First Results of Monitoring the New Invasive Species Prunus serotina Ehrh. Population inside the Regeneration Area of Common Oak-Hornbeam Forest in Western Croatia

Black cherry ( Prunus serotina Ehrh., Rosaceae) is a widespread invader of the European temperate forests and a significant component of the human-caused part of the global environmental changes. Its successful invasion results from a complex interaction between the species life traits and the recipient ecosystem attributes. While it has been recorded to develop spontaneously in numerous European countries, in Croatia information details on its population distribution, as well as its current status, are still missing. The individuals of P. serotina were found in the pedunculate oak (Quercus robur L.) forest regeneration area of Jastrebarsko forest management unit in 2018. This alerted us to start to monitor its spreading area, status and impact on the native plant species in a four-year period (2018-2021). In order to investigate the habitat characteristics, phytosociological approach was applied. In addition, the area was surveyed using an unmanned aerial vehicle (UAV) DJI Mavic 2 Pro and DJI Ground Station Pro. The results showed that P. serotina spread considerably in the regeneration area, which indicates its invasive character. It also caused alteration in current vegetation. Fast initial expansion of P. serotina in 2019 was slowed down in the next 2 years due to performed tending activities, suggesting mechanical measures could help to control its invasive spreading at an early stage of development. This research brought up the first record of the Prunus serotina species in pedunculate oak forest regeneration area of western Croatia with a recommendation to continue the monitoring survey in order to help prevent its spread in the future.

Health Condition of European Beech (Fagus sylvatica L.) According to Provenances in International Provenance Trial

The performance of European beech ( Fagus sylvatica L.) is severely threatened by abiotic and biotic stresses, but the resilience of its provenances from distinct geographic areas has not been sufficiently studied. Therefore, the performance of European beech was investigated in an international provenance trial consisting of twenty-one natural populations originating from Central Europe and Southeast Europe located on Medvednica Mountain (Croatia). The performance of European beech was investigated by characterizing I) damage types, II) crown damage intensity, III) damage frequency, and IV) clustering of provenances based on damage types. Anthracnose, galls, chewing damages, and aphids were recorded on leaves, and canker on the trunk and branches. The crown damage intensity was minute (less than 10%) for all types of disease. Anthracnose was the most common damage, followed in descending order by galls, canker, chewing damages and aphids. When the types of damage were analysed using descriptive statistics (frequency analysis and clustering), significant differences were recorded between provenances (χ2=322.19, p<0.0001). European beech provenances were classified into four clusters. Aphids and galls caused the least and the highest damage, respectively, in each cluster, except for Cluster 4, where anthracnose caused the highest damage. The results of this study showed generally good health condition of European beech provenances originating from Central and Southeast Europe in the period of the investigation.

Insight into Market Supply and Demand of Private Forests in Croatia

Due to their modest 23% share, private forests in Croatia are a resource that is perceived as less important than state-owned forests. One of the basic characteristics of private forests is fragmentation, which is also the biggest obstacle to a successful and, economically speaking, sustainable management of private forests. The cases in which a private forest with its area and integrity can generate a sustainable economic income to its owner are not common. However, from an economic point of view, private forests still have one advantage. Unlike state-owned forests, private forests can be the subject of investment and change hands. Based on this, this paper investigates the supply of private forests on the free market. For private forests that were publicly put for sale in the period from 2010 to 2020, their spatial-temporal distribution and supply dynamics and trends (price and quantity) were analyzed. The data were collected from the leading real estate advertising platform in Croatia (Njuškalo.hr), and a total of 866 advertisements were analyzed, relating exclusively to the sale of raw wood material along with the accompanying forest land. On the other hand, in order to assess the demand, data were collected on the number of potential buyers who viewed the advertisements (period 2020-2021). In the observed ten-year period, a total of 1,890.63 ha of private forests with a total asking value of €32.14 million were offered on the market. The share of advertisements advertised through real estate agencies is 42.1%. The average total annual supply is 170 ha and has a growing trend (in the advertisements in the coastal part of Croatia, the average area is 1.3 ha, while the average area in the continental part is 3 ha). The prices are not constant but rising. According to compound interest, the price increase in the coastal area is 1.57% and 7.49% in the continental area. From the relationship between supply and demand or, more precisely, the relationship between price and the quantity, it was concluded that the market is not well developed and that the price is not affected by the supply/demand quantity of private forests. Furthermore, it was concluded that this market is developing in the direction of a typical real estate market in Croatia due to the fact that forest management and wood processing characteristics of forests do not define the price, but that the price is largely determined by a market with greater financial importance (the market in real estate near the Adriatic coast).

Nitrogen Deposition in Different Mediterranean Forest Types along the Eastern Adriatic Coast

Mediterranean forests along the eastern Adriatic coast have an important ecological role. However, few studies have been conducted on nitrogen deposition so far. To improve this knowledge, the main aims of our study were: (i) to estimate nitrogen inputs and determine differences among the four Mediterranean forests, (ii) to determine the seasonal behaviour of N deposition compounds, and (iii) to discuss the results in relation to forest type and precipitation. Measurements were carried out over a two-year period on four plots in two regions: holm oak and pubescent oak in Istria, Aleppo pine and black pine in Dalmatia. Bulk open field and throughfall deposition were sampled with continuously exposed collectors. Measurements, analyses and data validation of precipitation and N compounds were carried out. The results showed that the highest average monthly precipitation was recorded in the black pine plot and the lowest in the Aleppo pine plot. Nitrate and ammonia in conifer plots in throughfall samples were lower than in bulk open field samples, indicating possible retention by the tree canopy. The results revealed a higher amount of N deposition collected in broadleaved forests than in conifer forests indicating the washing out of N compounds previously deposited and accumulated in forest canopy. The chemistry of N deposition was strongly influenced by local and anthropogenic sources as well as neighbouring countries. Our results may fill the knowledge gap in understanding the influence of precipitation and seasonality of N compounds in different Mediterranean forest types along the eastern Adriatic coast.

Perception and Attitudes of Residents Towards Green Spaces in Croatia – an Exploratory Study

Green spaces are important parts of urban infrastructure. COVID-19 pandemic and lockdown periods around the world have confirmed benefits that people derive from using green spaces for their physical and mental health. Green spaces need to meet the needs of users so that people can use them and benefit over time. It is important to consider users' perceptions and attitudes. User input proves beneficial in improving management practices. We investigated the differences in attitudes and perceptions of respondents from different large settlements in Croatia towards green spaces. Data on the use and perception of green spaces were collected in the first lockdown period in Europe and processed the part of the questionnaire on attitudes and perceptions towards green spaces. People have similar, mostly positive perceptions of green spaces regardless of the size of the settlement. Differences were found in the perception of disadvantages and needs related to the management of green spaces. This is the first study of the attitudes and perceptions on a large spatial scale in Croatia, so the results are exploratory and important. This study contributes to research on the social aspects of green spaces by investigating the influence of environmental context on perceptions and attitudes.

First Record of the Saproxylic Beetle Cossonus parallelepipedus (Coleoptera, Curculionidae) in Bosnia and Herzegovina

Balkan Peninsula is considered to be a hotspot of beetle biodiversity. Registering occurrence of saproxylic beetles is an important first step for expanding the general knowledge about saproxylic beetles as ecologically important insect species. Cossonus parallelepipedus is a European saproxylic species distributed from Iberian Peninsula in the west to Russia in the east, and from the Mediterranean in the south to Fennoscandia in the north. The first, and until now the only find of this species for the Balkan Peninsula is from Croatia. We report the first find of C. parallelepipedus in Bosnia and Herzegovina (BiH). In April 2020, larvae, pupae and imagoes were collected, in the central part of BiH, north of Sarajevo, on Zvijezda Mt. near Vareš from decaying moist wood in the lower part of a tree trunk of European silver fir, Abies alba. We expect that this species has a wider presence, especially in mountain areas in the central part of the country. Due to the similar environment conditions for other two European Cossonus species ( C. cylindrus and C. linearis) their presence is also possible.

Growth Dynamics and Tree Shape of Common Beech ( Fagus sylvatica L.) in the International Provenance Test

Provenance tests of forest tree species are important experiments in silviculture and tree breeding. Their results provide information about provenances' growth, adaptability, and other features. The research aimed to determine the dynamics of growth and tree shape of common beech plants per provenances in the international provenance test in Bosnia and Herzegovina to choose the best provenances considering wood production and quality. Research was conducted in the provenance test containing eight provenances from Bosnia and Herzegovina, four from Germany, three from Serbia, two each from Croatia, Romania, and Switzerland, and one from Hungary. Provenance test was established in 2007 by planting 2-year-old and 3-year old seedlings. Height and root collar diameter were measured, and tree shape was assessed in 2019. Data were processed in SPSS 26.0. Descriptive statistics, variance analysis, multiple Duncan's test for all traits, and Pearson's coefficient of corelation among morphological traits and tree shape were calculated. Variance for the height and root collar diameter showed statistically significant differences among different ages of plants and among provenances. Provenance from Croatia (Dilj Čaglinski) had the highest, and provenance from Romania (Alba-Iulia) had the lowest average height. The highest average value of root collar diameter had provenance Dilj Čaglinski, and the lowest value had provenance Sihlwald (Switzerland). The highest percentage of category 10 (ideal tree form) had provenance Bad Wildbad (Germany), and categories 1-4 (no silviculture value) had provenance Alba-Iulia (Romania). Pearson's coefficient showed that height, root collar diameter, and tree shape are highly correlated. Considering all the above, when planning forest-breeding works, it is recommended to continue the research and favor provenances with the best growth and tree shape.

Assessment of How Natural Stand Structure for Narrow Endemic Cedrus brevifolia Henry Supports Silvicultural Treatments for Its Sustainable Management

Cedrus brevifolia Henry is a narrow endemic tree species of Cyprus flora. The objectives of this study are to develop silvicultural treatments for the conservation of the species formations based on the stand structure analysis of C. brevifolia natural forest and to present the characteristics of the first application of the treatments through silvicultural interventions. Six structural types were distinguished in C. brevifolia formations in the study area located in the state forest of Paphos. For each structural type, six circular plots of approximately 500 m2 were established. In each plot, various measurements and estimations were recorded. Then, silvicultural interventions were applied in the plots of the mixed C. brevifolia formations. In the formations of C. brevifolia a great number of trees grow in the understory. In the very productive and in the poorly productive sites C. brevifolia occurs only in pure formations. The basal area of C. brevifolia in pure formations ranges from 19.04 m2·ha-1 in poorly productive sites to 38.49 m2·ha-1 in fairly productive sites. Cedrus brevifolia is the most competitive species of the study area as a result of both shade tolerance and the wide range of its site sensitivity behavior. The climax of the study area are the pure stands of C. brevifolia having an understory of Quercus alnifolia Poech and a sparse occurrence of Pinus brutia Ten., mainly in moderately productive sites. Forest practice has to, as much as possible, unite species formations in order to create extensive areas of C. brevifolia formations.

Correction

The authors wish to make the correction of the paper of Sarsekova et al. (2020). In the original paper, there was a mistake in the order of the first and the second name of the author Talghat Abbzhabnov. The correct order is Talghat Abbzhabnov.The original paper published on 11 May 2020 has been updated and both versions will be available on the paper webpage. The authors emphasize that this change does not affect the results of this research, and they apologize for any inconvenience this change may cause.

Comparative Analysis of Wood Fuels Consumption in Households in the Federation of Bosnia and Herzegovina

Analysis of the consumption of wood energy from wood-based fuels in households in the Federation of Bosnia and Herzegovina was the main purpose of this paper. A survey on wood fuel consumption was first conducted using the Wood fuel Integrated Supply/Demand Overview Mapping (WISDOM) methodology of the Food and Agriculture Organization (FAO) of the United Nations (UN). These results were compared to the results published by official statistics. The survey was conducted in ten cantons in the Federation of Bosnia and Herzegovina, namely in 5,475 households, 2,669 urban and 2,806 other households. The results of the research showed that wood fuels were used in 516,334 or 71.59% of the total number of households. Firewood was used in 497,139 households or in 96.28% in relation to the total number of households in the Federation of Bosnia and Herzegovina that used wood fuels. The surrounding countries showed similar trends. The estimated consumption of firewood in households using the WISDOM methodology is 4.10 (when compared to the official statistical data on total felled timber in and outside public and private forests) to 4.93 times higher than the official statistical data (when compared to the official statistical data on the sale of firewood in state forests), i.e. 4.52 times higher in average. This research indicates the need to apply a new methodological approach for the collection and analysis of data on the consumption of wood fuels in households for energy purposes. Some of the shortcomings of the existing official statistics are the neglect of statistically unregistered production of firewood from private forests and from areas not categorized as forests and forest land, as well as incomplete coverage in terms of conducting a survey on consumption of all categories of wood fuels and all major consumer categories. All the aforementioned, in addition to the economic consequences, has a negative impact on the fulfilment of commitments arising from international agreements in terms of the share of energy from renewable sources and greenhouse gas emissions in total energy consumption in Bosnia and Herzegovina. In addition, incomplete knowledge of the realistic supply and consumption of wood fuels can affect the reliability of planning documents in forestry, with many negative consequences for sustainability of a complex forest ecosystem.