| 释义 |
ˈlife-form
Also life form.
[f. life n. + form n.]
1. Biol. A habit or vegetative form exhibited by any particular plant or which characterizes a group of plants.
Various life-form classifications have been proposed. That of C. Raunkiær (or a modification of his system) based upon the position of the buds relative to the soil surface during the unfavourable season is the one generally employed.
1899Natural Sci. XIV. 109 Hence groups of similar adaptational form, ‘Lebensform’ of German authors, need by no means coincide with natural families or groups of species. For example, Empetrum and Erica, or Aloe and Agave, possess similar ‘life-forms’,..yet their floral characters indicate widely separate genetic affinities. 1913Jrnl. Ecol. I. 16 (heading) Raunkiær's ‘life-forms’ and statistical methods. 1926Tansley & Chipp Study of Vegetation ii. 11 Life form is the characteristic vegetative form of a species; in the first place whether it is a tree, shrub, herb, or a member of one of the lower group of the plant kingdom. 1960[see growth-form s.v. growth1 5]. 1964V. J. Chapman Coastal Vegetation i. 9 There is no generally recognized life-form system for the algae. 1971D. W. Shimwell Descr. & Classification of Vegetation iii. 74 Raunkiær..recognized fifteen main types of life form.
2. A living creature; any kind of living thing.
1905Daily Chron. 17 Aug. 5/7 In the beginning, before life forms appeared, the sun shone on the ocean. 1908Lit. Guide 1 Aug. 115/2 Proof..of an unbroken chain of psychical continuity between the lowest and highest life-forms. 1971Daily Tel. (Colour Suppl.) 30 Apr. 17/3 If only..it were possible to introduce some terrestrial life-form on to Venus. 1971I. G. Gass et al. Understanding Earth ix. 139/2 Once life had become universally distributed over the face of the globe, it must have prevented the further generation of new life-forms. |