Tongyang Li | PubMed Health

PubMed2002

[Fractal structure of Abies fabri, dominant tree species in dark coniferous forest at the upper reach of Yangtze River].

Based on the theory of fractal geometry, branching patterns of primitive Abies fabri in the dark coniferous forest ecosystem at the upper reach of Yangtze River were studied. The results showed that the maximum crown width was appeared at inferior 20% of the crown height, and its volume could be simulated by the combination of a round table and a cone. The surface of the crown and their branching patterns of Abies fabri had the common typical fractal characters, the fractal dimensions (FD) were 2.3232 and 1.8119, and the correlation coefficient was 0.99.

Abies↗

PubMed2002

[Plot analysis in the dark coniferous ecosystem using GPS and GIS techniques].

It is generally difficult to survey in primary forests located on high-altitude region. However, it is convenient to identify and to recognize plots accompanied by GPS and GIS techniques, which can also display the spatial pattern of arbors precisely. Using the method of rapid-static positioning cooperated with tape-measure, it is concluded that except some points, the positioning was relatively precise, the average value of RMS was 2.84, variance was 2.96, and delta B, delta L, and delta H were 1.2, 1.2, and 4.3 m with their variances being +/- 0.6, +/- 1.1, and +/- 21.1, respectively, which could meet the needs of forestry management sufficiently. Accompanied by some other models, many ecological processes under small and even medium scale, such as the dynamics of gap succession, could also be simulated visually by GIS. Therefore, the techniques of "2S" were patent for forest ecosystem management under the fine scale, especially in the area of high altitude.

Altitude↗