Phenological Spectrum

a graphic representation of the seasonal development of plants and animals, as well as their communities. The depiction of phenological spectra is a standard method of geobotanical research. The basic principle of the phenological spectrum was formulated by V. N. Sukachev in 1903 and developed further by the Swiss botanist H. Gams in 1918. The Soviet geobotanist A. P. Shennikov made important contributions (1921, 1927) to the methodology of the phenological spectrum; Shennikov also proposed the term “phenological spectrum.” Variations on the phenological spectrum have been developed by several scientists, including the Soviet botanist I. G. Se-rebriakov (1947) and the Polish scientist A. Lukasiewicz (1967).

The phenological spectrum shows a rectangle corresponding to each plant species. The beginning and end of the phases of plant development, for example, leaf formation, blossoming, and ripening of fruit, are marked in a uniform scale on the rectangle. The phenological spectra of communities are composed of a series of species rectangles (see Figures 1 and 2).

V. B. Sochava has stated that the phenological spectrum of a plant community, considered from an ecological standpoint, provides basic information on habitat regimes. It describes the bio-type and, to some extent, the ecological potential of a facies. Phenological spectra are employed in the protection of nature, meadow cultivation, beekeeping (phenological spectra of honey crops), landscaping, and ornamental floriculture.

Figure 1. Phenological spectrum of a whortleberry-pine forest in Yaroslavl Oblast: (a) Scotch pine, (b) Norway spruce, (c) Old World white birch, (d) European aspen, (e) alder buckthorn, (f) marsh tea, (g) bog bilberry, (h) whortleberry, (i) cowberry, (j) chickweed winter-green, (k) field cowwheat; the narrow strips show the development of the reproductive structures (budbreak, budding, blossoming, and setting and ripening of fruit). The wide strips show the development of the vegetative structures (development of leaves or needles in different years, phases of summer growth, and autumn coloration and fall of leaves).

Figure 2. Phenological spectrum of the annual developmental cycle of mountain forests in the northwestern Caucasus. (A) lower mountain belt: (a) chestnut-filbert forests, (b) azalea-Iberian oak forests, 790 m above sea level; (B) intermediate mountain belt: (c) fir-beech forbs, 1,100 m above sea level; (C) upper mountain belt: (d) fern-beech forests, 1,560 m above sea level; (D) subalpine belt: (e) subalpine beech elfin woodlands, 1,880 m above sea level.