Epiphytic Lichen and Bryophyte Vegetation as a Bioindicator of Air Pollution

• Published in: Journal of Japan Society of Air Pollution Vol. 19; no. 6; pp. 462 - 472
• Main Authors: OMURA Makoto, MURATA Atsuko
• Format: Journal Article
• Language: English; Japanese
• Published: Japan Society for Atmospheric Environment 1984; 公益社団法人 大気環境学会
• ISSN: 0386-7064; 2186-3695
• DOI: 10.11298/taiki1978.19.462

The regional differences and changes with year in total air pollution levels in the main industrial zones of Fukuoka Prefecture, the Omuta and Kitakyushu areas, were evaluated on the basis of the epiphytic lichen and bryophyte vegetation on the tree trunks of shrine woods. The 1st investigation was made in the preiod from 1978 to 1979 to learn the regional differences and the 2nd investigation in 1982 to manifest the chronic changes.In order more reasonably to determine air pollution levels, a new index “IAP” is devised instead of the “IAP” of LeBlanc & De Sloover (1970) in the present study: preparatorily, the IAP index was given at each spot (50×200 cm2 quadrat), and then the new index IAP at a given quadrat is expressed as the arithmetic mean of the four IAP values including those at the relevant quadrat and its adjacent four quadrats, but excluding the lowest value among them.In both investigations, a considerable correspondence was recognized between the regional differences in the IAP value and those in the air pollution level which was indicated by the sulfur oxides concentration measured by the lead dioxide method.The IAP levels determined in the 2nd investigation were, in general, higher than those of the 1st one in the two areas. This fact may suggest that the chronic total air pollution level is changing for the better condition in both areas. The increasing tendency of the IAP values was more obvious in the Kitakyushu area than in the Omuta area.As a result of the analysis of the species composition and its chronic change in the zones classified by the IAP values, a general reciprocal relationship was found between the specific sensitivity of epiphytes as represented by the number of companion species per quadrat and the air pollution levels. 福岡県内の主要工業地域である大牟田および北九州地区の大気汚染度の地域差および近年の変化を, 神社境内樹木の幹の着生地衣・蘇苔植生の第1回 (1978～1979) および第2回 (1982) 調査資料によって評価した。評価はLeBlancとDeSloover (1970) のIAP値 (大気清浄度指数) から本研究で新たに“IAP”値を求めて行った.ある調査方形区のIAP値は, その方形区とそれに近接する4方形区すなわち5方形区のIAP値のうち最小値を除き, 残り41AP値の算術平均である。各地区における評価結果の地域差は, 第1回, 第2回調査のいずれの場合も, 硫黄酸化物濃度 (PbO2法) の各測定点における測定資料から判断される大気汚染度の地域差とかなり良く対応した.両地区とも, 全域的にみると, 第2回調査に基づく評価結果が第1回調査の場合よりも良くなり, 長期的総合的にみて, 大気環境が好転していると考えられ, そして, 北九州地区のほうが大牟田地区よりも顕著に好転した。また, 各地区における着生地衣・蘇苔植生の種組成およびその変化を, IAP値によって区分した地域ごとに明らかにした。なお, 平均共存種数によって評癒したそれぞれの種の大気汚染に対する感受性の大小は, 全体的にみて, IAP値によって評価した大気汚染度の高低との相反的な関係をかなり良く示した。