Geostatistical approach to spatial analysis of forest damage

Background and Purpose: Significantly increased forest damage has recently been observed in the Republic of Croatia, as well as increased proportion of unplanned felling in prescribed cuts, which has negative repercussions for sustainable management. The objective of this study was is to explore the possibilities of simple and reliable detection, inventorying (mapping) and monitoring forest health condition by means of color infrared (CIR) imagery and geostatistical methods. Materials and Methods: Four trees (crowns) closest to the point of the raster (100 ´ 100 m) which was set up in the digital orthophoto for the area, were interpreted in CIR images. Forest damage indicators, mean damage and damage index were calculated for the whole area under observation. The assessment and identification of spatial distribution of these damage indicators were performed using raster point data, from which a random (966 points) and a systematic (445 points) sample were created. The results on forest damage acquired by interpreting CIR images were used for geostatistical analysis. A model of theoretical semivariograms provided parameters which were used for interpolation of both damage indicators with ordinary kriging. Continuous maps of damage degree distribution were then constructed. The results of interpolation were tested with the cross-validation method. Results and discussion: Damage indicator maps are the result of the following: data variability, sampling intensity and method, form of experimental and theoretical semivariograms which were subsequently used to compute kriging matrices, method of selecting a particular semivariogram, assessment accuracy, the choice of interpolation methods (kriging, cokriging, stochastic simulation, inverse distance, etc.). Tree damage generally does not have regular, but rather random spatial distribution. This is why the primary aim in identifying forest damage is to incorporate the whole area of interest into sampling. Sampling intensity should be adapted to the required accuracy and to the time and funds at our disposal. Conclusions: This research relies on the application of CIR aerial photographs and geostatistical tools in spatial analysis of forest damage. Continuous maps of damage indicators acquired with kriging provide a better insight into the spatial distribution of damage than do thematic maps obtained by interpreting CIR aerial imagery on the basis of a systematic sample (the raster method). Integration of interpretation results of CIR aerial images and geostatistical approach ensures a more precise distribution of damage indicators, and consequently, the possibility of better spatial analysis of the occurrence, trends and development of damage in the study area

The Occurence of Lower Sensitivity Pollen Beetle (Meligethes spp.) Populations to Chlorpyriphos in Winter Oilseed Rape (Brassica napus L.)

Pollen beetle (Meligethes spp.) is the most important oilseed rape pest. If no control measures are conducted, this pest could cause even more than 50% reduction of the yield which is the reason of high insecticides input every year. Due to frequent use of insecticides for its control in the last decade, the resistance of pollen beetle to pyrethroids was confirmed. In order to test sensitivity of adult forms to chlorpyriphos, 52 populations were collected from different oilseed rape fields in 2013 and 2014. For each sample were determined coordinates using GPS (Global positioning system). Based on the collected data the database in GIS (Geographic information system) was created. In a laboratory experiment they were tested according to IRAC Susceptibility Test Method No: 025. Results show lower chlorpyriphos efficiency, with potential to be tolerant, on eight pollen beetle populations located in three eastern counties where the highest amount of arable crops is located. This is the first record of low sensitivity pollen beetles to chlorpyriphos in Europe

Assessing Forest Damage in the Spačva Basin with Colour Infrared Aerial Photographs

Na temelju fotointerpretacije infracrvenih kolornih (ICK) aerosnimaka mogu se odrediti pouzdani statistički podaci o oštećenosti šuma. Inventarizacija oštećenosti šuma pomoću aerosnimaka temelji se na ustanovljavanju stupnja oštećenosti pojedinačnih stabala (krošanja), koja se vide na aerosnimkama. Preduvjet za postizanje takvih rezultata je kvalitetno izrađen fotointerpretacijski ključ. Na osnovi predodžbe o načinu preslikavanja pojedinih vrsta drveća i stupnjeva oštećenosti, izrađen je fotointerpretacijski ključ za glavne vrste drveća (hrast, jasen). Također su izračunati pokazatelji oštećenosti (O, SO, IO, SO1) za pojedine vrste drveća, za sve interpretirane vrste zajedno, po prugama snimanja, za gospodarske jedinice te ukupno za područje Spačvanskog bazena (UŠP Vinkovci). Interpretacijom ICK aerosnimaka ustanovljeno je stanje šumskih sastojina na snimljenom području. Za cijelo snimljeno područje (5575 ha), na temelju sistematskog uzorka 100x100 m, ukupno je interpretirano 17 439 stabala, te je utvrđena srednja oštećenost (SO) svih vrsta drveća 26,18 %, hrasta lužnjaka 31,80 %, jasena 17,93 %. Iz dobivenih podataka može se zaključiti da je stupanj oštećenosti inventariziranih šuma na prijelazu male i srednje oštećenosti. Za istraživano područje Spačvanskog bazena značajna oštećenost hrasta lužnjaka, tj indeks oštećenosti (IO) iznosi 45,27 %, što znači da je taj postotak stabala hrasta lužnjaka na snimljenom području oštećeniji od 25 %. Na cijelom području snimanja značajna oštećenost jasena iznosi 26,15 %. Interpretacijom ICK aerosnimaka ustanovljeno je stanje šumskih sastojina na snimljenom području. Aerosnimke ostaju kao trajan dokument o tom stanju. Na aerosnimkama opažanja se u svakom trenutku mogu ponoviti, provjeriti i nadopuniti, a prema potrebi i nastaviti.Photointerpretation of colour infrared aerial photographs (CIR) provides reliable statistical data on forest damage. Inventorying forest damage with aerial photographs is based on the assessment of the extent of damage to particular trees (crowns) recorded in aerial photographs. A precondition for the achievement of such results is a good quality photointerpretation key. A photointerpretation key was made for the principal tree species (oak, ash) based on the method of mirroring tree species and damage indicators. Damage indicators (damage-O, mean damage-SO, damage index-IO, mean damage1-SO1) were also calculated for each tree species, for all the interpreted species together, per surveying stripes, for management units, and for the entire area of the Spačva basin (Forest Administration Vinkovci). CIR aerial photographs were interpreted to obtain the status of forest stands in the surveyed area. For the whole study area (5,575 ha), a total of 17,439 trees were interpreted on the basis of a systematic 100 x 100 m sample. Mean damage (SO) for all tree species was found to be 26.18 %, for pedunculate oak 31.80 % and for ash 17.93 %. It may be concluded that the degree of damage of inventoried forests is between low and medium. The considerable damage index (IO) of 45.27 % for pedunculate oak in the Spačva basin means that the said percentage of pedunculate oak in the surveyed area is damaged by more than 25 %. In the entire surveyed area considerable ash damage amounts to 26.15 %. CIR aerial photographs were interpreted in order to assess the condition of forest stands in the study area. Aerial photographs are a lasting document of forest stand condition. In aerial photographs observations may be repeated, checked, updated and continued at any given moment

Granulomatozna upala orbite: dijagnoza, praćenje i terapija

During the 2000-2005 period, we treated 32 patients with unilateral or bilateral granulomatous inflammation of the orbit. After careful exclusion of specific systemic and local diseases, the diagnosis was based on a combination of clinical and radiological findings. Examinations were performed to exclude the presence of a malignant or other form of tumor. Subsequently, we started treatment with high-dose steroids or a combination of steroids and surgical therapy. After therapy, we analyzed visual acuity, exophthalmometry, intraocular pressure and visual fields. There was no tumor recurrence during the follow up of 1-4 years. The findings suggested the treatment with high-dose steroids or a combination of steroids and surgical therapy to be an efficient therapeutic option for granulomatous inflammation.U razdoblju od 2000. do 2005. godine na Klinici za očne bolesti Kliničke bolnice .Sestre milosrdnice. liječili smo 32 bolesnika s jednostranom ili obostranom granulomatoznom upalom orbite. Nakon pažljivo učinjenih pretraga kako bi se isključilo postojanje specifičnih sustavnih ili lokalnih bolesti postavili smo dijagnozu koja se temeljila na kombinaciji kliničkih i radioloških nalaza. Kod svih bolesnika prije i nakon liječenja analizirana je vidna oštrina, mjeren je očni tlak, učinjena egzoftalmometrija po Hertelu te vidno polje po Goldmannu. Svi bolesnici najprije su bili podvrgnuti kirurškom zahvatu orbitotomije, eksploracije i uklanjanja tumorskog tkiva, potom su svi primili pulsnu dozu kortikosteroida kroz tri dana, a nakon toga se nastavilo s liječenjem per os kroz dva mjeseca. Kod 75% bolesnika nakon završetka liječenja došlo je do porasta vidne oštrine za jedan ili više redova po Snellenu, a kod 96.88% bolesnika došlo je do smanjenja protruzije očne jabučice za 2 ili više mm. Tijekom razdoblja praćenja nismo zabilježili znakove reaktiviranja upale. Zaključuje se kako se pažljivim kliničkim pretraživanjem i primjereno postavljenom dijagnozom te kombiniranim liječenjem steroidima i kirurškim zahvatom postižu dobri rezultati kod bolesnika s granulomatoznom upalom orbite

Application of Colour Infrared Aerial Photographs for the Assessment of Forest Damage in the Gospić Forest Administration

U radu su prikazani rezultati istraživanja provedenoga s ciljem utvrđivanja oštećenosti šuma na ICK aerosnimkama. Interpretacijom ICK aerosnimaka, ustanovljeno je stanje šumskih sastojina na istraživanom području (UŠP Gospić). Za cijelo snimljeno područje po prugama snimanja izrađen je infracrveni digitalni ortofoto (DOF 1:5000), preko kojega je postavljen sistematski uzorak (mreža točaka) 100x100 m. Na svakoj od točaka (uzorku) interpretirane su 4 krošnje najbliže točki, te je tako ukupno određen stupanj oštećenosti za 21 011 stabala. Izračunati su pokazatelji oštećenosti (O, SO, IO, SO1), za pojedine vrste drveća, za sve interpretirane vrste zajedno i to za pojedine pruge snimanja, ukupno za cijelo snimljeno područje, te za gospodarske jedinice (odjeli/odsjeci zahvaćeni snimanjem). Na interpretiranoj površini od 5 548 ha utvrđena je srednja oštećenost (SO) svih vrsta drveća 23,60 %, jele 37,81 %, bukve 12,61 %. Iz tih rezultata može se zaključiti da je stupanj oštećenosti inventariziranih šuma na prijelazu male i srednje oštećenosti. Indeks oštećenosti (IO) jele za područje Like iznosi 61,96 %, tj. taj postatak stabala jele na snimljenom području oštećeniji je od 25 %. Unutar 61,96 % značajno oštećenih stabala jele, srednja oštećenost (SO1) jele iznosi 51,03 %. Sukladno dobivenim rezultatima, izrađene su tematske karte mjerila 1:10000 s prostornom raspodjelom srednje oštećenosti (SO) i indeksa oštećenosti(IO) za glavne vrste drveća, te ukupno za gospodarske jedinice (odjeli/odsjeci) na pojedinim prugama snimanja. Primjenom ICK aerosnimaka za procjenu oštećenosti šuma dobile su se informacije, koje se ne razlikuju od podataka dobivenih terestrički, a aerosnimke ostaju kao trajan dokument o tom stanju.The paper presents the results of research conducted with the goal of assessing forest damage in CIR aerial photographs. The interpretation of CIR aerial photographs provided the condition of forest ecosystems in the study area (the Gospić Forest Administration). An infrared digital orthophoto (DOP 1:5,000) was made by surveying strips for the entire surveyed area. The DOP was overlaid with a systematic 100x100 m sample (dot grid). Four crowns closest to the point were interpreted at each of the points (sample) and damage to a total of 21,011 trees was assessed. Damage indicators (O, SO, IO, SO1) were calculated for individual tree species and for all the interpreted species together by individual surveying strips, by the entire surveyed area and by management units (compartments /subcompartments included in the survey). In the interpreted area covering 5,548 ha, the recorded mean damage (SO) for all tree species amounted to 23.60 %, for fir to 37.81 %, and for beech to 12.61 %. The results suggest that the damage degree of the inventoried forests is between low and moderate. The damage index (IO) of fir for the area of Lika is 61.96 %; in other words, this percentage of fir trees in the surveyed area is damaged by more than 25 %. Within the 61.96 % of severely damaged fir trees, the mean damage (SO1) of fir is 51.03 %. In terms of the interpretation of results by surveying strips, we can conclude that the mean damage (SO) and the damage index (IO) for all the trees together are the highest in the surveying strip 5. The obtained results were used for the construction of thematic maps on a scale 1:10,000. They contain spatial distribution of mean damage (SO) and damage index (IO) for the principal tree species, and overall for management units (compartments/subcompartments) in individual surveying strips. Application of CIR aerial photographs for the assessment of forest damage provided data which do not differ from terrestrially-obtained data; however, aerial photographs represent a lasting document of the condition

Possibilities of applying lightweight unmanned aerial vehicles to big game counting

U provedenom istraživanju pokušalo se istražiti u kojoj mjeri je moguće aplicirati sustav bespilotne letjelice opremljene termalnom kamerom u procjeni nekih populacijskih parametara krupne divljači. Istraživanje je provedeno u nizinskom području kontinentalnog dijela Republike Hrvatske unutar lovišta Opeke II. Za istraživanje je odabrana divlja svinja kao najčešća vrsta krupne divljači u Republici Hrvatskoj. Unutar dva lokaliteta (I dobni razred,uređajni razred hrasta lužnjaka) provedeno je testiranje dvije metode prebrojavanja. Prvom metodom pokušala su se prebrojiti sva grla unutar istraživanog odsjeka. Rezultati dobiveni tom metodom pokazuju relativno visoku brojnost divlje svinje od prosječno 1,26 +/– 0,18 grla/ha unutar istraživanjem obuhvaćenog područja. Druga korištena metoda predstavlja prebrojavanje divljih svinja na unaprijed određenim prugama, čiji udio u ukupnoj promatranoj površini iznosi 10%. Kod te metode podaci su veće varijabilnosti te je ustanovljena nešto manja brojnost divljih svinja unutar promatranog odsjeka od 0,61 grla/ha uz vrlo visok sd= +/– 0,53. Istraživanjem je potvrđena mogućnost primjena sustava bespilotnih letjelica s termalnim kamerama. Od dvije primijenjene metode, prva (apso­lutno prebrojavanje svih životinja) je pogodna za manje površine, dok je metoda primjernih pruga pogodna za veće površine uz svjesni rizik generiranja veće pogreške prebrojavanja.Different techniques and technologies are being used in wild animal research. Goals of such research and monitoring are various, most common are numbers per area and size of population for a researched species (Myslenkov i Miquelle, 2015). Development of new techniques and technologies that are used everyday in practial wild animal monitoring has made many tasks much easier and more precise, usage of technology often decreases the number of people needed to be involved in research and has made some until now unfeasable methods a reality. In conducted research we wanted to explore to what amount is it possible to apply a drone system equiped with thermal camera in assessing some population parameters for big game. Research was conducted in lowland teritorry of continental part of Republic of Croatia within hunting ground Opeka II. Wild boar has been chosen for the research as the most common species of big game in Republic of Croatia. Within two localities (I age grade of Oak forest) testing of two counting methods was conducted. First method was to try and count all neck within researched department. Given results show relatively high numbers of wild boar in average of 1,26 with sd=+/- 0,18 necks/ha within researched plane. Second utilized method was to count wild boar on in advance determined strips, whose share in total observed surface amounts to 10%. In this method infomation are of bigger variability and somewhat smaller number off wild boar within observed plane has been determined in amount of 0,61 neck/ha with very high sd=+/- 0,53. Researched confirmed the posibility of applying drone systems with thermal cameras. From two applied methods, first (absolute counting of all animals) is more suitable for smaller surfaces, while the method of appropriate strips is more suitable for larger surfaces with conscious risk of generating greater counting error

Climate and relief properties influence crown condition of common beech (Fagus sylvatica L.) on the Medvednica massif

Background and Purpose: Common beech is a dominant broadleaved tree species in European forests, and also on the Medvednica massif. Since climate is a decisive factor in the development of a certain type of vegetation, it might have an equally important role in its survival. The influence of relief properties on the crown condition of common beech (Fagus sylvatica L.) can also be significant, since beech stands on Medvednica vary in their elevation and exposition. Materials and Methods: Twelve common beech research plots, with complete defoliation data sets in the period 2004–2006 were chosen to represent the variety of environmental conditions present on the Medvednica massif in the western Pannonian region of Croatia. Climate parameters used in the model included annual precipitation (AP), precipitation in the vegetation period (VP), mean annual air temperature (AT), and mean air temperature in the vegetation period (VT). The elevation (EL) of the experimental plots and data from the meteorological station of Puntijarka were used to obtain an estimate of the AT, VT, AP and VP on each research plot. Results: The share of moderately to severely damaged trees (crown defoliation over 25%) was highest in 2004, an expected result of the 2003 drought. This value was significantly higher than in the following two years. The determining climate parameter explaining the changes in defoliation was VP, and the most decisive relief parameter was EL. Defoliation was higher with low VP and higher EL. D was higher predominantly on southern expositions. Conclusions: Climate and relief properties were found to significantly influence the crown condition of beech trees. Although there is a significant positive trend of temperature change on Medvednica, in the period 2004–2006 precipitation in the vegetation period had the dominant effect on the crown condition

Comparison of crown damage assessment on analog and digital infrared color (CIR) aerial photographs

Negativne posljedice propadanja šuma nastoje se umanjiti provođenjem gospodarskih mjera i praćenjem zdravstvenog stanja stabala, odnosno procjenom oštećenosti krošanja. Utvrđivanje zdravstvenog stanja šuma provodi se, osim terestričkim načinom, i metodama daljinskih istraživanja – interpretacijom infracrvenih kolornih (ICK) aerosnimaka. Inventarizacija oštećenosti šuma pomoću aerosnimaka temelji se na ustanovljavanju stupnja oštećenosti pojedinačnih stabala (krošanja), uz kvalitetno izrađen fotointerpretacijski ključ. Na temelju provedene fotointerpretacije infracrvenih kolornih (ICK) aerosnimaka, mogu se odrediti pouzdani statistički podaci o oštećenosti šuma. Inventarizacije oštećenosti šuma na ICK aerosnimkama do sada su se provodile fotointerpretacijom analognih aerosnimaka na analitičkim stereoinstrumentima. Napretkom tehnologije analogne snimke su zamijenjene digitalnim, analitički stereoinstrumenti - digitalnim fotogrametrijskim stanicama, a interpretacija se obavlja u programu na zaslonu računala. Osnovni cilj istraživanja bio je usporediti rezultate procjene oštećenosti krošanja na analognim i digitalnim ICK aerosnimkama istoga područja, zbog čega je bilo potrebno aerosnimke iz 1989. godine skeniranjem prevesti u digitalni oblik, te digitalne snimke iz 2008. godine prevesti u analogni oblik.Za dio gospodarskih jedinica Josip Kozarac i Opeke, provedena je interpretacija analognih i digitalnih aerosnimaka iz dva perioda snimanja (1989. i 2008. godina). Na svakoj točki rastera 100x100 m procijenjena su 4 najbliža stabla (krošnje) te izračunati pokazatelji oštećenosti (O, SO, IO, SO1) za pojedine vrste drveća, za sve interpretirane vrste zajedno, po prugama snimanja, te ukupno za područje istraživanja. Na temelju izračunatih pokazatelja oštećenosti, dobivenih interpretacijom analognih i digitalnih snimaka iz 1989., te 2008. godine, utvrđeno je da između rezultata ne postoji značajna razlika s obzirom na procjenu zdravstvenog stanja stabala (oštećenosti krošanja).Time su poboljšane postojeće metode procjene zdravstvenoga stanja i ukazano na mogućnosti primjene digitalnih ICK aerosnimaka u šumarstvu.Efforts to mitigate negative consequences of massive forest dieback include the implementation of economic measures, monitoring the health status of individual trees i.e. assessment of crown damage. Apart from terrestrial methods, forest health is also determined with remote sensing methods, which involve interpretation of color infrared (CIR) aerial photographs. The inventory of forest damage by using aerial photography is based on the establishment of the degree of damage to individual trees (crowns) using a well-designed photo interpretation key. Reliable statistical data of forest damage can be obtained on the basis of photo interpretation of CIR aerial photography.Inventories of forest damage have so far been conducted with photo interpretation of analog aerial photographs on analytical stereo instruments. With the advancement of technology, analog images have been replaced by digital and analytical stereo instruments – by digital photogrammetric workstations, and interpretation is done on the computer screen.The main goal of the research was to compare the results of crown damage assessment on analog and digital ICK aerial photographs of the same area, which is why it was necessary to convert aerial photographs from 1989 by scanning into digital form, and convert digital images from 2008 into analog form.Analog and digital aerial photographs from two recording periods (1989 and 2008) were interpreted for a part of the management units Josip Kozarac and Opeke. At each point of a 100x100 m grid, 4 nearest trees (crowns) were estimated and damage indicators (damage-O, mean damage-SO, damage index-IO, mean damage1-SO1) were calculated for individual tree species, for all the interpreted species together, per surveying strips, and for the total research area.On the basis of calculated damage indicators obtained by interpreting analog and digital images from 1989 and 2008, it was found that there was no statistically significant difference between the results in terms of tree health assessment.The conducted research improved the existing methods of assessing the health status of individual trees and stands, and pointed out the possibilities of applying digital CIR aerial photographs in forestry