Search

Terrestrial laser scanning (TLS) technology is a powerful tool for assessing tree growth based on time series analysis, as it allows a level of scrutiny not achievable using established destructive techniques. We applied TLS technology to 21 wild cherry trees grown in a research plot near Breisach (southern Germany) in order to build quantitative structure models (QSMs) for each tree. Scans were carried out over three subsequent years (2012-2014), so that three QSMs per each tree were constructed. Using the above approach, we were able to assess the annual growth of the individual wild cherry trees in terms of diameter and height, stem and branch volume, and the merchantable timber fraction. In addition, the growth of single branches of sample trees was detected and quantified. The availability of QSMs based on TLS-derived data allowed the accurate determination of crown length and width, as well as the volume reduction as the result of the tree pruning applied after the first scan (2012). The aboveground biomass (AGB) was assessed for each tree based on the QSM-derived volume and published wood density values for wild cherry, and then compared with AGB values estimated with standard allometric methods, obtaining a very high correlation (r2adj = 0.941). We concluded that the proposed approach is an effective non-destructive technique to accurately assess the increase of tree biomass, and discuss its future application in the forestry sector.

When adapting forest management practices to a changing environment, it is very important to understand the response of an unmanaged natural forest to climate change. The method used to identify major climatic factors influencing radial growth of Siberian spruce and Scots pine along a latitudinal gradient in north-western Russia is dendroclimatic analysis. A clear increasing long-term trend was identified in air temperature and precipitation. During the last 20 years, all meteorological stations experienced temperature increases, and 40 years ago precipitation began to increase. This is shown by the radial increment of Siberian spruce and Scots pine. Therefore, climate change could partly explain the increased forest productivity. The total variance explained by temperature varied from 22% to 41% and precipitation from 19% to 38%. The significant climatic parameters for radial increment in Komi Republic were identified, and the relation between temperature and precipitation in explained variance changes over time for Siberian spruce.

When adapting forest management practices to a changing environment, it is very important to understand the response of an unmanaged natural forest to climate change. The method used to identify major climatic factors influencing radial growth of Siberian spruce and Scots pine along a latitudinal gradient in north-western Russia is dendroclimatic analysis. A clear increasing long-term trend was identified in air temperature and precipitation. During the last 20 years, all meteorological stations experienced temperature increases, and 40 years ago precipitation began to increase. This is shown by the radial increment of Siberian spruce and Scots pine. Therefore, climate change could partly explain the increased forest productivity. The total variance explained by temperature varied from 22% to 41% and precipitation from 19% to 38%. The significant climatic parameters for radial increment in Komi Republic were identified, and the relation between temperature and precipitation in explained variance changes over time for Siberian spruce.

Examines the photodissociation of tert-butyl nitrite (TBN) at 193 nanometer. Distribution of probing nascent nitrogen oxide fragments time delayed yield quantum state; Determination of the internal and the transitional energy distributions; Graphical representation of the absorption spectrum of TBN.

Laser induced fluorescence of microwave stimulated OH molecules from H[SUP2]O photodissociation is investigated as a first step in a series of laboratory experiments to understand features of astronomical OH masers. The inversion between the Π[SUB3/2], J = 7/2 Λ-doublet states of OH generated via photodissociation of cold H[SUP2]O at 157 nm is shown to be 1.8:1. Within a microwave, Fabry--Perot cavity tuned to the resonance of one of the main hyperfine transitions in this Λ doublet it is possible to stimulate all inverted OH molecules. The linewidth of the two main microwave transitions is measured as a function of the microwave power and interaction time. The results show that Doppler broadening is negligible at short interaction times of the molecules with the microwave field. [ABSTRACT FROM AUTHOR]