Forest surveys

Despite the impression made by occasional widespread pest outbreaks such as those of the gypsy moth, severe defoliation of forested ecosystems is quite unusual. Fewer than 10% of the species listed in the Canadian Forest Survey of Lepidoptera (1, 2) exhibit periodic or occasional outbreaks. Generally, defoliation in forests is less than 7% of primary production per year P, but see. The vast majority of forest Lepidoptera are quite rare almost all of the time, and their numbers do not fluctuate to a noticeable degree. These observations suggest that some factor or factors normally regulate forest insect populations and keep defoliation at low levels. 

There have been numerous estimates made on the total biomass and biomass potential of our forests 3,1Q). The inventory procedure used is based on estimates and averages, and is fully described by Wahlgren and Ellis (U). Forest surveys based on biomass measurement techniques are needed to accurately determine the quantities and location of our wood resource. Many studies on measuring the weight of individual trees, and to a lesser extent forest stands, have been made. This work has been summarized by Keays (12). and Hitchcock and McDonnell (12)- As work in forest biomass measurement is refined, regional weight tables can be developed and accurate biomass inventories compiled. 

Forest survey statistics indicate we harvest and use upwards of 30 percent of current forest production for conventional forest products. The remaining 70 percent has been shown to be potentially available for various energy uses (3,10). However, before such increased wood use occurs, a number of factors need to be examined and hopefully resolved. 

Human activity, particularly in the developing world, continues to make it more difficult to sustain the world s biomass growth areas. It has been estimated that tropical forests are disappearing at a rate of tens of thousands of hm per year. Satellite imaging and field surveys show that Brazil alone has a deforestation rate of approximately 8 x 10 hm /yr (5). At a mean net carbon yield for tropical rain forests of 9.90 t/hm yr (4) (4.42 short ton /acreyr), this rate of deforestation corresponds to a loss of 79.2 x 10 t/yr of net biomass carbon productivity. 

Vanillosmopsis erythropappa Schultz-Bip. is a component of the Atlantic coastal forest in Brazil, where it is exploited as a source of an essential oil used in the pharmaceutical industry. A survey of specimens from four locations showed markedly different compositions of their essential oil fraction (Lopes et al., 1991). The compounds identified were bisabolol [160], costunolide [161], eremanthine [162], and five related compounds, six compounds based upon the cyclocostunolide skeleton [163], and the two esters 15-deoxygoyazenolide [164] and lychnopholide [165]... 

As inputs of THg appear to be strongly retained in the forest floor, we reconunend a forest floor survey be conducted in areas that are receiving elevated Hg deposition and where it is expected that deposition will change markedly. In this site, permanent sampling sites would be established. We envision that forest floor samples would be resurveyed at appropriate time intervals (e.g., 10 years). A forest floor survey would help clarify current patterns of total Hg deposition and potentially quantify the response of forests to decreases in Hg emissions and deposition. 

Fig. 3. Thottea grandiflora Rottb. From KL 1719. Phytochemical Survey of the Federation of Malaya. Geographical localization Fort Iskandar, South Pahang, primary forest. Field collector M. C. Wood, 3/2/1959. Botanical Identification Ding Hou, November, 1984. 

Stott P (1984) The savanna forests of mainland southeast Asia an ecological survey. Prog Phys Geogr 8 315-335... 

McMahon, C.K. and S.N. Tsoukalas. 1978. Polynuclear aromatic hydrocarbons in forest fire smoke. Pages 61-73 in P.W. Jones and R.I. Freudenthal (eds.). Carcinogenesis —A Comprehensive Survey. Vol. 3. Polynuclear National Symposium on Analysis, Chemistry, and Biology. Raven Press, New York. 

Hamilton, S.M., Burt, A.K., Hattori, K.H., Shirota, J. 2004. The distribution and source of forest ring-related methane in northeastern Ontario. In Summary of Field Work and Other Activities 2004. Ontario Geological Survey, Open File Report, 6145, 21-1 to 21-26. 

Wilson GA (1992) A survey on attitudes of landholders to native forest on farmland. J Environ Manage 34 117-136... 

The forest energy potential of Canada has been surveyed ( ). The available material is essentially of 3 types. The lowest cost material is wood residue at the existing forest industry processing sites. While about half of the mill... 

The present chapter deals exclusively with the scientific issues of point (2). It is based on the results of an extensive study under the authority of the Swiss Agency for Environment, Forests and Landscape (SAEFL/BUWAL Perret et al. 2000,2002). The in-depth survey was performed on 23 HT materials originating from 16 different advanced thermal treatment facilities developed by 10 different companies in Switzerland, Germany, France, and Italy, and operated under realistic conditions (e.g., from wastes representative of average MSW). On the basis of the results, two options are tested to assess the long-term behaviour of HT materials ... 

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