Kinds Of Ash Research Articles

雲仙普賢岳と桜島火山灰の付着がキュウリの葉温と気孔コンダクタンスに与える影響

This study was conducted to infer the effects of volcanic ash accumulating on a leaf surface on its photosynthesis. Particle size distribution and shading ratio were measured on 2 kinds of ash from Mt. Sakurajima (white and black) and 4 kinds from Mt. Unzen-Fugendake. Reflected spectral radiant flux density, temperature and Stomatal conductance of cucumber leaves covered with those ashes were also measured.Particle size distribution of ashes were different each other, Particle (<3μm) contents of them were 6 to 13%. Shading ratios were 8 to 20% at 5gm-2 of ash load. The ash with smaller particle size had bigger shading ratio. Integrated radiant flux density (280-2500nm) of reflection from leaves covered with ashes from Mt. Sakurajima (black and white) and Mt. Unzen-Fugendake at 50gm-2 were 65, 53 and 106% to control leaves, respectively. Temperature of leaves covered with these ashes at 50gm-2 increased by 2.4, 2.6 and 1.2°C, respectively, at a solar radiation of 876 W m-2. The ash from Mt. Unzen-Fugendake, with the smallest particle size, decrease stomatal conductance significantly even after it was washed out from the leaf surface. These results suggest that the volcanic ash with dark color and small particle size reduces photosynthesis through shading, increasing temperature and plugging stomata.

Etymologies

The adjective Οὖλος is used very frequently by Theophrastus in his History of Plants. The English word 'curly’ may be accepted as its equivalent in phrases like ‘curly leaves’ or ‘curly roots’; but there is something not quite so natural in an expression like ‘curly wood,’ as when Theophrastus says (H.P. III. 11. 3) that the ξνуα (which is a variety of maple-tree) ἒϰει τὐ ξύλον ξανθὐν καἰ οὖλον, ‘has yellow and curly wood.’ Sir Arthur Hort has accordingly translated it in many passages by the word ‘close-grained,’ and this not only gives a permissible sense in a large number of passages, but seems to be the only one which yields a good sense in III. 11. 3, where Theophrastus says ‘there are two kinds of ash. Of these one is lofty and of strong growth, with white wood of good fibre, softer, with fewer knots, and of more compact texture (τ ξύλον ἒϰουσα οὐλότερον).’ Schneider, who recognized only the sense ‘curly,’ felt the absurdity of saying ‘with fewer knots and curlier, and he therefore proposed to substitute νουλότερον (comparative of ἂνουλος, a word which does not occur anywhere in Greek literature). The difficulty vanishes if Sir Arthur Hort's rendering is accepted.

2. On the Carboniferous Volcanic Rocks of the Basin of the Forth

After referring to a previous communication to the Society, in which the author had given an outline of the chronology of the igneous rocks of Scotland, he proceeded in the present paper to describe in detail the character of the volcanic phenomena in one district—that of the carboniferous system of the Forth basin. The igneous rocks of this district consist partly of doleritic and felspathic lava-form masses, and partly of various kinds of ash or traptuff. These materials present a considerable diversity in their modes of arrangement. But the author had found that all the volcanic hills of the district might be reduced to three types of structure:—1. A simple cone of ash, round and over which the ordinary sedimentary accumulation of the carboniferous period had been deposited. 2. A cone of ash with the crater filled up by a neck or plug of basalt. 3. Sheets of different lavas with intercalated ash or sedimentary matter.