Issues

Abstract

Understanding the essential contribution of community forests for industrial development or climate change mitigation principally requires the accurate measurement of merchantable wood and aboveground biomass. However, the quantification of those parameters using the destructive method requires high cost and time consuming. To anticipate these constraints, allometric equations development has a potential contribution to facilitate a more efficient estimation of wood and biomass production without disturbing forest regeneration capacity. Therefore, this study aimed to develop allometric equations for quantifying merchantable wood and aboveground biomass of community forest tree species. The destructive sampling was carried out on 45 trees from three species (15 trees each), namely Swietenia macrophylla King, Falcataria moluccana (Miq.) Barneby et J.W.Grimes, and Tectona grandis L.f. Furthermore, three general allometric equations were examined using some predictor variables, i.e. diameter at breast height (D), quadrat diameter at breast height combined with tree height (D²∙H), as well as D and H separately. The results showed the highest average of merchantable wood and aboveground biomass recorded in S. macrophylla (0.41 ±0.10 m³; 0.33 ±0.07 t), followed by T. grandis (0.20 ±0.07 m³; 0.18 ±0.06 t) and F. moluccana (0.16 ±0.05 m³; 0.06 ±0.02 t). Meanwhile, the relative contribution of foliage biomass to total aboveground biomass gradually declined along with the increasing diameter classes. In contrast, a fluctuating trend was observed in the stem and branch. Also, equation ln Y = lna + b∙lnD was best in quantifying the wood and biomass. The addition of H as a predictor variable in the equations did not show a meaningful influence to increase accuracy estimation in the species. Based on these results, it was concluded that the development of allometric equations was reliable to facilitate more efficient estimation of merchantable wood and aboveground biomass for community forest tree species with over 95 % accuracy.

Abstract

We examined the effects of two mycorrhizae fungi (endomycorrhiza and ectomycorrhiza) and varying moisture supply on certain growth parameters of Cassia fistula L. seedlings. The seedlings were inoculated with endomycorrhiza and ectomycorrhiza, compared with no mycorrhiza, and watered every day, every other day and once a week for a period of 12 weeks. The results revealed that mycorrhiza contributed significantly to relative water content while moisture supply also significantly influenced shoot height, collar diameter, leaf number, fresh weight of leaves, turgid weight of leaves, fresh weight of shoots, and fresh weight of roots. However, interaction of mycorrhiza and moisture supply had no significant effect on seedling growth of C. fistula but endomycorrhiza at watering every other day had the best growth performance.

Abstract

In Ukraine and elsewhere on the planet, study of climate change effects on forests is ofgreat public interest. The study aimed to evaluate climate humidity dynamics in the 21st century according to Vorobiev indicator under RCP 4.5 and RCP 8.5 scenarios. E-OBS and EURO-CORDEX project climate data were used. Climate humidity indicator by Vorobiev was used to assess the suitability of climatic conditions for forests (suitable conditions are from fresh to wet forest types). In the current climate condition in Ukraine the climate humidity varies from very dry in the south to very wet in the Carpathians. Dry (30 %) and fresh (40.1 %) types dominate. Comparing to 1961–1990, aridity has increased, boundaries of climatic zones shifted by 1 class to the north for the plains of Ukraine and to higher elevation for the Carpathians. In the Forest and the Forest-Steppe zones the fresh climate prevails, wet climate becomes less represented. Climate condition suitable for forests covers about 50 % of the country area. Both scenarios show a further aridity increase and climate zones shift to the north. Under the RCP 4.5, the areas of wet and fresh climate are expected to decrease with substitution by dry climate. In 2040–2060 the area of conditions suitable for forests will decrease to 37 % of the country area, and to 30 % in 2080–2100. Favourable conditions for the forest will remain only in the Carpathians, the western Forest-Steppe and partly in Forest zones. Under the RCP 8.5 scenario, the process of climate aridization will accelerate: dry climate types are expected to dominate. The area suitable for forest conditions will decrease significantly to 30 % in the middle and to 10 % at the end of the century. 

Abstract

This work depicts the plan of the volume-space arrangement of the Novooleksandrivsky park in Melitopol, Zaporizhzhya region, Ukraine. All of the landscape composition structures are present in the park plan. Nevertheless, in some cases the ornamental plant species and forms of the trees aren´t regularly used. The low percentage of open spaces doesn’t permit to create multiplan compositions. Some species like Platycladus orientalis, Juniperus virginiana tend to lose their ornamental properties, reducing their aesthetic values. It is not characteristic of a national monument of gardening art.

Abstract

To optimize the use and management of Ukrainian Carpathians forest fund territories, ecological tourism is actively promoted by the government and reflected in the leisure sector. The attention of economists is mainly drawn to the market value of forest areas and forest resources. However, the trend is changing as the non-market values of forests are increasingly assessed and measured. This case study assessed the potential value of ecological tourism development using the contingent valuation method. A total of 235 respondents were interviewed in four regions of Ukraine. The results showed that most visitors to the Ukrainian Carpathians are willing to pay for ecological tourism on these territories. The average value was 35 USD per day in the conditions of organised ecological tourism and 10 USD per day in the conditions of individual ecological tourism on the territories of Ukrainian Carpathians forest fund. The results may justify financial support from the state for the development of ecological tourism and the adoption of relevant regulations. Prospects for it depend on the level of well-being and education of citizens, as well as the distance from the place of residence of the respondents to the territories of Ukrainian Carpathians forest fund. Regarding organised ecological tourism, the prospects for the development depend on certification of tour operators providing services.

Abstract

Variations in some physiological parameters of European beech (FS) and wild cherry (PA) saplings were studied in the second (2016), fifth (2019), and seventh year (2021) after windthrow disturbance in a monodominant European beech forest. Net photosynthetic rate (A_N), transpiration rate (E), water-use efficiency (WUE), and total chlorophyll content (TCC) of FS and PA saplings were measured both in a windthrow site (W) and in a closed-canopy site (C). The physiological measurements in C-site were used as a control for the comparisons with W-site. European beech leaves on W-site had a positive photosynthetic response to higher light intensity only in 2019, while in the wild cherry leaves, similar increase was observed in 2016 and 2021. At the end of the study period, E of FS and PA leaves were equalized between W-site and C-site and between the two species. However, two years after windthrow, FS saplings had a similar transpiration rate in the two sample sites, while PA saplings had significantly higher transpiration in the W-site. In 2019, FS leaves managed to increase its Е in windthrow site, but it remained high in the PA’s leaves. WUE remained unchanged in W-site at the beginning of the experimental period for both species, but this physiological parameter was significantly higher in FS saplings. In 2019, the WUE in FS leaves was stabilized, while in the PA leaves, it even increased. In 2021, both species had stable levels of WUE. In W-site, the FS leaves had the same TCC throughout the experimental period, while such a parameter was higher in W-site in the PA leaves. Better physiological adaptation of PA to changed microclimatic conditions after the windthrow disturbance is probably the main reason for this species’ pioneer character and rapid colonization of the territory. The protective role of herbaceous plants, which invade in a windthrow site, allows FS to save the physiological activity and even increase physiological processes and parameters a few years after disturbances.

Abstract

This study analyses the implementation of forest education in 13 German federal states in combination with the number of applicants for a vocational education in forestry, as well as the number of students at the faculties of forestry in Germany. Obtained results show that establishing the basics of forest didactics and taking into account educational topics beside the classical knowledge of woodland species, furthers the interest in forests and forest professions in general. The number of students in the university can be considered to be a suitable indicator for a good establishment of forest didactics and a general interest in forests, while the number of applicants in vocational education can be considered to be an indicator for a holistic and sustainable approach to forest education, according to this study.

Abstract

Indonesia’s natural forests consist of various land and stand qualities, both highly degraded. In the past few years, the forest area has continued to decline. Gap planting is one of the silviculture techniques which can increase the productivity of the low potential tropical natural forest, mainly by using fast-growing species with short cutting rotation. The objective of this research was to study the impacts of gap planting on soil compaction and erosion in the Indonesian lowland tropical rain forest. Soil compaction was measured using Humbolt-Digital Statis Cone Penetrometer, soil erosion was measured using erosion pins and gap area was measured using Hexadecagon Method. The result shows that using gap planting causes soil compaction in gaps with an area of less than or equal to 250 m² and 1250–1500 m². However, the compaction value is classified as very loose soil so that it can be ignored. Otherwise, gap planting, using planting strips and chop off strips, has a positive impact by lowering erosion at gap size less than or equal to 250 to 2000 m².

Abstract

Taxus contorta Griff. is an endangered conifer tree species. It is found in patchy habitats throughout its natural occurrences along with certain altitudinal ranges in the Himalayan region. The present study involves the stand structure, regeneration status and biomass of Taxus species in the Narkanda forest that occupies an area of 11.4 km² with an altitudinal range of 2400 m to 3000 m a.s.l. in Shimla district of Himachal Pradesh. A total of 24 square plots, each plot of area 0.16 ha, were laid in four main geographical directions (i.e., north, northeast, southwest and southeast) with equal six plots in each slope exposure. The result showed that T. contorta is found only in three slopes (north, northeast and southwest) exposures with the main association of Abies pindrow (Royle ex D.Don) Royle species. The absence of Taxus species occurrences slope exposure (southeast) was dominated by Quercus semecarpifolia Sm. Based on the results, this study documented that conservation of an endangered species should be done through silvicultural practices for its sustainable regeneration in northern slope exposure. Additionally, the adult tree of T. contorta must be conserved specially for pollination purposes, fertile seed production and dispersion of seeds exposing the open canopy closure through the thinning of common and dominated species. Finally, it is recommended that any kind of human disturbances should be strictly prohibited inside Taxus occurrence forest.

Abstract

Seed germination experiments were conducted at Botswana University of Agriculture and Natural Resources to determine the best possible pre-sowing treatment methods that maximize seed germination of Albizia versicolor and Faidherbia albida. The experiments were laid out in a completely randomized design (CRD) with 10 pre-sowing treatments, namely the control, mechanical scarification, soaking in concentrated sulphuric acid with four levels of time exposure (15, 30, 45 and 60 min), immersion in boiling water with three levels of time exposure (1, 3 and 5 min) and soaking in hot water (allowed to cool for 24 h). Treated seeds were germinated for 30 days at room temperature (25 °C). The raw data were subjected to analysis of variance (ANOVA). The results showed that seeds treated mechanically, sulphuric acid (all levels), boiling water (1 and 3 min) and hot water had significantly (p < 0.01) higher mean germination percentages than the control and boiling water (5 min) for A. versicolor, whereas for F. albida seeds treated mechanically and exposed to sulphuric acid (all levels) had significantly (p < 0.01) higher mean germination percentages than the rest. Significant (p < 0.01) mean germination time and index were revealed among the treatments for the two species. 

Abstract

The oak forests in Mediterranean are widespread and dynamic natural ecosystems. For millennia, oak forests have provided vital ecosystem services to humans in the Mediterranean including social, economic and environmental services and goods; however, in parallel, human exploitation has altered their structure. Consequently, targeted management approaches are required to optimize the production. In the current study we analyzed the structural characteristics of the Foloi oak forest (Quercus frainetto) in the wider area of Ancient Olympia, Peloponnese, Greece. An extensive fieldwork was applied in 29 randomly located plots in order to collect dendrometric characteristics of 938 individual trees. The collected data were used to build models for estimating tree age, tree height and canopy length from diameter at breast height (DBH). All models were found to have an adequate fit and provide useful tool for the assessment of site structural and growth characteristics. Furthermore, we present a model for assessing site quality from topographic characteristics such as slope and exposition. Finally, we employed a stand visualization tool to get a graphical representation of the stand structure, which can be used in order to adopt appropriate silvicultural practices. We believe our findings will provide useful tools to forest managers and practitioners for the sustainable management and restoration of oak forests.

Abstract

Climate change is among the main challenges for achieving sustainable development of aquaculture. It is likely to cause changes in the temperature and hydrological regimes of inland waters. Air temperatures in the region of Dospat Dam have been rising over the past 15 years. This impacts the water temperature in the dam and on rainbow trout (Oncorhynchus mykiss) farming in it. The average water temperatures measured in the surface layer in the 1970s (10.18 ±6.79 °C), and the 1980s (10.16 ±7.07 °C) were lower than the ones today (12.40 ±7.12 °C). Higher summer temperatures of the water in the dam have an unfavourable impact on the key biological indicators which determine the aquaculture efficiency, such as fish growth (AG, g), survival rate of fish (SR, %) and feed conversion ratio (FCR). The water temperatures in July and August are above 18–20 °C. This period is marked by the lowest fish growth and the lowest survival rate of fish. At the same time, feed conversion ratio is 3.3:1 which is higher than recommended in feed charts and it is economically inefficient. Global warming is likely to have a negative impact on the development of cold-water aquaculture in Bulgaria. It will result in a longer production cycle and higher costs.

Abstract

The high-resolution layers (HRLs) are Pan-European land cover datasets aimed at monitoring soil sealing (imperviousness, forest, grasslands, wetness and water, and small woody features. The main purpose of this article is to present the methodology and results from verification of two Forest HRL products for the 2015 reference year for Bulgarian territory: Dominant Leaf Type (DLT) and Tree Cover Density (TCD). The verification task aims at identifying systematic classification errors and the results are supposed to be used for improvement in future product updates. Qualitative approach for assessment of the HRL quality is applied in two steps, called General overview of data quality and Look-and-feel verification. The latter is performed within dedicated strata through non-random sampling, checking HRLs for omission and commission errors. We show results from a verification at country level based on local expertise and best available in situ data. We also provide comments and recommendations concerning commission and omission strata. Several cases of both of the above types of errors are identified and analysed in the DLT and TCD high resolution layers. Despite of errors found, both DLT and TCD receive a ‘good’ mark, and the same rating prevails in the strata level evaluation.

Abstract

The aim of the present study was to improve the use and operational efficiency of the truck-mounted tower yarders in deciduous stands and to determine the time, log’s volume transported per turn by the yarder, as well as the yarding costs. The study was carried out in the Sredna Gora Mountains, Central Bulgaria, in deciduous stand with species composition of European beech (90 %), European hornbeam (10 %). The mean productivity of truck-mounted tower cable yarder at shift level is close to the maximum for that type (9.12 m³·PMH^-1 and 8.41 m³·SMH^-1). In order to improve the yarder productivity a remote control of the carriage is advisable to be used, also used by the choker-setter. In this way the loaded carriage could wait for the operator before the landing. Another option to reduce choker-setter‘s fatigue and to decrease the time for lateral outhaul and hook is to use a carriage with mechanical slack-pulling. The gross costs for yarding uphill a whole deciduous tree by the studied tower yarder were calculated at 146.52 € per productive machine hour and 13.02 € per m³. In the distribution of the gross costs, labour costs (21.44 %) are lower than variable costs (29.86 %) and fixed costs (26.84 %). The results from the study are useful to integrate the cable yarders in group shelterwood system and to achieve economic and environmental efficiency of timber transportation in deciduous forests in sensitive sites.

Abstract

The aim of this study was to estimate the aboveground carbon sequestration and the amount of CO₂ emissions at logging operation in Hyrcanian forests of Iran. Required data, such as forest standing stock, annual growth increment of trees, wood density and timber harvesting, were collected from secondary sources. Allometric equation was used for estimating the carbon sequestration. The amount of CO₂ emission was calculated. Results showed that the annual growth per hectare and the amount of carbon sequestration per growth were 3.37 m³·yr^-1 and 1.14 t·ha^-1, respectively. Results also indicated that the value of aboveground sequestrated carbon and its net present value were 71,217.63 (10,000 IRR∙ha^-1) and 12,668.28 (10,000 IRR∙ha^-1), respectively. Finally, the amount of carbon emission per hectare was calculated, as it was 0.01078 t∙h^-1 per year. The results of emission and carbon sequestration per hectare of the forest show that not only logging per hectare of forest will eliminate annual carbon sequestration, but also leads to an increase in CO₂ into the atmosphere due to harvest activity.

Abstract

The moss Hypnum cupressiforme Hedw. was used as biomonitor in three urban and five mountain sites with different pollution loads. The concentrations of 22 macro- and microelements were determined in moss-bags and were compared with those of the same elements in moss samples naturally growing in the Rhodope Mountains area. Most of the elements had highest concentrations in moss-bags exposed in Plovdiv. Strong accumulation of Cd and Pb was registered in all moss-bags with maximum in moss-bags from Sofia, reflecting that urban activities could induce more severe air pollution than mining. Cd reached saturation at the 30th day of  exposure, while Pb continued to accumulate. Analysed levels of Hg and Pb during passive monitoring confirmed the Rhodope Mountains as a region with constant high toxic element levels.

Abstract

Modern agriculture often leads to a reduction in small game species and loss of biodiversity. The study area includes MG-14 (35 T) square of the Universal Transverse Mercator (UTM). The density of hares during the study period varied between 0.7–2.7 ind./km². Their number reported in 2014–2015 is significantly higher than in the other years. In 2018, the lowest hare density was reported in the study area. Most were counted in May. The density of hares was positively related to habitat diversity and negatively to Wild cat density.

Abstract

Knowledge of protein food used by honey bees is important, as proteins are main component of pollen. The objective of this research was to determine and compare the protein content of bee pollen from different forestry areas in Bulgaria of some popular bee plants. The analysis showed that in pollen it depended on the botanical origin. The protein content in the pollen from Oryahovo ranged from 12.8 % for Taraxacum officinale L. to 25.35 % for Cornus sanguinea L., and the average was 20.66 %, from Borushtitsa ranged from 12.3 % for Chondrilla juncea L. to 27.51 % for C. sanguinea, and the average was 21.16 %. The protein content in pollen from Brassica napus L., Cornus mas L., C. sanguinea, Robinia pseudoacacia L. and Salix sp. showed variability for both forestry areas.

Abstract

Lipids are main components of bee pollen grains, and vary among different pollen taxa. The objective of this study was to determine the lipid content in pollen of 20 popular bee plants and the impact of lipids to honey bees. The analysis showed, that the percentage of the total lipid content in the examined bee pollen ranged from 0.87 % for Zea mays L. to 13.6 % for that of Echinops ritro L., and the average was 3.91 %. The average level of lipids for the entomophilous plants was 4.20 % and 1.31 % for anemophilous, for Asteraceae was 5.42 % and 1.88 % for Fabaceae. The average weight of one hundred worker bees fed on pollen from Z. mays was 8208.2 mg, whereas it was 9882.2 mg for the bees fed on pollen from E. ritro. The weight of bees that consumed pollen with higher lipid content is higher compared to that consumed pollen with lower lipid content.