microthermaladj.
/ˌmʌɪkrə(ʊ)ˈθəːml/, U.S. /ˌmaɪkroʊˈθərm(ə)l/, /ˌmaɪkrəˈθərm(ə)l/ Ecology.
1. Designating a plant that can grow or survive in low temperatures; = microtherm adj. rare. Perhaps Obsolete.
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the world > plants > by habitat or distribution > [adjective] > that grow in cold environments or at high altitude
uplandish1545
upland1639
alpestrine1787
alpestral1852
nival1884
microthermal1901
microthermic1903
microtherm1964
1901 Bull. Torrey Bot. Club 28 393 In cold countries there is a corresponding form of vegetation..; these are microthermal plants.
2. Science. Of, relating to, or involving small quantities of heat.
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1929 Bull. Amer. Assoc. Petroleum Geologists 13 828 The microthermal tests constitute the first part [of the plan of study].
1935 Proc. Royal Soc. A. 152 137 The amount of HD formed during the reaction was estimated by means of the micro-thermal conductivity.
1953 Proc. Royal Soc. A. 220 137 Analysis of mixtures of ortho-hydrogen and para-hydrogen and of hydrogen, deuterium, and hydrogen deuteride..were carried out in a hot-wire micro-thermal conductivity gauge.
1963 Science 578/2 (advt.) The Ficklen Micro-thermal Precipitator.
1993 Proc. National Acad. Sci. U.S.A. 90 2995 The temperature was measured by inserting a microthermal resistor into a filled cuvette in a second water-jacketted cuvette holder.
3. Of a climate: cool temperate; characterized by cold winters and short summers. Of an organism: inhabiting such an environment.
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1931 C. W. Thornthwaite in Geogr. Rev. 21 646 On the basis of temperature efficiency summation six temperature provinces were defined. They are as follows..Tropical..Mesothermal..Microthermal..Taiga..Tundra..Frost.
1935 Sci. Monthly Jan. 40/1 Microthermal Climates (D—Climates of Köppen): These are the cool temperate climates.
1973 Nature 12 Oct. 311/2 The climate is cool and microthermal, with mean temperatures near sea level ranging from 1°C during the coldest months to 8°C during the warmest.
1989 Encycl. Brit. XXVI. 893/1 Microthermal [river] regimes, which are influenced by snow cover, include winter minima and summer maxima resulting from snowmelt and convectional rain.
1994 Amer. Jrnl. Bot. 81 1158/1 The Neogene microthermal flora was largely derived from the preceding flora of that area.
This is a new entry (OED Third Edition, December 2001; most recently modified version published online March 2022).
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adj.1901