31. Zanesljivost volumenskih funkcij na primeru drevesne vrste smreke v SlovenijiGal Kušar, David Hladnik, Milan Hočevar, 2013 Povzetek: Primerjali smo različne volumenske funkcije za ocenjevanje volumnov dreves. S pomočjo sekcijskih meritev (Newtonova metoda) smo izračunali prave ocene volumnov dreves 88 posekanih smrek na Pokljuki. Te smo uporabili za izdelavo regionalnih trovhodnih volumenskih funkcij, (dvovhodnih) deblovnic in tarif. Standardna napaka ocene povprečne vrednosti volumna drevesa je najmanjša pri trovhodnih volumenskih funkcijah (5,0 %), nato pri deblovnicah (11,7 %) in največja pri tarifah (15,1 %). Zanesljivost in uporabnost izdelanih regionalnih ter drugih volumenskih funkcij smo preverili na dveh hektarskih raziskovalnih ploskvah. Ugotovili smo, da s prirejenimi nemškimi deblovnicami smrekam določimo previsoke volumne. Ker volumne iz teh deblovnic uporabljamo tudi pri določanju prirejenih tarif na Slovenskem, je s takim postopkom določen tarifni razred z vsaj za 5 % previsokimi volumni dreves.
Ključne besede: volumenske funkcije, volumen dreves, lesna zaloga, smreka, Picea abies, Pokljuka
DiRROS - Objavljeno: 12.07.2017; Ogledov: 2647; Prenosov: 1115
 Celotno besedilo (791,99 KB) |
32. |
33. |
34. |
35. |
36. Razlike v fenološkem razvoju prevladujočih drevesnih vrst na Pahernikovi gozdni posesti ocenjene z analizo satelitskih posnetkovDavid Hladnik, Anže Martin Pintar, 2019 Povzetek: Fenološke razlike prevladujočih drevesnih vrst na območju Pahernikove posesti smo ocenjevali na podlagi satelitskih posnetkov misije Sentinel-2. Analizirali smo normirane diferencialne vegetacijske indekse (NDVI) v obdobju od 29. marca do 15. oktobra 2017. Na podlagi razlik v vegetacijskem indeksu NDVI je mogoče ocenjevati fenološki razvoj prevladujočih drevesnih vrst bukve (Fagus sylvatica L.), smreke (Picea abies L. (Karsten)) in macesna (Larix decidua Mill.) v gozdnih sestojih. Na območju posesti ugotavljamo omejitve ocenjevanja fenološkega razvoja smreke v mešanih sestojih smreke in jelke (Abies alba Mill.), ki imajo podobne vrednosti NDVI. Pri bukvi pa smo ugotovili manjšanje vrednosti NDVI na posnetkih 21. aprila in 5. oktobra z višanjem nadmorske višine, kar povezujemo s poznejšim olistanjem in hitrejšim rumenenjem listov bukve na višjih nadmorskih višinah.
Ključne besede: raznodobni gozdovi, bukev, Fagus sylvatica L., smreka, Picea abies L. (Karsten), gradient nadmorske višine, Sentinel-2, NDVI, kompozitna slika, Dravsko Pohorje
DiRROS - Objavljeno: 19.10.2019; Ogledov: 1933; Prenosov: 600
Celotno besedilo (512,90 KB) |
37. Genetic diversity of core vs. peripheral Norway spruce native populations at a local scale in SloveniaHojka Kraigher, Gregor Božič, Marjana WestergrenPovzetek: We investigated the levels of genetic diversity and population differentiation among core and peripheral populations of Norway spruce along an altitudinal gradient (from inversions to upper tree line) using isoenzymes (ISO) and nuclear simple-sequence repeats (SSR) markers on overlapping set of populations. Twenty-seven to seventy trees from 11 and 7 populations were genotyped with isoenzymes and SSRs, respectively. The results partially conform to the expectations of the central-peripheral hypothesis (CPH) and are consistent for both marker sets. Genetic differentiation among peripheral populations was low but significantly different from zero (FST-ISO = 0.013, FST-SSR = 0.009) and higher than that among core populations (FST-ISO = 0.007, FST-SSR = 0.005), conforming to central peripheral hypothesis. Contrastingly, levels of genetic diversity assessed by both richness and equitability measures did not significantly differ between peripheral and core populations (AR-ISO = 2.20 vs. 2.14, AR-SSR = 17.16 vs. 17.68, HE-ISO = 0.183 vs. 0.185, and HE-SSR = 0.935 vs. 0.935 for peripheral and core populations, respectively).
Ključne besede: central peripheral hypothesis, Picea abies (L.) Karst., genetic diversity, genetic differentiation, upper tree line, inversion
DiRROS - Objavljeno: 07.05.2018; Ogledov: 7242; Prenosov: 1241
 Celotno besedilo (0,00 KB)
Gradivo ima več datotek! Več...
|
38. Kratkoročna napoved ulova osmerozobega smrekovega lubadarja (Ips typographus) v kontrolne pasti tipa Theysohn za leto 2019 za SlovenijoMaarten De Groot, Marija Kolšek, 2019 Ključne besede: Ips typographus, navadna smreka, Picea abies, osmerozobi smrekov lubadar, šesterozobi smrekov lubadar, prenamnožitev, pasti, gostota populacije
DiRROS - Objavljeno: 10.10.2019; Ogledov: 1748; Prenosov: 999
Celotno besedilo (1,77 MB)
Gradivo ima več datotek! Več...
|
39. Estimating the most effective and economical pheromone for monitoring the European spruce bark beetleMaarten De Groot, Marija Kolšek, Andreja Kavčič, Nina Šramel, 2021 Povzetek: In recent decades, there have been an increasing number of outbreaks of Ips typographus in Europe. A large amount of sanitary felling has taken place, with significant economic and ecological consequences. In order to anticipate such large%scale outbreaks, an effective monitoring system should be set up. One important aspect of monitoring is deciding which pheromone to use. Therefore, we decided to test five different commercially available pheromone lures under different disturbance conditions: Pheroprax%, IT Ecolure Extra%, Ipstyp%, Ipsowit% and Typosan%. We investigated the ability of the pheromones to distinguish between disturbed and undisturbed locations, their cost%efficiency ratio, and side effects such as bycatch abundance and composition. We set 50 traps in two areas with sites that were disturbed and undisturbed by windstorms. We collected the catch from traps every 1%2 weeks from the end of March until the end of September in 2019. We found that IT Ecolure Extra%, Ipsowit% and % Pheroprax% caught the most I. typographus and best showed changes in the trap catch of I. typographus throughout the whole season. There was a low amount of bycatch (<6% of the total catch) and a low number of predators (a few specimens), but some groups seem to prefer certain pheromones. The cost of the pheromones increased with their effectiveness. However, pheromone costs are low relative to the personnel costs involved in setting traps and collecting the catch. Based on all of the gathered data, we created an index which helps to assess the cost%efficiency of the five chosen commercially available pheromones. We also present guidelines on how to make such an index to assist other researchers in choosing the right pheromone for monitoring populations of I. typographus or other bark beetle species.
Ključne besede: bark beetles, cost-efficiency, Ips typographus, monitoring pheromones, Picea abies
DiRROS - Objavljeno: 21.01.2021; Ogledov: 688; Prenosov: 279
Celotno besedilo (1,21 MB) |
40. Poročilo o preskusu št.: LVG 2019-164 : opis vzorca: Picea abies, veja (z listi ali brez) ali poganjki : namen testiranja: sum na: glivaNikica Ogris, 2019 Ključne besede: varstvo gozdov, morfološke analize, navadna smreka, Picea abies, rjavenje smrekovih iglic, Rhizosphaera kalkhoffii, stres, fakultatitvni parazit, smrekov zavijač, Epinotia tedella
DiRROS - Objavljeno: 12.11.2019; Ogledov: 1282; Prenosov: 84 |
