A n a l y s i s o f A n t a r c t i c S o i l A l g a e by t h e D i r e c t O b s e r v a t i o n U s i n g t h e C o n t a c t S l i d e Method
S h u j i 0HTANI1, Masaru AKIYAMA2 and Hiroshi KANDA1
ス ラ イ ド グ ラ ス 埋 設 法 に よ り 南 極 土 壌 か ら 検 出 さ れ た 藻 類 大 谷 修 ザ ・ 秋 山 優 2 ・神田啓史 1
要旨:南極ラングホブデ雪鳥沢において,スライドグラス埋設法を用い,土壌含 水星と関連させ,土壌藻類の種類組成とその分布を調在した.沢の 5カ所において,
沢の流れに直交する方向に数 m 問隔で 3 6 の地点,スライドグラスを垂疸に 1 9 8 8 年 1月より翌年 1月まで埋設した.
種類としてほ, 1 1 種類の藍藻類, 8 種類の緑藻類, 4 種類の珪癌類が検出された.
それらのうち, A c t i n o t a e n i u m c u c u r b i t a と P i n n u l a r i ab o r e a l i s がしばしば優占 種として出現した.走査刑電子顕微鏡による観察では, I E 葉類は薄い粘液を分泌し,
糸状性藍痰類の Lyngbyam a r t e n s i a n a は厚い粘液を分泌してスライドグラスに固 着していた.
藻類の種類数,細胞数及び士壌中のクロロフィル景は土壌の含水観と強い関連が 見られた.これらはいずれも七壌含水景が高い沢近くの地点では多く,沢から数m 離れると士壌含水閑は激減し,そこでは許しく少なくなった.
A b s t r a c t : The s p e c i e s c o m p o s i t i o n and d i s t r i b u t i o n o f s o i l a l g a e i n s i t u w e r e i n v e s t i g a t e d by t h e d i r e c t o b s e r v a t i o n u s i n g t h e c o n t a c t s l i d e method w i t h r e f e r e n c e t o t h e a v a i l a b l e w a t e r i n s o i l s o f t h e Y u k i d o r i V a l l e y , L a n g h o v d e , A n t a r c t i c a . G l a s s s l i d e s w e r e v e r t i c a l l y b u r i e d a t f i v e s i t e s w i t h a f e w m e t e r s i n t e r v a l s a l o n g a s t r e a m f o r a y e a r from J a n u a r y 1 9 8 8 .
E l e v e n t a x a o f C y a n o p h y c e a e , e i g h t t a x a o f C h l o r o p h y c e a e and f o u r t a x a o f B a c i l l a r i o p h y c e a e w e r e r e c o g n i z e d on t h e c o l l e c t e d g l a s s s l i d e s . A c t i n o t a e n i u m c u c u r b i t a ( R A L F S ) T E I L I N G and P i n n u l a r i a b o r e a l i s E H R E N B . w e r e o f t e n d o m i n a n t . The r e s u l t s o f t h e o b s e r v a t i o n by t h e s c a n n i n g e l e c t r o n m i c r o s c o p e showed t h a t d i a t o m s s e c r e t e d t h i n m u c i l a g e , b u t a f i l a m e n t o u s b l u e ‑ g r e e n a l g a , Lyngbya m a r t e n s i a n a MENEGH. s e c r e t e d t h i c k m u c i l a g e and a d h e r e d t o t h e s u r f a c e o f g l a s s s l i d e s .
Both t h e s p e c i e s number and t h e a l g a l c e l l number o f t h e s o i l a l g a e and t h e c h l o r o p h y l l c o n t e n t i n s o i l s w e r e w e J I r e l a t e d t o t h e w a t e r c o n t e n t o f s o i l s . V a l u e s o f t h e s e t h r e e i t e m s w e r e h i g h a t t h e n e a r e s t t r a n s e c t p o i n t s t o t h e s t r e a m w h e r e t h e w a t e r c o n t e n t o f s o i l s was h i g h , and s u d d e n l y d e c r e a s e d a t a f e w m e t e r s d i s ‑ t a n c e from t h e s t r e a m w h e r e t h e w a t e r c o n t e n t o f s o i l s was l o w .
1 . I n t r o d u c t i o n
Algal c o l o n i e s developed on the s u r f a c e and within the shallow p a r t of s o i l s i n the Antractic c o n t i n e n t . The d i l u t i o n method has been commonly used f o r t h e counting of microbes of s o i l or mosses i n the Antractic (CAMERON and DEVANEY, 1 9 7 0 ; BROADY, 1 国立極地研究所. N a t i o n a l I n s t i t u t e o f P o l a r R e s e a r c h , 9 ‑ 1 0 , Kaga 1 ‑ c h o m e , l t a b a s h i ‑ k u , Tokyo
1 7 3 .
2 島根大学教育学部 D e p a r t m e n to f B i o l o g y , F a c u l t y o f E d u c a t i o n , Shimane U n i v e r s i t y , N i s h i ‑ k a w a t s u , Matsue 6 9 0 .
南極資料, V o l .3 5 , No. 3 , 285 — 295, 1 9 9 1
Nankyoku S h i r y o ( A n t a r c t i c R e c o r d ) , V o l . 3 5 , No. 3 , 285 — 295, 1 9 9 1
286 S h u j i O H T A N I , M a s a r u A K I Y A M A a n d H i r o s h i KANDA
1 9 7 9 a , b ) . D i l u t i o n method, h o w e v e r , i s n o t s u i t a b l e f o r t h e e c o l o g i c a l s t u d y o f s p e c i e s which a r e d i f f i c u l t t o grow under t h e c u l t u r e c o n d i t i o n s . The c h l o r o p h y l l c o n t e n t of s o i l h a s been a l s o a p p l i e d t o e s t i m a t e t h e a l g a l abundance ( H o s H I A I and MATSUDA, 1 9 7 9 ; FRIEDMANN e t a l . 1 9 8 0 ; BROADY, 1 9 8 6 ; AKIYAMA e t a l . , 1 9 8 6 ) . With t h e pigment e x t r a c t i o n method, i t i s d i f f i c u l t t o know t h e s p e c i e s c o m p o s i t i o n o f a l g a e and t o d i s t i n g u i s h t h e p i g m e n t s o f a l g a e from t h e p i g m e n t s o f o t h e r p l a n t s . On t h e o t h e r hand, t h e c o n t a c t s l i d e method h a s been known a s a c o n v e n i e n t method f o r t h e d i r e c t c o u n t i n g o f s o i l m i c r o b e s and f o r t h e i d e n t i f i c a t i o n o f t h e s o i l a l g a e under t h e c o n d i t i o n i n s i t u (CHOLODNY, 1 9 3 0 ; P I P E and CuLLIMORE, 1 9 8 0 ) . P I P E and CuLLIMORE ( I 9 8 0 ) i d e n t i f i e d t h e s o i l a l g a e t o t h e g e n u s l e v e l such a s C h l o r e l l a , H a n t z s c h i a , O s e i ! ‑ l a t o r i a , e t c . I n o r d e r t o o b t a i n t h e d e t a i l s o f d i s t r i b u t i o n o f t h e s o i l a l g a e i n s i t u w i t h r e f e r e n c e t o a v a i l a b l e w a t e r i n s o i l s , we s t u d i e d t h e s p e c i e s c o m p o s i t i o n of t h e s o i l a l g a e and measured t h e a l g a l c e l l number by t h e d i r e c t o b s e r v a t i o n u s i n g t h e c o n t a c t s l i d e method, n a m e l y , t h e s o i l a l g a e on t h e g l a s s s l i d e s b u r i e d i n A n t a r c t i c s o i l s were i n v e s t i g a t e d .
The p r e s e n t s t u d y was conducted a s p a r t o f t h e f o u r ‑ y e a r r e s e a r c h p r o j e c t "The s t u d i e s on t h e mechanism o f A n t a r c t i c t e r r e s t r i a l e c o s y s t e m s " from 1 9 8 6 t o 1 9 9 0 (JARE‑27 3 1 ) .
2 . M a t e r i a l s and Methods
F i v e s i t e s f o r t h i s s t u d y were chosen a l o n g t h e s t r e a m i n t h e Y u k i d o r i V a l l e y , Langhovde, A n t a r c t i c a about 20 km s o u t h o f Syowa S t a t i o n ( F i g . I ) . The v a l l e y i s about 2 . 5 km l o n g , and r u n s from c a s t t o w e s t . I t c o n t a c t s t h e c o n t i n e n t a l i c e s h e e t a t t h e e a s t e n d , and t h e s h o r e o f Liitzow‑Holm Bay a t t h e w e s t e n d . A m e l t
F i g . I . Map s h o w i n g t h e s i t e s s t u d i e d b y t h e c o n t a c t s l i d e m e t h o d i n t h e Y u k i d o r i V a l l e y , L a n g h o v d e , A n t a r c t i c a .
零
stream f l o w s along t h e v a l l e y during t h e a u s t r a l summer. At each s i t e , we chose s e v e r a l p o i n t s a s a s u i t a b l e p l a c e f o r s e t t i n g a g l a s s s l i d e a t a few meters i n t e r v a l s along a l i n e t r a n s e c t which was s e t a c r o s s t h e stream i n o r d e r t o s u r v e y t h e r e l a t i o n of both s p e c i e s composition and c e l l number of t h e s o i l a l g a e t o t h e a v a i l a b l e water i n s o i l s ( F i g . 2 : 1 ‑ 3 ) . V e g e t a t i o n and s u b s t r a t a of t h e s i t e s a r e shown i n Table I .
The t r a n s l u c e n t f r o s t e d g l a s s s l i d e s ( c a . 76 x 26 mm) were v e r t i c a l l y b u r i e d mainly i n sandy s o i l s a t t h e chosen p o i n t s f o r a year from middle January I 988 ( F i g . 2 : 4 , a r r o w ) . The top p o r t i o n of g l a s s s l i d e s corresponds t o t h e s u r f a c e of s o i l . The l i g h t may p e n e t r a t e i n t o t h e deeper p a r t of t h e s o i l through t h e top s u r f a c e of g l a s s s l i d e than t h e r e a l depth i n t h e f i e l d c o n d i t i o n . Among s i t e s I , 2 and 3 which were used f o r t h e q u a n t i t a t i v e s t u d y of s o i l a l g a e , g l a s s s l i d e s of s i t e 2 ‑ E , s i t e 3 ‑ 1 and s i t e 3‑H were l i f t e d 3 mm, 3 m m and I O mm, r e s p e c t i v e l y by f r e e z e and thaw c y c l e of s o i l s . A f t e r c o l l e c ‑ t i o n of t h e g l a s s s l i d e s , t h e y were k e p t i n a f r e e z e r (‑‑20°C) u n t i l ready f o r e x a m i n a t i o n . Samples were o b s e r v e d f o r t h e i d e n t i f i c a t i o n u s i n g t h e l i g h t t r a n s m i s s i o n m i c r o ‑ scope (Nikon, OPTIPHOT) w i t h m a g n i f i c a t i o n up t o x 1 0 0 0 . Two samples were examined by t h e scanning e l e c t r o n microscope (JEOL, JSM‑5200) t o o b s e r v e d e t a i l f e a t u r e s of a l g a l c e l l s on t h e g l a s s s l i d e . A p a r t of samples ( 5 m m x 5 mm) was d r i e d a t room temperature i n t h e d e s i c c a t o r . A f t e r g o l d c o a t i n g , t h e y were observed by SEM w i t h m a g n i f i c a t i o n up t o x 2 0 0 0 .
~
F i g . 2 . L i n e t r a n s e c t o f t h e f i v e s i t e s a n d s e t t i n g o f f r o s t e d g l a s s s l i d e . 1 : S i t e 1 . 2 : S i t e 2 . 3 : S i t e 3 . ( a r r o w s h o w i n g t h e d i r e c t i o n o f l o w e r c o u r s e i n F i g
2 : / ‑ 3 ) . 4 : A f r o s t e d s l i d e g l a s s ( a r r o w ) v e r t i c a l l y b u r i e d i n t h e s o i l a t
e a c h t r a n s e c t p o i n t .
288 S h u j i O H T A N I , Masaru AKIYAMA a n d H i r o s h i KANDA T a b l e 1 . V e g e t a t i o n a n d s u b s t r a t a o f t h e s t u d i e d s i t e s . S i t e No. V e g e t a t i o n S u b s t r a t a
‑‑
‑ ‑ ‑
‑‑‑ ‑ ‑ ・ ‑ ・ ‑ ‑ ‑ ‑ ‑
‑‑S i t e 1
A ( 0 . 5 r n ) * Moss S o i l B ( 3 . 5 m) Moss S o i l C ( 6 . 5 m) S o i l S i t e 2
D ( 0 . 3 m) Moss S o i l E ( 1 . 6 m) Moss S o i l F ( 2 . 9 m) Moss S o i l G ( 4 . 2 m) S o i l S i t e 3
H ( 0 . 0 m) Moss S o i l ( 1 . 5 m) Moss S o i l J ( 3 . 0 m) Moss S o i l K ( 4 . 5 m) Moss S o i l S i t e 4
L ( 0 . 1 m) Moss S o i l M ( 1 . 6 m) Moss S o i l N ( 3 . 1 m) Moss S o i l
゜ Q p ( ( ( 6 7 4 . . . 1 6 6 m) m) m) Moss S S S o o o i i i l l l S i t e 5
R ( 0 . 0 m) A l g a e S o i l
s ( 1 . 5 r n ) A l g a e S o i l T ( 3 . 0 m) Moss Moss
u ( 4 . 0 m) Moss Moss V ( 5 . 0 m) S o i l
* D i s t a n c e f r o m t h e s t r e a m i n m i d d l e J a n u a r y 1 9 8 8 . —: No v e g e t a t i o n .
Algal numbers on g l a s s s l i d e s were counted u s i n g t h e r e f l e c t e d l i g h t microscope (OLYMPUS) a t t h e depth of 0 . 5 , l , 2 , 3 and 5 cm, r e s p e c t i v e l y . A f i l a m e n t o u s b l u e ‑ g r e e n a l g a , Lyngbya martensiana MENEGH. occurred abundantly a t s i t e 2‑0, b u t , c e l l count was not achieved because of t h e d i f f i c u l t y of a c c u r a t e count of c e l l number.
A colony of Nostoc was counted a s one c e l l .
The water c o n d i t i o n of s o i l s was recorded w i t h t h r e e ranks such a s d r y , moist and wet on January 1 9 8 8 , w h i l e s o i l s and mosses a t t h e s u r f a c e and a t t h e 5 cm depth were sampled a t each s i t e on January 1 9 8 9 . The water content of s o i l s and mosses was e x p r e s s e d by t h e f o l l o w i n g formula:
Water content (%)=(Wet weight‑Dry weight)/Dry weight x 1 0 0 .
The c h l o r o p h y l l a content of t h e s o i l was measured according t o t h e standard method by UNESCO ( 1 9 6 6 ) .
A n a l y s i s of t h e s p e c i e s composition was a c h i e v e d w i t h samples from a l l f i v e s i t e s ,
but measurements of t h e water content of s o i l s , c e l l number of s o i l a l g a e and t h e
c h l o r o p h y l l content were done with samples from s i t e s I , 2 and 3 .
3 . Results 3 . 1 . S o i l algae detected on t h e g l a s s s l i d e
Eleven taxa of Cyanophyceae, e i g h t taxa of Chlorophyceae and four taxa of Bacillariophyceae were recognized on the c o l l e c t e d g l a s s s l i d e s (Table 2 ) . Among them, Actinotaenium c u c u r b i t a (RALFS) TEILING and P i n n u l a r i a b o r e a l i s EHRENB. were often dominantly occurred. Stigonema minutum ( A g . ) HASSALL, Gloeocapsa magma (BREB.) HoLLERBACH, Gloeocapsa r a l f s i a n a (HARV.) K‑OTz. and a filamentous green alga were detected from the g l a s s s l i d e buried i n a moss colony ( S i t e 5 ‑ T ) . Other algae were d e t e c t e d from the g l a s s s l i d e s buried i n s o i l s . Most of blue‑green algae and diatoms were i d e n t i f i e d t o the s p e c i f i c l e v e l because modification of c e l l shape by the p r e s e r v a t i o n i n a f r e e z e r and the d e s i c c a t i o n was so small ( F i g . 3 : I , 2 ) . Although e i g h t taxa of green algae were found, they were not i d e n t i f i e d t o the genus l e v e l except Actinotaenium and S t i c h o c o c c u s , because c e l l contents of them were not c l e a r ( F i g .
T a b l e 2 . S o i l a l g a e d e t e c t e d from t h e s u f a c e of t h e g l a s s s l i d e s b u r i e d i n t h e f i v e s i t e s a l o n g t h e Y u k i d o r i V a l l e y .
S i t e
S p e c i e s 2 3 4 5 Cyanophyceae
S y n e c h o c o c c u s a e r u g i n o s u s N
泣S y n e c h o c o c c u s m a i o r S c H R .
* G l o e o c a p s a magma ( B R E B ) HOLLERBACH G l o e o c a p s a r a l f s i a n a ( H A R V . ) KOTZ.
* G l o e o c a p s a c o m p a c t a KOTZ.
Lynghya m a r t e n s i a n a MENEGH.
Lynghya s p . 1 (width~I , , m ) Lynghya s p . 2 (width~0 3 1 1 m ) N o s t o c commune V AUCHER N o s t o c s p .
* S t i g o n e m a m i n u t u m ( A G . ) HASSALL B a c i l l a r i o p h y c e a e
H a n t z s c h i a a m p h i o x y s ( E H R E N B . ) GRUN.
N a v i c u l a m u t i c o p s i s VAN HEURCK N a v i c u l a s p .
P i n n u l a r i a h o r e a l i s E H R E N B . C h l o r o p h y c e a e
A c t i n o t a e n i u m c u c u r h i t a ( R A L F S ) T E I L I N G S t i c h o c o c c u s s p .
C o c c o i d a l g a n o . I (diam.= I O 1 i m ; t e t r a d s ) C o c c o i d a l g a n o . 2 (diam.= 1 0 ‑ 1 6 1 1 m ; u n i c e l l ) C o c c o i d a l g a n o . 3 ( d i a m . =6‑8 1 i m ; c o l o n i e s
w i t h m u c i l a g i n o u s s u b s t a n c e )
C o c c o i d a l g a n o . 4 ( i r r e g u l a r l y s h a p e d c o l o n i e s composed o f d e n s e l y a g g r e g a t e d c e l l s ) Cocco i d a l g a n o . 5 ( c o l o n i e s o f 1 , 2 , 4 t o I 6
c e l l s w i t h t h i c k m u c i l a g i n o u s s u b s t a n c e )
* F i l a m e n t o u s a l g a
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• O c c u r r e d i n moss c o l o n i e s .
290 S h u j i 0 H T A N I , M a s a r u AKIYAMA a n d H i r o s h i KANDA
芯\<~さ ぃ t
べゞ 婆忍
︸
ヽ`ヽ~‘‘、~
、、、~`~ヽ
4ベ ゞヽr
F i g . 3 . S o i l a l g a e o n t h e g l a s s s l i d e s o b s e r v e d b y t h e l i g h t m i
け()双I : F i l a m e n t s o / S t i g o n e m a m i n u t u m . 2 : A c o l o n y l J { G l o e o c a p s a r a l f s i a n a . 3 : C e l l s < I f A c t i n o t a e n i u r n c u c u r b i t a . 4 : C o l o n i a l g r e e n a l g a e w i t h t h i c k m u c i l a g i n o u s s u b s t a n c e .
3 : 3 , 4 ) . Other coccoid o r f i l a m e n t o u s green a l g a e need t h e c u l t u r e examination f o r t h e i r i d e n t i f i c a t i o n .
D e t a i l f e a t u r e s of t h e a l g a l c e l l s on t h e g l a s s s l i d e s were observed by t h e scanning e l e c t r o n microscope ( F i g . 4 ) . A f i l a m e n t o u s b l u e ‑ g r e e n a l g a , Lyngbya martensiana
MENEGH. adhered t o t h e g l a s s s l i d e w i t h t h i c k mucilaginous s u b s t a n c e . U n i c e l l u l a r a l g a e were sometimes wrapped i n t h e mucilage of L . martensiana ( F i g . 4 : 2 , a r r o w ) . Synechococcus maior NAG, and t h r e e diatoms were a t t a c h e d t o t h e g l a s s s l i d e w i t h t h i n , and unapparent mucilages ( F i g . 4 : 3 ‑ 6 ) . I t i s observed by t h e l i g h t t r a n s m i s s i o n microscope t h a t c o l o n i e s of green a l g a e adhered on t h e s u r f a c e of t h e g l a s s s l i d e w i t h t h i c k mucilage ( F i g . 3 : 4 ) a s w e l l a s f i l a m e n t o u s b l u e ‑ g r e e n a l g a e .
3 . 2 . The d i s t r i b u t i o n q f t h e s o i l a l g a e
The water c o n d i t i o n of s o i l s and mosses, t h e s p e c i e s number on a g l a s s s l i d e , t h e mean a l g a l c e l l number ( c e l l s / m m 2 ) on a g l a s s s l i d e and t h e c h l o r o p h y l l a c o n t e n t i n t h e s o i l a t s i t e s I , 2 and 3 along t h e stream a r e shown i n Table 3 .
During t h e a u s t r a l summer 1 9 8 8 , meltwater flowed i n t h e stream from t h e upper
c o u r s e t o lower c o u r s e . At s i t e I ‑ A , s i t e 2‑0 and s i t e 3‑H which a r e t h e n e a r e s t
t r a n s e c t p o i n t s t o t h e s t r e a m , t h e water c o n d i t i o n on January 1 9 8 8 was m o i s t o r w e t .
The water c o n d i t i o n showed a tendency t o change from w e t , m o i s t t o dry w i t h t h e
d i s t a n c e from t h e s t r e a m . At s i t e 1 ‑ C , s i t e 2‑G and s i t e 3‑K, t h e f a r t h e s t t r a n s e c t
F i g . 4 . S o i l a l g a e o n t h e g l a s s s l i d e s o b s e r v e d b y t h e s c a n n i n g e l e c t r o n m i a o s c o p e . I : Lyngbya m a r t e n s i a n a a d h e r e d t o t h e s u r f a c e o f t h e g l a s s s l i d e b y m u ‑ c i l a g i n o u s s u b s t a n c e . 2 : P i n n u l a r i a b o r e a l i s ( a r r o w ) w r a p p e d i n m u c i l a g i n o u s s u b s t a n c e o f L . m a r t e n s i a n a . 3 : C e l l s o f S y n e c h o c o c c u s m a i o r . 4 : A c o l o n y o f P i n n u l a r i a b o r e a l i s . 5 : N ' . l v i c u l a m u t i c o p s i s . 6 : H a n t z s c h i a a m p h i o x y s .
p o i n t s from the s t r e a m , t h e water condition was dry except a t 5 cm depth of s i t e 2 ‑ G .
During t h e a u s t r a l summer 1 9 8 9 , meltwater hardly ran i n t h e stream from t h e west
margin of Lake Yukidori t o t h e mouth of t h e s t r e a m , and t h e water was s u p p l i e d
mainly from snow d r i f t s . The water content on January 1989 ranged from 0 . 1 t o
30.9%. I t decreased suddenly a t a few meters d i s t a n c e from t h e stream a t s i t e I and
s i t e 3 . At s i t e 2 , water c o n d i t i o n was low and almost t h e same among a l l t h e t r a n s e c t
2 9 2 S h u j i OHTANI, M a s a r u AKIYAMA a n d H i r o s h i KANDA
T a b l e 3 . H o r i z o n t a l c h a n g e o f t h e w a t e r c o n d i t i o n o f s o i l s , t h e s p e c i e s n u m b e r o n a g l a s s s l i d e , t h e m e a n a l g a l c e l l n u m b e r o n a g l a s s s l i d e a n d c h l o ‑ r o p h y / 1 a c o n t e n t i n s o i l s a t s i t e s 1 , 2 a n d 3 .
‑ = = ‑ ‑ ‑ = ‑ ‑ = : : . .
ニニニニニ―::ニ:..‑:---—---- ‑ ‑ ‑ = ‑ = ‑ = ‑ ‑ ‑ ‑
‑‑‑‑‑=‑ごこニ‑‑‑‑=二:―̲̲. 一 ‑‑‑ . :ーニニ―.....:.―.:..::こニーーニ~ こ二:.::::..:‑ニご二ニ―‑̲:̲‑̲‑こ:― ーニニ=ニニニ―:...:~ーニ文―二~-- ": =‑‑=‑‑==‑―‑‑‑‑=ご==‑‑---—
―W a t ‑‑‑―̲ e r c o n d i ̲ t ̲ i ̲ o ̲ n ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ ̲ Mean a l g a l C h l o r o ‑ S i t e N o . J a n u a r y ‑ 1 9 8 8 ‑ J a n ‑ u ‑ a ‑ ‑ r ― y ‑ ‑ ‑ 1 9 ‑ ‑ 8 ‑ ‑ ‑ 9 ‑ ‑ ― ‑ ‑‑‑Species ・ ・ c ‑ e l l 1 . . ph·y~ll ~ t
s -~--- 5 s ‑ " ‑ ‑ n u m b e r n u i u u e r c o n ,
叩u 1 1 a 1 . c ‑ cm u ( 1 % 1 迅) e ‑ ( 5 % c ) m ( c e l l / m m り ( μ g / g )
m中‑‑‑‑ ‑‑ ‑
‑ ― ‑ ---—
S i t e l
A ( 0 . 5 m) Moi . s t M o i s t 3 0 . 9 2 1 . 6 1 0 4 1 1 8 . 6 B ( 3 . 5 m) Dry M o i s t O . 1 l . 7 3 2 3 . 5 C ( 6 . 5 m) D r y D r y < 0 . 1 1 . 1 <1 1 . 9 S i t e 2
D ( 0 . 3 m ) Wet Wet 0 . 1 0 . 2 * 9 2 1 2 2 3 . 5 E ( 1 . 6 m) D r y Moi . s t 0 . 1 0 . 2 4 <1 2 . 4 F ( 2 . 9 m) D r y M o i s t O . 1 0 . 3 < 1
G ( 4 . 2 m ) D r y M o i s t 0 . 1 0 . 5 < I S i t e 3
H ( O . O m ) Wet Wet I . I * * 2 . 5 5 3 1 6 9 . 5 I ( 1 . 5 m) M o i s t Moi . s t 1 . 6 * * 1 . 2 < I 9 . 4 J ( 3 . 0 m ) Dry Dry 0 . 1 0 . 9 0 0
K ( 4 . 5 m ) D r y Dry 0 . 1 0 . 3 0 0
‑ ‑ . . ‑ ‑‑‑ ‑‑ ‑ ‑‑‑‑ ‑‑‑‑‑
-—.
‑ ‑‑‑‑‑ ‑‑‑ ‑‑‑‑――‑‑* D e p t h i s 2 . 5 c m . * * W a t e r c o n t e n t o f m o s s c o l o n y . ‑No d a t a . p o i n t s , because l i t t l e water was s u p p l i e d from snow d r i f t s .
The s p e c i e s number o f t h e s o i l a l g a e was w e l l c o r r e l a t e d w i t h t h e water c o n t e n t s of s o i l s and mosses a s shown i n Table 3 . For example, a t s i t e 1‑A ( 0 . 5 m d i s t a n t from t h e s t r e a m ) where t h e water c o n t e n t was h i g h , t e n s p e c i e s were f o u n d . On t h e o t h e r hand, a t t h e t r a n s e c t p o i n t s i t e 1 ‑ C ( 6 . 5 m d i s t a n t from t h e s t r e a m ) where t h e water c o n t e n t o f s o i l was q u i t e l o w , o n l y one s p e c i e s was f o u n d .
At s i t e s I , 2 and 3 , t h e a l g a l c e l l number and t h e c h l o r o p h y l l c o n t e n t of t h e s o i l were measured. The mean a l g a l c e l l number ranged from O t o 316 c e l l s / m m 2 . The c h l o r o p h y l l c o n t e n t ranged from 1 . 9 t o 2 3 . 5 μ g / g . The r e s u l t s s u g g e s t e d t h a t t h e a l g a l c e l l number and t h e c h l o r o p h y l l c o n t e n t were w e l l c o r r e l a t e d w i t h t h e water c o n ‑ t e n t of s o i l s a s w e l l a s t h e number of s p e c i e s . H i g h e s t v a l u e s of them were r e c o r d e d a t t h e n e a r e s t t r a n s e c t p o i n t s t o t h e stream where t h e water c o n t e n t of s o i l s was h i g h . The c e l l number o b t a i n e d by t h e c o n t a c t s l i d e method was c l o s e l y r e l a t e d t o t h e v a l u e s o f c h l o r o p h y l l c o n t e n t o f t h e s o i l which were d e r i v e d from mainly episammic a l g a e a t t h e same s i t e ( r = 0 . 7 5 ) .
V e r t i c a l change o f a l g a l c e l l number a t s i t e s 1 , 2 , and 3 i s shown i n Table 4 . The
o c c u r r e n c e o f s o i l a l g a e on t h e s u r f a c e o f each g l a s s s l i d e was r e c o g n i z e d between t h e
top p o r t i o n of t h e g l a s s s l i d e s which almost corresponded t o t h e s o i l s u r f a c e and t h e
l o w e r p o r t i o n o f t h e g l a s s s l i d e co rr es po nd in g t o t h e s o i l of c a . 7 cm d e p t h . The
m a j o r i t y o f a l g a e o c c u r r e d on t h e g l a s s s l i d e l e s s than 5 cm d e e p . The s t r u c t u r e o f
a l g a l community, p a r t i c u l a r l y of t h e i r v e r t i c a l m i c r o ‑ d i s t r i b u t i o n , v a r i e d w i t h s i t e s ,
v i z . t h e depth showing a maximal a l g a l growth a t each s i t e was a s f o l l o w s : ‑0.5 cm
( 5 3 c e l l s / m m 2 ) a t s i t e 1 , ‑1 cm (318/mm2) a t s i t e 2 and ‑2 cm ( 5 5 5 cells/mm り a ts i t e 3
( F i g . 5 ) . Among s p e c i e s shown i n Table 4 , t h e c e l l number o f P i n n u l a r i a b o r e a l i s was
h i g h e s t and i t s c e l l s o c c u r r e d a t 5 cm d e p t h o f s i t e 1 ‑ A and s i t e 3 ‑ H . The remark‑
T a b l e 4 . V e r t i c a l c h a n g e of a l g a l c e l l number ( c e l / s / m m 2 ) on t h e g l a s s s l i d e s a t t h e l i n e t r a n s e c t s of s i t e s I , 2 and 3 .
‑‑=‑‑・‑ ‑ ‑ ‑‑
ー:い一ごS i t e No. Algae
ー・=,
̲̲̲̲̲●● c~・
Depth ( c m )
‑ ‑‑
0.5 2 3 5
S i t e I
S i t e 2
S i t e 3
A ( 0 . 5 m)
B
C ( 6 . 5 m) D ( 0 . 3 m)
E
F G
[ J K
( 3 . 5 m)
( 1 . 6 m)
( 2 . 9 m) ( 4 . 2 m) H (Om)
( 1 . 5 m) ( 3 . 0 m) ( 4 . 5 m)
A c t i n o t a e n i u m P i n n u l a r i a H a n t z s c h i a N a v i c u l a *
T o t a l
3 4 1 9
0 0 53 P i n n u l a r i a
N o s t o c * * T o t a l
A l g a l c e l l number l e s s t h a n 1 c e l l / m m 2 0 5 5
3 1 5 2 I O O O 1 2 4
5 2 6 0 3 0 0 0 3 4
2 9 8 0 9 3 0 3 2 3
0262028202
A ctmotaemum ・
P i n n u l a r i a H a n t z s c h i a N a v i c u l a N o s t o c
T o t a l P i n n u l a r i a N a v i c u l a
T o t a l
4 3 7 4 8 8 0 3
3 0
0 0
ー
4 4 0 0 0 8 0 0 0 9 1 l l 2 3
1 9 2 2 5 9 0 0 0 3 2 2 8 l l
0 2 2
2 0 2 A l g a l c e l l number l e s s t h a n 1 c e l l / m m 2
I I
A c t i n o t a e n i u m P i n n u l a r i a H a n t z s c h i a N o s t o c
T o t a l
5 1 6 7 2 0 2 0 2 3
9 5 0 0 4 5 5 1 1 2
280 2 4 5
゜
30 5 5 5
1 1 0 209
゜ 2
3 2 1
10 1 6 0 2
゜
1 7 2 A l g a l c e l l number l e s s t h a n 1 c e l l / m m 2
Algae n o t d e t e c t e d from t h e g l a s s s l i d e
I I
* N a v i c u l a m u t i c o p s i s , * * N o s t v c s p .
T o t a l c e l l number (cell/mm2>
0 200
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