|FROM THE HISTORY OF FORESTRY
|The 250th anniversary of Croatian forestry and the 169th year of the foundation of the Croatian Forestry Association and the publication of the 139th issue of the scientific-professional and specialist magazine Forestry Journal offer an ideal opportunity to look back at the texts published in the first issues and draw a parallel with present times.
The very first volume from the year 1877 contains an interesting article by Adolf Danhelovski "Recommendations on saving wood in the production of French staves", which states that the production process has improved slightly "although this type of goods requires maximal saving in its production, since they are produced of the most beautiful oak trees". Work should be performed by a "skilful labourer", otherwise much of the wood "might go to waste".... Narrower staves should be made of thinner trees or logs". Furthermore, logs should be classified according to the length and width of stave dimensions required. Other recommendations for saving follow. Let us draw a parallel with the present manner and recommendations related to saving and present squandering of national resources by using "the most beautiful oak forests", so that the non-market prices of the assortments allows the production of semi-finished goods and not high-quality products with a high added value and maximal employment. What is detrimental is the fact that veneer assortments are camouflaged into sawmill products intended for export; this also means "export" of working places which we sorely need. We discussed this in more detail in the Editorial of the Forestry Journal No. 5-6/2012, "The relationship between forestry and wood processing". This is why we do not agree with the words of the competent minister said after a Press conference, which we discuss in the column Current Affairs. The minister claimed that non-market contracts with wood processors had saved home wood processing from foreign competition. We continue to perceive this as a way of squandering national wealth for momentary gain of an individual and not for the benefit of the society as a whole.
The article published in the third year of publication in 1879, written by Alex. Ni. Sshulz and entitled "Seven main points of forest management and their theoretical-practical use" starts with a motto: "Production of he highest quantitative and qualitative amount of wood in the smallest area: and the best management". According to the article, forest management activities are divided into basic and auxiliary. The basic activities are mathematics and natural sciences and the auxiliary ones are technology, law-making, political sciences, book keeping, history and geography. Practical parts of forest management are divided into "a) silviculture, b) forest protection together with forest surveillance, c) use of forests together with forest technology, d) forest inventory with rotation and calculation of value and e) forest administration and forest directorate". From the present standpoint, the motto of the article suggests maximum possible use of the productivity of a particular forest site, whose degradation would mean catastrophe. In his comment of the seven points that follow, the author stresses that the first and the main point of management and work lies in "highly educated management personnel who posses theoretical and practical knowledge for useful and sustainable management of forests". He asks himself: "How can a person who has absolutely no knowledge of the basic sciences manage such a highly complex system as a forest?" The second point is independent management devoid of "greed for profit". The third point is primarily concerned with stand regeneration methods - artificial or natural regeneration. The fourth point contains a conclusion: "An honest forester who knows how to calculate will never allow his master, who, if faced with financial problems and forced to exploit his forest, to become a victim of swindlers and forest exploiters, and will use all his spiritual strength to at least limit what is unavoidable to the smallest space with regard to the future". The fifth point refers to "use of forests together with forest technology, which is more important that might seem at first glance". In his detailed explanation, the author concludes that the development and application of new technologies should be given due importance. The sixth point comprises "forest taxation together with rotations and value calculation". All the above points are mutually intertwined and cannot be separated from one another, "since without knowing one it is impossible to perform another". In the author´s words, the seventh point concerning "forest administration and forest directorate" requires no comments because everything is contained in the previous points, but he concludes that, as the old proverb says, "the fish rots from the head down", or translated into forest industry: if the directorate is no good, then the entire subordinate personnel will be no good. This refers to all branches of economy, and has been proven myriad of times in the human society and in all the professions". We conclude this text with the message – compare!
|IZVORNI ZNANSTVENI ČLANCI
|Ante P. B. Krpan, Željko Tomašić, Željko Zečić, Dijana Vuletić
|UDK 630* 537 (001)
|BIOPRODUCTIVITY OF INDIGOBUSH (Amorpha fruticosa L.) IN ONE-YEAR, TWO-YEAR AND FOUR-YEAR ROTATION
At the beginning of 2008, within the scope of the project Forest products and harvesting technology agreed with Croatian Forests Ltd, Zagreb, we have set up a research of biopotential, energetic characteristics and harvesting technology and use of indigobush biomass. From the above mentioned project, in 2012, a separate project Biopotential and energy characteristics of indigobush was transferred to the Academy of forestry sciences. The research ground was established in the pure indigobush stand in the forest management unit of the Posavina Forests, department 126a, Forest Office Sunja, Forest Administration Sisak. Within the block system, four test fields have been established; each with six 5 x 5 m large sub-test plots. (Figure 1)
This paper shows the results of the fourth year of research of indigobush considering its bioproductivity potential with a reference to the prescribed standards, harvesting characteristics and market demands, all which determines its position within the family of renewable resources of wood biomass for energy purposes. The research has encompassed plots 1, 2 and 4, i.e. bioproductivity of indigobush in one-year, two-year and four-year rotations. Within the scope of forest biomass issues, a higher number of HRN EN standards was considered, and a critical review of the terminology related to forest biomass, i.e., hard fuels, a term unscrupulous authors use in their publications.
Data of plots 1 are shown in Figures 3 and 4. In a one-year rotation per hectare, there were 87 200 to 140 400 one-year-old sprouts of indigobush. Mean height of sprouts on plots vary in a narrow range of 16 cm, taking a value of 2.07 m on the test field IV and up to 2.23 m on the test field II. The smallest mean diameter is recorded on the test field II and it amounts to 7.11 mm, while the largest was found on the test field III and it was 7.56 mm. Green indigobush mass on plots 1 ranges between 18.50 kg to 33.00 kg or in the calculation per hectare of the surface, it ranges between 7.40 t/ha and 13.20 t/ha. The difference between the smallest and the biggest value of green mass production on plots 1 is significant and it amounts to 5.80 t/ha. Average bioproduction of the green mass of indigobush on plots 1 in the fourth year of research amounts to 10.15 t/ha. Mean mass of one sprout of indigobush for all four plots is 0.0897 kg.
Data of plots 2 are shown in Figures 5 and 6. Number of sprouts on plots 2 ranges from 225 on fields II and IV up to 303 on field I, respectively, from 90 000 pcs/ha to 121 000 pcs/ha. Minimal mean height of 2.67 m is recorded in field I, and the maximal in field II, namely, 2.81 m. Mean diameter was the lowest on plot 2 in field I and it amounts to 9.82 mm, while the largest of 11.77 mm was recorded on test field IV. After long vegetation the established production of green mass of indigobush on plots amounts from 55.50 kg to a maximum of 70.50 kg or from 22.20 t/ha to 28.20 t/ha.
Average biannual production of green biomass amounts to 24.52 t/ha, respectively, average annual value amounts to 12.26 t/ha. Mean mass of one sprout of indigobush on plots assumes the value from 0.199 kg to 0.264 kg, i.e. 0.240 kg on average for all plots.
The parameters of bioproduction of indigobush for plots 4 are shown in Figures 7 and 8. Mean sprout height on plots 4 varies from 2.82 m to 3.04 m, and the diameter from 11.49 mm to 13.96 mm. The accumulated green biomass of indigobush during four vegetative periods varies between 83.10 kg/plot to a maximum of 128.50 kg/plot. After four-year rotations, per hectare, we acquired from 90 800 to 131 600 or an average of 109 000 sprouts and green biomass between 33.24 t/ha and 51.40 t/ha or an average of 42.06 t/ha. Average annual production of green biomass on plots 4 ranges from 8.31 t/ha to 12.85 t/ha and the mean value for all plots is 10.52 t/ha. Mean mass of one sprout of indigobush on all plots is 0.386 kg.
Table 1 and Figures 9, 10 and 11 show data of the variation analysis of diameter at breast height, and Table 2 and Figures 12, 13 and 14 show data of the variation analysis of mean sprout height of indigobush, including a discussion.
Table 3 shows the production of green biomass, laboratory determined percentages of moisture ratio of green indigobush and dry biomass matter. On plots 1, the percentage of moisture of indigobush wood ranges from 35.27 % to 37.02 % with a mean value of 35.92 %, on plots 2 the range of moisture is between 35.26 % and 36.03 % with mean value of 35.71 %, while on plots 4 it ranges between 30.91 % and 35.59 % with a mean value of 33.19 %. The proportion of dry matter in the samples of indigobush wood, relevant for all tested plots, ranges from 62.98 % to 69.09 %. In average, it is lowest on plots 1 with 64.08 %; on plots 2 the average value is 64.29 %, and on plots 4 it is the highest and it amounts to 66.81 %. Absolute values of the produced dry indigobush biomass in 2011 on plots 1 ranges from 11.88 kg/plot to 21.36 kg/plot or in average 16.26 kg/plot, i.e., or 6.5 t/ha of dry biomass.
On plots 1, which are harvested on a yearly basis at the end of every vegetative period, the annual level of bioproductivity of dry biomass after the first vegetation in 2008, it amounted to 12 t/ha (Krpan and Tomasic, 2009), after the second (2009) it was 7.87 t/ha (Krpan et al. 2011 –2), after the third (2010) it was 9.79 t/ha, and in 2011 it was 6.5 t/ha, and thus it could be concluded that bioproductivity of indigobush in one year rotation varies and has a decreasing trend in comparison with the first vegetation.
In a two-year rotation on plots 2, it was produced between 35.64 kg and 52.30 kg, with an average of 40.99 kg/plot (Krpan et al. 2011 –2). Therefore, the mean biannual bioproductivity of dry indigobush matter amounted 16.40 t/ha or on an annual average basis it was 8.20 t/ha which increases the value of bioproductivity for 0.31 t/ha in comparison with the second biannual yield in 2011.
In the four-year rotation of indigobush on plots 4, the established bioproductivity of dry biomass of indigobush has a value from 55.05 kg/plot to a maximum of 86.62 kg/plot or an average of 70.25 kg/plot, respectively, 28.10 t/ha. Mean annual bioproductivity of dry biomass in the four year rotation was 7.03 t/ha.
Bioproductivity of indigobush in this paper, based on the measurements of growth and increment parameters, density of the sprouts, parameters of laboratory research, its green mass, moisture and dry matter per plot unit in one-year, two-year and four-year rotation, despite the understandable variations, shows the potential benefit of indigobush within the family of solid fuels derived from forest biomass for energy. This paper showed previous research results based on which, due to the variations in the annual biomass production, it is not possible to choose and recommend an optimal rotation.
Key words: Indigobush bioproductivity; biomass standards; lowland forest ecosystems; Croatia
KRPAN, P.B. Ante ŠL
TOMAŠIĆ, Željko ŠL
ZEČIĆ, Željko ŠL
VULETIĆ, Dijana ŠL
|Marijan Grubešić, Josip Margaletić, Duško Čirović, Marko Vucelja, Linda Bjedov, Jelena Burazerović, Kristijan Tomljanović
| UDK630* 153
(Castor fiber L.)(001)
|ANALYSIS OF BEAVER (Castor fiber L.) MORTALITY IN CROATIA AND SERBIA
Population monitoring of beavers in Croatia and Serbia is being continuously run since the first release of beavers in 1996. in Croatia(Grubešić i Krapinec, 1998, Grubešić, 2014). Serbia has started with monitoring in 1999. When the first beak has been registered in the north of Vojvodina and it has been intensified since 2004. when they started with inhabitation – reintroduction (Ćirović, 2010). As a part of monitoring beavers in Croatia and Serbia since their reintroduction, beaver losses are being recorded by place and time of death, cause, sex and age of individuals. Information is being gathered with help of a network of associates, and by evidence of events. Based on the analysis of gathered information on beaver killings in the past 18 years a growth of killed beavers has been noticed, especially after the population growth and territorial expansion of beavers, and 10 years after the release in Croatia. In the observed period in Croatia a total of 111 beaver losses have been registered, while in Serbia this number is significantly lower and amounts to 36 individuals. Based on registered beaver losses a significant rise in beaver losses in the past 7 years has been noticed on the territory of Republic of Croatia. Actually the number of killed individuals has risen significantly when the beaver population has stabilized and increased its numbers and after 10 years since the inhabitation. In Serbia, despite the stabilization and territorial expansion, registered losses are relatively small, and stagnation or slight drop in killed or died animals has been noted. The main factor of mortality in Croatia and Serbia has been traffic. About one third of beavers (50 individuals) have been killed in traffic accidents. Traffic share in beaver mortality is equal or even somewhat smaller when compared to results from some parts of Germany, where this share is from 50 % to even 86,5 % (Pokorny and associates 2014., Muller 2014).
Strangulation in fishing nets has been the second most significant beaver loss in populations on the territory of Posavina and Podravina (22 beavers – 15 %). Autopsy unquestionably proved that 17 beavers (11.6 %) died from illness. For 33 of them (22,4 %), due to untimely findings or delivery to autopsy, a precise cause of death could not have been determined. When we look at beaver loss causes on the territory of Republic of Croatia traffic absolutely dominates, followed by unknown causes, and in third place illegal hunting and fishing (especially gillnets). In Serbia alongside unknown causes significant influences have diseases. From all 147 losses, only one beaver has been killed underneath a tree. Even though it has been noted he has been “killed at work”
the position of the beavers body and tree points that the killing was not a consequence of knocking down the tree in question (Picture 1 and 2), but that the tree fell on the beaver as it has been passing by, most likely as a consequence of wind blowing the bitten tree down or exceptionally that an another individual knocked down the tree and it fell on the beaver passing by.
Mostly adult individuals are being killed (Croatia 39, Serbia 14 beavers) which is linked to their increased activity in search for food and in moving about in general. Reasearch of other authors also shows that adult individuals are mostly being killed and mainly females (Pokorny and associates 2014).
Sub adult individuals are being killed when exploring the territory (new locations) or when they inhabit a zone where the get killed easily, especially in traffic. This age group has mostly been killed in Serbia (15 beavers).
In relation to sexual structure in Croatia and in Serbia a larger number of males were killed than females. Unfortunately, for half of killed beavers we were not able to tell the sex.
If we look at beaver killing on a seasonal level, then two periods stick out, mostly spring then autumn. In spring beavers move more, especially the sub adult ones in search for foo and exploration of new habitats, while in autumn when they are more active in agricultural lands, they are being killed in traffic or in illegal hunting (this influence is most likely significantly bigger than the recorded one, but the prefix “illegal” points to unavailability of information and data on individuals killed this way).
Illness for now are not a more significant cause of population loss, but in the future, especially in areas overcrowded by beaver, the might have a more significant role in the reduction of population, considering that we are dealing with a species (rodents) that are sensitive to certain diseases (leptospirosis, tularemia) (Parker and ass. 1951, Hopla 1974, Hornfeldti sur. 1986, Morneri sur., 1988, Wolli sur. 2012).
Certain problems or flaws in delivering information on losses emerge due to associates not being educated; these are accidental findings by people who have seen this species most likely for the first time. Apart from that some information has been delivered without details that would give a clearer picture in determining a cause of death, age and sex.
As a measure of protecting beavers first in line is respecting the legislation connected to illegal hunting and fishing, and the traffic killing might be decreased or somewhere completely prevented by setting up a wire fence alongside roads in troubling crosses. Also losses can be successfully prevented in watercourse construction in territories inhabited by beavers, that the personnel that is carrying out the construction is being educated and pointed to beaver protection measures while carrying out the work (lodge and animal protection from excavators). So called “dangerous” objects in which beavers can fall into and get hurt, can be adjusted in a way that beavers are enabled to get into such spaces but also to ensure the possibility of getting out from such a space. Beaver protection is being carried out by good media presentation and informing the public of beavers and their way of life, protection measures and citizen education. Such direct communication enables and simplifies information gathering on beavers, also including information on killed or died individuals.
Key words: beaver; Castor fiber; mortality; population; causes casualties; losses
GRUBEŠIĆ, Marijan ŠL
MARGALETIĆ, Josip ŠL
TOMLJANOVIĆ, Kristijan ŠL
|Damir Drvodelić, Tomislav Jemrić, Milan Oršanić, Vinko Paulić
|UDK 630* 232.3 + 283 (001)
|FRUITS SIZE OF WILD APPLE (Malus sylvestris (L.) Mill.): IMPACT ON MORPHOLOGICAL AND PHYSIOLOGICAL PROPERTIES OF SEEDS
The paper presents the results of the impact of fruit size of wild apples on a number of morphological and physiological seed properties. The fruits were divided into three groups with respect to mass: small (< 10 g), medium (10-20 g) and large (> 20.00 g). Significant morphological properties of fruits were measured. WinSEEDLE 2011 software was used for morphological analysis of seeds. SAS 9.2. package was used for statistical
analysis of ten morphological and physiological characteristics of seeds. The main components were analyzed using PCA (Statistica 7.0) in order to determine the variability of data and the relationship between some morphological characteristics of the seed. There was a statistically significant difference between small, medium and large fruits in the following variables: fruit length (mm), fruit width (mm), number of filled seeds per fruit (pieces), weight of fresh seeds (g), weight of air-dry seed (g) and loss of moisture in the seed (%). These variables increase with fruit weight. The loss of moisture in the seed was higher by 8.667% on average in large fruits in relation to small ones. In the case of small fruits (< 10 g), a positive and very high correlation was found between fruit width and length, between fruit weight and length, and between fruit width and weight of fresh and air-dry seed. In medium-sized fruit (10-20 g), there was a positive and very high correlation between fruit weight and fruit length and width, between fruit width and weight of fresh and air-dried seeds, between the number of filled seeds per fruit and seed weight in fresh or air-dry state and between weight of seeds in the air dry and fresh state. In the case of large fruits (> 20 g), there was a positive and very high correlation between the fruit shape index (FL/FW) and fruit length, fruit weight and fruit width, number of filled seeds per fruit and seed weight in fresh air or dry state, and between the weight of seeds in fresh and air-dry state. The conducted PCA analysis resulted in two functions that had eigen values larger than 1.00 and that explained 97.82% of the total variability in the morphological features of seeds from the investigated fruits of different weight. The projected area, the curved width, the volume of the ellipsoid, the surface area of the ellipsoid and the seed shape index showed extremely high negative values to the first axis, whereas the curved length (negative) and the seed shape index (positive) contributed the most to the second axis.
Key words: wild apple; fruit morphology; seed morphology; seed physiology; WinSEEDLE
DRVODELIĆ, Damir ŠL
ORŠANIĆ, Milan ŠL
|Vera Batanjski, Eva Kabaš, Nevena Kuzmanović, Snežana Vukojičić, Dmitar Lakušić, Slobodan Jovanović
|UDK 630* 188 (001)
|NEW INVASIVE FOREST COMMUNITIES IN THE RIPARIAN FRAGILE HABITATS – THE CASE STUDY FROM RAMSAR SITE CARSKA BARA (VOJVODINA, SERBIA)
The phytosociological investigation of habitats with highly invasive tree species Acer negundo L. and Fraxinus pennsylvanica Marshall was performed in Ramsar site Carska bara (Vojvodina, Serbia). A total of 107 species were noticed within 32 relevés. Recorded relevés are georeferenced and analysed in detail. The results of the relevant numerical analyses suggest the existence of two floristically and coenologically well defined groups of stands defined as the forest communities: Rubo caesii–Aceretum negundi ass. nova and Carici otrubae–Fraxinetum pennsylvanicae ass. nova. The increasing dispersal rate of the invasive trees is detected as a problem amongst many fragile wet habitats across Serbia and SE Europe, alerting their urgent and effective control.
Key words: invasive trees; Acer negundo; Fraxinus pennsylvanica; forest communities; wetland
|Vid Privora, Mirjana Herak Ćustić, Marko Petek, Ivan Šimić, Igor Palčić, Nikolina Sabljić
|UDK 630* 272 + 114.2 (001)
|THE STATUS OF LAWN NUTRITION WITHIN URBAN PARKS IN PUBLIC AREAS OF THE CITY OF ZAGREB
Urban parks play an important role in the ecology of human habitats because they filter the air, produce oxygen and provide shelters and habitats for many species, especially birds. They also represent green oases where people affected by stress or overwork may find a place to rest. Urban parks provide a variety of recreational activities for city residents. The aim of this study is to determine the content of macronutrients (nitrogen, phosphorus and potassium) in grass leaves in the urban parks of public areas in order to recommend optimal lawn fertilization. In addition, nutritional grass leaves statuses as well as analyses were made to determine the amount of macronutrients (N, P, K). Within recreational sport public buildings of the City of Zagreb were selected Recreational Sports Centre (RSC) Jarun and Bundek Park facilities as large green areas that are along with Maksimir Park the “lungs” of the city. Grass leaves and soil sampling were carried out on both lawns three times during the growing season. The content of nitrogen in grass leaves of both lawns is within the limits suggested by current literature whilst there was an determined lack of potassium and especially phosphorus. The determined average value of nutrients in the grass leaves during the vegetation period for Jarun were 3.14% N, 0.31% P and 2.78% K, and for Bundek 3.24% N, 0.41% P and 3.17% K. In general, the results show a slightly higher nutrient value of lawn in the Bundek Park compared to Jarun. On the study sites the largest share of grasses belongs Lolium perenne L. with 70%, Festuca rubra Huds. with 20% and 10% belongs to other plant species. Chemical properties of investigated soils show that the soil on RSC Jarun is alkaline and moderately supplied with nitrogen, very poorly supplied with phosphorus and well supplied with potassium. The soil in the Park Bundek is neutral and moderately supplied with nitrogen, very poorly supplied with phosphorus and slightly supplied with potassium. Consequently, we suggest spring fertilization on both locations with 100 g m–2 NPK 5-20-30 or 7-14-21 with the addition of 20 g m–2 superphosphate because of low P status both in soil and grass leaves and two topdressings during the growing season with 10 g m–2 KAN because of mowing.
Key words: grass; lawn; nitrogen; park; phosphorus; potassium
Herak Ćustić, Mirjana
|Petr Zahradník, Marie Zahradníková
|UDK 630* 453 (001)
|THE EFFICACY OF A NEW PHEROMONE TRAP SETUP DESIGN, AIMED FOR TRAPPING IPS TYPOGRAPHUS (COLEOPTERA, CURCULIONIDAE, SCOLYTINAE)
The primary aim of this paper is to compare the efficacy of traditional set-up of pheromone traps (along a stand wall at a distance of 20 m between each other) and a new arrangement where the pheromone baited trap is placed in the middle of a stocking area with no space between single traps. A secondary aim is to find the best use of pheromone baits in trapping systems where: i) every trap is baited, ii) every second trap is baited, iii) only traps at the edges and middle of arrangements are baited.
The results showed that the new organisation of pheromone baited traps is more effective than the traditional one and can provide a better tool for active forest protection in managing outbreaks of spruce bark beetles.
Key words: spruce bark beetle; pheromone baited traps; spatial trap design; control