Pine forests canopy

Schade, G. W., Solomon, S. J., Dellwik, E. et al. (2011) Methanol and other VOC fluxes from a Danish beech forest during late springtime. Biogeochem. 106,337. Rinne, J., Taipale, R., Markkanen, T. et al. (2007) Hydrocarbon fluxes above a Scots pine forest canopy measurements and modeling. Armo5. Chem. Phys. 7, 3361. 

Saxena R. K. (1986) Estimation of canopy reservoir capacity and oxygen-18 fractionation in throughfaU in a pine forest. Nordic Hydrol. 17, 251 -260. 

Ellsworth D. S. (1999) CO2 enrichment in a maturing pine forest Are CO2 exchange and water status in the canopy... 

Figure 1.3 Turbulence intensity in various canopies 1 - spruce and 2 - pine forests [155], 3 -deciduous forest in winter and 4 - in summer [124], 5 - jungle [124], 6 - in a wind tunnel forest model [410]. Cited from [155],...

C., Vygodskaya, N. N., and Ziegler, W. (2000). Canopy transpiration in a chronosequence of central Siberian pine forests. Global Change Biol. 6, 25-37. 

The vertical concentration profiles of biogenic VOCs in a forest canopy were measured, and there were major differences in VOC emission between daytime and nighttime [70,71]. The canopy fluxes of isoprenoids above the Norway spruce forest were determined by GC and PTR-MS with relaxed eddy accumulation (REA) method [72], In the use of REA, samples were analyzed at two different reservoirs, which depended on the direction of the vertical wind w ( up-draught reservoir in case of w > 0 and down-draught reservoir in case of w < 0). Subsequently, the diurnal variation of biogenic VOCs was measured at 12 m (in the treetop) and at 24 m (above the canopy) [73], By using PTR-MS coupled with the eddy covariance technique and GC-flame ionization detector (FID) with a REA system, the mixing ratios and fluxes of total monoterpenes, from a ponderosa pine plantation [74] and from Scots pine... 

The research was carried out in the obligatory settling out zone (Zhytomyr region, Polissya of Ukraine) in summer 2004, using three experimental plots which represented distinct pine wood forest ecosystems. The experimental plots were selected on the basis of approximate equal age of the tree canopy (50 years), and similarity of species composition and type of growth conditions. Each l.Oha plot was defined using standard methods (Yunatov, 1964). 

Wildfire is a very important factor in western forest ecosystems. In the San Bernardino Mountains, the fire frequencies were determined by McBride and Laven in two stand types before and after 1893, when the area was first set aside as a forest preserve and fire protection began. Before 1893, the average interval between fires in ponderosa stands was 12 yr after 1893, it was 24 yr. The comparable numbers for Jeffrey pine stands were 16 and 38 yr. The buildup of heavy fuels due to ozone-caused mortality and fire protection results in hotter fires, and the thinning of the tree canopy results in increased rates of fire spread. Hotter fires decrease tree survival. Moisture interception by condensation in living tree crowns would decrease as the stands became thinner, thus causing some sites to be drier. ... 

Fig. 6.12. Normalised velocity of deposition A, radioactive particles to grass, m = 0.35 m s 1 B, C, D, calculations for forests by Slinn (Eucalyptus, M = 0.7 m s 1), Belot (pine, M = 0.6 m s-1) and Lovett (fir, u — 1.1m s-1). Reference height = twice canopy height.

An example of a highly efficient interception system is the canopy of a coniferous forest. The large specific surface area of pine and spruce trees exceeds that of broadleaved deciduous trees, giving them a high scavenging efficiency for radioactive aerosol particles. Pine needles have been acknowledged as useful monitors of atmospheric pollution (Eriksson et al., 1989). However, radionuclides will be redistributed in the forest ecosystem due to various removal mechanisms such as rain... 

The cover and composition of understory vegetation in all these forest cover types varies and depends on site (climate and soil), associated tree species, stand developmental stage, and stand density. Relative to other tree species, light interception by lodgepole pine canopies is intermediate, thus providing light conditions for the development of diverse understory vegetation. 

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