Tendencies to change in the compositions of the karstic soil and the vegetation in the dolines in the hungarian b�kk mountain
ENDINS, n.' 13.1987. Ciutat de Mallorca.
TENDENCIES TO CHANGE IN THE
COMPOSITIONS OF THE KARSTIC SOlL AND
THE VEGETATION IN THE DOLINES IN THE
HUNGARIAN BUKK MOUNTAIN
Résurné
Au cours des dernieres décennies les conditions oecologiques des territoires carstiques ont subi
des changements, par suite de I'inte~ention
humaine.
Les changements des indicateurs les plus sensibles de I'environnement, ceux de la végétation
et du sol, signalent les changements de la valeur oecologique.
En ce qui concerne les sols, notre évaluation a porté sur le teneur en humus, la réaction et la
compacité du sol, le teneur en rnicro-élérnents, et les cations et les anions hydrosolubles. Au cours
de I'analyse, pour montrer les tendances des changements, nous avons comparé les données de
trois ans (1978, 1984 et 1985).
Le teneur en substance organique du sol est élevé, en raison de la minéralisation lente. Les
valeurs du phosphore sont moins importantes dans la subsurface que dans les couches situées plus
bas. La réaction chirnique est généralement indifférente ou Iégérement acide. La corrélation entre la
quantité des anions et des cations hydrosolubles a été tres étroite en 1978. En 1985 ce rapport est
moins marquant.
Les valeurs de la réaction du sol, d'apres I'indication d'espece de plante étaient plus basses en
1985 que dans les années précédentes. La valeur des indices de I'economie therrnique a dirninué,
tandis que celle des indices de I'hydro-économie a augmenté.
Lusarnrnenfassung
In den letzten Jahrzehnten haben in den okologischen Verhaltnissen der Karstlandshaíten durch
den Einfluss des Menschen Anderungen stattgefunden. Die Wandlungen in der Zusamrnensetzung
des Bodens un der Vegetation die die sensibelsten lndikatoren unserer natürlichen Unwelt sind, wei-
sen auf die vor sich gegangenen Anderungen des okologischen Wertes hin.
In Bezug auf die Boden hat unsere Bewertung die Angaben des Hurnusgehalts, der Bodenreak-
tion, der Bindigkeit, des Mikroelementsgehalts und die irn Wasser Loslichen Anionen und Kationen
erfasst.
Zur Darstellung der Tendenzen in den Veranderungen haben wir die Angaben von drei Jahren
(1978, 1984, 1985) veglichen.
Der Hurnusgehalt der Boden war hoch infolge der langsamen Mineralisierung der organischen
Stoffe. Die pH-Werte waren in den der Oberflache nahen Schichten kleiner als in den tieferen Schi-
chten. Die Reaktion war irn allgenseinen neutral und schwachsauer. Zwischen der im Wasser Iosli-
chen Anionen- und Kationen-menge bestand irn Jahre 1978 eine feste Korrelationsbeziehung. Im
Jahre 1985 wurde diese Beziehung mischen den Anionen und Kationen lockerer.
Nach der lndikation der Vegetation waren die Werte der Bodenreaktion kleiner irn Jahre 1985
als in den vorangegangen Jahren. Die Verzeichniszahle des Warmehaushalts haben sich vermindert,
die Werte des Wasserhaushalts haben dagegen engenommen.
One of the most important tasks of environ-
these days to find out, for example, about the cau-
ment management today is the study of ecological
ses of damages to the vegetation, primarily to fo-
factors with a view to maintain the balance of eco-
rests. The deterioration of vegetation indicates the
systems. This goes hand in hand with the develop-
changes in the environmental factors tiaat in the
ment of the evaluation methods of ecological re-
long run lead to the upsetting of the ecological ba-
sources. Detailed ecological studies are carried on
lance. Forest damages are usually attributed to,
and can also be proved to be the result of, the
* University of Szeged. Hungary.
harmful effect of acidic precipitation. Researchers,

however, seldom conduct detailed analysis of the
The phenomena outlined above have been
processes that occur as the consequence of acidic
triggered off on a larger scale in the last decades,
precipitation, but also within the ecological system
by human activity. The present paper attempts to
of the soil itself. W.D. Blümel (1986) points out four
show the changes in the ecological valeie of karstic
sources of soil acidification. The first he mentions
areas by examining in detail the soil and the vege-
is the natural atmospheric H deposition, a result of
tation as the most important ecological indicators.
volcanic activity, nitrogen circulation, etc ... He also
Those karstic areas are adequate for microarea
regards as important anthropogenic atmospheric H
ecological studies that have been formed as the re-
deposition, the result of burning processes during
sult of the interaction of externa1 and interna1 envi-
industrial production, etc ... The third source is par-
ronmental factors, but stili represent autonomous
ticularly important for us, and that is the result of
dynamic units. The dolines of karstic areas satisfy
processes within the ecosystem of the soil, such as
these requirements since in respect of the microcli-
soil breathing, cation intake, and the H eduction of
mate determining the microarea ecofactors, they
plants, and humus producing processes. The fourth,
are considered as third-rate microclimate areas
but not the least significant source of acidity accor-
with independent heat ecologies.
ding to him is the acidifying effect of the nutriment
Of the ecological components, the soil and the
intake during the agricultural utilization of the soil.
vegetation were minutely examined, blut the pecu-
Acidification occurs, if less forcefully (due to
liarities and change trends of the soil microclimate
the stronger buffer effect of the soils on calcic rock-
and of the biogenic processes in the soil will also
bed), in karstic soils as well. In the soil this process
be referred to, when necessary.
goes hand in hand with the increase of H ions and
cation-acids (Al3+, Fe3+, and Mn2+ ) on the sorption
carrier. This process, in the long run, leads to the
Tendencies to change ira
structural deterioration of karstic soils and an in-
karstic soils
creased danger of erosion. At the same time, the
intensity of the karstic corrosion also changes,
The properties of karstic soils are influenced
which may cause changes in the superficial and
by the fact that these soils are thick in karstic va-
sub-superficial processes.
lleys and sink holes, while they form thinner or
thicker layers on slope surfaces, depending on the
angle of the slope.
On the surfaces with relatively little relief
energy, the processes of redeposition go on verti-
cally, while on sloping surfaces these processes
are vertical and horizontal, depending on the incli-
nation. On the slopes the processes of leaching
and redeposition intensify, the aggresivity of the
solvent water increases, which adds up in the de-
~ressions.
In the dolines of the Hungarian Bükk mountain
clay soils, usually indicative of the dynamics of
brown forest soils are the rule, with dark, often
black, rendzina soils on the rock-extrusions and the
northern exposures. Owing to the horizontally layer-
ed soil profile, the little soil depths, and horizontal
(sloping) redepositional processes, in addition to
elluvial and illuvial processes, good soil could not
form here.
As regards its physical qualities, this soil con-
sists of less classified sediment in terms of the finer
soil components (warp, clay), and better classified
sediment in respect of the larger components. This
indicates that the soils are immature and unconso-
lidated, made up of solution residue to a larger,
and of loess-like sediment to a smaller extent. The
unconsolidated state allows a smaller degree of
Photo 1. One of the examined dolines of the Hungarian Bükk
protection from erosional damages. Fine silt sand
Mountain. Typical solution doline. Deep: 18 m. Diame-
(0,l m m - 0,02
m m 0)
makes up 50-60 per cent of
ter: 50 m.


Denotation of
pH
Total CaCO,
Tot. hu-
PPm
so2
soilsamples
Depth
(KCI) salt %
%
K,
mus%
Zn
Cu
Mn
Na
Mg
P202 &O
so4
NO2
Ea
5cm
5 3 4 0,02
0,O
73
5,08
6,2
3,l
303,6
54
198
11,8
16
187
16,6
E,
30crn
5,41
0,02
0,O
52
2,46
1,O
1,4
138,5
25
62
3,4
3
64
7,3
E,
5crn
5,55
0,02
0,O
66
5,16
11,O
7,3
361,8
29
199
11,4
13
151
10,l
E6
30crn
6,16
0,02
0,O
62
5,19
6,2
7,l
358,2
47
83
6,8
11
131
9,l
E,
5crn
6,25
0,03
0,5
81
5,69
16,4
8,l
360,9
31
189
23,9
33
177
21,3
Es
30cm
6,56
0,02
0,9
71
5,45
12,9
7,2
341,l
21
125
13,2
24
159
17,5
El
2
5cm
6,39
0,03
0,5
74
6,07
17,4
6,2
356,6
54
218
31,3
51
227
32,2
El
2
30cm
6,75
0,02
2,2
80
5,82
13,O
5,l
221,O
37
139
19,3
40
160
17,7
''
3 ''
5cm
5,66
0,02
0,O
70
5,07
9,5
3,4
347,9
25
230
18,3
15
159
15,9
w3
30cm
5 5 5 0,02
0,O
52
3,44
3,2
2,2
286,9
18
124
3,3
7
74
7,7
'e '
5cm
6,32 0,02
0,5
68
5,24
15,6
8,2
369,6
27
200
9,9
19
2 6 1 . 1 3 , 3
W6
30cm
6,90
0,03
1,5
56
4,86
9,3
7,5
346,5
41
93
4,O
12
180
12,6
''
9 ''
5cm
6,85
0,03
3,6
66
5,29
15,9
8,O
291,7
36
180
23,l
33
439
26,6
W9
30cm
6,94
0,05
5,l
63
5,20
12,9
7,2
225,7
72
1 2 1 . 8,l
24
243
42,2
w12
5crn
6,99
0,03
5,5
78
5 3 3 15,5
6,5
221,4
46
197
27,4
45
357
22,6
wi 2
30cm
7,04 0,03
5,8
79
5,25
13,2
5,2
107,3
58
134
10,4
35
250
15,O
K, = Qualifying numbers according to Arany S.
E, E, etc. = eastern slope at the levels of 3, 6 etc. metres.
W, W, etc. = western slope at the levels of 3, 6 etc. metres.
Table 2. Data of Basical Researches of Soil on the East (E) and
West (W) Slopes of Doline (Bükk Mountain, Hungary 1985)
ded up effects at deeper levels of the water filter-
the dolines in 1984, where close correlation could
ing in. The K+ and Na+, as the most frequently mo-
be detected only in 2 or 3 places. in 1985 the corre-
ving ions, remain at the bottom of the dolines in
lation between the amounts of anions and cations
smaller quantities, naturally, which results in the
was stronger on the northern slope (southern ex-
acidification of the soil, while the Fe3+ and Fe2+
posure). At the same places on the other slopes
ions are abundant in the deeper parts, this also
the correlation was loose between %he CI- and
being an acidifying factor.
S04*- ions and the total cation content. The cause
In the case of water-soluble anions and ca-
of the weakening of the correlation may have been
tions, we have compared the data for 1979 and
the change in the soil composition as a consequen-
1984 from 38 places.
ce of the acidic precipitation, but this proposal
Of the cations, the amount of K+ ions decrea-
needs further proving.
sed in rnost places, but in several instances the
No earlier data concerning of microelements
quantity of Mg2+ ions also decreased. The amount
(Zn, Mn, Mg) being available for comparisons, the
of Na+ ions increased, on the other hand, which
examination of these remains a task of the years to
impairs the physical and chemical properties of the
come.
soil. The increase of Ca2+ ions can be the result of
Besides, and taken as a function of, the soils,
the solution of CaC03 in the presence of S04'- ions
we also examined the changes in the composition
(CaS04 . 2H20 being the result), and a simultaneous
of the vegetation. Naturally, a few years are not
increase of Ca2+ ions. An increase of the S04'-
sufficient for an examination like that, but still, with
anions suggests the effects of acidic precipitation.
a knowledge of the tendencies of soil changes, the
At most places, however, the amount of HCO3-
modifications in the indications of plant species,
and CI- ions decreased.
together with soil processes can indicate the chan-
The changes of the correlation between anions
gesto be expected in ecological values.
and cations were also examined in three years
The characteristic association of Hungarian
(1978, 1984, and 1985) (Table 3).
karstic dolines is the Nardo-Festucetosum ovinae,
With the exception of Mg2+, in 1978 there was
Nardetum strictae, which is the association of sub-
a close correlation (R = 0,5 or more) between the
alpine pastures.
amounts of the cations and the anions. It rnay be
We have compared the data from 1979 and
food for thought that this correlation could no Ion-
1985, with special regard to the species composi-
ger be detected everywhere in 1984 and 1985. This
tion, domination, and plant ecological indication. In
was particularly true for the northern and western
the examination of plant ecological indication we
slopes (¡.e. the southern and eastern exposures) of
used indicators for heat balance (T), water balance

HCO,
CI
so4
1978
1984
1985
1978
1984
1985
1978
1984
1985
z
Ca
0,83
0,47
0,58
0,61
0,35
-0,66
0,73
0,17
0,83
p %
Mg
0,31
0,37
0,78
0,16
0,35
-0,87
0,41
0,06
0,62
g 2
K
033
-0,ll
0,70
0,55
0,49 -0,70
0,58
0,64
0,72
m TI
Na
0,72
-0,48
0,84
0,67
0,42 -0,60
0,73
0,89
0,48
Z
Ca
0,91
0,47
0,70
0,71
0,74
-0,28
0,60
0,75
0,29
0)
r C
Mg
0,38
0,86
0,71
0,77
0,Ol
-0,41
0,83
0,31
-0,43
K
0.94
0,91
0,28
0,71
0,11
0,37
0,94
0,22 -0,90
%
m m
2
n
Na
0,07
0,27
-0,47
0,74
0,71
0,88
0,81
0,75 -0,55
z
--
-
Ca
0,94
-
0,99
0,46
0,54
-
0,22
0,75
0,31
Mg
0,53
-056
0,84
0,63
-0,50
-0,20
0,56
-0,05
0,38
K
0,81
0,29
0,72
0,46
0,49
0,47
0,20
- -0,19
Na
0,09
-0,85
0,92
0,68
0,lO
0,Ol
0,73
0,88
0,46
Ca
0,05
0,41
0,30
0,33
-0,35
-0,66
0,91
-0,07
-0,23
Mg
0,15
-0,07
0,20
0,35
0,82
0,12
0,50
0,67
-0,57
K
0,13
0,17
0,49
0,50
0,16
-0,16
0,85
0,40
-0,32
Na
-
-0,14
0,63
0,18
0,96
-0,13
0,03
0,85 -0,31
Table 3. Correlation coeificients between in water soluble anions
and cations
(W), soil reaction (R), and nitrogen dernand (N)
(ZÓLYOMI, B. 1966), then ecological average num-
bers were calculated:
x, . vi
~á = -
, where
I
n
I á = the nurnber of the average heat balance va-
lue for the found species,
xi = the given ecological value,
y, = the species nurnber of the given ecological
value,
n =the nurnber of the found species.
The average value of the heat balance nurn-
bers calculated according to the relationship above
is higher (5,5) than it was in 1985 (5,17), which
means that in addition to the species characteristic
of ternperate zone deciduous forest clirnate, a few
of the species of the subrnediterranean forest and
the warrn steppe clirnate could still be found in
1979, mostly on the northern and western slopes.
The water balance indicator nurnbers ranged bet-
ween 3,67 and 3,77 in 1979, and between 3,62 and
4,89 in 1985. In the latter year several species fa-
vouring higher moisture contents could be found
in the dolines.
The average values of the soil reaction indica-
Photo 3. Afforested doline in the Hungarian Bükk Mountain. The
age of the pine saplings are the same. The growing of
tors range between 2 and 3, indicative of weakly
pines is slowly in deeper part of doline because of the
acidic and nearly neutral soil reaction. This average
cold-airlake (Kaltluftsee).

value, however, on one hand, hides the presence
The planted dolines contained associations ri-
of lime-favouring plant species, occurring with
cher in species than the open dolines. The diffe-
great frequency while, on the other, several plant
rence in composition is the consequence of the
species are neutral as regards the soil reaction.
presence of the forest, which is closely related to
These two extreme values irnpair the chances of
soil ecological conditions.
assessing the real situation. In both years the spe-
We can sum up with the conclusion that even
cies that favour lime could be found in the greatest
minor anthropogenic interventions (e.g. periodical
numbers in the dolines. During the seven years in
mowing or pasturing) on the karstic surfaces with
question the average number indicating the value
their restricted ecological features may lead to
of soil reaction decreased a little, indicating, it is
changes in the soil and the natural vegetation, and
inferred, a shifi of the soil pH in the acidic direc-
these changes, if coupled with the increasing ef-
tion. The soil reaction average values of the occu-
fects of acidic precipitation, may have appreciable
rring plant species indicate the tendencies of the
effects on the nature (character) of the processes
soil change detailed earlier. Today the karstic sink
of karstic corrosion proceeding through the qoil.
holes contain more plant species, compared with
All this should focus our attention on the fu-
1979, which favour a neutral or weakly acidic soil
ture importante of microarea ecological research.
PH.
The indicator nurnber of the nitrogen demand
(N) ranges beiween O and 3 in the area. Its value
Literature
was 2-3 or 1-2 most of the time, which means me-
dium nitrogen requirements.
BLUMEL, W.D. (1986): Waldbodenversauerung. Gefahrdung eines
On the basis of earlier data we also exarnined
okologischen Puffers und Reglers. Geographische Rundschau,
Jahrgang 38, Heft. 6. 312-316. pp.
the association of a dolines planted with pine sap-
ZOLYOMI, B. (1966): Einreichung von 1400 Arten der ungarischen
lings, and it was possible to analyse the differences
Flora in okologische Gruppen nach TWR-Zahlen. Fragmenta
and similarities in the association compositions of
Botanica Musei Historico Naturalis Hungariei. Tom. IV. Fasc.
an open, grass-grown, and an afforested dolines.
1-4. 101-142. PP.