The impact of artificial mycorrhizal inoculation on the growth of common oak seedlings and development of mycorrhiza: inoculation may not positively affect growth of seedlings

Background and Purpose: This study evaluated the effect of the VAMBAC(c) mycorrhizal inoculum on the growth and mycorrhizal characteristics of Quercus robur seedlings. Materials and Methods: The oak seedlings soaked in an inoculum containing mycorrhizal fungi were planted on six study plots. The non-inoculated seedlings were planted on control plots. Two-year-old plants were evaluated at three of the plots, while 9-to-10-year-old plants were evaluated at the remaining three plots. Seedlings’ above-ground height, main root length, root dry mass, above-ground dry mass and stem diameter were evaluated. For five plants, mycorrhizal characteristics (the density of active and inactive mycorrhizae and the proportion of active mycorrhizae) were also evaluated in the laboratory. Results and Conclusions: Inoculated seedlings demonstrated significantly higher proportion of active mycorrhizae in all plots as well as a higher density of active mycorrhizae only on some studied plots when compared to control. Among growth characteristics, inoculated seedlings demonstrated higher values for all evaluated variables. The most striking differences were observed in stem diameter, which was significantly different for all young stands and for one plantation. For the remaining growth characteristics, inoculated and control seedlings displayed significant differences only on some plots. These results showed that artificial mycorrhizal inoculation can be used in forestry practice, but its effects may not always be necessarily positive

A monitoring network for the detection of invasive ambrosia and bark beetles in the Czech Republic: principles and proposed design

Invasive bark beetles pose a threat to native biodiversity and to functional ecosystems and the economic productivity of forests, parks, and orchards. In the Czech Republic, there are six species of invasive ambrosia and bark beetles with a stable natural population, and it can be assumed that other invasive species that will be found. In the Czech Republic, there are no guidelines or methods for the early detection of invasive ambrosia and bark beetles. We propose monitoring at a total of 24 locations considering the following: (i) monitoring approaches used in other countries; (ii) identified entrance gates of invasive ambrosia and bark beetles found in the Czech Republic; (iii) presumed invasive species that occur in surrounding countries and are expanding their range; (iv) substances attractive to all the above mentioned species; (v) commonly available traps; and (vi) minimization of operating costs. Most of the chosen locations are located on the state borders and in river valleys, which are probably the entrance gates to the Czech Republic for invasive ambrosia and bark beetles. In addition, two large timber warehouses where international trade takes place, all international airports and three botanical gardens with tropical greenhouses were selected. Three Theysohn or Ecotrap impact traps should be installed every year at all locations. Traps should be baited with ethanol and exposed from mid-April to the end of July and should be checked every 2 weeks

Impact of mycorrhizal inoculation on spruce seedling: comparisons of a 5-year experiment in forests infested by honey fungus

Background and Purpose: The eastern part of the Czech Republic is afflicted by a decline in spruce stands. Forests stressed by drought are subsequently infested by honey fungus. Treating the root systems of spruce seedlings with a mycorrhizal preparation could present a certain possibility for protection against honey fungus. Mycorrhizal preparations are used in forestry, nursery management, horticulture and agriculture for soil reclamation, planting the slopes and shoulders of roads, planting urban green areas, cultivating medicinal plants, and so forth. In this paper, preliminary results of pilot tests are shown. Materials and Methods: In the Nízký Jeseník area in the vicinity of the town of Skøipov, Norway spruce (Picea abies) seedlings were treated at five sites with the ectomycorrhizal preparation Ectovit. Four years after treatment, the treated and control seedlings were evaluated. Furthermore, seedlings were removed from the areas for laboratory evaluation of growth parameters and mycorrhizal characteristics. Results and Conclusions: The results showed that artificial inoculation, or treatment of spruce seedlings with mycorrhizal preparation, positively supported the rooting, growth and development of spruce seedlings

Usporedba ulova smrekinog pisara (Ips typographus) na kemijski tretiranim lovnim trupčićima i feromonskim klopkama

The numbers of Ips typographus beetles captured in treated tripod trap logs (tripods) were compared to catches from Theysohn phero­mone traps (TPTs). In 2010, at each of the three localities, five TPTs and five tripods baited with Pheagr IT pheromone evaporators were installed with 10 m spacing. Weekly inspections were made during the entire period of I.typographus flight activity (April 30 – October 1). The tripods were treated with insecticide Vaztak 10 SC on April 23, 2010 and then repeatedly every seven weeks along with the renewal of the pheromone evaporator. The study showed that the TPTs trapped approximately one-third more beetles than did the tripods. The TPT captures showed a dominance of females over males, while in tripods the sex ratio was balanced. The TPTs and tripods both trap­ped approximately the same numbers of males, but the females were distinctly more numerous in the TPTs. In both cases, more adults were captured during spring than in summer.Provedenim istraživanjem testirana je učinkovitost ulova smrekova pi­sara (Ips typographus) na kemijski tretiranim lovnim trupčićima (TRIPODs) u odnosu na feromonske klopke tipa Thesohn (TPTs). Tijekom 2010. godine, na svakoj od tri eksperimentalne lokacije u Češkoj, postavljeno je po 5 lovnih TRIPODs i TPTs kompo­zicija opremljenih feromonom Pheagr IT međusobno udaljenih 10 metara. Jednom tjed ­no lovne kompozicije obilažene su i sakupljan je ulov smrekina pisara kroz cijelo razdoblje njegova rojenja (30. travnja do 1. listopada). Lovni trupčići, načinjeni od svježe posječenih smrekovih stabala, tretirani su piretroidnim insekticidom Vaztak 10 SC 23. travnja i zatim ponovno, svakih 7 tjedana, usporedo sa zamjenom feromon­skih dispenzera (Slika 1). Tijekom čitavog razdoblja trajanja eksperimenta ukupno je ulovljeno 15.657 jedinki smrekova pisara, od čega 6.343 mužjaka i 9.314 ženki. U lov ­nim kutijama postavljenim ispod kemijski tretiranih lovnih trupčića ukupno je ulovljeno 6.254 jedinki potkornjaka, od čega 2.995 mužjaka i 3.529 ženki. Na feromonskim klop­kama ukupno je ulovljeno 9.403 jedinki potkornjaka, od čega 3.348 mužjaka i 6.055 ženki (Tablica 1). Prvo proljetno rojenje nakon zimovanja prošlogodišnjih imaga smrekinog pisara, zabilježeno je u trećem kvartalu travnja. U drugoj polovici svibnja došlo je do naglog pada ulova uzrokovanog padom temperature i povećanim padalinama (Slika 2). Maksi­mum rojenja proljetne generacije potkornjaka zbio se prvom polovicom lipnja. Počet­kom srpnja zamijećena su prva imaga nove, ljetne generacije (potkornjaci svjetlo smeđe boje). Maksimum rojenja druge, ljetne generacije zbio se sredinom srpnja. Tijekom ko­lovoza i rujna rojenje je polagano opadalo u intenzitetu i posljednji ulovi potkornjaka datiraju početkom listopada 2010. godine. Razlike u dinamici doleta i ulova smrekinog pisara na oba tipa lovnih kompozicija nisu utvrđene (Slika 3 i 4). Dva glavna maksi­muma u ulovu smrekinog pisara tijekom 2010. godine predstavljaju pojavu dvije gene­racije na području istraživanja. Ovakav biološki ciklus tipičan je za područje središnje Europe, osim u slučaju povišenih nadmorskih visina. Na sjeveru Europe smrekin pisar obično ima samo jednu generaciju godišnje, dok se na njenom jugu, zahvaljujući dugim i toplim ljetima i druga generacija u potpunosti razvije do spolno zrelih imaga. Na istraživanom području tijekom 2010. godine uvjeti za razvoj potkornjaka nisu bili opti­malni (Slika 2) tako da su na lovnim kompozicijama lovljena imaga prve proljetne gene­racije i imaga filijalne generacije (druga, prava ljetna generacija smrekinog pisara). Rojenje ženki druge serije polaganja imaga (sestrinske generacije) bilo je slabo izra­ženo i vidljivo je u slabo izraženom maksimumu 2. srpnja. Što se imaga druge genera­cije tiče, nije bilo zabilježeno rojenje ženki sestrinske generacije jaja, a imaga ove generacije bivala su zaustavljena u različitim stadijima razvoja ulazeći u dormantnu fazu mirovanja tijekom zime 2010/2011. U prosjeku, tijekom razdoblje istraživanja ulovljeno je 417 ± 154 jedinki smrekinog pisara na svakoj TRIPODs kompoziciji, od čega 200 ± 74 mužjaka i 217 ± 85 ženki (Slika 5). Srednji ulovi za TPTs feromonske klopke iznosili su 627 ± 250 ukupno, odno­sno 223 ± 81 mužjaka i 404 ± 175 ženki (Slika 5). Manji broj potkornjaka ulovljenih na TRIPODs lovnim trupčićima bio je signifikantno različit od ulova na feromonskim klop­kama (Wilcoxonov test usklađenih parova: z = 3.07; p < 0.01). U usporedbi sa feromon­skim klopkama glavna prednost TRIPODs lovnih trupčića je jednostavnija i brža kontrola naleta potkornjaka. Ovdje se podrazumijeva jednostavna vizualna kontrola lovne kutije postavljene ispod trupčića. Također, korištenje trupčića duljine 2 metra (Slika 1) osigurava funkcionalnost lovne kompozicije tijekom sezone i rasta travne ve­getacije, pa nije potrebna košnja ili primjena herbicida. S druge strane, negativno sta­jalište ove metode lova potkornjaka je nepoznati udio jedinki koje nakon slijetanja na intoksiciranu koru trupčića odlijeću sa kompozicije i ugibaju negdje u okolnom pro­storu. Kao problem u evaluaciji učinkovitosti javlja se i mogućnost gubitka već uginulih jedinki uslijed naleta vjetra ili predacije pticama. Gubitak nepoznatog udjela jedinki postoji i kod feromonskih klopki (doduše, bez naknadnog ugibanja), a za obje je metode problematična i činjenica da u izvjesnoj mjeri love (i usmrćuju) korisne kukce – priro­dne neprijatelje potkornjaka. Razlike u ulovima mužjaka i ženki smrekinog pisara na TRIPODs lovnim trupčićima nisu bile signifikantne (z = 1.48; p > 0.05) dok su te razlike u ulovima na TPTs feromon­skim klopkama bile signifikantne (z = 3.41; p 0.05) dok su kod ulova ženki razlike bile signifikantne (z = 3.45; p < 0.001). Brojna su istraživanja potvrdila statistički značajne razlike u omjeru spolova na ulovima feromonskih klopki gdje su ulovi ženki brojniji od ulova mužjaka. U provedenom istraživanju obje su lovne kompo­zicije (TRIPODs i TPTs) u prve tri stjedna lova hvatale više mužjaka nego ženki. Ovo se može objasniti činjenicom da se mužjaci javljaju ranije u prirodi, zbog činjenice da oni započinju s ubušivanjem i produkcijom agregacijskog feromona. Isto vrijedi i za poče­tak naleta druge generacije. Postoje mišljenja da mužjaci smrekinog pisara trpe veći pritisak predatora i redukciju uslijed obrambenih mehanizama smrekovih stabala (pri­tisak smole). Dok ženke u načelu nisu sposobne izazvati prvi napad/ubušivanje (osim di­jela populacije koji formira sestrinsku generaciju), mužjaci mogu izazvati sušenje i propadanje stabala tijekom inicijalnog ubušivanja, pogotovo u epidemičnim gustoćama populacije. Stoga je redukcija mužjaka u rojećoj populaciji potkornjaka iznimno važna sa stajališta opće redukcije njihove populacije i zaštite smrekovih šuma od njihova na­pada. Ukupno gledajući, TIPODs lovni trupčići lovili su u većem omjeru muški spol u odnosu na TPTs feromonske klopke. Ss tog gledišta, uporaba TRIPODs lovnih trupčića povoljnija je sa stajališta redukcije populacije smrekinog potkornjaka od primjene samih feromonskih klopki. Objašnjenje ovakvoj pojavi leži u biologiji potkornjaka: dok se mužjaci u načelu šire nastojeći kolonizirati materijal u blizini već naseljenog (i “markiranog” feromonom), ženke se ponašaju upravo suprotno, bivaju privučene višim koncentracijama populacijskog feromona. Posljedično, razmjerno visoke koncen­tracije feromona u feromonskim klopkama jače privlači ženke od mužjaka, što se i poka­zalo u provedenom istraživanju. Zaključno, može se reći da su u provedenom jednogodišnjem istraživanju zabilje­žena dva rojenja smrekinog pisara, s maksimumom rojenja u prvoj polovici lipnja i sre­dinom srpnja, da su TPTs feromonske klopke ulovile oko 35 % više jedinki potkornjaka nego TRIPODs lovni trupčići, te da je u ulovima iz feromonskih klopki bilo gotovo dvo­struko više ženki nego u ulovima na TRIPODs lovnim trupčićima. Ulovi mužjaka na obje lovne kompozicije bili su podjednaki

Using ethanol and other lures to monitor invasive ambrosia beetles in endemic populations: case study from the Czech Republic

Bark and ambrosia beetles pose significant threats to the stability of forest stands worldwide, making their control crucial. Among these pests, Gnathotrichus materiarius, a polyphagous invasive ambrosia beetle living on conifers, has successfully established itself in Europe. Early identification of these pests plays a fundamental role in designing effective pest control strategies. The work aimed to assess the efficacy of different lures in Ecotrap® for capturing of invasive ambrosia bark beetles. The lures tested included Wood Stainers Lure (containing the potential pheromone sulcatol for capturing Gnathotrichus materiarius adults), α-pinene, ethanol UHR, and Cembräwit. The objective was to determine the most suitable lure for use in traps. In four locations in western Bohemia, a total of 7,410 individuals from 46 species of ambrosia and bark beetleswere captured. The abundance of invasive ambrosia beetles (Gnathotrichus materiarius, Cyclorhipidion bodoanum, Xyleborinus attenuatus, and Xylosandrus germanus) primarily depended on the day of the season and secondarily on the lure used. Although their population density was low, more beetles were caught using ethanol as the lure. Notably, these invasive ambrosia beetles accounted for less than 3 % of the total number of ambrosia and bark beetles detected (187 individuals). Ethanol was found to be a universal lure for attracting ambrosia beetles, with the majority of Scolytinae species being captured in traps baited with ethanol

A Mobile Hydraulic Winch for Use in Small-Scale Forestry

Winches have recently been used to extract timber from forests. Winches are often components of tractors, but tractors cannot be used on difficult terrain and are generally too expensive for small forest owners. The current study considers the use of an experimental winch for the extraction of timber from small plots with difficult terrain. The mobile hydraulic winch used in this study weighs 50 kg and has a pulling force of up to 53 kN, a 12 V motor, and a 64x224 mm drum. The associated power unit is a gasoline, single-cylinder, four-stroke, air-cooled KIPOR KG 390D (400D), 389 cm3 engine, with 7.7 kW of power, and a torque of 22.6 Nm at 2500 rpm. The engine powers a high-pressure oil pump with an output pressure of 3 MPa and a flow rate of 60 litres per minute. The input torque of the pump shaft is 25 Nm at 3000 rpm. The hydraulic winch can be fixed to tree trunks, stumps, or wooden pegs by lashings. The winch was tested at three locations with different assortments of wood. The results showed that the experimental winch was practical for timber extraction and that <250 kN of force was needed for successful extraction. At the test sites, the expense of lumber removal was on average 140% greater with the winch than with a horse but the advantage of the hydraulic winch is high pulling force. Because of its small size and low weight, the unit can be easily handled by two workers, easily moved at short distances in small plots with rough terrain, and easily transported among plots. With a one-man crew, the percentage of direct costs represented by wages dropped to 56%, and the percentage represented by fuel increased to 40%

ROJENJE, GUSTOĆA I RASPORED POPULACIJE NA LOVNIM STABLIMA I PREZIMLJAVANJE ARIŠEVOG POTKORNJAKA (Ips cembrae) U ČEŠKOJ

The increasing threat to forests from the gradual increase in Ips cembrae abundance necessitates more precise information concerning its ecology, monitoring, and control.Cembräwit® pheromone traps and trap trees were used to evaluate I. cembrae flight activity and infestations, respectively, during outbreaks in 2007–2009 in the Czech Republic. Emergence of the next generation was also evaluated from trap logs and forest litter.Flight activity was detected from late April to early July and lacked clear peaks. Trap trees were invaded evenly along the entire profile of the trunk. Parent galleries were longer and numbers of larval galleries were fewer in the upper parts than in the lower parts of trap tree trunks. Gradual fly-out of beetles from infested larch wood under laboratory conditions during winter confirmed that adults, larvae, and pupae of the offspring generation overwinter in such wood. The trapping of beetles emerging from litter confirmed that I. cembrae also overwinters in the litter near the trees where development was completed.Na cijelom arealu, od najniže nadmorske visine do subalpinskog pojasa, glavni domaćin potkornjaku Ips cembrae je europski ariš, Larix decidua Mill. Samo ponekad ova vrsta naseljava i smreku, Picea abies (L.) Karsten. Osnovna bionomija potkornjaka I. cembrae razlikuje se od ostalih vrsta roda Ips i više-manje je poznata. Unatrag nekoliko godina publicirano je tek nekoliko istraživanja vezano za bionomiju i zaštitu šuma od ovog štetnika. Cilj ovog rada je stjecanje novih saznanja oRojenju, kroz pokus korištenja sintetskih mamaca; kornjaši I. cembrae su se lovili pomoću Theysohn® naletnih klopki te korištenjem feromonskih pripravaka Cembräwit®;Prostornoj i vremenskoj distribuciji kornjaša na lovnim stablima; u drugom dijelu ožujka zdrava stabla ariša obarana su radi postavljanja prvog seta lovnih stabala u razmaku od 10–15 m na rubovima sastojina. Krajem srpnja drugi set postavio se unutar sastojine. Ulazne rupe evidentirane su na četiri sekcije svakog lovnog stabla;Prezimljavanju kornjaša; pet trupčića dužine 0,7 m dobivene iz gornjeg dijela četiriju lovnih stabala. Četiri trupčića iz svakog lovnog stabla postavljeni su na pet mjesta u ariševoj sastojini. Od kraja rujna u mjesečnim intervalima (listopad–siječanj) setovi sekcija postepeno su se premještali u kaveze u laboratoriju.Ukupna sanitarna sječa koja se u Češkoj provodi zbog napada potkornjaka I. cembrae mala je u odnosu ukupnu sanitarnu sječu radi potkornjaka. S druge strane, u nekim europskim zemljama takvi napadi predstavljaju ozbiljan problem. Primjerice ekstremna suša u 2003. godini uzrokom je gradacija u Srednjoj Europi. Drvna masa zaražena potkornjacima I. cembrae u Češkoj kulminirala u 2006. godini sa trendom opadanja (slika 1, tablica 1), dok je u Poljskoj količina potkornjacima zaražene drvne mase povećana za šest puta između 2006. i 2007. godine.Potkornjak I. cembrae najčešće ima 2 generacije godišnje (Slika 2). Proljetno izlaženje iz zimovališta počinje na nižim i srednjim nadmorskim visinama početkom svibnja, rjeđe krajem travnja. Potkornjaci druge generacije izlaze na prijelazu lipnja i srpnja. Nova generacija imaga obavlja dopunsko žderanje u kasno ljeto u granama mladih stabala ili u blizini larvalnog hodnika gdje ima svježe kore. Nakon dopunskog žderanja imaga prezimljavaju dijelom u hodnicima ispod tanke kore oblovine ili češće u šumskoj stelji.U slučaju kada se ne stignu potpuno razviti, prezimljavaju kao ličinka ili kao kukuljica. Tada njihovo preživljavanje ovisi o vremenskim prilikama u zimi. Razmjer populacije koja prezimljava u stadiju imaga i njihova niša prezimljavanja ovisi o vremenskim prilikama u jesen i uvjetima koji vladaju kada završavaju razvoj. Dio potkornjaka koji rano završi razvoj napušta to mjesto i prezimljava u šumskoj stelji ili ostaje na mjestu gdje se hrani. Ispitali smo prisutnost prezimljujućih potkornjaka u trupčićima u zimi i njihovu aktivnost nakon što su premješteni u laboratorijske uvjete (slika 3). Produženo vrijeme napuštanja pokusnih trupčića potvrdilo je kako dio populacije prezimljuje kao larva i kukuljica. Potkornjaci koji prezimljavaju u stelji to čine blizu stabala na kojemu završavaju svoj razvoj.Potkornjaci prve generacije naseljavaju lovna stabla kontinuirano od polovice svibnja, a druge generacije od polovice srpnja (tablica 2). Naseljavanje donjih dijelova stabla bilo je jednoliko u gotovo svim slučajevima, a samo je ponekad veća abundanca nađena u gornjem dijelu.Duži materinski hodnici s manjem brojem položenih jaja i larvalnih hodnika (tablica 3) karakteriziraju sekcije iz gornjeg dijela debla lovnog stabla. Taj je odnos eksponencijalan, što se tumači interspecifičnom kompeticijom na prostoru za polaganje jaja između ženki i ograničenog resursa hrane između ličinki. Kako je gustoća hodnika na lovnim stablima bila jednolika, ženke su u tanjem floemu reagirale manjim brojem položenih jaja i povećavanjem udaljenosti između materinskih hodnika. Na taj način larvama su omogućile izradu dužih larvalnih hodnika i pristup adekvatnoj hrani.Kontrola potkornjaka I. cembrae istovjetna je sa drugim vrstama potkornjaka koji dolaze na četinjačama i obavlja se:(i) uzgojnim zahvatima: čistom sječom, selektivnom proredom, selekcijom;(ii) kemijskim tretiranjem oborenih stabala;(iii) mjerama izlova: lovnim stablima, lovnom oblovinom, klopkama, lovnom sječkom;(iv) monitoringom uz pomoć feromonskih atraktanata, lovnih stabla/oblovine, vizualnim nadzorom, upitnicima.U Europi se koriste četiri tipova feromonskih pripravaka: Cembräwit® (www.witasek.com), Cemprax (Shell Agrar Ltd.) (www.witasek.com), Cemsan (www.fluegel-gmbh.de) i Cembrodor. Feromonski pripravak Cembräwit® koristi se za ciljani ulov I. cembrae; tijekom pokusa i pregledavanjem ulova feromonskih klopki nisu zabilježeni ulovi neciljane floemofaune.U terenskim pokusima, drvo posječeno u travnju prvo jer bilo napadnuto i intenzivno naseljavano. Za vrijeme pokusa lovna stabla promjera d1.3 30–45 cm pripremljena u drugoj polovici ožujka na osunčanoj poziciji bila su intenzivno napadnuta, a lovna stabla ostala su aktivna sve do prve kukuljice. Bez obzira na veliku abundancu ulaznih rupa, naseljavanje lovnih stabala nije se zaustavilo. Moguće je i da su se prethodno ubušeni potkornjaci ponovno ubušivali.U usporedbi s drugim europskim vrstama potkornjaka roda Ips, evidentan je problem zaštite protiv I. cembrae iz razloga što se: (i) razvija u granama; (ii) određen dio populacije može prezimiti u šumskoj stelji (kao i druge Ips vrste), i (iii) stabla obrađena harvesterom nisu zaštićena protiv napada.I. cembrae se razvija u granama koje su od 3 cm promjera. To se mora uzeti u obzir prilikom poduzimanja zaštitnih mjera. Uz to treba uništiti drvne ostatke i izbojke (paljenjem i malčiranjem) kako ne bi došlo do žderanja i rasploda štetnika u tom materijalu. Prorjedama u mladim sastojinama nezbrinuti drveni ostaci također budu napadnuti.Kako I. cembrae može prezimiti u šumskoj stelji, uklanjanje stabala napadnutih potkornjacima, vjerojatno nije dovoljna učinkovita mjera u smanjivanju gustoće populacije. Produljen vegetacijski period te povoljne temperature povećavaju broj imaga koji prezimljuju u šumskoj stelji, što intenzivira opasnost od napada u proljeće.Ariš nakon obrade modernim harvesterima u proljeće može biti uspješno koloniziran jedinkama Ips cembrae, ponajprije dijelova s tankom korom, što znači da je zaštita i dalje potrebna. Kada prorjedom materijal dodatno ostaje u sastojini, napad postaje ozbiljniji, zbog čega treba ostaviti prostorni ili vremenski razmak između sječe i prorjede

A Mobile Hydraulic Winch for Use in Small-Scale Forestry

Winches have recently been used to extract timber from forests. Winches are often components of tractors, but tractors cannot be used on difficult terrain and are generally too expensive for small forest owners. The current study considers the use of an experimental winch for the extraction of timber from small plots with difficult terrain. The mobile hydraulic winch used in this study weighs 50 kg and has a pulling force of up to 53 kN, a 12 V motor, and a 64x224 mm drum. The associated power unit is a gasoline, single-cylinder, four-stroke, air-cooled KIPOR KG 390D (400D), 389 cm3 engine, with 7.7 kW of power, and a torque of 22.6 Nm at 2500 rpm. The engine powers a high-pressure oil pump with an output pressure of 3 MPa and a flow rate of 60 litres per minute. The input torque of the pump shaft is 25 Nm at 3000 rpm. The hydraulic winch can be fixed to tree trunks, stumps, or wooden pegs by lashings. The winch was tested at three locations with different assortments of wood. The results showed that the experimental winch was practical for timber extraction and that <250 kN of force was needed for successful extraction. At the test sites, the expense of lumber removal was on average 140% greater with the winch than with a horse but the advantage of the hydraulic winch is high pulling force. Because of its small size and low weight, the unit can be easily handled by two workers, easily moved at short distances in small plots with rough terrain, and easily transported among plots. With a one-man crew, the percentage of direct costs represented by wages dropped to 56%, and the percentage represented by fuel increased to 40%

Ambrosia Beetles Prefer Closed Canopies: A Case Study in Oak Forests in Central Europe

Research Highlights: The percentage of canopy closure was found to be the main factor associated with ambrosia beetle abundance and species richness. The latter two variables increased as canopy closure increased, probably because a high percentage of canopy closure provides a stable and humid environment suitable for the growth of ambrosia fungi. Objectives: Oak is a common host tree for ambrosia beetles (Coleoptera: Curculionidae: Scolytinae), which have independently evolved a nutritional mutualism with fungi. We suspected that ambrosia beetles might have specific habitat preferences that are different from those of other saproxylic beetles and that reflect the specific habitat preferences of their food, i.e., ambrosia fungi. Methods: We assessed ambrosia beetle abundance with ethanol-lured traps in five old-growth oak dominated forests and five managed oak dominated forests (one trap per forest) during the vegetation period in 2020. We determined whether ambrosia beetle abundance and species richness depend on forest type (managed vs. unmanaged), degree of canopy closure, abundance of oak trees, abundance of coarse deadwood, and abundance of dead oak branches. Results: In total, 4137 individuals of six species of ambrosia beetles associated with oaks were captured. The native ambrosia beetle Anisandrus dispar represented the majority of trapped ambrosia bark beetles. A. dispar along with another ambrosia beetle, Xyleborinus saxesenii, represented 99% of all captured beetles. Conclusions: In addition to canopy closure, the abundance of oak trees and the abundance of dead oak branches were significantly associated with ambrosia beetle abundance and species richness. The abundance of A. dispar was mainly correlated with dead oak branch abundance and the degree of canopy closure, whereas the abundances of X. saxesenii and of the invasive species Xyleborinus attenuatus and Cyclorhipidion bodoanum were mainly correlated with the net area occupied by oak trees