridge (Alectoris graeca) is included in Annex I of the EU Birds Directive as Species
of Conservation Concern (SPEC 1), because of the continuing decline in the area of occupancy.
In this context, ex situ conservation programs and production systems of captive Rock partridges
suited to the wild are necessary to ensure that insurance, reintroduction or restocking goals are
met. Anyway, morphological changes occurring in captive-reared animals indicate the loss of
animal’s ability to survive in natural environment. In this study, we used the offspring of wild Apennine
rock partridges (Alectoris graeca graeca). The young birds were divided into two groups,
the first (G1) was housed in enriched and wild-like environment, the second (G2) was subjected
to intensive-rearing conditions. Starting at 14 days post-hatching (DPH) and continuing up to 98
DPH, body mass (BM), tarsus length (TL), tarsus depth (TD), tarsus width (TW), head width (HW),
head length (HL), wing length (WL) and beak length (BL), were measured fortnightly. Birds in G1
showed shorter heads (F = 10.50, p = 0.000) and thinner tarsi (F = 9.80, p = 0.000) at 84 DPH. At
98 DPH also the TD measurement (F = 8.71, p = 0.001) became significantly lower in G1 then in
G2. Birds in G1 showed morphological disadvantages (shorter heads and less developed limbs)
as a possible result of limited physical and cognitive exercise in simple artificial environment. Our
results suggest that intensive rearing does not contribute to relevant morphological disadvantages
within 70 DPH. Accordingly, birds for restocking or reintroduction should be translocated
within this time limit into enriched and wild-like environment where they can exercise before the
release into the wild. A first figure of morphological measurements for Apennine Rock partridge
is reported.

Abstract

A complex of humus parameters was studied and a database was created about the content
of soil organic matter and org. C stock in the surface 20 cm layer of Umbrisols in order to monitor
the relationship ‘climate changes – organic C stock’ over time. Geo-coordinated stations located
near the Cherni Vrah meteorological station were used, where the temperatures and precipitation
have been observed since 1935. Higher acidity (рНН2О), higher amount of total carbon and free
low-molecular humic acids were determined in the surface 10 cm soil layer in comparison with
the 10–20 cm layer. The share of humic and fulvic acids in the total carbon of the two layers did
not differ and was characterized by stable values. The org. C stock in the surface 10 cm layer was
7.00 ±1.31 t.ha-1 and 15.55 ±2.72 t.ha-1 in the 10–20 cm layer. The total org. C stock in the surface
20 cm layer of Umbrisols was 18594.15 t. The obtained results allow future statistical evaluations
of information about monitoring the relationship ‘climate changes – org. C stock’ over time.

Abstract

The biogeochemical data of pine (Pinus sylvestris L.) forests have been studied in the impact
and buffer zones of the influence of technogenic emissions from the large industrial center
Usolie-Sibirskoe (East Siberia, Russia). Changes in the acid-base balance, accumulation and
migration of elements-pollutants, the content of nutrient elements in the components of forest
ecosystem – tree-stands, forest litter, soil horizons – on contaminated areas compared to the
background sample plot have been revealed. A significant shift in the acid-base balance to the
alkaline range and an active migration of elements-pollutants in soil horizons and forest litter have
been shown to be key processes causing a disturbance of exchange reactions of Ca2+, Mg2+, K+,
Na+ cations in the soil absorbing complex (SAC) and a decrease in nutrient elements migration
into root systems of trees. Pronounced changes in the acid-base balance, high accumulation of
elements-pollutants, binding of nutrient elements by pollutants in the soil horizons and in plant
tissues lead to the disruption of nutrition and to the inhibition of pine trees growth processes. The
biogeochemical parameters observed are characterized by interconnected changes in the main
components of the forest ecosystem (soil and tree-stand) and can serve as adequate criteria for
assessing its state under technogenic pollution.

Abstract

The main aim of the CORINE Land cover 2018 project is to identify and map the changes of
land cover/land use for the period 2012–2018 using multitemporal/multispectral satellite imagery.
Harmonized methodology with a 44 class nomenclature and a computer assisted photo-interpretation
are applied for creating a geospatial database of Bulgarian territory for the year 2018. A brief
description of the applied methodology and the main results achieved are presented. The whole
Bulgarian territory is mapped in details adequate for the 1:100 000 scale with a minimum mapping
unit of 25 ha and a minimum change area of 5 ha. A statistical analysis of the created databases
is made. For the investigated period (2012–2018) the largest in number (2720), the largest as
area (53,558 ha) and with the highest percentage (53.54 %) of the total area of the changes are
the changes occurring in class 3 ‘Forests and semi-natural areas’. Six types of changes prevail,
forming over 3/4 of the area of all changes – loss of coniferous forests (23,392 ha – 23 %), loss
of broad-leaved forests (18,389 ha – 18 %), pastures into non-irrigated arable land (14,534 ha –
14 %), vineyards into non-irrigated arable land (9451 ha – 9 %), fruit trees and berry plantations
into non-irrigated arable land (6051 ha – 6 %) and restored broad-leaved forests (4865 ha – 5 %).
The area of recovered broad-leaved forests (change 324-311) is 4865 ha, which is almost 4 times
less than the lost (18,389 ha). Two negative change processes were identified – conversion of
vineyards (221) and orchards (222) into non-irrigated arable land (211), i.e. extensification of
agriculture, but also was an intensification one – change of pastures (231) to non-irrigated arable
land (211).

Abstract

This study investigated the relationships between physiographical factors and trees structural
characteristics in Arasbaran forest, northwest of Iran. Systematic randomized sampling method
was used to collect data and in sample plot used the distance method for determination of spatial
distribution pattern. Results of spatial distribution pattern indices showed the clumped spatial distribution
for Caucasian oak trees (Quercus macranthera Fisch. & C.A.Mey. ex Hohen). In addition,
the altitude affected the tree’s characteristics significantly. The greatest tree’s diameter at breast
height was found in R3 and density of trees was decreased by increasing of altitude. Distance to
neighbour index showed four to six meter distances between trees. DBH and height differentiation
indices demonstrated uniformity in trees. Landform indices had the greatest average on R3 and
had a significant correlation with trees density and crown area. It could be concluded that the
difference in physiographical condition is one of the main factors of the tree’s spatial distribution
and forest structure variation at physiographical units in this study area.