Within the Central Rocky Mountains, spruce beetle populations have the potential to rapidly transition from endemic to epidemic levels in the spruce-fir (Engelmann spruce and subalpine fir) forest type. Conventional management has focused on creating resistance to spruce beetle outbreaks by manipulating the overstory density and composition. Three silvicultural treatments, single tree selection...

Gross canopy photosynthesis (P(g)) can be simulated with canopy models or retrieved from turbulent carbon dioxide (CO2) flux measurements above the forest canopy. We compare the two estimates and illustrate our findings with two case studies. We used the three-dimensional canopy model MAESTRA to simulate P(g) of two spruce forests differing in age and structure. Model parameter acquisition and ...

A large and growing body of evidence has demonstrated that airborne scanning light detection and ranging (lidar) systems can be an effective tool in measuring and monitoring above-ground forest tree biomass. However, the potential of lidar as an all-round tool for assisting in assessment of carbon (C) stocks in soil and non-tree vegetation components of the forest ecosystem has been given much ...

We used a four-point resistivity method to detect wood decay in living trees. A low-frequency alternating current was applied to the stem and the induced voltage measured between two points along the stem. The effective resistivity of the stem was estimated based on stem cross-sectional area. A comparison within a group of trees showed that trees with butt rot had an effective resistivity that ...

Christine M. Richter and Aloysius Wild Institut für Allgemeine Botanik der Johannes Gutenberg-Universität, Saarstraße 21, D-55099 Mainz, Bundesrepublik Deutschland Z. Naturforsch. 49c, 619-627 (1994); received January 31/June 16, 1994 Phenolic Compounds, Picea abies, Novel Forest Decline, Picein, Catechin The content of several phenolic compounds in needles of 20to 30-year-old Norway spruce tre...

4apillary gas chromatography and mass spectrometry were used to quantify the amounts of Eand Zchalcogran and methyl (E,Z)-2,4-decadienoate (E,Z-MD), pheromone synergists of the bark beetle Pitygenes chalcographus (Coleoptera: Scolytidae). Males were exposed or not to vapours of host (Norway spruce, Picea abies) oleoresin or allowed to feed in host logs prior to extraction of body parts and hind...

Forekomst av gibberellinliknande substanser hos gran (Picea abies (L.) Karst.) och deras betydelse for tillvaxt och blomning Abstract ODC 161.4-174.7 Growing shoots and young seedlings of Norway spruce (Picea abies) contain at least six different gibberellin-like substances; most probably none o f them is identical to gibberellic acid or gibberellin A l. The gibberellin-like substances are all ...

ODC 174.7 Picea abies 181.521: 165.4 (455) T h e female and male flowering frequency >*'ere studied in a clone frial o j Picea abies at Roskar nine kilonzeters north-east of Stockholm. During 1971 the e s t m ~ i o n in time of pollen shedding and fenzale receptivity was recorded follo~ving daily esurnination of individual strobili. T h e data obtained revealed a great variation in fenlale as w...

BACKGROUND Local timber is still one of the main sources of work and income for mountain communities. However, illegal logging is a major cause of deforestation in many countries and has significant impacts on local communities and biodiversity. Techniques for tracing timber would provide a useful tool to protect local timber industries and contribute to the fight against illegal logging. Altho...