- Email: [email protected]
Vitality and ageing of the ectomycorrhizae of damaged and undamaged trees
415
Agriculture, Ecosystems and Environment, 28 E l s e v i e r S c i e n c e P u b l i s h e r s B.V., A m s t e r d a m P r i n t e d in C z e c h o s l o v a k i a
(1989)
415-419
VITALITY AND AGEING OF THE ECTOMYCOllRtlIZAE OF DAMAGED AND UNDAMAGED TREES
Unlverslt~t Tilblngen. l n s t l t u t f~Ir
Thomas Rltter, Ingrld Kottke, Franz Oberwlnkler, Blologle I, Spezlelle Botanik, Auf der Morgenstelle
I, D-7400 Tilbingen
1. INTRODUCTION In r e s e a r c h on f o r e s t decline, a t t e n t i o n h a s been d r a w n to t h e fine root s y s t e m of t r e e s . In t h i s r e l a t i o n ecto w c o r r h l z a e are of s p e c i a l i n t e r e s t as t h e y make up t h e l a r g e s t p a r t of v e r y
rhizal dynamics mycorrhlzae.
fine, a b s o r p t i v e r o o t s . A problem of i n v e s t i g a t i o n s of m y c o r -
and activity is to distinguish
clearly between
living and
dead
However, the possibility of determining exactly the physiological sta-
tus of mycorrhlzae Is a prerequisite for reliable results on mycorrhlzal dynamics of a forest stand (FOGEL, 1983). 2. MATERIALS AND METHODS
The i n v e s t i g a t i o n s
MIll.)
and
were c a r r i e d
Norway s p r u c e
out
on e c t o m y c o r r h i z a e
(Picea abies
(L.) Karat.)
fir ( A b i e s
of Silver
from
natural
N o r t h e r n Black F o r e s t (West Germany). Root sample.s were t a k e n
stands
in
alba the
from s e v e n t r e e s
of two testing grounds: ANALYSED TREES 1 S i l v e r fir 20% 1 S l i v e r fir 65% 1 Norway s v r u c e 30% I S i l v e r fir 50% Ziefle, plot a. n o t limed severe 1 Norway s p r u c e " 75% 1 S i l v e r fir 20~, Ziefle, plot b. limed little l Norway ~Pr~ce 15% NL=needle loss, Y=yellowing; * = e x t r e m e l y damaged, cut in a u t u m n 1987,
TESTING G R O U N D Pfalzgrafenweller
TREATMENT not limed
CANOPY DAMAQ~ llttle-severe
+ ++ + ++ -
-
V i t a l i t y o f e c t o m y c o r r h t z a e was a s c e r t a i n e d u n d e r t h e f l u o r e s c e n c e microscope a f t e r vital staining light g r e e n
with
1966..ZIEGLER et physiological
FDA ( F l u o r e s c e l n - D I - A c e t a t e ) .
f l u o r e s c e n t r e s p o n s e to F D A - v i t a l al.,
status
Since
cells
give
a
1975) t h i s t e c h n i q u e d e l i v e r s d e t a i l e d I n f o r m a t i o n a b o u t the of
ectomycorrhlzae
(RITTER
et
al.,
s t a i n i n g with FDA, five s t a g e s of e c t o m y c o r r h l z a l v i t a l i t y Furthermore the
only l i v i n g
s t a i n i n g (ROTMAN & PAPERMASTER, 1986).
Based
v i t a l i t y of t h e m y c o r r h l z a l s y s t e m s of damaged and
was compared In a q u a n t i t a t i v e
way (RITTER, 1989).
on
vital
could be d i f f e r e n t i a t e d . healthy trees
416
3. RESULTS 3.a: S t u e s
of ectomycorrhizal vitality
Sta~e 1: e n t i r e l y
mycorrhiza, the hyphal vascular
cylinder
sheath
(VC) a n d
m u s t be a s s u m e d t h a t t a k e of s u b s t a n c e s ,
" E n t i r e l y a c t i v e " m e a n s t h a t all r e g i o n s of a
(H$), t h e c o r t e x
the
i n c l u d i n g t h e H a r t i g n e t (HN). t h e
meristematic
region
(M)
are active
(Fig.
la).
It
in t h e s e m y c o r r h l z a e all i m p o r t a n t f u n c t i o n s a r e i n t a c t ( u p -
s t o r a g e of r e s e r v e s
merlstematlc growth). s t a g e is t y p i c a l
(Fie. | ~ - l e )
active mvcorrhizae.
in t h e v a s c u l a r c y l i n d e r a n d t h e a b i l i t y of
T h i s is i n d i c a t e d
by t h e s y m b o l " + + ÷ " .
The entirely
active
for m o s t g r o w i n g a n d y o u n g m a t u r e m y c o r r h i z a e . By t h e lack of a
m e t a c u t i z a t i o n l a y e r , g r o w i n g m y c o r r h i z a e c a n be d i s t i n g u i s h e d from d o r m a n t r o o t s . S t a 2 e ~: l a r g e l y
active
and the Hartig net
m y c o r r h i z a e . In a f i r s t p h a s e of a g e i n g ,
loose vitality.
c o r t e x . T h e d e c e a s e of t h e h y p h a l lb). T h e a c t i v i t y
c e a s e of t h e h y p h a l
starts
the cortical
is p r e s e r v e d a r o u n d t h e a p i c a l m e r l s t e m . It
on t h e s p e c i e s of t h e m y c o r r h i z a l f u n g u s w h e t h e r sheath
or m y c o r r h i z a e w i t h
precedes a very
deceases earlier than the sheath result, young mature and even r a t h e r c o r r e s p o n d to s t a g e
or follows
that
of t h e
thin prosenchymatic
cortex.
mantle
growing mycorrhlzae to s t a g e
(CHILVERS,
of t h e
intracellularly dead cortical
cortex,
by f u n g i
in t h e lc).
In a n
vascular
a s well a s t h e (Fig.
with a prosenchymatic mantle
advanced
cylinder hyphal
Mostly the
uptake
h a s to be e x p e c t e d ,
and
sheath
1.
p h a s e of a g e i n g l i v i n g the meristematic region. are
mycorrhizal
c e l l s . T h e s y m b o l "+" i n d i c a t e s t h a t ,
t i o n of n u t r i e n t
1968)
1. P r o b a b l y , t h e f u n c t i o n of m y c o r r h i -
z a e in s t a g e 2 ( " + + " ) is I n s i g n i f i c a n t l y r e d u c e d c o m p a r e d to s t a g e S t a g e 3: m ~ c o r r ~ i z a e o~ r e d u c e 4 a c t i v i t y . Dead c e l l s
the de-
The hyphal
o f m y c o r r h i z a e w i t h a s y n e n c h y m a t l c m a n t l e . As a
2 than
c e l l s c a n o n l y be d e t e c t e d
cells
in t h e o u t e r l a y e r s of t h e
s h e a t h , b e g i n s more or ~less s i m u l t a n e o u s l y (Fig.
of t h e h y p h a l s h e a t h
s e e m s to be d e p e n d a n t sheath
This process
frequently
fungus
first
colonized colonizes
in t h i s s t a g e a d i s t i n c t r e d u c -
w h e r e a s t h e c a p a c i t y of s t o r a g e
and
g r o w t h is p r e s e r v e d . Sta~e 4:dyin2 that
mycorrh~zae. The vascular
looses vitality.
c y l i n d e r is t h e l a s t p a r t
T h e d e c e a s e of t h e v a s c u l a r
cylinder starts
of a m y c o r r h i z a at
the apex and
t h e n m o v e s b a c k to t h e b a s i s of t h e r o o t l e t . L i v i n g a n d d e a d p a r t s of t h e v a s c u l a r cylinder are layer
is
often separated
not obligatory.
by a l a y e r
Dying
roots
of l i g n i f i e d a n d s u b e r i z e d c e l l s , b u t t h i s
("+/-")
are
not
able
to
grow
but
a large
a m o u n t of s t a r c h Is o f t e n s t o r e d in t h e l i v i n g p a r t of t h e v a s c u l a r c y l i n d e r . S t a 2 e 5: d e a d m y c o r r h i z a e . All r o o t c e l l s a r e i n t r a c e l l u l a r l y c o l o n i z e d by f u n g i .
417
FIG. 1 Stages of ectomycorrhizal vitality, determined by FDA vital s t a i n i n g of hand cut medial l o n g i t u d i n a l sections. a
b
c
t
I
, l.l:<+m
d
, i
{ t{
llI
I .I i I
ill I
Ill
fill
I II
Iii I
I I I|
I I
~ { I II+IiI+ 5 q lli Iii Ill I I 5
i I II
ii
-I-+
+
2a
% 30
~'~
=
I i $}*IIi i I I
I
, +:++:
+++
[~=
e
,
{ I I
l
I I
I I :iii
+I
, I ,', I
.
.
I
I
I k,',,,',',,,,'~ +
.
.
.
[]
:
living hyphal sheath living Hartig net living v a s c u l a r and meristematic tissue deceased p a r t s with secondary intracellular infections metacutlzatlon layer
FIG. 2 Frequency of the five stages of ectomycorrhizal v i t a l i t y as p e r centage of the total number of analyzed mycorrhlzae/tree. The p e r c e n t a g e values In each t r e a t m e n t add to 100~. x - a x i s = v i t a l i t y corresponding to FIG. 1 Ordinate Values = means and s t a n d a r d deviation of 6 samples (resp. 7 samples of Silver fir. Pfalzgrafenweiler) between May 1986 and July 1987
2C 1G
*÷÷
*+
÷
* -
--
2a: Testing ground Ziefie, Norway spruce 2b: Testing ground ZiefTe, Sliver fir 2c: Testing ground P f a l z g r a f e n weiler, left & mid=silver fir, right=Norway spruce Shading Indicates h e a l t h y t r e e s Unshaded indicates damaged t r e e s
10
@
2c ~0 20
+
~
÷
-
-
418 8.b: V i t a l i t y o f t h e m y c o r r h l z a l s y s t e m s o f h e a l t h y a n d d a m a e e d t r e e s . Although considerable
differences
in
the
degree
of n e e d l e
l o s s were
o b v i o u s , all
t h r e e t r e e s ( d a m a g e d a n d u n d a m a g e d S i l v e r f i r s , d a m a g e d Norway s p r u c e ) from t h e unlimed testing
ground "Pfalzgrafenweiler"
of m y c o r r h l z a e
of d i f f e r e n t
"Ziefie" c l e a r
of
showed an almost identical distribution
vitality
d i f f e r e n c e s in m y c o r r h l z a l v i t a l i t y
from t h e , u n l l m e d
(in g e n e r a l
lowing) a n d t h e limed plot, t h e p e r c e n t a g e percentage
stages trees
with
plot (in g e n e r a l
(Fig.
2c).
On t h e
testing
c o u l d be o b s e r v e d
a high degree
healthy trees)
of n e e d l e
(Fig. 2a,b).
of e c t o m y c o r r h i z a e w i t h full v i t a l i t y ( s t a g e
ground
between trees loss
and yel-
On t h e u n l i m e d
1) a s well a s t h e
o f d y i n g a n d d e a d m y c o r r h i z a e ( s t a g e s 4 & 5) w a s h i g h e r c o m p a r e d to
t h e limed plot. H o w e v e r m y c o r r h i z a e of m e d i u m v i t a l i t y ( s t a g e 2 & e s p e c i a l l y s t a g e 3) c o u l d be d e t e c t e d
more o f t e n on t h e limed plot.
u n l l m e d S i l v e r fir from t h e s t a n d t h e t r e e s from t h e u n l l m e d s t a n d
"Ziefle" ( F i g .
Ectomycorrhizal vitality of the
2b) w a s q u i t e
s i m i l a r to t h a t
of
" P f a l z g r a f e n w e i l e r " . T h e h i g h e s t a m o u n t s of d y i n g
a n d d e a d v e r y f i n e r o o t s were f o u n d a t t h e u n l i m e d Norway s p r u c e from t h e s t a n d "Zlefie" (Fig. 2a). 4. DISCUSSION
T h e f i v e s t a g e s of m y c o r r h i z a l v i t a l i t y p r o c e s s o f a g e i n g of e c t o m y c o r r h i z a e :
(Fig.
1) c a n be r e g a r d e d
younger mycorrhlzae that
a s p h a s e s in t h e are largely active
( s t a g e s 1 & 2), a g e i n g ( s t a g e 3), d y i n g a n d d e a d m y e o r r h i z a e ( s t a g e s 4 & 5). T h e process derivable
from t h e s e
stages
is
p r o c e s s a s d e s c r i b e d by o t h e r a u t h o r s
in
accordance
to t h e
mycorrhizal
ageing
(KOTTKE & OBERWINKLER, 1986; HAUG, 1987;
NYLUND. 1987). V i t a l i t y of e c t o m y c o r r h l z a e c a n r a t h e r than
to t h e
younger
(la,
regeneration
degree lb)
of n e e d l e
mycorrhlzae
be c o r r e l a t e d
loss and
to t h e c o n d i t i o n s of t h e soil
yellowing
of t r e e s .
of m o s t d a m a g e d t r e e s
(Fig.
The
of v e r y f i n e r o o t s I s ' n o t a f f e c t e d a s long a s ' t h e
n o t too s e v e r e .
Diminished
regeneration
the extremely damaged Norway spruce
of m y c o r r h l z a e
high
2b, 2c)
a m o u n t of
indicate
that
c a n o p y d a m a g e is
c o u l d o n l y be
stated
for
(Zlefie, u n l i m e d ) w h i c h s h o w e d a d e g r e e of
7 5 ~ n e e d l e l o s s . In t h i s c a s e a slow d e g e n e r a t i o n of t h e w h o l e r o o t s y s t e m h a s to be e x p e c t e d .
T h e g e n e r a l low p e r c e n t a g e
"+") on t h e u n l i m e d p l o t s
indicate
that
of m y c o r r h i z a e
of m e d i u m v i t a l i t y
d e c e a s e of m y c o r r h l z a e on t h e s e
going fast when the fungal partner has lost vitality.
This must-result
("++", p l o t s is
in a h i g h e r
t u r n o v e r r a t e of v e r y f i n e r o o t s on t h e u n l l m e d p l o t s , a s c a n a l s o be s e e n in t h e higher percentage
of d y i n g
the
the
vascular
relative
and
long time a f t e r
Hartig net
("+") h a d
It s e e m s t h a t
the hyphal
tissue sheath
of m y c o r r h t z a e ("++")
on t h e limed p l o t s
retained
or t h e h y p h a l
died. T h i s i n d i c a t e s a lower t u r n o v e r
rate
vitality sheath
for
a
and the
on t h e limed plot.
on t h e limed s t a n d s f i n e r o o t s y s t e m s a r e a b l e to t a k e up a s u f f i -
c i e n t a m o u n t of n u t r i e n t s rhizae.
a n d d e a d m y c o r r h t z a e . In c o n t r a s t ,
meristematic
w i t h a r e l a t i v e low p e r c e n t a g e of e n t i r e l y a c t i v e m y c o r -
419
C h l l v e r s , G. A. (1968) Some d i s t i n c t i v e t y p e s of e u c a l y p t m y c o r r h i z a s . A u s t . J. Bot. 16, 4 9 - 7 0 , Fogel, R. (1983) Root t u r n o v e r a n d p r o d u c t i v i t y of c o n i f e r o u s f o r e s t s , P l a n t & Soil 7 l, 7 5 - 8 6 . Haug, 1. (1987) L i c h t - u n d e l e k t r o n e n m i k r o s k o p i s c h e U n t e r s u c h u n g e n a n F i c h t e n m y k o r r h t z e n a u s dem S c h w a r z w a l d . - Diss. T i l b i n g e n , K o t t k e , I., O b e r w i n k l e r , F. (1986) M y c o r r h l z a o f f o r e s t t r e e s - s t r u c t u r e a n d f u n c t i o n . T r e e s 1, 1 - 2 4 , N y l u n d , J. E. (1987) T h e e c t o m y c o r r h l z a l i n f e c t i o n zone a n d i t s r e l a t i o n to acid p o l y s a c c h a r i d e s of c o r t i c a l cell walls. New P h y t o l . 108, 5 0 5 - 5 1 6 , R l t t e r , T., K o t t k e , I. & O b e r w l n k l e r , F. (1986) N a c h w e l s d e r Vltailt•t y o n M y k o r r h l z e n d u r c h F D A - V l t a l f l u o c h r o m i e r u n g . Blologle in u n s e r e r Zelt 16, 1 7 9 - 1 8 5 [titter, T. (1989) D i s s e r t a t i o n , T f l b l n g e n . In p r e p a r a t i o n , R o t m a n , B. & P a p e r m a s t e r , B. W. (1966) M e m b r a n e p r o p e r t i e s of l i v i n g m a m m a l i a n c e i l s a s s t u d i e d by e n z y m a t i c h y d r o l y s i s o f f l u o r o g e n i c e s t e r s . Proc. Nat. A c i d . Scl. U.S.A. 55, 1 3 4 - 1 4 1 o Zlegler, G. B., Ziegler, E. & W l t z e n h a u s e n , R. (1975) N a c h w e l s d e r S t o f f w e c h s e l a k t l vitltt yon Mlkroorganlsmen durch Vltal-Fluoro-chromierung mit Y,6'D i a c e t y l f l u o r e s c e l n . Zbl~ Bakt. Hyg., I. Abt. Orig. A 230, 2 5 2 - 2 6 4 ,
Ritter, T., Kottke, I. and oberwinkler, F., 1989: Vitality and ageing of the ectmsycorrhizae of damaged and undamaged trees. Agric., Ecosystems Environ., 28: 415-419.
Agriculture, Ecosystems and Environment, 28 E l s e v i e r S c i e n c e P u b l i s h e r s B.V., A m s t e r d a m P r i n t e d in C z e c h o s l o v a k i a
(1989)
415-419
VITALITY AND AGEING OF THE ECTOMYCOllRtlIZAE OF DAMAGED AND UNDAMAGED TREES
Unlverslt~t Tilblngen. l n s t l t u t f~Ir
Thomas Rltter, Ingrld Kottke, Franz Oberwlnkler, Blologle I, Spezlelle Botanik, Auf der Morgenstelle
I, D-7400 Tilbingen
1. INTRODUCTION In r e s e a r c h on f o r e s t decline, a t t e n t i o n h a s been d r a w n to t h e fine root s y s t e m of t r e e s . In t h i s r e l a t i o n ecto w c o r r h l z a e are of s p e c i a l i n t e r e s t as t h e y make up t h e l a r g e s t p a r t of v e r y
rhizal dynamics mycorrhlzae.
fine, a b s o r p t i v e r o o t s . A problem of i n v e s t i g a t i o n s of m y c o r -
and activity is to distinguish
clearly between
living and
dead
However, the possibility of determining exactly the physiological sta-
tus of mycorrhlzae Is a prerequisite for reliable results on mycorrhlzal dynamics of a forest stand (FOGEL, 1983). 2. MATERIALS AND METHODS
The i n v e s t i g a t i o n s
MIll.)
and
were c a r r i e d
Norway s p r u c e
out
on e c t o m y c o r r h i z a e
(Picea abies
(L.) Karat.)
fir ( A b i e s
of Silver
from
natural
N o r t h e r n Black F o r e s t (West Germany). Root sample.s were t a k e n
stands
in
alba the
from s e v e n t r e e s
of two testing grounds: ANALYSED TREES 1 S i l v e r fir 20% 1 S l i v e r fir 65% 1 Norway s v r u c e 30% I S i l v e r fir 50% Ziefle, plot a. n o t limed severe 1 Norway s p r u c e " 75% 1 S i l v e r fir 20~, Ziefle, plot b. limed little l Norway ~Pr~ce 15% NL=needle loss, Y=yellowing; * = e x t r e m e l y damaged, cut in a u t u m n 1987,
TESTING G R O U N D Pfalzgrafenweller
TREATMENT not limed
CANOPY DAMAQ~ llttle-severe
+ ++ + ++ -
-
V i t a l i t y o f e c t o m y c o r r h t z a e was a s c e r t a i n e d u n d e r t h e f l u o r e s c e n c e microscope a f t e r vital staining light g r e e n
with
1966..ZIEGLER et physiological
FDA ( F l u o r e s c e l n - D I - A c e t a t e ) .
f l u o r e s c e n t r e s p o n s e to F D A - v i t a l al.,
status
Since
cells
give
a
1975) t h i s t e c h n i q u e d e l i v e r s d e t a i l e d I n f o r m a t i o n a b o u t the of
ectomycorrhlzae
(RITTER
et
al.,
s t a i n i n g with FDA, five s t a g e s of e c t o m y c o r r h l z a l v i t a l i t y Furthermore the
only l i v i n g
s t a i n i n g (ROTMAN & PAPERMASTER, 1986).
Based
v i t a l i t y of t h e m y c o r r h l z a l s y s t e m s of damaged and
was compared In a q u a n t i t a t i v e
way (RITTER, 1989).
on
vital
could be d i f f e r e n t i a t e d . healthy trees
416
3. RESULTS 3.a: S t u e s
of ectomycorrhizal vitality
Sta~e 1: e n t i r e l y
mycorrhiza, the hyphal vascular
cylinder
sheath
(VC) a n d
m u s t be a s s u m e d t h a t t a k e of s u b s t a n c e s ,
" E n t i r e l y a c t i v e " m e a n s t h a t all r e g i o n s of a
(H$), t h e c o r t e x
the
i n c l u d i n g t h e H a r t i g n e t (HN). t h e
meristematic
region
(M)
are active
(Fig.
la).
It
in t h e s e m y c o r r h l z a e all i m p o r t a n t f u n c t i o n s a r e i n t a c t ( u p -
s t o r a g e of r e s e r v e s
merlstematlc growth). s t a g e is t y p i c a l
(Fie. | ~ - l e )
active mvcorrhizae.
in t h e v a s c u l a r c y l i n d e r a n d t h e a b i l i t y of
T h i s is i n d i c a t e d
by t h e s y m b o l " + + ÷ " .
The entirely
active
for m o s t g r o w i n g a n d y o u n g m a t u r e m y c o r r h i z a e . By t h e lack of a
m e t a c u t i z a t i o n l a y e r , g r o w i n g m y c o r r h i z a e c a n be d i s t i n g u i s h e d from d o r m a n t r o o t s . S t a 2 e ~: l a r g e l y
active
and the Hartig net
m y c o r r h i z a e . In a f i r s t p h a s e of a g e i n g ,
loose vitality.
c o r t e x . T h e d e c e a s e of t h e h y p h a l lb). T h e a c t i v i t y
c e a s e of t h e h y p h a l
starts
the cortical
is p r e s e r v e d a r o u n d t h e a p i c a l m e r l s t e m . It
on t h e s p e c i e s of t h e m y c o r r h i z a l f u n g u s w h e t h e r sheath
or m y c o r r h i z a e w i t h
precedes a very
deceases earlier than the sheath result, young mature and even r a t h e r c o r r e s p o n d to s t a g e
or follows
that
of t h e
thin prosenchymatic
cortex.
mantle
growing mycorrhlzae to s t a g e
(CHILVERS,
of t h e
intracellularly dead cortical
cortex,
by f u n g i
in t h e lc).
In a n
vascular
a s well a s t h e (Fig.
with a prosenchymatic mantle
advanced
cylinder hyphal
Mostly the
uptake
h a s to be e x p e c t e d ,
and
sheath
1.
p h a s e of a g e i n g l i v i n g the meristematic region. are
mycorrhizal
c e l l s . T h e s y m b o l "+" i n d i c a t e s t h a t ,
t i o n of n u t r i e n t
1968)
1. P r o b a b l y , t h e f u n c t i o n of m y c o r r h i -
z a e in s t a g e 2 ( " + + " ) is I n s i g n i f i c a n t l y r e d u c e d c o m p a r e d to s t a g e S t a g e 3: m ~ c o r r ~ i z a e o~ r e d u c e 4 a c t i v i t y . Dead c e l l s
the de-
The hyphal
o f m y c o r r h i z a e w i t h a s y n e n c h y m a t l c m a n t l e . As a
2 than
c e l l s c a n o n l y be d e t e c t e d
cells
in t h e o u t e r l a y e r s of t h e
s h e a t h , b e g i n s more or ~less s i m u l t a n e o u s l y (Fig.
of t h e h y p h a l s h e a t h
s e e m s to be d e p e n d a n t sheath
This process
frequently
fungus
first
colonized colonizes
in t h i s s t a g e a d i s t i n c t r e d u c -
w h e r e a s t h e c a p a c i t y of s t o r a g e
and
g r o w t h is p r e s e r v e d . Sta~e 4:dyin2 that
mycorrh~zae. The vascular
looses vitality.
c y l i n d e r is t h e l a s t p a r t
T h e d e c e a s e of t h e v a s c u l a r
cylinder starts
of a m y c o r r h i z a at
the apex and
t h e n m o v e s b a c k to t h e b a s i s of t h e r o o t l e t . L i v i n g a n d d e a d p a r t s of t h e v a s c u l a r cylinder are layer
is
often separated
not obligatory.
by a l a y e r
Dying
roots
of l i g n i f i e d a n d s u b e r i z e d c e l l s , b u t t h i s
("+/-")
are
not
able
to
grow
but
a large
a m o u n t of s t a r c h Is o f t e n s t o r e d in t h e l i v i n g p a r t of t h e v a s c u l a r c y l i n d e r . S t a 2 e 5: d e a d m y c o r r h i z a e . All r o o t c e l l s a r e i n t r a c e l l u l a r l y c o l o n i z e d by f u n g i .
417
FIG. 1 Stages of ectomycorrhizal vitality, determined by FDA vital s t a i n i n g of hand cut medial l o n g i t u d i n a l sections. a
b
c
t
I
, l.l:<+m
d
, i
{ t{
llI
I .I i I
ill I
Ill
fill
I II
Iii I
I I I|
I I
~ { I II+IiI+ 5 q lli Iii Ill I I 5
i I II
ii
-I-+
+
2a
% 30
~'~
=
I i $}*IIi i I I
I
, +:++:
+++
[~=
e
,
{ I I
l
I I
I I :iii
+I
, I ,', I
.
.
I
I
I k,',,,',',,,,'~ +
.
.
.
[]
:
living hyphal sheath living Hartig net living v a s c u l a r and meristematic tissue deceased p a r t s with secondary intracellular infections metacutlzatlon layer
FIG. 2 Frequency of the five stages of ectomycorrhizal v i t a l i t y as p e r centage of the total number of analyzed mycorrhlzae/tree. The p e r c e n t a g e values In each t r e a t m e n t add to 100~. x - a x i s = v i t a l i t y corresponding to FIG. 1 Ordinate Values = means and s t a n d a r d deviation of 6 samples (resp. 7 samples of Silver fir. Pfalzgrafenweiler) between May 1986 and July 1987
2C 1G
*÷÷
*+
÷
* -
--
2a: Testing ground Ziefie, Norway spruce 2b: Testing ground ZiefTe, Sliver fir 2c: Testing ground P f a l z g r a f e n weiler, left & mid=silver fir, right=Norway spruce Shading Indicates h e a l t h y t r e e s Unshaded indicates damaged t r e e s
10
@
2c ~0 20
+
~
÷
-
-
418 8.b: V i t a l i t y o f t h e m y c o r r h l z a l s y s t e m s o f h e a l t h y a n d d a m a e e d t r e e s . Although considerable
differences
in
the
degree
of n e e d l e
l o s s were
o b v i o u s , all
t h r e e t r e e s ( d a m a g e d a n d u n d a m a g e d S i l v e r f i r s , d a m a g e d Norway s p r u c e ) from t h e unlimed testing
ground "Pfalzgrafenweiler"
of m y c o r r h l z a e
of d i f f e r e n t
"Ziefie" c l e a r
of
showed an almost identical distribution
vitality
d i f f e r e n c e s in m y c o r r h l z a l v i t a l i t y
from t h e , u n l l m e d
(in g e n e r a l
lowing) a n d t h e limed plot, t h e p e r c e n t a g e percentage
stages trees
with
plot (in g e n e r a l
(Fig.
2c).
On t h e
testing
c o u l d be o b s e r v e d
a high degree
healthy trees)
of n e e d l e
(Fig. 2a,b).
of e c t o m y c o r r h i z a e w i t h full v i t a l i t y ( s t a g e
ground
between trees loss
and yel-
On t h e u n l i m e d
1) a s well a s t h e
o f d y i n g a n d d e a d m y c o r r h i z a e ( s t a g e s 4 & 5) w a s h i g h e r c o m p a r e d to
t h e limed plot. H o w e v e r m y c o r r h i z a e of m e d i u m v i t a l i t y ( s t a g e 2 & e s p e c i a l l y s t a g e 3) c o u l d be d e t e c t e d
more o f t e n on t h e limed plot.
u n l l m e d S i l v e r fir from t h e s t a n d t h e t r e e s from t h e u n l l m e d s t a n d
"Ziefle" ( F i g .
Ectomycorrhizal vitality of the
2b) w a s q u i t e
s i m i l a r to t h a t
of
" P f a l z g r a f e n w e i l e r " . T h e h i g h e s t a m o u n t s of d y i n g
a n d d e a d v e r y f i n e r o o t s were f o u n d a t t h e u n l i m e d Norway s p r u c e from t h e s t a n d "Zlefie" (Fig. 2a). 4. DISCUSSION
T h e f i v e s t a g e s of m y c o r r h i z a l v i t a l i t y p r o c e s s o f a g e i n g of e c t o m y c o r r h i z a e :
(Fig.
1) c a n be r e g a r d e d
younger mycorrhlzae that
a s p h a s e s in t h e are largely active
( s t a g e s 1 & 2), a g e i n g ( s t a g e 3), d y i n g a n d d e a d m y e o r r h i z a e ( s t a g e s 4 & 5). T h e process derivable
from t h e s e
stages
is
p r o c e s s a s d e s c r i b e d by o t h e r a u t h o r s
in
accordance
to t h e
mycorrhizal
ageing
(KOTTKE & OBERWINKLER, 1986; HAUG, 1987;
NYLUND. 1987). V i t a l i t y of e c t o m y c o r r h l z a e c a n r a t h e r than
to t h e
younger
(la,
regeneration
degree lb)
of n e e d l e
mycorrhlzae
be c o r r e l a t e d
loss and
to t h e c o n d i t i o n s of t h e soil
yellowing
of t r e e s .
of m o s t d a m a g e d t r e e s
(Fig.
The
of v e r y f i n e r o o t s I s ' n o t a f f e c t e d a s long a s ' t h e
n o t too s e v e r e .
Diminished
regeneration
the extremely damaged Norway spruce
of m y c o r r h l z a e
high
2b, 2c)
a m o u n t of
indicate
that
c a n o p y d a m a g e is
c o u l d o n l y be
stated
for
(Zlefie, u n l i m e d ) w h i c h s h o w e d a d e g r e e of
7 5 ~ n e e d l e l o s s . In t h i s c a s e a slow d e g e n e r a t i o n of t h e w h o l e r o o t s y s t e m h a s to be e x p e c t e d .
T h e g e n e r a l low p e r c e n t a g e
"+") on t h e u n l i m e d p l o t s
indicate
that
of m y c o r r h i z a e
of m e d i u m v i t a l i t y
d e c e a s e of m y c o r r h l z a e on t h e s e
going fast when the fungal partner has lost vitality.
This must-result
("++", p l o t s is
in a h i g h e r
t u r n o v e r r a t e of v e r y f i n e r o o t s on t h e u n l l m e d p l o t s , a s c a n a l s o be s e e n in t h e higher percentage
of d y i n g
the
the
vascular
relative
and
long time a f t e r
Hartig net
("+") h a d
It s e e m s t h a t
the hyphal
tissue sheath
of m y c o r r h t z a e ("++")
on t h e limed p l o t s
retained
or t h e h y p h a l
died. T h i s i n d i c a t e s a lower t u r n o v e r
rate
vitality sheath
for
a
and the
on t h e limed plot.
on t h e limed s t a n d s f i n e r o o t s y s t e m s a r e a b l e to t a k e up a s u f f i -
c i e n t a m o u n t of n u t r i e n t s rhizae.
a n d d e a d m y c o r r h t z a e . In c o n t r a s t ,
meristematic
w i t h a r e l a t i v e low p e r c e n t a g e of e n t i r e l y a c t i v e m y c o r -
419
C h l l v e r s , G. A. (1968) Some d i s t i n c t i v e t y p e s of e u c a l y p t m y c o r r h i z a s . A u s t . J. Bot. 16, 4 9 - 7 0 , Fogel, R. (1983) Root t u r n o v e r a n d p r o d u c t i v i t y of c o n i f e r o u s f o r e s t s , P l a n t & Soil 7 l, 7 5 - 8 6 . Haug, 1. (1987) L i c h t - u n d e l e k t r o n e n m i k r o s k o p i s c h e U n t e r s u c h u n g e n a n F i c h t e n m y k o r r h t z e n a u s dem S c h w a r z w a l d . - Diss. T i l b i n g e n , K o t t k e , I., O b e r w i n k l e r , F. (1986) M y c o r r h l z a o f f o r e s t t r e e s - s t r u c t u r e a n d f u n c t i o n . T r e e s 1, 1 - 2 4 , N y l u n d , J. E. (1987) T h e e c t o m y c o r r h l z a l i n f e c t i o n zone a n d i t s r e l a t i o n to acid p o l y s a c c h a r i d e s of c o r t i c a l cell walls. New P h y t o l . 108, 5 0 5 - 5 1 6 , R l t t e r , T., K o t t k e , I. & O b e r w l n k l e r , F. (1986) N a c h w e l s d e r Vltailt•t y o n M y k o r r h l z e n d u r c h F D A - V l t a l f l u o c h r o m i e r u n g . Blologle in u n s e r e r Zelt 16, 1 7 9 - 1 8 5 [titter, T. (1989) D i s s e r t a t i o n , T f l b l n g e n . In p r e p a r a t i o n , R o t m a n , B. & P a p e r m a s t e r , B. W. (1966) M e m b r a n e p r o p e r t i e s of l i v i n g m a m m a l i a n c e i l s a s s t u d i e d by e n z y m a t i c h y d r o l y s i s o f f l u o r o g e n i c e s t e r s . Proc. Nat. A c i d . Scl. U.S.A. 55, 1 3 4 - 1 4 1 o Zlegler, G. B., Ziegler, E. & W l t z e n h a u s e n , R. (1975) N a c h w e l s d e r S t o f f w e c h s e l a k t l vitltt yon Mlkroorganlsmen durch Vltal-Fluoro-chromierung mit Y,6'D i a c e t y l f l u o r e s c e l n . Zbl~ Bakt. Hyg., I. Abt. Orig. A 230, 2 5 2 - 2 6 4 ,
Ritter, T., Kottke, I. and oberwinkler, F., 1989: Vitality and ageing of the ectmsycorrhizae of damaged and undamaged trees. Agric., Ecosystems Environ., 28: 415-419.