Issues

Abstract

It was observed an appearance of antler in female Red deer (Cervus elaphus). The emergence
of right antler was established in early January 2015. At that very time it was at the length of
10 cm. The antler was covered with velvet and was not changed. The hind gave birth to a normally
developed female yearling in 2014. The hind was shot in November 2015, and then the antler
was 18 cm. The internal organs were normal and an embryo in the uterus was found formed.
Craniometrical measurements fell within the normal for Red deer. Probable cause of this case is
the occurrence of changes of hormone levels.

Abstract

The study investigates the shoot regeneration ability of ten willow clones in an experimental
plantation planted in the same initial density scheme (2.0 x 0.30 m). They were planted in lots
with identical soil characteristics on the second terrace of the Danube River. The soil is Haplic
Kastanozem with alkalinity (pH) between 7 and 8 and underground water below 8 m. The climatic
conditions are typical for the continental climate of Northern Bulgaria. Development of new shoots
was recorded in three consecutive years - from the seventh to the ninth year of their growth. The
degree of preservation of the coppiced stumps, the number of shoots and their biometric data
(height, basal diameter, fresh and dry weight, as well as their health status (live or withered), were
recorded and compared. The results show that the shoot regeneration ability and the productivity
of the various clones depend on the climatic conditions and the age of the plants. This shows that
certain clones are more suitable for biomass production depending on the type of wood needed
and the specific soil and climatic conditions of the designated planting area.

Abstract

Different kinds of compositions are used in landscape architecture practice, despite the fact
that composition types are not deeply theorized or defined precisely as composition styles. The
conception of styles concerned in landscape history and theory is a general issue. The current
paper aims to explore the geometrical construction types as a concept which gives to composition
specific and aesthetic qualities. The research methodology includes the following three
steps: several compositions have been analyzed and evaluated by different experts; a model for
typology has been made, and as a result a conception for typology has been created. Exemplary
compositions are explored through their drawings, plans or satellite images and are perceived as
abstract, plane, graphic images. In this way their aesthetic qualities are explored isolated. The
evaluation has been statistically checked. On the basis of comparative analysis of the best compositions,
criteria for creation of a type model have been suggested. As a combination between
the variables of the particular criteria certain types of compositions have been finally established.
Thus the geometrical patterns could be understand better and effectively use in the creation of
plan drawings.

Abstract

Identification and assessment of quantitative characteristics of forest communities are the basic
components of forest planning. Modeling frequency distributions of tree parameters such as diameter
and height in various fields of forest sciences, including forest management, silviculture and forest
biometrics plays an important role. The objective of this study was to determine the best probability
distribution functions of tree diameter and height in each of three development stages (i.e., initial,
optimal, and decay) in an unmanaged, uneven-aged mixed beech (Fagus orientalis Lipsky) forest.
For this purpose, three sample plots of one hectare (100 m x 100 m), one in each of three development
stages, were selected in the Hyrcanean region of Iran. Diameter and height of all trees with a
diameter at breast height larger than 7.5 cm were measured. Beta, Johnson's SB, lognormal, gamma
and Weibull probability distribution functions were fitted to each diameter and height distribution.
The comparison of observed and predicted probabilities was performed using Kolmogorov-Smirnov,
Anderson-Darling and Chi-square tests. The goodness of fit of each distribution function varied among
development stages. The three-parameter lognormal, the three-parameter Weibull and the Johnson's
SB functions showed the highest goodness of fit for tree diameter distribution at the initial, optimal and
decay stages, respectively. For tree height distribution, the Johnson's SB was the best fitted function
for the optimal and decay stages, while none of these functions adequately explained the height distribution
of trees at the initial stage. Best fitted models can be used to characterize the diameter and
height distributions of similar stands and help achieve an optimal structure.

Abstract

Previous studies have demonstrated that monochromatic LEDs could be used as an alternative
to conventional lighting sources for cultivation of several species in artificial environments,
which have led to satisfactory results. However, the application of LED lights of continuous spectrum
as an artificial light source in plant growth chambers has not been tested yet. This study
examines the influence of five different LED light qualities (L20AP67, AP673L, G2, AP67 & NS1)
that emitted a mixture of continuous spectrum based on various percentages of ultraviolet, blue,
green, red, far-red and infra-red radiation or Fluorescent light (FL as a control) on growth of sweet
chestnut seedlings into mini-plug containers during one month indoor cultivation. Leaf characteristics
of chestnut seedlings were better promoted under LEDs by means of faster leaf formation of
greater leaf area that showed significantly higher stomata and epidermal cell number compared
to the FL light. Therefore among LEDs G2, NS1 and AP67 showed the greatest effect by inducing
significantly higher stomatal density (SD), stomatal index (SI%) and cell density (CD) compared
to the FL light and L20AP67 LED. Similar shoot development was found irrespective of light
spectrum; however, significantly longer roots were formed by the L20AP67 than the FL light that
showed the shortest. Further, root system architecture analysis revealed that NS1 and AP673L
LEDs produced seedlings with significantly higher root fibrosity index compared to the FL. Dry
weight accumulation especially of the shoots and roots of the seedlings treated with the AP673L
was the highest by far. In contrast, FL light demonstrated the lowest dry weight mass thus exhibited
the lowest R/S ratio compared to LEDs. These results provide new strategies for using LEDs
of continuous spectrum for adequate cultivation protocols into growth chambers for Castanea
sativa Mill. and possibly other forest tree species.

Abstract

The balance between CO2 income during photosynthesis and H2O release during transpiration
is strongly influenced by differentiation of leaves within the canopy. Gas-exchange and water use
efficiency (WUE) were studied in respect to branch position in the crown of 37-year-old Norway
spruce [Picea abies (L.) Karst.] tree, growing in the Western Stara Planina. The needles of the
middle-crown branches had significantly highest rate of net photosynthesis compared to the upper
and lower crown. The rate of transpiration and vapour pressure deficit gradually decreased
to the upper-crown branches. The highest water use efficiency was established for the needles
in the top of the crown. The lowest photosynthesis and WUE, along with the highest transpiration
and vapour pressure deficit of the branches in the crown base of the tree are indicative for the
diminished adaptive capacity. The study results could contribute to better understanding of the
physiological mechanisms of branch self-pruning.

Abstract

The paper presents an applicable method for investigation and assessment of the damage
caused by beech weevil (Orchestes fagi L.) on the leaves of Common beech (Fagus sylvatica
L.). Selecting of appropriate ecophysiological approaches is a workable tool for an assessment of
leafminers' effects as these methods can be applied for leaves with a gradient of damaged area.
Thus, it can be established a tendency in the attack effect and determined the limits of the plant
protective system. This methodology was applied successfully and can provide reliable set of
data for clarifying the relationship between the mining larvae, developing in the infested leaves,
and the host plant. The application of this methodology in other environmental conditions and
woody species could contribute to a development of biological means for a control on the leafminers
in the forests.

Abstract

In this study, the results of recent surveys (during the period between 2012 and 2015) on alien
insects infesting ornamental plants in Bulgaria are reported. Fourteen species, associated with urban
landscape areas and indoor plants, are discussed. Two of them, Ceroplastes sinensis Del Guercio and
Lepidosaphes flava (Signoret), are reported for the first time in Bulgaria. Furthermore, Acizzia jamatonica
(Kuwayama), Ceroplastes ceriferus (Fabricius), Pseudaulacaspis pentagona (Targioni Tozzetti)
and Cydalima perspectalis (Walker) have been found in new localities. Metcalfa pruinosa Say has
widened its host range in Bulgaria. Additional distribution data are also provided about Aulacaspis
yasumatsui Takagi and Cacoecimorpha pronubana (Hubner). Details on current status, host plants,
zoogeographical origin and probable pathways of introduction into Bulgaria are reported for each species.
Morphological and biological remarks are given for C. perspectalis and C. sinensis.

Abstract

By its nature agroforestry is a form of multifunctional, environmentally friendly and sustainable
land management and could provide good income, employment, economic and social stability in
many less favoured rural and mountainous areas in Bulgaria. Achievements, policies, legislation,
financial instruments and prospects for the development of agroforestry in Bulgaria are reviewed.
The review underlines the priorities and opportunities, such as development of agroforestry in
mountainous areas of the country; renovation and establishment of new forest protective belts
and coastal buffer agroforestry systems; introducing of new agroforestry practices in production
of fruit productive trees with high value timber, and in the forest farms. We are pointing out the
need for a comprehensive strategy and policy in this field, for facilitating financial access, and for
introducing of an assessment system for “good practices” and new agroforestry technologies.
Implementation of agroforestry systems in the practice would have important economic, environmental
and social impact on the development of local communities and the society as a whole.