Modelling Stand Variables of Beech Coppice Forest Using Spectral Sentinel-2A Data and the Machine Learning Approach

Background and Purpose: Coppice forests have a particular socio-economic and ecological role in forestry and environmental management. Their production sustainability and spatial stability become imperative for forestry sector as well as for local and global communities. Recently, integrated forest inventory and remotely sensed data analysed with non-parametrical statistical methods have enabled more detailed insight into forest structural characteristics. The aim of this research was to estimate forest attributes of beech coppice forest stands in the Sarajevo Canton through the integration of inventory and Sentinel S2A satellite data using machine learning methods. Materials and Methods: Basal area, mean stand diameter, growing stock and total volume data were determined from the forest inventory designed for represented stands of coppice forests. Spectral data were collected from bands of Sentinel S2A satellite image, vegetation indices (difference, normalized difference and ratio vegetation index) and biophysical variables (fraction of absorbed photosynthetically active radiation, leaf area index, fraction of vegetation cover, chlorophyll content in the leaf and canopy water content). Machine learning rule-based M5 model tree (M5P) and random forest (RF) methods were used for forest attribute estimation. Predictor subset selection was based on wrapping assuming M5P and RF learning schemes. Models were developed on training data subsets (402 sample plots) and evaluations were performed on validation data subsets (207 sample plots). Performance of the models was evaluated by the percentage of the root mean squared error over the mean value (rRMSE) and the square of the correlation coefficient between the observed and estimated stand variables. Results and Conclusions: Predictor subset selection resulted in a varied number of predictors for forest attributes and methods with their larger contribution in RF (between 8 and 11). Spectral biophysical variables dominated in subsets. The RF resulted in smaller errors for training sets for all attributes than M5P, while both methods delivered very high errors for validation sets (rRMSE above 50%). The lowest rRMSE of 50% was obtained for stand basal area. The observed variability explained by the M5P and RF models in training subsets was about 30% and 95% respectively, but those values were lower in test subsets (below 12%) but still significant. Differences of the sample and modelled forest attribute means were not significant, while modelled variability for all forest attributes was significantly lower (p<0.01). It seems that additional information is needed to increase prediction accuracy, so stand information (management classes, site class, soil type, canopy closure and others), new sampling strategy and new spectral products could be integrated and examined in further more complex modelling of forest attributes

Interpopulation variability of some morphological characteristics of silver fir (Abies alba Mill.) from central Bosnia

U radu je istraživana međupopulacijska varijabilnost morfoloških svojstava obične jele (Abies alba Mill.) iz središnje Bosne. Ukupno je istraživano 12 svojstava: četiri morfološka svojstva češera, šest svojstava sjemena, dva svojstva ljuski češera te određeni odnosi svojstava češera. Istraživana je varijabilnost za pet populacija koje se razlikuju u geološkoj i pedološkoj podlozi, različitim fitocenozama, a pripadaju i različitim sjemenskim regijama, uz primjenu multivarijantne analize. Sva istraživana morfološka svojstva češera, sjemena i ljuski obične jele u populacijama središnje Bosne pokazala su značajnu individualnu, kao i međupopulacijsku varijabilnost.The study investigated the discriminant interpopulational variability of the morphological characteristics of Silver fir (Abies alba Mill.) from central Bosnia. Four morphological characteristics of the cone, six characteristics of the seed, two characteristics of the cone scale, and certain quotients of the cone traits, were investigated. Variability was investigated by the application of multivariant analysis of five populations which differ by geological and pedological parent rock, different phytocoenoses and which belong to different seed zones. The investigated morphological characteristics of the cone, seed and cone scale of Silver fir (Abies alba Mill.) in populations of central Bosnia displayed significant individual, as well as interpopulational variability. Differences in altitude, pedological and geological soil structure between the populations had no effect on interpopulational variability of the investigated characteristics, or on the distance between populations. Statistically significant difference between populations, and their five relations, was determined for three out of four investigated morphological characteristics of the Silver fir cone. Five investigated morphological characteristics of the seed of Silver fir showed statistically significant interpopulational variability. One of the two investigated morphological characteristics of the cone scale, i.e. the length of the scale, showed statistically significant interpopulational variability. According to the discriminant analysis populations are grouped in three separated groups. Cone characteristics show the best separation, as well as seed characteristics in the discriminant analysis, while the characteristics of seed scales show less separation. Investigations of the characteristics of the cone, seed and scales could not be statistically correlated with age, d b h and height of the trees from which the samples were collected

Importance and structural diversity of trees in a historical park

U ovome radu istražena je važnost vrsta i porodica drveća u starom povijesnom parku Ilidža površine 16,5 ha, smještenom u blizini grada Sarajeva u Bosni i Hercegovini. Izvršeno je mjerenje najvažnijih dendrometrijskih varijabla (prsni promjer, visina i promjer krošnje) te je utvrđena i analizirana raspodjela broja stabala po debljinskim klasama. Važnost vrsta drveća i njihovih porodica iskazana je pomoću indeksa relativne važnosti, koja je određena pomoću relativne brojnosti i relativne dominantnosti. Rezultati istraživanja ukazuju na linearno inverzno proporcionalnu debljinsku raspodjelu kakva je poželjna u povijesnim parkovima, ali s neodgovarajućim udjelom stabala u najnižoj i višim debljinskim klasama. Najznačajnije vrste drveća, prema indeksu relativne važnosti većem od 10 %, su: gorski javor (Acer pseudoplatanus L.), obični jasen (Fraxinus excelsior L.), velelisna lipa (Tilia platyphyllos Scop.) i javor mliječ (Acer platanoides L.). Dobiveni rezultati imaju i praktičnu primjenu, jer mogu nam pomoći u planiranju kratkoročnih mjera njege i razvoju dugoročnih strategija radi održivog ostvarivanja biološke stabilnosti te svih funkcija urbanih zelenih površina (ekoloških, bioloških, estetskih, socijalnih i dr.).This study investigated the importance of tree species and their families in the old historical park Ilidža, which has an area of 16.5 ha and is located near the city of Sarajevo in Bosnia and Herzegovina. The dendrometric variables of greatest importance (diameter at breast height, height, and crown diameter) were measured and the diameter distribution were determined and analyzed. The importance of tree species and their families was determined by an index of relative importance which was calculated using relative abundance and relative dominance. The results of this study show that the inversely proportional linear distribution of diameters is within acceptable parameters for historical parks, however there is an insufficient number of trees in the lowest and higher diameter classes. The most significant tree species having an index of relative importance greater than 10% were: sycamore maple (Acer pseudoplatanus L.), European ash (Fraxinus excelsior L.), largeleaf linden (Tilia platyphyllos Scop.) and Norway maple (Acer platanoides L.). These results of this study have a practical application in planning short-term measures for maintenance and care, as well as for the development of long-term strategies in order to achieve sustainable biological stability and other functionalities of urban green surfaces (ecological, biological, aesthetic, social, etc.)

IMPACT OF MICRO-LOCALITY FACTORS TO THE INTENSITY OF INFESTATION OF SILVER FIR TREES WITH WHITE MISTLETOE

SažetakBijela imela (Viscum album L.) je poluparazitska biljka, koja se u različitom intenzitetu javlja na brojnim bjelogoričnim i crnogoričnim vrstama drveća. Istraživanje utjecaja mikrolokaliteta na intenzitet zaraze stabala obične jele bijelom imelom provedeno je u travnju 2012. godine na šumsko-gospodarskom području &quot;Ključko&quot;, gospodarska jedinica &quot;Šiša-Palež&quot;, u dijelovima odjela 5, 6 i 7/1, koja pripadaju gospodarskoj klasi 1211 – Šume bukve i obične jele sa smrekom na pretežito dubokom kalkokambisolu, luvisolu i njihovim kombinacijama na vapencu i dolomitu. Prema važećoj šumsko-gospodarskoj osnovi, za ove šume predviđen je grupimično-preborni sustav gospodarenja. Kao obilježja mikrolokaliteta zaraženih stabla obične jele procjenjivani su ili mjereni sljedeći parametri: prsni promjer, nagib, nadmorska visina i zasjenjenost krošnje zaraženog stabla krošnjama susjednih stabala. Intenzitet prisutnosti bijele imele na stablima obične jele procjenjivan je primjenom Hawksworth-ovog indeksa zaraze.Istraživanjima je obuhvaćeno 517 zaraženih stabala obične jele, čija je raspodjela po navedinim obilježjima navedena u tablicama 1.–4. Utvrđeno je da se s povećanjem prsnog promjera stabla (debljinski stupanj) povećava i prosječni indeks zaraze (slika 1). Analizom varijance utvrđene su statistički visoko značajne razlike u intenzitetu zaraze bijelom imelom stabala iz različitih debljinskih klasa (tab. 1; F = 9,239; sig. 0,000). U većini slučajeva, porast nagiba terena je uvjetovao jači intenzitet zaraženosti stabala. Međutim, analizom varijance nisu utvrđene statistički značajne razlike u prosječnom intenzitetu zaraze bijelom imelom stabala iz različitih kategorija nagiba (tab. 2; F = 2,237; sig. 0,083). Kada je u pitanju nadmorska visina mikrolokaliteta, provedene analize nisu potvrdile postojanje statistički značajnih razlika u prosječnom intenzitetu zaraze stabala koja su se nalazila na različitim nadmorskim visinama (tab. 3; F = 1,095; sig. 0,358). Utjecaj svjetlosti na pojavu imele istraživan je preko zasjenjenosti krošanja zaraženih stabala krošnjama susjednih stabala. Analizom varijance utvrđene su statistički visoko značajne razlike u prosječnom intenzitetu zaraze bijelom imelom stabala iz različitih kategorija zasjenjenosti njihovih krošanja (F = 17,761; sig. 0,000). Usporedbom svih kategorija zasjenjenosti utvrđen je opći model koji ukazuje da intenzitet zaraze imelom opada s povećanjem zasjenjenosti krošnje zaraženog stabla (slika 3).White mistletoe (Viscum album L.) is semi-parasitic plant which in different intensity occurs on numerous deciduous and coniferous tree species. The research on the impact of micro-localities to the intensity of infestation of Silver fir trees with white mistletoe was conducted in April 2012 in forest management area &quot;Ključko&quot;, management unit &quot;Šiša-Palež&quot;, in parts of units 5, 6 and 7/1 which belong to management class 1211 – Forests of Beech and Silver fir with Spruce on mainly deep calco-cambisole, luvisole and combinations of it on dense limestone and dolomites. According to the valid forest management plan for these forests is predicted a group-selective system of management. As characteristics of the micro-locality of infested Silver fir trees were assessed or measured the following parameters: breast-height diameter, inclination, altitude above the sea level and shading of the crown of infested tree caused by crowns of neighboring trees. The intensity of the presence of white mistletoe on Silver fir trees was assessed by implementation of Hawksworth Index of InfestationResearch covered 517 infested Silver fir trees by the characteristics of which are given in the tables 1–4. It was determined that with the increase of breast-height diameter of tree (diameter class) increases the average index of infestation (Figure 1). By the analysis of variance were determined statistically highly important differences in the intensity of infestation by white mistletoe of trees from different diameter classes (Table 1; F = 9,239; sig. 0,000). In majority of cases, the increase of the inclination of the terrain has caused higher intensity of infestation of trees. However, by the analysis of variance were not determined statistically significant differences in intensity of infestation by white mistletoe of trees from different inclination category (Table 2; F = 2,237; sig. 0,083). Regarding the altitude above the sea level of the micro-locality, the conducted analyses did not confirm the existence of statistically significant difference in average index of infestation of trees which were located at different altitudes above the sea level (Table 3; F = 1,095; sig. 0,358). The impact of light to the occurrence of mistletoe was researched through the level of shading of infested crown caused by crowns of neighboring trees. By the analysis of variance were determined statistically highly significant differences in the intensity of infestation by white mistletoe of trees from different categories of shading of their crowns (F = 17,761; sig. 0,000). By comparison of all categories of shading was determined a general model which points that the intensity of infestation by mistletoe declines with the increase of the level of shading of the crown of infested tree (Figure 3)

Population differentiation in the wild cherry (Prunus avium L.) in Bosnia and Herzegovina

Background and Purpose: The wild cherry (Prunus avium) has great and multiple importance. The fruits it produces are used for several purposes (as food for people, birds and other animals, as well as in phytotherapy). As many birds and mammals feed on the fruit of the wild cherry, it has the ability of dispersion over large areas in a very short time. It is present in from river deposits up to 1900 m/alt, while it is quite rare in the Submediterranean. Wild cherry grows as a solitary tree or in small groups, usually at the edge of the forest or within the forest in areas with more sunlight. The significance of the wild cherry is reflected in the high conomic value of its wood, which makes itmuch demanded and popular, and thus endangered. Materials and Methods: The plant material was collected from 22 natural populations in Bosnia and Herzegovina. The fruit and leaves were collected from marginal or solitary trees, usually from the south-facing,outer sun-exposed parts of the tree crown. We measured the following fruit characteristics: fruit length (FL), fruit width (FW), fruit thickness (FT), seed length (SL), seed width (SW), seed thickness (ST), length of the stalk (LOS) and width of the stalk (WOS), and leaf characteristics: length of the petiole (LP), length of the leaf blade (LB), distance from the blade base to the blade’s widest part (BBW), width of the leaf blade (WB), insertion angle of the leaf venation (AV), number of leaf teeth on a 2-cm length (NT), blade width at 1 cmfrom the blade apex (WBA) and blade width at 1 cm from the blade’s base (WBB). All statistical analyses of the data were made using the SPSS 15.0 package for Windows. Results: The results obtained show the presence of a high level of intrapopulational, as well as interpopulational, morphological variability in the natural populations of the wild cherry which have been investigated. Analyses of population differentiation have not confirmed our expectations. Our results only indicate differentiation in fruit size characteristics, but the indicators are very weak. The resulting high values of the regression coefficient in this research can serve to estimate the values of some features and characteristics without their measurement. Conclusions: The analyses of 16 morphological characteristics in 22 natural populations of the wild cherry in Bosnia and Herzegovina showed statistically significant differences between investigated populations. Differentiation in natural populations of the wild cherry was very low and identified only in fruit dimension characteristics

Variability of Scots Pine (Pinus Sylvestris L.) in the Provenance Trial Glasinac – Sokolac (Bosnia and Herzegovina)

U okviru programa “Revizija postojećih i izdvajanje novih sjemenskih sastojina i proučavanje bioloških karakteristika smreke, jele, običnog i crnog bora u funkciji proizvodnje kvalitetnog sjemena za potrebe šumarstva SRBiH”, pristupilo se eksperimentalnoj rajonizaciji običnog bora (Pinus sylvestrisL.) u Bosni i Hercegovini. Tijekom 1989. godine osnovana je pokusna površina na Glasinačkom polju – Sokolac, sa 11 provenijencija običnog bora pod rijetlom iz prirodnih populacija te materijalom iz dvije sjemenske plantaže i s kontrolom s podrućja Bosne i Hercegovine. Istraživana su svojstva promjera, temeljnica, visina, volumena srednjeg stabla i drvne zalihe po hektaru u starosti od 21 godinu. Najbolja od istraživanih provenijencija u ovom pokusu po svojoj proizvodnosti pokazala se provenijencija Romanija – Glasinac, koja je, inače, predstavnik populacije najbliže pokusnoj plohi, u kojoj vladaju isti ekološki uvjeti.Experimental regional division of Scots pine (Pinus sylvestris L.) in Bosnia and Herzegovina was initiated with development of framework of the program “Revision of existing and selection of new seed stands, and study of biological traits of Norway spruce, silver fir, Scots pine and European black pine in the function of production of qualitative seed needed for forestry in SRBiH”. During 1989 test surface in Glasinac filed – Sokolac was established with 11 provenances, material from two seed plantations and control group. Research was carried out on diameters, basal areas, heights, volume of medium tree, and total volume per ha of trees which are 21 years old. Analyses carried out on size of medium diameter, basal area, height, and volume on the test surface showed that provenance Romanija-Glasinac had best results. Taking into consideration poor conditions in the place of origin of this population, conclusion could be made that their good results were obtained based on the extremely competitive selection in the unfavorable conditions, and on qualitative genetic construction. Although the trait of survival is not statistically processed because it belongs to the group of qualitative traits, it is very significant because it does not have direct influence to the trait of volume per ha. The best survival was demonstrated by the provenance Romanija-Glasinac, and the poorest by the provenance Zavidovići with minimal portion of survived plants. Statistically significant difference was determined by analysing the height of trees in the test surface, meaning that differentiation between the provenances is still present on the test surface. The best provenances are Romanija-Glasinac, Šipovo, and Bugojno. According to the soil type, which is in this case brown limestone (calcocambisol), sea level, and ecological conditions at the Glamoč plateau, the best provenance is Romanija – Glasinac which has the best productivity under these conditions. Obtained medium heights for Scots pine in this experiment showed that some provenances go above site class I. if they are compared with data from volumetric tables for even aged forests. According to the Wiedemann’s volumetric tables, the provenance Romanija – Glasinac is significantly larger in regards to average basal area and volume from volumetric tables for the site class I. of habitat. Reliable conclusions about productive possibilities of some species, and of a provenance inside some species, can be made only after one third of estimated fertilization. Having that in mind, obtained results up to now are only partially reliable when making conclusions about which provenance is the best for introduction on the defined habitat while good conclusions will be reached in the following period. Present variability intra and inter provenances, which is registered in this experiment, can be used for subsequent selections of material when installing intensive clone or seed plantation

Uzročnici truleži drveta obične smreke /Picea abies (L.) Karst./ na planini Zvijezda

Wood decay fungi reduce the vitality of infected trees, predispose the surrounding trees to be attacked from other harmful agents and damage the most valued part of the stem. Because of these multiple influences it is necessary to explore the presence of these fungi in the forests of Bosnia and Herzegovina, in order to be able to prevent and reduce the damage they cause. Norway spruce in Bosnia and Herzegovina represents one of economically important trees. Because of that, this research is focused on role and implementation of molecular methods and determination of wood decaying fungi on Norway spruce from the genera Heterobasidion and Armillaria on mountain Zvijezda. The reliable identification of species of genus Heterobasidion can be made by analyzing the differences in the structure of the ITS region of rDNA. The reliable identification of species of genus Armillaria can be done by analyzing the differences in the structure of the ITS region of rDNA (genus level), or IGS rDNA regions (interspecies diversity). Inside the object of research were found 9 trees with fungus Heterobasidion parviporum Niemelä & Korhonen, 1 tree with a fungus Armillaria cepistipes Velenovský, 2 trees with the fungus Armillaria ostoyae (Romagnesi) Herink, and 17 trees whose decay was caused by other decaying fungi. Heterobasidion annosum (Fr.) Bref. was identified from decaying wood of Scots pine (Pinus sylvestris L.).Utjecaj gljiva truležnica roda Heterobasidion i Armillaria na pojavu truleži na stablima obične smreke provedeno je na Šumskogospodarskom području “Gornjebosansko”, gospodarska jedinica “Gornja Stavnja”, odjeljenje 65. Utvrđivanje prisutnosti truleži vršeno je na srušenim stablima obične smreke na premjernim površinama koje su raspoređene u sistematski postavljenoj mreži 100 m x 100 m. Uzorci su prikupljeni sa tri mjesta na dijelu debla zahvaćenom procesom truleži (početak zone truleži, sredina i vršna zona truleži). Na mjestima uzorkovanja uzimani su kolutovi drva debljine 5 cm. Analize uzoraka su provedene u laboratorijima Šumarskog fakulteta Univerziteta u Sarajevu. Za izravnu  izolaciju gljivične DNA su pripremljeni uzroci drva mase 10-20 mg. Za  amplifikaciju ciljanog  segmenta  DNK  korištene su tubice s pripremljenim reagensima, proizvod ReadyToGo PCR beads tvrtke Amersham, Bioscience. Za amplifikaciju ciljanog segmenta ITS regije za rod Heterobasidion su korišteni početnice MJ-F, MJ-R, KJ-F i KJ-R, pomoću kojih je utvrđena međuvrsna raznolikost (tablica 2). Za amplifikaciju ciljanog segmenta ITS regiona za rod Armillaria su korišteni početnice ITS-1 i ITS-4, pomoću kojih je utvrđena samo pripadnost rodu. Za međuvrsnu raznolikost je vršena amplifikacija ciljanog segmenta IGS regiona za rod Armillaria pomoću početnice LR12 i O-1, te razgradnja endonukleazom AluI (tablica 3). Uspješnost amplifikacije je provjerena elektroforezom na agaroznom gelu. Interpretacija profila je izvršena pomoću  molekularnog markera poznate veličine (100 bp) (slika 1).Na osnovi provedenih istraživanja unutar istraživane sastojine utvrđeno je 9 stabala s gljivom H. parviporum, 2 stabla s gljivom A. ostoyae, 1 stablo s gljivom A. cepistipes, te 17 stabala čiju trulež su uzrokovale ostale gljive truležnice (tablica 4). Gljiva H. annosum je uspješno identificirana iz plodišta. Na osnovi svega navedenog, može se zaključiti da je molekularnim analizama moguće utvrđivati međuvrsnu raznolikost gljiva ova dva roda iz uzoraka drveta sa truleži i plodišta gljiva

Variability of Scots Pine (Pinus Sylvestris L.) in the Provenance Trial Glasinac – Sokolac (Bosnia and Herzegovina)

U okviru programa “Revizija postojećih i izdvajanje novih sjemenskih sastojina i proučavanje bioloških karakteristika smreke, jele, običnog i crnog bora u funkciji proizvodnje kvalitetnog sjemena za potrebe šumarstva SRBiH”, pristupilo se eksperimentalnoj rajonizaciji običnog bora (Pinus sylvestrisL.) u Bosni i Hercegovini. Tijekom 1989. godine osnovana je pokusna površina na Glasinačkom polju – Sokolac, sa 11 provenijencija običnog bora pod rijetlom iz prirodnih populacija te materijalom iz dvije sjemenske plantaže i s kontrolom s podrućja Bosne i Hercegovine. Istraživana su svojstva promjera, temeljnica, visina, volumena srednjeg stabla i drvne zalihe po hektaru u starosti od 21 godinu. Najbolja od istraživanih provenijencija u ovom pokusu po svojoj proizvodnosti pokazala se provenijencija Romanija – Glasinac, koja je, inače, predstavnik populacije najbliže pokusnoj plohi, u kojoj vladaju isti ekološki uvjeti.Experimental regional division of Scots pine (Pinus sylvestris L.) in Bosnia and Herzegovina was initiated with development of framework of the program “Revision of existing and selection of new seed stands, and study of biological traits of Norway spruce, silver fir, Scots pine and European black pine in the function of production of qualitative seed needed for forestry in SRBiH”. During 1989 test surface in Glasinac filed – Sokolac was established with 11 provenances, material from two seed plantations and control group. Research was carried out on diameters, basal areas, heights, volume of medium tree, and total volume per ha of trees which are 21 years old. Analyses carried out on size of medium diameter, basal area, height, and volume on the test surface showed that provenance Romanija-Glasinac had best results. Taking into consideration poor conditions in the place of origin of this population, conclusion could be made that their good results were obtained based on the extremely competitive selection in the unfavorable conditions, and on qualitative genetic construction. Although the trait of survival is not statistically processed because it belongs to the group of qualitative traits, it is very significant because it does not have direct influence to the trait of volume per ha. The best survival was demonstrated by the provenance Romanija-Glasinac, and the poorest by the provenance Zavidovići with minimal portion of survived plants. Statistically significant difference was determined by analysing the height of trees in the test surface, meaning that differentiation between the provenances is still present on the test surface. The best provenances are Romanija-Glasinac, Šipovo, and Bugojno. According to the soil type, which is in this case brown limestone (calcocambisol), sea level, and ecological conditions at the Glamoč plateau, the best provenance is Romanija – Glasinac which has the best productivity under these conditions. Obtained medium heights for Scots pine in this experiment showed that some provenances go above site class I. if they are compared with data from volumetric tables for even aged forests. According to the Wiedemann’s volumetric tables, the provenance Romanija – Glasinac is significantly larger in regards to average basal area and volume from volumetric tables for the site class I. of habitat. Reliable conclusions about productive possibilities of some species, and of a provenance inside some species, can be made only after one third of estimated fertilization. Having that in mind, obtained results up to now are only partially reliable when making conclusions about which provenance is the best for introduction on the defined habitat while good conclusions will be reached in the following period. Present variability intra and inter provenances, which is registered in this experiment, can be used for subsequent selections of material when installing intensive clone or seed plantation