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Mycorrhizal, association and forest decline (yellowing of spruce)
381
Agriculture, Ecosystems and Environment, 28 (1989) 381-387 Elsevier Science Publishers B.V., Amsterdem Printed in Czechoslovakia
MYCORRHIZAL FOREST (YELLOWING
.ASSOCIATION DECLINE OF SPRUCE)
AND
R o b e r t PERPAN a n d Dol~lnlque ESTIVALET S t a t i o n d e R e c h e r c h e e s u r l a Flol~ P a t h o g 6 n e d i m s le 8ol 17 r u e Sully, B.V.1540. 9.1084 DIJON c 6 d e x PRANCE SUMMARY
T h e m y c o r r h i z a l s t a t u s of Norway s p r u c e w a s i n v e s t i g a t e d from a n i n v e n t o r y d r a w n u p in v a r i o u s f o r e s t s t a n d s in v o s g e s a r e a (FRANCE). D e c l i n i n g t r e e s generally have fewer living short roots and mycorrhizae than healthy ones. A l a r g e n u m b e r of m y c o r r h i z a l t y p e s a n d a wide v a r i a b i l i t y b e t w e e n t r e e s c a n be o b s e r v e d w i t h o u t a n y r e l a t i o n s h i p w i t h t h e h e a l t h o f th, e t r e e s . T h e f o r e s t s o i l s in t h e w h o l e r e g i o n a n d more p a r t i c u l a r l y in d e c l i n i n g s t a n d s , s e e m to be u n a b l e to p r o d u c e n o r m a l m y c o r r h i z a l i n f e c t i o n o f s p r u c e . INTRODUCTION T h e e n t i r e i n v e s t i g a t i o n s i n c l u d e a n i n v e n t o r y d r a w n up in Norway s p r u c e s t a n d s in the V o s g e s a r e a a n d a n experimental a p p r o a c h in greenhouse. Inventory Trees of declining stands have generally fewer living mycorrhizae than h e a l t h y o n e s in a g r e e m e n t w i t h p r e v i o u s s t u d i e s (W,H. L i v i n g s t o n a n d H, B l a s c h k e , 1984). A g r e a t n u m b e r o f m o r p h o l o g i c a l t y p e s of m y c o r r h i z a e a n d a ' h i g h v a r i a b i l i t y a m o n g t r e e s were o b s e r v e d . Nevertheless a clear relationship between rootlets decline and severity of the f o r e s t d i e b a c k c a n n o t be e s t a b l i s h e d from i n v e n t o r y r e s u l t s (D. E s t i v a l e t a n d al., 1988). Experimental approach Principle: D i f f e r e n t t r e a t m e n t s were a p p l i e d to s a m p l e s of s o i l s c o l l e c t e d u n d e r d e c l i n i n g or h e a l t h y s t a n d s in o r d e r to i n f l u e n c e m i c r o b i o l o g i c a l b a l a n c e or n u t r i e n t s t a t u s . We t r i e d to p u t in r e l a t i o n g r o w t h a n d a s p e c t m o d i f l c a t o n s of p l a n t s a f t e r soil t r e a t m e n t s w i t h c h a n g e s of m y c o r r h i z a l s t a t u s . A m o n g t h e t r e a t m e n t s t h e f o l l o w i n g o n e s were p a r t i c u l a r l y i n t e r e s t i n g for o u r purpose: - u n t r e a t e d soil c o n t r o l , - p a s t e u r i z a t i o n (70 "~C d u r i n g 30 rain.), -pasteurization (70 °C d u r i n g 30 mln.) a n d a d d i t i o n }accats i n o c u l u m ( 1 / 1 0 , v / v ) g r o w n in a v e r m i c u l i t e - p e a t m i x t u r e
of L~ccarJa
382
-pasteurization and a d d i t i o n of soil (1/10 v / v ) from the declining s t a n d into t h e t h e soil from h e a l t h y s t a n d . Norway s p r u c e s e e d l i n g s and s a p l i n g s (2+1, 2+2) were h a r v e s t e d a f t e r six and e i g h t e e n m o n t h s g r o w t h on t h e s e t r e a t e d soils in a g r e e n h o u s e . P l a n t s were a s s e s s e d for : - s h o o t and r o o t dry w e i g h t -mycorrhizal frequency, - m i n e r a l . c o n t e n t s of t h e n e e d l e s .
RESULTS OF EXPERIMENTAL APPROACH S a p l i n g s in c o n t r o l p o t s filled with soil from declining s t a n d were s t u n t e d and chlorotlc . The p a s t e u r i z a t i o n p r o m o t e d t h e g r o w t h of p l a n t s in b o t h s o i l s and r e s t o r e d t h e n o r m a l a s p e c t of p l a n t s d e v e l o p e d in soil from declining s t a n d . The 70 ~C t r e a t m e n t s t i m u l a t e d t h e d e v e l o p m e n t of m y c o r r h i z a l a s s o c i a t i o n of only t h o s e p l a n t s g r o w i n g in h e a l t h y soil. N e v e r t h e l e s s , t h e d e v e l o p m e n t of t h e main morphological t y p e of m y c o r r h l z a e was e q u a l l y i m p r o v e d in s o i l s from h e a l t h y s t a n d as in s o i l s from d e c l i n i n g s t a n d (Figure 1). During t h e f i r s t s e a s o n of g r o w t h , t h e p a s t e u r i z a t i o n allows t h e r e s t o r a t i o n of a good m i n e r a l n u t r i t i o n w h e r e a s in t h e s e a s o n we n o t i c e a N deficiency (Figure 2). From t h e s e r e s u l t s , g r o w t h i m p r o v e m e n t , a s p e c t and n u t r i t i o n r e s t o r a t i o n could be a s s o c i a t e d w i t h q u a l i t a t i v e a m e l i o r a t i o n of m y c o r r h i z a l s t a t u s , w i t h o u t a n y r e l a t i o n s h i p w i t h soil origin. T h e r e was no a d d i t i o n a l g r o w t h and n u t r i t i o n a l e f f e c t of L ' a c c a r i a l a c c a t a i n o c u l a t i o n a f t e r p a s t e u r i z a t i o n as compared with p a s t e u r i z a t i o n a l o n e ( f i g u r e s 3 and 4). Inoculation with Laccarls Iaccata works significantly only upon mycorrhizae status of plants growing on a soil from declining stand especially by 'increasing the proportion of Laccaria Laccata mycorrhizae. The addition of soil from declining stand into the pasteurized soil from healthy stand had a depressive effect on the top blomass of seedlings and saplings, but less accentuated on the former .The level of mycorrhizal association was only significantly different on saplings. However a significant drop in the proportion of the main morphological type of mycorrhizae can be observed for both kind of plants, until a n entire disappearance on saplings (Figure 5). This experiment revealed that the depressive influence of soll from declining stand, seemed to be in relation to the diminution of the mycorrhizal frequency, particularly of the main morphological type. The foliar analysis of saplings did not reveal any important modification of the mineral nutrition except a N deficiency which was a general rule for the saplings after two seasons of growing in pots (Figure 6). In spite of more marked changes, the l~vel of mineral nutrition of seedlings was poorly affected by the addition of a soll from declining strand (Figure 7). The depressive effect of adding soll from declining stand can not be related to a m i n e r a l n u t r l t i o n deficiency.
383
j
TOP BIOMASS
L Mvco.s.,zAz,o. ]
H E$ A! TN HD Y
b
i £ CS LT In NN
COilTIROL
! D
H G
b
70
GO 50
t0
I 30
x
I?O'C 2e
10
s
x 0
cg clrN ueight
~
20
30
,to
50
60
?'0
z ~caz-~.J,l¢~! sJ~et ~ootlr
FIGURE I : Effect of ( dry weight cg/plant
sell pasteurization ( 70'c ) on the average top blomass ) a n d t h e l e v e l o f mycorrhiza! ~ s s o c l a t l o n ( p e r c e n t a g e of mycorrhlzal short roots ) of saplings after t w o years growth in Ireenhouse
,in soils collected under healthy or decllnin£ stands. The frequency of the main morphological type of mycorrhlzae, is noted. Means associated with the same letter are not siHrtificufLtly different according to N e w m a n and Keuls test (alpha = 0,05).
DECLINING STAND FOLIA~ ARALYSIS
70degree8
% m c.-it lcal
d 1,5 •
r
con,.,
Y W e*
i g
1.
0,5 •
h t N~
PZ
~z Minerals
~x
~IX
F I G U R E 2 : Mineral c o n t e n t s ( % d r y w e i g h t ) o1' tt~e n e e d l e s o f N o r w a y s p r u c e s a p l i n g s , t w o g r o w i n g s e a s o n s after t r a n s p i a n t h ~ g in a p a s t e u r i z e d soil from declining stand.
384
DECLINING STAND FOLIAR ANALYSIS Lsccsria lacca%a 70 degrees
H Crl|lc~| d r
t© v e l
1,5 y I
Y
I Castro|
|JB
|
0 r~.,.-,t
....
t
Minerals
3 : Effect of Lacca#'J. Aaccata Inocularlon In pasteurized soil (70"0 -P Lac ) on the average top biomass ( d r y w e i g h t cEJplant ) and the l e v e l ot m y c o r r h l z a l association ( pareentaze ot m y c o r r h i z a l shorL roots ) o f s & p l l n i i after two years Erowth In i[reenhouse . In soils coli~c/ed under healthy &rid decllning stands T h e frequency of the ma~n morpholozical Wpe of mycorrhizae FIGURE
is noted. M e a n s associated wlth the s a m e letter are not stgnlrtc~ntly to N e w m a n and Keuls ~est (alpha = 0,05}.
F 1 TOP B I O M A S S
tl Es FiT LR TN
. i MYCORRHIZATION
I
.l I'
T0"C,L~c.
h
xD Y
~0~3
__
l
~
C I.
H G
"J
different according
"'! C0rITllt~J.
J
I, 1 ~.-
D ?0
b ~0
SO
tS
x
?O°C"
LaC.
3e
ZS
cg drg ucLg|lt
tO
S
o
tQ
zo
30
,to 50
66
?0
z aUC~L-rhiz~l sl~ort roQts
4 : Mineral contents ( % dr:/ weight ) of th~ rLeedles of N o r w a y spruce saplings, two growing seasons after transplshth~_ IrL a pssteurlzed soll fr#m declining stand Inoculated with LaccsJ.Ja J~e~,,~a .
FIGURE
385
I
TOP B I O M A S S
_ RH,ZAT,O. I
1 70"C
7e'C, I),S
$ ? L I N
G $
70"C, 6e
50 ~0 30
20
10
o
ql dry mlllht
i
10
28
M
48
58
M
x ~fco~rhlut IlwrL N o t l
PIG~RE _6 : Effect of t h e addlUon a t soil from declining s t a n d ( 1056 ) In p a s t e u r i s e d soil from h e a l t h y s t a n d ( 70"C + DS ) on the avarnlta top bJom~8o { d r y weight el~plant ) I m d t h e l e v e l of myeorrhlza! sssoclatlom ( p e r c d m ~ o of mycorrhiza! s h o r t foetal ) a t saplluSs and s e e d i l n l s a f t e r two y e a r s J / ~ w t h In tp'eenhouse , The f r e q u e n c y a t t h e main morphological type ot mWeorrhlsae is noted. Means a s s o c i a t e d with the o~me l e t t e r a r e not slgnlfl~,~ntl¥ d i f f e r e n t aocording to Newman and Keuls t e s t ( a l p h a t 0.06) .
HEALTHY STAND POLIAR ANALYSIS
SA~PLIN6S
• Crl~i~.sl
% d r
1.5
~ ~'o'c
eJ~o'c •
y 1 W e
0 e,5 h t e n~.
Px
Ex Minerals
~
ajx
FIGURE 6 : Effect of addition a t sol/ tram docilnlnl s t a n d on t h e .m$~aral c o n t e n t s ( % dry welght ) of t h e noodles of Norway s p r u c e anpllx~8, two growing s e a s o n s a f t e r t r a n s p l a n U n | In a p a s t e u r i z e d sou tram healthy s t a n d (70"C + DS ) .
386
HEALTHY STAND FOLIAR ANALYSIS seedlings Z
% I-'I ?e'C d
1,s
[ ] ?6"C • 9S
r Y W
1
e
i g
e.5
h t
N×
F×
Kx
i,
I II Ca
~ , Mg X
Minerals
FIGURE 7 : Effect of addition Of soll or oecliiLir~tt stand or, mineral contents (% dry weight ) of the needles or two ye~i.s old saedilngs, £rowft In pasteurized soll from healthy stand (70"C e DS ),
a
387
CONCLUSION E x p e r i m e n t a l r e s u l t s p r e s e n t e d h e r e , s u b s t a n t i a t e t h e c o n c l u s i o n of t h e i n v e n t o r y : f o r e s t d i e b a c k In p a r t i c u l a r t h e y e l l o w i n g of s p r u c e c a n be a s s o c i a t e d w i t h a d e t e r i o r a t i o n of m y c o r r h i z a l a s s o c i a t i o n e s p e c i a l l y of t h e m a i n m o r p h o l o g i c a l t y p e of m y c o r r h i z a e . T h e s e c h a n g e s in m y c b r r h i z a l s t a t u s do n o t d i s t u r b m i n e r a l n u t r i t i o n . P r e v i o u s s t u d i e s r e v e a l e d t h e d e l e t e r i o u s e f f e c t of a n o n - s y m b i o t i c m i c r o f l o r a (D. ESTIVALET, R. PERRIN a n d F. LE TACON,1986 ) w h i c h s e e m s t o p r e v a i l o v e r t h e c o n s e q u e n c e s of t h e d e g e n e r a t i o n of m y c o r r h i z a l s t a t u s The deleterious microflora could interfere with mycorrhizae association development. D e l e t e r i o u s m i c r o o r g a n i s m s c a n be f o u n d i n a n y s o i l , b u t t h e e x p r e s s i o n of t h e i r d e p r e s s i v e e f f e c t , a s well a s t h e b e n e f i c i a l i n f l u e n c e of m y c o r r h i z a l a s s o c i a t i o n d e p e n d on . t h e m i c r o b i o l o g i c a l b a l a n c e . T h i s e q u i l i b r i u m c a n be m o d i f i e d u n d e r t h e I n f l u e n c e of n u m e r o u s f a c t o r s s u c h a s c l i m a t e , p o l l u t i o n , a c i d i f i c a t i o n of s o i l . . . . . I n c r e a s i n g i n f l u e n c e of d e l e t e r i o u s m i c r o f l o r a a s s o c i a t e d w i t h r e c e s s i o n of m y c o r r h i z a l a s s o c i a t i o n c o u l d be a k e y p r o c e s s in t h e f r a m e work of s p r u c e yellowing.
REFERENCES LIVINGSTON W. H. a n d BLASCHKE H., (1 984) . D e t e r i o r a t i o n of m y c o r r h i z a l s h o r t r o o t s a n d o c c u r r e n c e of Mycellum radlcl$ a t r o v i r e n s on d e c l i n i n g N o r w a y spruce. ESTIVALET D.,PERRIN R. a n d LE TACON F. ,(1986) . I n v e s t i g a t i o n s on t h e t e l l u r i e m i c r o b i o l o g i c a l f e a t u r e s of f o r e s t d i e b a c k in V os ge s .
Perrin, R. and Estivalet, D., 1989: Mycorrhizal association and forest decline (yellowing of spruce). Agric., Ecosystems Environ., 28: 381-387.
Agriculture, Ecosystems and Environment, 28 (1989) 381-387 Elsevier Science Publishers B.V., Amsterdem Printed in Czechoslovakia
MYCORRHIZAL FOREST (YELLOWING
.ASSOCIATION DECLINE OF SPRUCE)
AND
R o b e r t PERPAN a n d Dol~lnlque ESTIVALET S t a t i o n d e R e c h e r c h e e s u r l a Flol~ P a t h o g 6 n e d i m s le 8ol 17 r u e Sully, B.V.1540. 9.1084 DIJON c 6 d e x PRANCE SUMMARY
T h e m y c o r r h i z a l s t a t u s of Norway s p r u c e w a s i n v e s t i g a t e d from a n i n v e n t o r y d r a w n u p in v a r i o u s f o r e s t s t a n d s in v o s g e s a r e a (FRANCE). D e c l i n i n g t r e e s generally have fewer living short roots and mycorrhizae than healthy ones. A l a r g e n u m b e r of m y c o r r h i z a l t y p e s a n d a wide v a r i a b i l i t y b e t w e e n t r e e s c a n be o b s e r v e d w i t h o u t a n y r e l a t i o n s h i p w i t h t h e h e a l t h o f th, e t r e e s . T h e f o r e s t s o i l s in t h e w h o l e r e g i o n a n d more p a r t i c u l a r l y in d e c l i n i n g s t a n d s , s e e m to be u n a b l e to p r o d u c e n o r m a l m y c o r r h i z a l i n f e c t i o n o f s p r u c e . INTRODUCTION T h e e n t i r e i n v e s t i g a t i o n s i n c l u d e a n i n v e n t o r y d r a w n up in Norway s p r u c e s t a n d s in the V o s g e s a r e a a n d a n experimental a p p r o a c h in greenhouse. Inventory Trees of declining stands have generally fewer living mycorrhizae than h e a l t h y o n e s in a g r e e m e n t w i t h p r e v i o u s s t u d i e s (W,H. L i v i n g s t o n a n d H, B l a s c h k e , 1984). A g r e a t n u m b e r o f m o r p h o l o g i c a l t y p e s of m y c o r r h i z a e a n d a ' h i g h v a r i a b i l i t y a m o n g t r e e s were o b s e r v e d . Nevertheless a clear relationship between rootlets decline and severity of the f o r e s t d i e b a c k c a n n o t be e s t a b l i s h e d from i n v e n t o r y r e s u l t s (D. E s t i v a l e t a n d al., 1988). Experimental approach Principle: D i f f e r e n t t r e a t m e n t s were a p p l i e d to s a m p l e s of s o i l s c o l l e c t e d u n d e r d e c l i n i n g or h e a l t h y s t a n d s in o r d e r to i n f l u e n c e m i c r o b i o l o g i c a l b a l a n c e or n u t r i e n t s t a t u s . We t r i e d to p u t in r e l a t i o n g r o w t h a n d a s p e c t m o d i f l c a t o n s of p l a n t s a f t e r soil t r e a t m e n t s w i t h c h a n g e s of m y c o r r h i z a l s t a t u s . A m o n g t h e t r e a t m e n t s t h e f o l l o w i n g o n e s were p a r t i c u l a r l y i n t e r e s t i n g for o u r purpose: - u n t r e a t e d soil c o n t r o l , - p a s t e u r i z a t i o n (70 "~C d u r i n g 30 rain.), -pasteurization (70 °C d u r i n g 30 mln.) a n d a d d i t i o n }accats i n o c u l u m ( 1 / 1 0 , v / v ) g r o w n in a v e r m i c u l i t e - p e a t m i x t u r e
of L~ccarJa
382
-pasteurization and a d d i t i o n of soil (1/10 v / v ) from the declining s t a n d into t h e t h e soil from h e a l t h y s t a n d . Norway s p r u c e s e e d l i n g s and s a p l i n g s (2+1, 2+2) were h a r v e s t e d a f t e r six and e i g h t e e n m o n t h s g r o w t h on t h e s e t r e a t e d soils in a g r e e n h o u s e . P l a n t s were a s s e s s e d for : - s h o o t and r o o t dry w e i g h t -mycorrhizal frequency, - m i n e r a l . c o n t e n t s of t h e n e e d l e s .
RESULTS OF EXPERIMENTAL APPROACH S a p l i n g s in c o n t r o l p o t s filled with soil from declining s t a n d were s t u n t e d and chlorotlc . The p a s t e u r i z a t i o n p r o m o t e d t h e g r o w t h of p l a n t s in b o t h s o i l s and r e s t o r e d t h e n o r m a l a s p e c t of p l a n t s d e v e l o p e d in soil from declining s t a n d . The 70 ~C t r e a t m e n t s t i m u l a t e d t h e d e v e l o p m e n t of m y c o r r h i z a l a s s o c i a t i o n of only t h o s e p l a n t s g r o w i n g in h e a l t h y soil. N e v e r t h e l e s s , t h e d e v e l o p m e n t of t h e main morphological t y p e of m y c o r r h l z a e was e q u a l l y i m p r o v e d in s o i l s from h e a l t h y s t a n d as in s o i l s from d e c l i n i n g s t a n d (Figure 1). During t h e f i r s t s e a s o n of g r o w t h , t h e p a s t e u r i z a t i o n allows t h e r e s t o r a t i o n of a good m i n e r a l n u t r i t i o n w h e r e a s in t h e s e a s o n we n o t i c e a N deficiency (Figure 2). From t h e s e r e s u l t s , g r o w t h i m p r o v e m e n t , a s p e c t and n u t r i t i o n r e s t o r a t i o n could be a s s o c i a t e d w i t h q u a l i t a t i v e a m e l i o r a t i o n of m y c o r r h i z a l s t a t u s , w i t h o u t a n y r e l a t i o n s h i p w i t h soil origin. T h e r e was no a d d i t i o n a l g r o w t h and n u t r i t i o n a l e f f e c t of L ' a c c a r i a l a c c a t a i n o c u l a t i o n a f t e r p a s t e u r i z a t i o n as compared with p a s t e u r i z a t i o n a l o n e ( f i g u r e s 3 and 4). Inoculation with Laccarls Iaccata works significantly only upon mycorrhizae status of plants growing on a soil from declining stand especially by 'increasing the proportion of Laccaria Laccata mycorrhizae. The addition of soil from declining stand into the pasteurized soil from healthy stand had a depressive effect on the top blomass of seedlings and saplings, but less accentuated on the former .The level of mycorrhizal association was only significantly different on saplings. However a significant drop in the proportion of the main morphological type of mycorrhizae can be observed for both kind of plants, until a n entire disappearance on saplings (Figure 5). This experiment revealed that the depressive influence of soll from declining stand, seemed to be in relation to the diminution of the mycorrhizal frequency, particularly of the main morphological type. The foliar analysis of saplings did not reveal any important modification of the mineral nutrition except a N deficiency which was a general rule for the saplings after two seasons of growing in pots (Figure 6). In spite of more marked changes, the l~vel of mineral nutrition of seedlings was poorly affected by the addition of a soll from declining strand (Figure 7). The depressive effect of adding soll from declining stand can not be related to a m i n e r a l n u t r l t i o n deficiency.
383
j
TOP BIOMASS
L Mvco.s.,zAz,o. ]
H E$ A! TN HD Y
b
i £ CS LT In NN
COilTIROL
! D
H G
b
70
GO 50
t0
I 30
x
I?O'C 2e
10
s
x 0
cg clrN ueight
~
20
30
,to
50
60
?'0
z ~caz-~.J,l¢~! sJ~et ~ootlr
FIGURE I : Effect of ( dry weight cg/plant
sell pasteurization ( 70'c ) on the average top blomass ) a n d t h e l e v e l o f mycorrhiza! ~ s s o c l a t l o n ( p e r c e n t a g e of mycorrhlzal short roots ) of saplings after t w o years growth in Ireenhouse
,in soils collected under healthy or decllnin£ stands. The frequency of the main morphological type of mycorrhlzae, is noted. Means associated with the same letter are not siHrtificufLtly different according to N e w m a n and Keuls test (alpha = 0,05).
DECLINING STAND FOLIA~ ARALYSIS
70degree8
% m c.-it lcal
d 1,5 •
r
con,.,
Y W e*
i g
1.
0,5 •
h t N~
PZ
~z Minerals
~x
~IX
F I G U R E 2 : Mineral c o n t e n t s ( % d r y w e i g h t ) o1' tt~e n e e d l e s o f N o r w a y s p r u c e s a p l i n g s , t w o g r o w i n g s e a s o n s after t r a n s p i a n t h ~ g in a p a s t e u r i z e d soil from declining stand.
384
DECLINING STAND FOLIAR ANALYSIS Lsccsria lacca%a 70 degrees
H Crl|lc~| d r
t© v e l
1,5 y I
Y
I Castro|
|JB
|
0 r~.,.-,t
....
t
Minerals
3 : Effect of Lacca#'J. Aaccata Inocularlon In pasteurized soil (70"0 -P Lac ) on the average top biomass ( d r y w e i g h t cEJplant ) and the l e v e l ot m y c o r r h l z a l association ( pareentaze ot m y c o r r h i z a l shorL roots ) o f s & p l l n i i after two years Erowth In i[reenhouse . In soils coli~c/ed under healthy &rid decllning stands T h e frequency of the ma~n morpholozical Wpe of mycorrhizae FIGURE
is noted. M e a n s associated wlth the s a m e letter are not stgnlrtc~ntly to N e w m a n and Keuls ~est (alpha = 0,05}.
F 1 TOP B I O M A S S
tl Es FiT LR TN
. i MYCORRHIZATION
I
.l I'
T0"C,L~c.
h
xD Y
~0~3
__
l
~
C I.
H G
"J
different according
"'! C0rITllt~J.
J
I, 1 ~.-
D ?0
b ~0
SO
tS
x
?O°C"
LaC.
3e
ZS
cg drg ucLg|lt
tO
S
o
tQ
zo
30
,to 50
66
?0
z aUC~L-rhiz~l sl~ort roQts
4 : Mineral contents ( % dr:/ weight ) of th~ rLeedles of N o r w a y spruce saplings, two growing seasons after transplshth~_ IrL a pssteurlzed soll fr#m declining stand Inoculated with LaccsJ.Ja J~e~,,~a .
FIGURE
385
I
TOP B I O M A S S
_ RH,ZAT,O. I
1 70"C
7e'C, I),S
$ ? L I N
G $
70"C, 6e
50 ~0 30
20
10
o
ql dry mlllht
i
10
28
M
48
58
M
x ~fco~rhlut IlwrL N o t l
PIG~RE _6 : Effect of t h e addlUon a t soil from declining s t a n d ( 1056 ) In p a s t e u r i s e d soil from h e a l t h y s t a n d ( 70"C + DS ) on the avarnlta top bJom~8o { d r y weight el~plant ) I m d t h e l e v e l of myeorrhlza! sssoclatlom ( p e r c d m ~ o of mycorrhiza! s h o r t foetal ) a t saplluSs and s e e d i l n l s a f t e r two y e a r s J / ~ w t h In tp'eenhouse , The f r e q u e n c y a t t h e main morphological type ot mWeorrhlsae is noted. Means a s s o c i a t e d with the o~me l e t t e r a r e not slgnlfl~,~ntl¥ d i f f e r e n t aocording to Newman and Keuls t e s t ( a l p h a t 0.06) .
HEALTHY STAND POLIAR ANALYSIS
SA~PLIN6S
• Crl~i~.sl
% d r
1.5
~ ~'o'c
eJ~o'c •
y 1 W e
0 e,5 h t e n~.
Px
Ex Minerals
~
ajx
FIGURE 6 : Effect of addition a t sol/ tram docilnlnl s t a n d on t h e .m$~aral c o n t e n t s ( % dry welght ) of t h e noodles of Norway s p r u c e anpllx~8, two growing s e a s o n s a f t e r t r a n s p l a n U n | In a p a s t e u r i z e d sou tram healthy s t a n d (70"C + DS ) .
386
HEALTHY STAND FOLIAR ANALYSIS seedlings Z
% I-'I ?e'C d
1,s
[ ] ?6"C • 9S
r Y W
1
e
i g
e.5
h t
N×
F×
Kx
i,
I II Ca
~ , Mg X
Minerals
FIGURE 7 : Effect of addition Of soll or oecliiLir~tt stand or, mineral contents (% dry weight ) of the needles or two ye~i.s old saedilngs, £rowft In pasteurized soll from healthy stand (70"C e DS ),
a
387
CONCLUSION E x p e r i m e n t a l r e s u l t s p r e s e n t e d h e r e , s u b s t a n t i a t e t h e c o n c l u s i o n of t h e i n v e n t o r y : f o r e s t d i e b a c k In p a r t i c u l a r t h e y e l l o w i n g of s p r u c e c a n be a s s o c i a t e d w i t h a d e t e r i o r a t i o n of m y c o r r h i z a l a s s o c i a t i o n e s p e c i a l l y of t h e m a i n m o r p h o l o g i c a l t y p e of m y c o r r h i z a e . T h e s e c h a n g e s in m y c b r r h i z a l s t a t u s do n o t d i s t u r b m i n e r a l n u t r i t i o n . P r e v i o u s s t u d i e s r e v e a l e d t h e d e l e t e r i o u s e f f e c t of a n o n - s y m b i o t i c m i c r o f l o r a (D. ESTIVALET, R. PERRIN a n d F. LE TACON,1986 ) w h i c h s e e m s t o p r e v a i l o v e r t h e c o n s e q u e n c e s of t h e d e g e n e r a t i o n of m y c o r r h i z a l s t a t u s The deleterious microflora could interfere with mycorrhizae association development. D e l e t e r i o u s m i c r o o r g a n i s m s c a n be f o u n d i n a n y s o i l , b u t t h e e x p r e s s i o n of t h e i r d e p r e s s i v e e f f e c t , a s well a s t h e b e n e f i c i a l i n f l u e n c e of m y c o r r h i z a l a s s o c i a t i o n d e p e n d on . t h e m i c r o b i o l o g i c a l b a l a n c e . T h i s e q u i l i b r i u m c a n be m o d i f i e d u n d e r t h e I n f l u e n c e of n u m e r o u s f a c t o r s s u c h a s c l i m a t e , p o l l u t i o n , a c i d i f i c a t i o n of s o i l . . . . . I n c r e a s i n g i n f l u e n c e of d e l e t e r i o u s m i c r o f l o r a a s s o c i a t e d w i t h r e c e s s i o n of m y c o r r h i z a l a s s o c i a t i o n c o u l d be a k e y p r o c e s s in t h e f r a m e work of s p r u c e yellowing.
REFERENCES LIVINGSTON W. H. a n d BLASCHKE H., (1 984) . D e t e r i o r a t i o n of m y c o r r h i z a l s h o r t r o o t s a n d o c c u r r e n c e of Mycellum radlcl$ a t r o v i r e n s on d e c l i n i n g N o r w a y spruce. ESTIVALET D.,PERRIN R. a n d LE TACON F. ,(1986) . I n v e s t i g a t i o n s on t h e t e l l u r i e m i c r o b i o l o g i c a l f e a t u r e s of f o r e s t d i e b a c k in V os ge s .
Perrin, R. and Estivalet, D., 1989: Mycorrhizal association and forest decline (yellowing of spruce). Agric., Ecosystems Environ., 28: 381-387.