Issues

Abstract

During floristic studies in different floristic regions of Bulgaria in the period 2006-2012, we
found habitats of Juniperus deltoides, J. sibirica, J. pygmaea, Pinus nigra ssp. pallasiana,
Quercus coccifera, Q. dalechampii, Alnus incana, Rhamnus saxatilis, R. rhodopaeus, Astracantha
thracica, Ilex aquifolium that expand our knowledge of the vertical distribution of these species
in Bulgaria, and hence their ecological niche in the country. The work also specifies the vertical
distribution of Pseudotsuga menziesii, an adventitious species of the flora in Bulgaria, whose
vertical distribution has not been noted in any literary source.

Abstract

Lake Pamvotida offers an array of significant advantages to the inhabitants of the city of
Ioannina that are related both to the enhancement and recreation of the landscape, and the traditional
usages of water. However, the ongoing intensification of water use, in combination with
the pollution and faulty interventions that were undertaken in the past, have created problems in
the lake as well as in the wider area. According to the inhabitants who live within the extent of the
lake, the overuse of agricultural pesticides, lack of cleansing, increase of waste, as well as the inappropriate
use of biological cleaning material are among the most serious problems that the surrounding
lakeside region encounters. Lack of signposting and a museum of natural history also
constitute part of the problem in the area. More particularly, inhabitants consider that the causes
of their inability to solve these problems are to be found in the insufficient environmental education,
scarcity of financial resources and lack of coordinated actions on the part of public stakeholders,
such as the local administration, the prefecture administration and the central power, as
well as private individuals and groups in the area, the union of hotel owners and/or freelance etc,
environmental organizations and the local press, for instance. Based on the inhabitants' evaluations
with respect to the significance of the problems facing the lake display little satisfaction
concerning the actions that they have undertaken with regard to the protection of the lake.

Abstract

Actively growing root suckers from 4-year old shrubs of seed origin were collected in the beginning of spring (April 20, 2012) from open field grown shrubs. Softwood, apical and nodal explants (3-4 cm) were used as initial explants. For the induction of axillary shoots formation, the explants were cultured on Murashige and Skoog (1962) basal medium, supplemented with 0,0.5 mg·l^-1 or 1.0 mg·l^-1 BAP. The formed axillary shoots were cultivated on PGRs free MS medium, or supplemented with BAP (0.5, 1.0 or 5.0 mg·l^-1) or zeatin (0.5 or 1.0 mg·l^-1 + 0.1 mg·l^-1 IBA) for multiplication. For evaluation of the effect of subculture on the multiplication coefficient, the formed axillary shoots (≈ 30 mm) were transferred 3 times on same but fresh medium and cultured for 14 or 21 days. The subcultures did not affected the multiplication rate and maximal number of axillary shoots was reached when the MS medium was supplemented with 5.0 mg·l^-1 BAP (3.8 ± 0.4). The following variants of an inductive, half-strength MS medium were used for the rooting: free of auxin (variant 1), supplemented with 1.0 mg·l^-1 and 5.0 mg·l^-1 IBA (variant 2), supplemented with 5.0 mg·l^-1 IBA for 48, 72, and 168 h (variant 3), and supplemented with 7.5 mg·l^-1 IBA for 24, 48, and 72 h (variant 4) and then on half-strength MS medium without auxin. For comparison of the results, the shoots from variant 1 and 2 were rooted on the same medium without transfer to an expressive medium. All pulse treatments with high concentration of IBA (7.5 mg·l^-1) improved significantly the rooting (between 76.6 ± 8.0 % and 82.2 ± 4.4 %) in comparison with all other treatments. These results demonstrated that the type of initial plant material, the balance between the concentration of the used auxin and the duration of inductive phase are critical for the rooting rate and quality of the root system.

Abstract

European hop-hornbeam is a broadleaf deciduous tree, found from Southern France to
Anatolia and Transcaucasia, mainly on limestone and dolomite bedrock. The seedlings produced
in a mixture of quartz sand and peat in the ratio of 2:1 were transplanted after the first growing
season in raised beds filled with growing media of 3 different mixture ratios of peat and dolomite
stone. Detailed morphological development and nutrient concentration and content after a second
growing season were compared. An increase of the dolomite stone in the growing media has
a negative impact on the growth of European hop-hornbeam seedlings. The seedlings from growing
media with the highest content of peat in relation to the dolomite stone (70:30) had highest
values of all measured morphological attributes. Unlike morphological parameters, influence of
the dolomite stone content on studied macronutrients concentration is not conclusive.

Abstract

American chestnut (Castanea dentata) was once a dominant overstory species of eastern
North American forests before it was decimated by chestnut blight. Blight resistant hybrid chestnuts
share most morphological characteristics with C. dentata, so studying its establishment
and early growth will help develop effective methods for establishing blight resistant hybrids.
Supplementation with nutrients that are not sufficient in the soil likely will increase early C. dentata
performance, but optimal amounts and combination of nutrients have not been determined. We
examined the effect of three shade levels and a novel leaf spray fertilizer supplement on pure C.
dentata seedlings. Shade levels were 0 %, 50 %, and 34 % overstory of sweetgum (Liquidambar
styraciflua). After one growing season, fertilizer had a significant effect only on relative root collar
diameter growth. However, due to interaction with shade, the growth was not different among
the three fertilizer levels. Root collar diameter growth was about 53 % greater in the open than in
stands with 50 % residual overstory. The effects were non-significant for relative height growth.
By the end of the first growing season, seedling mortality was 57 %, 9 %, and 17 % in the open,
light shade, and heavy shade, respectively. Planting of chestnuts in light shade had the most acceptable
combination of survival and growth.

Abstract

From the middle stretch of Maritza catchment area 229 sexually mature individuals Barbus
cyclolepis Heckel, 1837 were examined. The height of anal fin in the two sexes was different. The
anal fin of the female fishes was higher than that of males. In the ratio (percentage) between the
height of the anal fin and standard length of the body there was a strong statistically significant
difference between females and males. This ratio had also much higher value in females as
compared to males.

Abstract

Fire can be a destructive ecological factor, but a good plan can provide appropriate tools for
ecosystem management. In this connection fire prevention must be paid special attention. For locating
fire susceptible zones as a first step in this research, effective factors for forest fires were
determined by studying different sources, and then we used weighed criteria to take advantage of
experts' views. Maps of slope gradient, exposure, forest type, hydrography, topography, distance
from roads and distance from settlements were studied. Results from the survey show that vegetation
coverage allocates the greatest weight to itself. From the results it can be seen that, 11.7 %
of the area is too adverse; it means that fire hazard is too high in these areas, 40.68 % is adverse,
14.48 % is average, 8.37 % is quite favorable, 18.72 % is favorable, and 6.05 % is very good. In
general, we can say half of the local area is susceptible to forest fire, and we should plan the access
to different areas for controlling probable fires, regarding the existing facility conditions and roads.

Abstract

Study of fish fauna of the rivers Topolnitsa, Luda Yana, Stryama, Chepinska and Vucha all tributaries
of the Maritza River was carried out. The research was conducted in the autumn of 2006
and 2007. The material was collected by electrofishing using unpuled direct current (DC). In the
studied rivers the 11 sampling areas were marked and explored. During the investigation in these
rivers 17 fish species belonging to 5 families were found. The family Cyprinidae was the most
representative in the sample. The fish fauna composition was predominated by two reofilic species
- Barbus cyclolepis and Squalius orpheus. Among the species found in this study there was
three alien fishes for the local fish fauna composition were found - Oncorhycus mykiss, Lepomis
gibbosus and Pseudorazbora parva. The present study identified four species endemic to Aegean
watershed - Gobio bulgaricus, Chondrostoma vardarense, Squalius orpheus and Vimba melanops.
The author was found also two species endemic to Balkan Peninsula - Cobitis strumicae
and Sabanejewia balcanica and one species endemic to Maritza River basin - B. cyclolepis.
The estimated composition of the fish fauna in this study was composed of species characteristic
mainly for the middle zone of the rivers. The present study showed some changes in the
species composition of fish fauna have occurred in recent years. The species like G. bulgaricus
which were prevalent before today are found in much smaller quantities. At the same time in the
fish fauna composition the number of the species such as Lepomis gibbosus, Pseudorazbora
parva, Carassius gibelio and Perca fluviatilis have increased. The author found some rarer species
like Rhodeus amarus while the species that was common before as Carassius carassius was
not established.

Abstract

This review aims at providing a short synopsis of the history, advances and future of genomics
sciences in various fields of research with focus on areas pertaining to forest tree species
and ecosystems. It also provides a broader outlook of the place of genomics and other 'omics'
approaches like transcriptomics, proteomics and metabolomics in future biology research at various
levels of organization, particularly on system level knowledge at organismal and ecosystem
scales. Specifically, emphasis is placed on new sequencing technologies that open the gate for
thorough exploration of the DNA and RNA world from a single cell and individual to population
and ecosystem scales. These and other technological innovations are holding great promise for
advanced breeding, deeper knowledge of developmental and physiological mechanisms and better
understanding of the processes occurring at ecosystem levels.