| 释义 |
zonation|zəʊˈneɪʃən|
[f. zone n. + -ation.]
a. Distribution in zones or regions of definite character; spec. in Ecol., the distribution of plants into specific zones which are characterized by their dominant species.
1898Rep. Brit. Assoc. Adv. Sci. 1897 863 (heading) The zonal constitution and disposition of plant formations. By Frederic E. Clements. Ibid., The author has here reviewed the phytogeographical contributions bearing upon the subject in hand, with especial reference to the part they have played in the elaboration of the conception of zonation. In addition, he has endeavoured to demonstrate the fundamental universality of zonation in all divisions of the floral covering. 1904[see ecotone]. 1926Tansley & Chipp Study of Veg. iv. 53 Adjacent plant communities are often arranged in more or less definite zones, following one another in constant order. This is specially noticeable in ascending a mountain (where it is called altitudinal zonation). 1936J. Muir Geol. Tampico Region, Mexico 121 Reliable local zonation of both the Eocene and the Oligocene has been worked out in the Tampico area. 1969Nature 15 Mar. 1005/2 Marine work during the first eight months concentrated on community structure and zonation on cliffs, reef flats and in mangrove woodland. 1971Scot. Jrnl. Geol. VII. 306 It is first necessary therefore to establish a regional metamorphic zonation. 1981Birds Autumn 63/3, I would have preferred to have seen an accompanying annotated sketch so that the plant zonations could be easily recognised.
b. Formation of zones in the oocytes of certain plants and animals.
1899Bot. Gaz. XXVIII. 237 There is a stage called zonation in which the nuclei, usually in metaphase, are lined up around the ooplasm. 1902Bot. Gaz. Dec. 421 During the completion of the mitosis the ooplasm and periplasm become clearly differentiated, but as yet no plasmoderma exists. This process of differentiation has been termed zonation. 1975Acta Anat. XCIII. 512 The zonation of the ooplasm reveals that a majority of the oocytes [of the teleost Schizothorax richardsonii] have a darkly stained inner and a lightly stained outer zone. |