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(1)

Conservation and restoration

prospects of some groundwater fed mires

A study on three base-rich sites in Drawiènski Park Narodowi

Poland.

R

ye,

G Alexander Verschoor

Iwan

Supervisors: Ab Grootjans

Department of Plant Ecology, UnIversity 1999

ofGroningen, Holland Leslaw Wolejko

Agricultural University of Szczecin, Poland

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Conservation and restoration prospects of some groundwater fed mires

Contents

P.

Prologue 3

Abstract 4

Introduction 5-9

Material and Methods 10-14

Reserve Kiocie Ostrowieckie

Results 15-18

Discussion Macro-rest Analysis 19

Vegetation 19

Wafer Levels and Water Chemistiy 19

Implication for Nature Management 20

Miradz Valley

Results 21-25

Discussion Macro-rest Analysis 26-27

Vegetation 27-28

Water Levels and Water Chemist,' 28-29

Implication for Nature Management 30

Pusta Valley

Results 31-34

Discussion Macro-rest Analysis 35

Vegetation 35

Water Levels and Water Chemistiy 35-37

Implication for Nature Management 37-38

Further Research 39-40

Literature 41-42

Supplements

Rkst1nI,prc+t

Jnn('r)

2 RlbUotheek Biofogisch C3'-

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Conservation and restoration prospects of some groundwater fed mires

Prologue

We would like to give many thanks to our supervisors in Poland and in The Netherlands:

Leslaw Wolejko of the Agricultural University in Szczecin, Poland and

Ab Grootjans of the Rijksuniversiteit of Groningen, Holland for their enthusiastic support and dedication. Of course we will never forget Robert, Isa (very nice augurki), Alma and her little bird, Jola (Viola), Pawel and Oksana and the foresters and their families. Thanks!

Further thanks go to the geologist Andrey Wolgrowski in Kielce, for providing us with essential information about the formation and stratigraphy of the area.

3

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Conservation and restorationprospects ofsome groundwater fed mires

Abstract

Drawa National Park is situated around the junction of the Drawa river and the Plociczna river. The area consists of a large sand plane, inter-spaced by gorges and valleys. A large part of the area is forested with mainly pine-wood, which forms the seepage area. In the valleys, the water discharges from the sandy subsoil, feeding rivers, lakes and mires.

In this area three mires were studied. All proved to be terrestrialized lakes, all showing some signs of disturbance and a stop in peat formation. The Reserve Kiocie Ostrowieckie is suffering from superficial rainwater accumulation and from peat decomposition. Animals seem to be the main factor in preserving the present Scorpidium scorpioides vegetation.

Closing of a superficial ditch seems necessary to restore peat formation and to redirect succession towards groundwater dependent vegetation.

The 'Miradz' valley is still suffering from drainage. At the northern end there are signs of rewetting, while at the southern part water, gushing from very active spnngs, cuts deep into the peat layers. On that side the peat is being eroded away most quickly and reconstruction shows a decrease in peat levels of several metres already. Here, the large flow velocities make recovery of the system improbable, while reconstruction of the middle and northern parts may be possible by damming the ditches.

In the 'Pusta' valley there is a large area where the peat is decomposing. In the past there must have been a major hydrological event, lowering groundwater levels over 2 metres. A change in the river course of the river Cieszynka may have occurred, thus causing such changes. The valley is still being drained, but the lower part, which terrestnalized most recently, seems more or less undisturbed. Rewetting might prevent forestation and will stop peat decomposition in a large part of the valley. Removal of the standing crop may be necessary for removing nutrients from the system.

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Conservation and restoration prospects of some groundwater fed mires

Introduction

Mires can exist only under conditions in which water is abundant. Provided that the climate is suitable, peat-forming vegetation can form a mire under these conditions anywhere on earth.

Mires have had a dominant impact on human lives for many hundreds, even thousands of years. People could either adapt to life in the mire, or they had to live somewhere else. This changed when agriculture made its entry in Europe some five thousand years ago. Improved agriculture did not always mean destruction of mires though. Sometimes people created new possibilities for peat formation, by cutting woods and thus decreasing evapo-transpiration by the surrounding forests. This led to increased infiltration of precipitation water (Succow &

Jeschke, 1986). However, the area covered by marshlands in the western world has decreased rapidly since people drained the marshes in the late Middle Ages and began using peat for burning. This process continued until this century. People began recognising the importance of marshes for both their role in enlarging biodiversity, and as regulators in the global atmospheric carbon cycle. Recently wetlands became protected in many countries. Many peatlands were however badly damaged, mainly by human impact in the regional hydrology, turning living, peat-forming mires into much dryer areas in which peat formation was no longer possible.

Nowadays, people are trying to restore many mires from a degraded state, into living peat- forming mires. One of these projects is taking place in Poland in 'Drawa National Park' —or Drawiênski Park Narodowi- in the north-western part of the country. The objectives of the park are to preserve the biodiversity and perhaps enlarge it; in other words conservation and restoration, preferably by using measures that are as simple and as economic as possible.

At this point a problem emerges: what measures can be taken to ensure a positive result, according to these objectives?

To give a sound advice considering conservation or restoration, one must first know the natural conditionss of that system. These conditions are dependent on a number of different abiotic and biotic factors determining the landscape as a whole and through this determining the occurrence of plants —and animals- as species and as individuals. These factors often

are considered as a hierarchical system, (Fig. 1: Everts & De Vries, 1991). Though this figure was designed for the Drenthian Plateau in the Netherlands, its content might also apply for areas such as the Drawa National Park.

Reconstruction of the hydrological conditions that prevailed during the peat formation implies a reconstruction of the vegetation succession that occurred in the area (Diggelen, 1998).

Since abiotic conditions of virgin mire vegetation in Central- Europe are quite well known, it is possible to estimate former hydrological conditions in systems now degenerated (Dierssen

& Dierssen, 1985).

Secondly, if the present system differs from the natural situation, one has to determine which influences, both abiotic and biotic, triggered the shift towards the present state of the area.

Thirdly one must study the present state of abiotic factors such as groundwater regime and nutrient availability.

Finally, one must study the present biotic factors and human influences in the area. These, obviously, include the present vegetation, which in itself is a reflection of the first three points of interest, as well as other —biotic- effects. As the vegetation reflects so many of the other influences, its present and former composition must be a major point of interest.

5

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Conservation and restoration of groundwater fed mires Introduction

From these four points one can give a prediction about the most likely changes and developments in the future, without any anthropogenic influences, but also with certain conservation and nature management practises.

Fig. 1. Hierarchyinlandscape-factorsforthe Drenthian Plateau (Vege:atieontwikkelingvan Beekdalsystemen; F. E. Everts & N. P. J. de Vries).

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Conservation and restoration prospects of some groundwater fed mires Introduction

Feed-back:

A. Precipitation;

B. Peat deposition;

C. Weathering, transportation, wash out, deposition;

D. (Reversed) erosion, meandering;

Direct Influence:

I (Local) Depth of deposits;

2 (Local) Rise;

3 Deposition, erosion;

4 Erosion;

5 Kind of parent material, texture;

6 Depth, permeability and composition of depositions: (strength) groundwater-flow and water quality;

7 "Relief-energy": surface and groundwater- flow (velocity and direction);

8 Ratio precipitation / evaporation;

9 Groundwater-flow;

10 Groundwater regime (supply and drainage), aeration, redox, toxicity, adsorption complex, temperature;

E. CO2 tension of groundwater (weathering), evaporation;

F. Formation impermeable layers;

G. Peat formation, drift sand fixation;

H. Humus formation, peat oxidation;

I. Structure of plant communities.

11 Pedogenesis (kind of parent material);

12 Pedogenesis (wash out, leaching);

13 Water-supply, nutrient availability, mineralisation;

14 Groundwater-level, groundwater quality and stream velocity;

15 Exposition;

16 Climate: temperature, air humidity, frost- days;

17 Air-humidity, air- and soil temperature, interception.

The area:

The Drawa National Park, or Drawienski Park Narodowi, is located in Northwest Poland. The park was established in 1990, and is situated in Mysliborsko-Waleckie Lake District. The total area of the park is 11000 ha, of which 83% is covered with forest and 10% with water.

The park is unique because of its large quantities of unpolluted waters of the first or second class of cleanliness. The climate in the area is mild with a mean annual temperature of 7.7°C and an average total precipitation of 592 mm. The landscape of the park was formed during the last glaciation of the Baltic. The glaciers induced the formation of elongated structures, which can now be recognized as lakes and valleys. The slopes of these valleys sometimes reach a height of 35 meter. The major part (70 %) of the area consists of sand. However, on some places, a peat layer has been formed on top of the sand.

In the park three sites of special interest were studied. The first of these valleys is the 'Miradz' valley. This valley is of special interest because several spring mire complexes can be found in this valley. These spring mires constitute less than 1% of the mire area in Poland (Jasnowski, 1975). It is situated east of the river Plociczna and west of and parallel to Lake Zdroje at approximately.

The second site, or the 'Pusta' valley, is located at the Cieszynka-nver, between Lake Dubie and Lake Ostrowiez. Both of these sites were meadows in the past, but have not been in use for several decades.

The last study-site is the Kiocie Ostrowieckie reserve. This is a former bay at the eastside of Lake Ostrowiez, which has become overgrown by peat. This area is well studied, because of its rare vegetation-type (D epanociado-C!adietum) and is considered to be natural and to be hardly influenced by human impact.

7

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Conservation and restoration prospects of some groundwater fed mires Introduction

Histoiy of the present landscape

To study any system, analysing the soil stratigraphy is a suitable method. The landscape was formed during the last glaciation of the Baltic. It consists of a large plateau, cut by valleys that were excavated by the icy tongues of the glacier and the fierce streams of melting-water during the deglaciation. The upper and youngest depositions were formed during the last ice-age. An impermeable layer of 3 to 4 m thick is present at some 50 to 60 metres below the soil surface. This layer was formed by a glacial till and is found at the bottom of some of the deepest lakes in the valleys. A fiuvio-glacial medium-sized sand deposit covers this impermeable layer. This deposit is difficult to distinguish from a more recent Pomeranian stage deposit. The latter was deposited by melting water in gorges, where the morainic till deposits had been eroded away in the early stages of deglaciation, when the amounts of water and the erosive forces were much higher. During two different periods these gorges were cut into the plane of morainic deposits, in two directions; one from north to south and one from east to west. The Pusta valley lies at a crossing of these gorges (Fig. 2). The Miradz valley is situated more to the north in a north to south tract. After this phase of deposition and erosion, a number of dead-ice blocks remained burled along the water tracks. These last remainders of glaciation melted away in the Pre-boreal until some 7000 years BC (Fraednch, 1996). The remaining depressions filled with groundwater from the surrounding plain and thus formed lakes and peatlands that still exist today.

Vegetation development

Fen vegetation began to develop under these groundwater fed, base-rich and mostly nutrient poor conditions. Kooijman (1993) suggests that in many groundwater fed systems the bryophyte vegetation will not only change due to anthropogenic influence, but also through natural succession. Scorpidium scorpidioides is a moss species with a wide distribution in Europe. It is common in nch-fen habitats in the north and north-western parts of Europe (Smith, 1978; Hedenäs, 1989). S. scorpioides is an indicator species of nutrient poor and base-rich fens (Sjärs, 1950).

It may disappear when the conditions become more

eutrophicated, while Calliergonella cuspidata emerges.

Sphagnum subnitens takes over when acidification occurs. In case of both acidification and eutrophication Sphagnum squarrosum becomes the dominating species. Especially acidification is a natural phenomenon, caused by rainwater accumulation and the subsequent occurrence of Sphagnum species escaping the influence of base-rich groundwater. Moreover Sphagnum species are capable of acidifying their direct environment (Van Breemen, 1995).

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Conservation and restoration prospects of some groundwater fed mires Introduction

:9

VciI,i-V

1g. 2. The location of two of the study-sites. The grey and the yellow area accentuate the valleys, created during the deglaciation period of the last ice age.

This may however not be the only successional pathway. Generally natural succession of

terrestrial plant communities —except for living mires- in this part of Europe is towards forest.

This applies also to mires that become dry enough for trees to settle. This can be caused by climatic change, or human impact. A positive feedback mechanism may occur from this point on. The higher evapo-transpiration rates of growing trees may decrease the water level even more, making their direct surroundings more suitable for other trees to grow (Klapp 1971;

Ellenberg 1963).

The aim of this study is to reconstruct the history of the study sites and to estimate the former hydrological conditions. By combining these it is possible to give a sound advice for restoration and conservation of the damaged mires in the valleys.

9

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"Miradz" valley

1OC)

s-I) 0

FIG 3.

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1/

I,

FIG 4.

"Pusta" valley

Solid point (SP) transect point

transect

2IIpublic road

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Conservation and restoration prospects of some groundwater fed mires

Material and Methods

Three spring complexes within Drawiènski Park have been selected for a study on

vegetation, hydrology and peat stratification. In this report we name them Miradz, Pusta and Klocie Ostrowieckie (K.O.). Investigations were carried out during the months July and August of 1998.

Miradz valley

Miradz valley has a total length of about 1200 m and an average width of over 120 m. The area is almost completely surrounded by sandy hills which rise up to over 20 m above the peat surface. Parallel to the valley, on the eastside, one can find lake Zdroje. This lake has a water level of approximately two metres above the water in the river. The valley itself is largely filled with peat. Large parts of the peat area have been used as agricultural grasslands. Drainage has probably been the most disturbing anthropogenic factor.

Drainage stopped the peat formation and caused enhanced mineralization of the peat, thus supplying extra nutrients to the grasslands. At the moment the grasslands have been abandoned for about half a century. Many old ditches are still recognisable in the field, but most of them have already lost much of their functionality, being overgrown by vegetation.

The studied area of the Miradz valley is shown in Fig. 3. In the northern part of the area a small bog is present (Mbog). After crossing the public road on top of a mineral hill, the first abandoned meadow appears (the 'upper' basin). Near point Ml remnants of a spring mire are visible as a small hill. The first meadow is directly connected with a second larger meadow (middle basin) by a small opening (L5). Where this meadow ends, an partly eroded active spring mire is present (L15), surrounded by a young alder wood. More towards the south until the "Plociczna" river, an older alder wood is growing, hiding even more seepage zones and spring cupolas (SC). A hole in the ground near L19 gives a good impression of the high seepage intensity. A long main ditch in both meadows and the alderwood, flowing towards the Plociczna river, is clearly visible. Especially from L15 onwards, this drainage shows increasing flow rates.

Pusta valley

The second site (Fig. 2 and 4), called Pusta consists of an abandoned meadow surrounded by Pinus forest. This area was also heavily drained in the past for agricultural purposes. At the moment one main ditch remains, which seems to be responsible for most of the drainage of the system towards the Cieszynka river. This area shows a clear tendency of rewetting resulting from decreased drainage during the last decades.

Reserve K/ode Ostrowieckie

The third site, named Klocie Ostrowieckie after Lake Ostrowiez is somewhat different from Miradz and Pusta. It is a former bay of the lake where the water level has lowered in the past (Fig. 2). The studied area is now situated above the lake surface and has probably never been used for agricultural purposes. The gyttja is almost exposed to the air enabling the development of unique fen vegetation. Probably for this reason late professor Jasnowski and Jasnowska have studied this area very intensively. In this report we refer to their vegetation data and soil profiles and only supplement this with hydrological information.

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Conservation and restoration prospects of some Qroundwater fed mires Material and methods

Field research

Markers were placed along transects which were chosen in such a way that the area was represented, including most its dominant vegetation types. Levels and distance between points and piezometers along transects were measured with an optical levelling instrument.

This instrument was also used for positioning and mapping of the vegetation. At every point of these transects vegetation releves have been taken according to Braun-Blanquet (1964).

In unforested areas we made relefees of maximal 25 m2 while in forested areas, plots of 200 m2 were used. Vegetation data were stored and sorted in the computer program Vegbase (Van Diggelen et al. 1990). Peat borings were made along transects to get information about the historical development of the area, using a Russian peat sampler (Fig. 8). Peat samples were analysed for macrofossils like

mosses, sedges and wood. The degree

of decomposition was estimated according to the "Von Post Squeezing method (Post &

Granlund, 1926).

Fig.5. Emptying of a piezometer with the peiistaltic handpump.

Locationsfor drilling were chosen and distributed in such a way that the peat stratigraphy and the development of the complete system could be studied.

The current hydrological

situation was studied with the help of

piezometers which were used for measuring water levels and for water sampling.

Piezometers were manually placed in holes created with the peat sampler. Directly after placing a piezometer, the soil structure surrounding it was restored to prevent infiltrating rain or surface water from disturbing the water composition near the filter.

Fig 7. Optical levelling instrument

11

PTub.

yiOtb

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Conservation and restoration prospects of some groundwater fed mires Material and methods

Tubes were all semi-sealed with a cork to prevent material from falling in.

One day before sampling all piezometers were emptied, using a penstaltic handpump (Fig.

5). This was done to allow refilling with fresh water. The next day two PVC bottles were filled to the brim with water. Prior to analysing, the bottles were preserved in the dark at a low

temperature. Water samples were subsequently analysed in Groningen.

Fig. 8. Russian peat sampler

H

The following parameters were analyzed:

pH-value, EC:

[Cli:

[HCO31:

[2+] [Mg2], [Na'], [K], [F&']:

[S0421, [P0421:

Approach:

pH, EC meter chioro-counter

tetnmetrical with H and OH

Atomic Absorption Spectro-photo meter auto-analyser

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Kiocie Ostrowieckie

Results Discussion

&

Conclusion

Implication for Management

is

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Conservation and restoration prospects of some groundwater fed mires Reserve Kiocie Ostrowleckie

Resu Its

Macro-restAnalysis

Jasnowski & Jasnowska (1991) described the terrestralisation of a lake by analysing plant remnants in the peat stratigraphy below the present peat forming vegetation (Fig. 9).

On the mineral subsoil a clay layer was found, followed by a several metres thick layer of gyttja. The overlying peat-layers, with a very low degree of mineralisation (about 1 or 2 on the Von Post scale), mostly consisted of brown-mosses, such as Scorpidium scorpioides,

Calliergon trifarium, Drepanocladus intermedius, Campylium stellatum found together with Cladium mariscus. Higher in the profile, remnants of Carexspecies, Thelyptens palustrisand Menyanthes trifoliataoccurred and Cladium finally disappeared. In the higher regions of the peat layer some Sphagnum peat was found. The top layer became increasingly mineralised towards the denser parts of the alder wood at the edges of the reserve. In the centre of the transect, a remnant water body was found underneath a shallow peat layer.

Soil Profile Klocie Ostrowieckie

12

sand

gyta peat water clay

Distance

Fig.9. This figure shows a recently overgrown bay. The peat layers at the sides are clearly much thicker and thus older, than the peat in the centre. (Jasnowski & Jasnowska

199 1).

Vegetation

Jasnowska & Jasnowski (1991) described the vegetation in great detail (Fig. 10). Special attention was given to plant communities with the rare species Scarpidium scorpioides and Cladium mariscus becauseof their role in the initial phase of peat formation. In the centre of the former bay the plant association Drepanoclado-Cladietum (Succow, Knap 1985) was present on almost all open sites, surrounded by an alder wood. Cladium mariscus and moss species (Calliergon giganteum and Calliergon trifarium)are still present here. Scorpidium scorpioides, however, has disappeared almost completely. Only in a few sites created by wild animals, Scorpidium scorpioides still survives.

0 20 40 60 80 100 120 140

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Conservation and restoration prospects of some groundwater fed mires Reserve Kiocie Ostrowieckie

Fig. 10. Peatforming vegetation of mossy fen and lakeside alder swamps in the nature reserve; plant communities:

1- Carici elongatae-Alnetum, 2- Athyriofihixftmina-Alnetum, 3- Carici acutformis-Alnetum, 4- Sphagno squarrosi-Alnetum, 5- Acrocladium-Valeriana dioica-Alnus Corn., 6- Drepanoclado-Cladietum, 7- Drepanoclado-Cladietum sphagnetosum, 8- Scorpidio- Eleocharitetum quinqueflorae, 9- Drepanocladus intermedius-Carex lepidocarpa Corn., 10- Carici-Sphagnetumteretis, 11- Sphagnum-Pinus-Alnus Corn., 12- Dicrano-Pinion All.

17

U

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Conservation and restoration prospects of some groundwater fed mires Reserve Kiocie Ostrowieckie

Water Levels and Water Chemistiy

Waterlevels measured in the Reserve Klocie Ostrowieckie are shown in supplement 4. In general groundwater levels below the surface are highest in the centre of the reserve.

Towards the flanks of the valley they decrease. A shallow stream discharges some water into Lake Ostrowieckie.

The HCO3 content of the samples is in general between 3 and 4 meq/l, suggesting that water

from these sites originates from the same source. The Ca concentration seems to

correspond well to most bicarbonate concentrations. The water sampled from point KOl forms an exception to this. Here the calcium concentration is high, compared to the bicarbonate content. Also the S042 concentrations are high, probably caused by enhanced mineralisation of the peat. Likewise the electro-conductivity rises towards the edges of the mire. The higher chloride content at the edges of the mire indicates a lower rainwater influence, probably caused by evaporation. Judging from this, two types of water can be distinguished; the calcareous groundwater in the centre of the reserve and the more mineral rich water at the edges of the mire. In between these two types a transition type was found.

Table I shows the chemistry of the samples.

Table 1: Chemistryofthe water samples from thereserveK.O.

Location

Filter depth below surface

meqll

KO cm [CO] EC, pH Ci HC03

§7

1 102 0.83 636 7.02 0.95 3.53 2.32 0.01 6.01 0.12 0.38 0.01 0.0

i

31 2.09 385 6.5 0.69 3.85 0.14 0.01 3.82 0.07 0.16 0.01 0.0;..

5 27 2.37 418 6.42 0.4 4.17 0.12 0 4.34 0.05 0.18 0.01 0

6 14 1.63 537 6.55 0.55 5.5 0.29 0.01 4.8 0.14 0.22 0.03 0.0

7 101 1.81 513 6.45 0.59 3.32 1.58 0 4.26 0.15 0.4 0.03 0.02

Sphagnum**

2.8

373

4.27

3.38

Sphagnum: an experimentalmeasurement offirmlysqueezed Sphagnumplants.

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Conservation and restoration prospects of some groundwater fed mires Reserve Kiocie Ostrowieckie

Discussion

Macro-rest Analysis

Clay layers at the bottom of mires occur quite often. At the end of the glacial period, dead-ice blocks remained buried in many places. During and after the melting of the ice, lakes were formed, which were frozen during the long winter periods. The finest materials could deposit, forming an impermeable layer at the base of the lake (Fraedrich, 1996). The clay layer at the bottom of the mire forms a possible bamer for incoming groundwater from beneath. The gyttja layer directly above the clay forms a second bamer. No active springs on the mineral sides were found and the gyttja and clay deposits do not reach the sides of the peat layer. It seems therefore probable that most of the groundwater discharge is directly from the mineral sands into the peat.

The small layer of peat in the centre of the K.O. site indicates that the last part of this former bay of Lake Ostrowieckie was overgrown quite recently. At a growth-rate of approximately I mm per year (lvanov, 1981; Succow, 1986), the thickness of some 25 cm suggests an age of about 250 years. The thickest peat layers, up to 2 metres, are at the sides. This could mean that terrestrialization began some 2000 years ago.

As the main draining activities probably started during the (late) Middle Ages, this might imply that terrestnalization started under natural conditions, non influenced by anthropogenic draining-activities.

The terrestrialization described by Jasnowski & Jasnowska (1991) might be valid also for other lakes in the area. Therefore the past developments and present situation in the reserve might offer a glimpse of the past of other terrestnalized lakes.

Vegetation

The presence of the rare Drepanoclado-Cladietum association (Succow, Knapp 1985) indicates that groundwater influence is still present. Scorpidium scorpioides is being succeeded by other phyto-communities and exists next to ecologically completely different Sphagna. That patches with Scorpidium scorpioides still do exist may be explained by the presence of animals, probably wild boars, grubbing the surface. We found many traces of recent animal activity that had removed the superficial vegetation. Similarly disturbed patches seem to have been overgrown by a Drepanoclado-Cladietum community.

There are some signs of advancing alder wood, indicating mineralisation and drying out of the peat layer. The presence of Sphagna indicates an escape from groundwater influence.

Therefore also the vegetation with Cladium mariscus might be expected to disappear from the reserve during succession. There is no indication that this will happen soon, because the reserve is too wet in the centre for trees to settle. Nevertheless, an increase of groundwater influence will probably be needed for securing the rare vegetationtypes on the long term.

Water Levels and Water Chemistiy

Water sampled from K04 and K05 resemble deeper groundwater most. This corresponds to the presence of the Drepanoclado-Cladietum association. The other samples are all influenced by mineralisation of peat, by vegetation or by rainwater. This results in a higher EC expressed in higher concentrations of most measured ions. Towards the edges of the transect, sulphate concentrations are rising, indicating an influence of fluctuating groundwater levels and increased peat decomposition.

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Conservation and restoration prospects of some groundwater fed mires Reserve Kiocle Ostrow$eckie

Implication for Nature Management

It is questionable that man can preserve all unique characters in Reserve Klocie Ostrowieckie. The presence of the alder wood at the sides does imply that peat formation has already stopped. If the alder wood proves to be moving towards the centre of the reserve, it poses a great threat for the survival of the present rare vegetation. This can be avoided by preventing tree settlement. Furthermore the presence of Sphagnum indicates an increasing rainwater influence. Without intervention this effect will increase and on the long term the reserve may change into a bog.

A simple way to slow down succession, would be to increase groundwater influence in the reserve site. This will keep the Sphagnum out, which needs rainwater and it will make the terrain too wet for tree settlement. To achieve this, one can attempt to cut off the outflow by filling it up with peat. It is however difficult to predict if and how soon the preferred effect will take place. It is possible that when the trees die, Phragmites australis together with tall sedges or other eutrophic vegetation will take their place. If this happens this means that mineralisation of the peat has developed already too far to keep the local conditions nutrient poor. To stop this it will be needed to remove the standing crop of the high productive areas once or twice a year. This should give the rare fen vegetation types a prolonged existence and could restore peat formation throughout the reserve.

Damming the outflow is not a universal method for mire restoration, however. Rainwater might accumulate as a result of damming, causing bog-like vegetation to appear instead of brown mosses. There appears to be enough groundwater input into the Reserve Klocie Ostrowieckie though, to prevent this.

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Miradz

Results

Discussion

&

Conclusion

Implication for Management

'1

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0>

0

Conservation and restoration prospects of some groundwater fed mires The Miradz Valley

Results

Macro-rest Analysis

The Miradz valley consists of three separate subsystems, which are all part of a larger system. Figure 3 shows that the valley is an elongated structure stretching out from north to south. Several mineral bafflers exist in the valley. A small living bog is situated on the northern side of the largest of these bamers. This bog system is very small, some 30 metres in diameter. It has been there for apparently a long time, for the peat profile shows a

Sphagnum peat layer from the top to a depth of 5.3 metres (Fig. 11). A layer of

Drepanocladus peat is

present, followed by a layer of moss-sedge peat with some

Phragmites and with Menyanthes seeds.

At a depth of some 7 metres Scorpidium

scorpioides was found. These Drepanocladus and Scorpidium peat layers are referred to as 'fen peat' in figure 11. A small-sedge moss peat surrounds the bog, which at greater depth contains some Menyanthes seeds, Phragmites remainders and some wood. From the depth of 5.2 metres downward, organic gyttja, brownmoss, sand and some shells were found. At the depth of some 6.5 to 7 metres the mineral subsoil was reached.

25 -

soil profile Miradz L-transect

1200

Fig. 11. Soil stratigraphy in Miradz. Level of 10 m in map(=heightof solid point S2 near M transect) is 14.84 1 m. below calibration marker BA1812.

On the other side of the large mineral baffler a second basin is present, referred to as the 'upper' basin. The middle and lower basin are situated to the south (Fig. 11). In the upper basin a large sedge peat was found on op of a sha!low gyttja layer.

In the middle basin, during that time a small-sedge brownmoss peat has developed. This small-sedge brownmoss peat has clearly decreased in thickness until the present size of three metres thick. Behind the first mineral hill, a black coloured gyttja layer was found on top of lighter coloured lake chalk. This darker gyttja was first covered with a layer of small- sedge brownmoss peat, which was followed by a layer of tall-sedge peat.

20 - 15 -

10

Upper basin

Middle basin

sandgyttja

small sedge

top layer

tall sedge

bogpeat

fen peat

pp.

Lower basin

distance (m)

(23)

Conservation and restoration prospects of some groundwater fed mires The Miradz Valley

Further to the south, in the direction of the river, only a tall sedge peat layer was found. The grade of mineralization on the Van Post scale differed per layer and was usually highest in the tall sedge peat layers and lowest in the small sedge-brownmoss, especially in the Sphagnum peat of the bog. Wood-remnants were more common in the tall-sedge peat, than in the small sedge brownmoss peat. The peat and gyttja layers were sometimes over eight metres thick, especially in the middle basin and between the mineral hills (points L15 and L19). The sandy hill apparently formed a bamer between the different small lakes in the past, but later on these bamers became overgrown with peat. It is unclear whether the former lakes between the mineral hills were separated, because the hill of point L15 does not seem to form a barrier crossing the whole width of the valley. The presence of a black gyttja (indicating the presence of water-plants in the past) on the one side and the lacking of this on the other suggests two separate lakes however.

The average thickness of the peat layer decreases towards the far end of the MiradzValley near the Plociczna river. On the river shore almost no peat was found.

Vegetation

Vegetation in the Miradz valley (Fig. 12) is very diverse. The basin in the northern part of the studied area (not shown in Fig. 12) has a typical bog vegetation in the centre. This almost

circular bog has a diameter of 30 m. Dominant species are Sphagnum fuscum,

S.

magellanicum, Oxycoccus palustris and Ledum palustre. The bog vegetation is surrounded by small sedge vegetation with Carex lasiocarpa with a large quantity of S. recuivum and some Carex rostrata. Inventarisation of the upper basin, showed that this former agricultural grassland is now covered mainly with different sedge communities. Carex nigra dominates the centre of this basin together with Carex panicea and mosses such as Climacium dendroides, Plagiomnium elatum and Plagiomnium undulatum. Closer to the mineral borders tall sedge and fern communities are more abundant. The vegetation indicated as meadow, surrounded by the Cancetum acutiformis, has developed on a former spring cupola. Many tussocks of Carex cespitosa mark the connection between both basins. The actual connection is covered with grasses.

The vegetation in the middle basin can be divided into two vegetation types. On the western

side a dry meadow vegetation has developed with much

Deschampsia cespitosa, Anthoxanthum odoratum and Holcus lanatus. The other side of the basin is dominated by different Carex communities, a Scirpetum sytvatici (Issler, 1936) and an Equisetum palustre community. In the far end of the second basin the former meadow turns into a young alder wood. The meadow vegetation in the centre of the alder forest is situated on top of a sand hill, which functions as a hydrological window. A Glycerenetum nemoralis vegetation is present near this spring cupola and on the sides of the mineral slopes where water seeps out. Typical species like G!yceria nemoralis, Ch,ysosplenium aftemifolium, Cratoneuron communatum, Cratoneuron fihicinum, Pelila, Cardamine amara and in the water Lemna tnsulca are present. Thelyptens palustre is abundant on the eastside of the spring cupola.

This Thelypteris palustre area borders directly to a beautiful meadow with Pamassia palustris, Equisetum paluste and Ho!cus lanatus. The area covered with a Glyceria maxima community is positioned alongside the point where many spring outflows converge. Towards the mineral outwash plain on the eastside a Carex nigra community is present, which is succeeded by a Carex rostrata community. Further on, a well-developed Alnus forest is present near the river Plociczna. This forest, largely belonging to a Circaeo-Alnetum

23

(24)

Conservation and restoration prospectsofsome groundwater fed mires The Miradz Valley

community, accommodates also small stands of typical spring vegetation (Cardamino- Alnetum) with Cardamine amara, Ribes nigrum, Carex acutiformisand Circaea eipina.

Water Levels and Water Chemistiy

We took water samples from only 7 piezometers. The other piezometers wereonly used to measure water levels. Sample L18 was taken directly from the active spring. An attempt was made to trace the local origin of the water, following the water path using a long rod. The water appeared to originate from somewhere underneath the sand hill at L19. Water from the outflow was sampled at the end of the main ditch.

A ground boring on top of L19 and on the active spring cupola (L15) revealed traces ofiron (red colour of sand) close to the top (Supplement 1). This red colour of the sand indicates former contact with groundwater.

Table 2 shows the results of the chemical analysis of the water samples. In general three types of water can be distinguished:

a. groundwater with low sulphate and chloride and high calcium and bicarbonate concentrations.

b. rainwater

like water with a low EC,, generally low ion

concentrations and a relatively high chloride concentration and c.

a transition type of water with usually a higher

and

sulphate concentration, probably caused by enhanced decomposition of the peat.

Table 2. Hydro-chemical parameters of water samples Miradz.

Location

Filter depth below surface

Meq/l

cm [GO2]

EC

pH C1 HCO3 SO42- P042-

Ca Mg Na

K

Fe

Mbogl 107 3.49 65 3.73 0.35 0 0.18 0.01 0.17 0.01 0.06 0.01 0.01

Mbog3 102 2.42 122 5.6 0.41 1.12 0.14 0.03 1.25 0.01 0.06 001 ccc

Ml 188 0.43 389 7.13 0.47 3.16 0.72 0.02 3.71 0.06 0.17 0.02 0Qç

.3 107 2.41 386 6.68 0.35 4.03 0.14 0.08 3.93 0.04 0.11 002 0.3

L7 102 0.98 525 6.92 0.63 4.16 08 0.02 5.18 0.08 0.28 0.01 0.0

LII

54 1.9 421 6.59 0.33 4.33 0.12 0.11 4.77 0.03 0.17 0.02 0.&

r

90 1.06 371 6.65 0.23 3.1 0.68 0.02 3.47 0.07 0.11 0.02 0.01

L18 0.24 291 7.38 0.24 2.94 0.08 0.01 2.78 0.07 0.14 0.02 0.0

)utflow* 0.2 327 7.68 0.13 2.91 0.22 0.01 3.14 0.07 0.14 0.01 0.0

* Outflow: water leaving the valley to convergewiththe river

The bicarbonate concentrations vary greatly, from zero to over 4 meq/l. The calcium concentrations vary similarly. At some points, like L7, the calcium content is relatively high compared to the bicarbonate concentration. Here the sulphate concentration is slightly

higher, indicating mineralisation

of the peat. The sulphate concentrations

in deep

groundwater are usually very low. This is confirmed by the sample from point L18, which was sampled from a very active spring. The water from point Ml, however, has a highersulphate content, while also sampled from a spring site. The difference between both samples indicates a difference in origin of the incoming water. As the chloride content is higher in the sample from point Ml, this water is probably from more local origin. Decomposition of the peat at point Ml may cause the higher sulphate content. The water levels and the filter depths, are shown in supplement 5

(25)

Vegetation-map 'Miradz'-valley

Phalaris comm.

Alnetumafter meadow Carex cespitosa comm.

Equisetum palustre comm.

Meadow / ecotone Scirpetum sylvatici ass.

Spring Glyceria nemoralis Parnassia meadow

Carex fuscae comm./ass.

Caricetum rostrata Carex acuta comm.

Spring Glyceria maxima Thelypteris palustre Carex acutiformis comm.

Alnus glutinosa

Forest River

El

Circaeo Alnetum comm.

(eroding)

Circaeo Alnetum comm.

(non-eroding)

0 7V & PY Poictio

Fig. 12

D

El El El

U U U

El

U

(26)

Conservation and restoration prospects of some groundwater fed mires The Miradz Valley

Discussion

Macro-restAnalysis

At first sight, the bog in the northern part of Miradz valley seemed to have escaped groundwater influences just recently. Peat borings however, showed that the bog in coexistence with its surroundings has been stable for a very long time. We found over five metres of Sphagnum peat very tightly bordered to a surrounding small sedge community. At an optimal peat growth rate of 1 mm per year (lvanov, 1981) this would still mean an age of over 5000 years! In

older peat layers, we found remnants of Menyanthes seeds,

Drepanocladus and Scorpidium scorpioides, close to a gyttja layer underneath. The upper basin, on the other side of the large mineral banier, once was covered with tall sedges and periodically also with trees. High decomposition rates (H7-8) indicate that this area has probably experienced very variable water levels. Natural eutrophication through mineralization apparently made the area a suitable habitat for tall sedges and trees.

A mineral threshold divides the upper basin from the middle basin. Peat on this threshold indicates at least a temporal contact between both basins. Peat formation in the middle basin differed from that in the upper basin. Here small sedge-moss peat Is present, indicating a lower nutrient supply. Low average decomposition values (H 4-6) indicate anaerobic conditions created by permanent inundation. The area behind the next mineral barrier with the spring cupola (L15) also started as a lake and became overgrown with small sedge peat. Later on in succession a tall sedge peat appeared, probably due to variable water supplies.

An attempt was made to obtain a reconstruction of a living mire in the valley, untouched by recent interference in the hydrology (Fig. 13). We assume that the river was already present during peat formation. This idea is confirmed by the presence of a bare sand plain on the other side (south) of the river. In a situation without river one would expect this area also to be covered with gyttja or peat. Furthermore, the slope of the peat in the studied area towards the Plociczna river is rather gradual, which points to a sloping mire.

Reconstruction of the peat implicates a reconstruction of the hydrological conditions because groundwater levels in a living peat are close near the surface. A concentric line from the mineral border in the upper basin via current seepage zones towards the river might be a good approximation of the position of the old peat surface. Height measurements indicated a collapse of the peat in the middle basin. The difference in height between the seepage in the east and the present peat level supports our reconstruction. The present peat surface is estimated to be 1.5 meter below undisturbed conditions. Degradation of peat depends on drainage depth and land use and varies between 5 and 25 mm/year Succow (1986). Ivanov (1981) mentions a speed of 10-80 mm/year. These rates implicate a maximum of three centuries during which drainage has taken place.

In the field we noticed that much erosion had taken place to the south of transect point L15 where we found remnants of peat lying on mineral slopes over two metres above adjacent

peat surface. We corrected for this difference in peat levels in the reconstruction.

Figure 13 shows the reconstruction of the living peat. Comparing the level of the peat on the mineral slopes of the middle basin with that in the centre tells that in the past this layer must have been at least one meter thicker. The peat levels in the southern part of the valley are based on the height of water discharging from the mineral sides and on the height at which iron oxide was found in the sand hill of point L15.

(27)

0 0

12

0 0

12

reccIndicncfsdI pfdeMrk

scil nAile Mrack

L-1raed

Fig. 13. Reconstruction of part of the Miradz valley compared to the actual situation.

Vegetation

The vegetation- and water composition in Mbogl, reflects the presence of precipitation water. The surrounding vegetation of the Carex Iasiocarpa type indicates a higher nutrient

availability and larger groundwater influence. Higher concentrations of calcium and bicarbonate in the water at Mbog3 confirm this idea.

The vegetation in the upper basin seems to have developed in a rather predictable way. The wet centre of this basin is dominated by nutrient poor sedge vegetation. Groundwater levels in this part of the basin are close to the surface. Near the mineral borders tall-sedge communities indicate a slightly higher nutrient availability as a result of lower groundwater levels. Comparison of the present-day vegetation with the description of the macrofossils on the same spot revealed a change. The upper basin used to accommodate tall sedge communities and some Phragmites, also in the centre. This change indicates a decrease in nutrient availability in the centre. The decrease in peat levels, might be the cause of this.

Nevertheless, no change into a living mire has taken place and moss species like

Calliergonella cuspidata, indicating disturbance rather than peat formation, were found between the Carex nigra plants.

27 10

date (n

cIst(n1

(28)

Conservation and ,estoret,on prospects of some groundwater fed mires The Miradz Valley

The middle basin houses well preserved grasslands on the western border with groundwater levels relatively far below the surface (supplement 5). The other side of this basin is very wet and covered with groundwater dependent brownmoss-sedge vegetation. The presence of some more eutrophic species like Geum nva!e, Cirsium oleraceum and Poa pratensis are the result of eutrophication and were also found in the upper basin. Drainage made the development of a young alder wood on the former grassland possible. The alnus forest near the river has evolved as a result of variable groundwater levels probably due to drainage.

The Phalaris community, together with the G!yceria maxima community, are both regularly flooded plant communities which are highly productive (Succow, 1986). The presence of highly productive plant communities in or near groundwater is probably due to high flow velocities. Although deep groundwater is often poor of nitrogen, plants near water streams can still gain sufficient nutrients to maintain high growth rates.

The first part of the alder wood, from L16 until point L21 (Fig. 12), can be charactensed as an eroding alder wood. Many of the trees have clear visible root systems with fragments of peat still attached. Near some of the trees, over 80 cm of peat has disappeared. Judging from their size, most of these trees are probably not older than 60 to 80 years. Therefore, this 80 cm of erosion must have taken place during this period.

A striking feature of the vegetation in the middle basin, but actually of the vegetation in a large part of the valley, is the distribution of the dry and the wet vegetation types. Most of the meadow communities are positioned on the west side of the valley, while seepage and spring vegetation is clearly more abundant on the east side.

Water Levels and Water Chemistiy.

As could be expected at a site with Sphagna, the water in the bog at point Mbogl was very acid (pH 3.7) and resembling rainwater. The higher concentrations of calcium, bicarbonate and iron in Mbog3 (pH 5.6) indicate decreasing influence of precipation water towardsthe edge of the bog system. The reason for the almost perfect circular shape of the bog in an almost circular basin might be incoming of outwash from the mineral slopes around the bog.

Nutrients in this outwash prevent the development of a Sphagnum peat near the mineral borders. We exclude the presence of a non-local groundwater flow around the bog. This idea which initially arose namely contradicts to the situation only a few hundred metres higher up in the valley. Here we came across a nutrient poor lake, partly overgrown by Sphagnum.

This lake as well as the bog has probably escaped from non-local groundwater influence.

In the Miradz valley water was sampled from different spring sites (Ml and L18). The water chemistry differed for these springs, indicating a different source. The higher CO2 tension indicates that water from the spring cupola Ml probably is from more local origin than the water from the active spring (L18 I KDT5). The higher CO2 tension correspondswith higher calcium and bicarbonate concentrations in the water from Ml. The water from L18 has probably a higher resemblance to deep groundwater. Traces of iron in the sand near the top of Ll5 and L19 imply that water pressure has decreased under both hills. Erosion of a large quantity of hardly permeable peat around these hills can be the cause of this changed hydrologic flow path. This change applies especially for the former spring cupola L19 where spring water seems to have chosen an easy path just next to the hill.

Studying geological maps of the area suggests that the Miradz valley belongs to one long hydrologically linked system. The high sand hill between the bog and the first meadow prevents an unrestrained groundwater flow towards the Plociczna river. However, the high permeability of this sand (±10 m/day) (Andrey Wolgrowski) might enable a groundwater flow towards the upper basin. In both meadows we found groundwater levels close to the peat

(29)

surface. The gradual slope of the entire peat surface (Fig. 11) supports the idea that the water level in the bog may be connected with that in the other basins. Plant communities indicating groundwater as well as seepage zones were clearly more abundant on the eastside. Most of the water enters the valley from the eastside to follow the slope towards the Plociczna river. Observation of the geological structure, surrounding the valley, gives a possible explanation for this tendency. On the eastside, parallel to the valley, Lake Zdroje represents a high water potential (Fig. 14). The Plociczna river, west of the valley, functions as a drain and attracts the water from the valley. Modelling in 'Flownet' supports the hypothetical groundwater flow, represented by the arrows in the figure. The model itself is presented in Supplement 8.

Conservation and restoration prospects of some groundwater fed mires The Miradz Valley

64.9]

Hkcz L

Fig. 14. Hypothetical groundwaterflow Miradz basedonFLOWNET modelling (supplement 8).

29

(30)

Conservation and restoration prospects of some groundwater fed mires The Miradz Valley

Implication for Nature Management

The bog site seems to be in the same stable state as it has been in during the last millennia.

Apart from the possible danger of a developing Pinus forest, this area does not seem to require measures to maintain the present conditions. Furthermore, due to an abundance of Sphagnum bogs in Northern Poland area in comparison to the number of spring mires, preservation of Mbog is not a main priority.

Since farmers have left these former meadows near Miradz, the ditches have slowly

disappeared and the hydrology of the system

is slowly recovering. A peat-building brownmoss-sedge community might eventually reappear in both the upper and in the middle basin. The speed and the final result of this process can however be improved by increasing the groundwater level. Since there is still some discharge via the old draining channels it seems wisely to dam the ones which still show water flow. A supporting measure can be the removal of the young alder wood, which is starting to overgrow the southern part of the meadow. Trees help draining through their relative height evapo-transpiration (Eggelsmann

& Schuch, 1976) and can therefore have a negative impact on the hydrology of a mire. A positive factor of trees is their inhibiting capacity on erosion. For this reason it is wise to maintain some trees near active water flows. Damming these ditches may lead to rainwater accumulation, but the amount of incoming groundwater will prevent any effect of this.

Erosion between transect point L15 and the Plociczna river has already reached a stage in which recovery of a living peat is improbable. Flow rates in this area are too high and an Alnus forest has established. Cuthng this wood will probably only increase erosion instead of creating a habitat for peat forming vegetation. Eventually, continuation of erosion below L15 can expand its effects towards zones higher up the valley. Disappearanceof more peat will increase water amounts and flow velocities towards the river and can thus ultimately help drying out the upper and middle basin.

A problem in restoring the natural conditions in groundwater fed areas is often an abundance of nutrients, giving reed and other fast growers a chance after inundation (Succow, 1986). In Miradz, however, the hydrology seems already to be partly recovered without appearance of reed. When reed shows up in the future, removal of standing crop through mowing (see K.O.) can improve nutrient status of the soil.

(31)

Pusta Valley

Results

Discussion

&

Conclusion

Implication for Management

11

(32)

Conservation and restoration prospects of some groundwater fed mires The Pusta Valley

Results

Macro-rest Analysis

A very calcareous gyttja layer was found in almost the whole of the 'Pusta' valley. This gyttja is covered with a layer of small-sedge brownmoss peat, sometimes inter-spaced by a small layer of tall-sedge peat. Mostly this peat is only slightly decomposed (about 3 to 4 on the Von Post scale), but at low groundwater levels, the decomposition of the top layer is about 8.

The thickness of the peat layer vanes from only centimetres to approximately 2 meters. At one point though the gyttja is not covered with peat, but reaches the surface (Fig. 15). More to the flanks of the valley, sometimes a little inwash of sand and small stones was found.

Wood remnants in the peat were sparse. Supplement 2 gives the detailed stratigraphy of the soil in Pusta.

Soil Profile Pusta Valley

This soil-profileof the Pusta-valley clearly shows the position of the fonner lake and the peat covering it.

'-transect

At this point the gyttja reaches the surface. I Isand gyta

small sedge I top layer

tall sedge

At this point the

ke tsrresised

most recently.

w

R-transect

E

S

Fig. 15.

(33)

Conservation and restoration prospects of some groundwater fed mires The Pusta Valley

Vegetation

The area described as Pusta can roughly be charactensed as a large abandoned grassland.

In the following text a north-south description will be given of the vegetation shown in figure (Fig. 16). A large part of the northern part of the basin is dominated by Molinia caeru!a. A small area evolved towards a bog-like Carex lasiocarpa community with minerotrophic Sphagnum species, Oxycoccus and Molinia. Brownmosses and Menyanthes trifoliata, however, occur in small quantities. A long strip along the valley is covered with a mixture of Phragmites australis and Molinia caeru!a . The large dry meadow on the left, with Thymus, Sedum and Potentilla aserina has developed on a dry gyttja hill. A fen vegetation, dominated by brownmosses, was found in the central part of the area. Here the moss cover reaches some 80%. Prominent mosses are Aulacomnium pa!ustre, Calliergonella cuspidata, He/odium blandowii, Rhytidiadeiphus squarrosus and near Cl 0/Cl I there was a spot with much Marchantia sp. On the R-transect near the centre, species like Berula erecta, Cardamine flexuosa, Caitha palustns and Menyanthes trifoliata were present. On wet spots along the A-transect even Lemna tnsu/ca, Lemna minor, Cardamine amara, Utricu/aria minor, Sparangium minimum and Thelyptens palustris were recorded. The Pusta valley is remarkably rich in Carex species (C. diandra, C. !imosa, C. nigra, C. panicea, C. rostrata, C.

ova/is, C. flava, C. disticha, C. cuprina, C. acutiformis, C. acuta and C. lasiocarpa).

Water Levels and Water Chemistiy

Generally the wettest sites are in the centre of the valley and towards the R-transect. A ditch, leading to the Cieszynka river, is sthl draining the mire complex. Table 3 shows the chemical composition of the samples. The bicarbonate contents vary from 2.49 to over 7 meq/l.

Usually the calcium concentration follow the variation in bicarbonate content quite well.

Sometimes relatively more calcium is present, usually accompanied by a higher sulphate concentration. This is caused by peat decomposition, which shows itself in a higher overall Electro-Conductivity. The high concentrations of bicarbonate and calcium may be caused by secondary dissolution of CaCO3 in the subsoil. At some points the chloride concentration is

relatively high. When this is accompanied by low EC, it

indicates a large rainwater influence. The water levels and filter depths are shown in supplement 5.

Table 3: Chemistry of the water samples fromthe Pusta Valley Location

Filter depth below surface

meq/1

cm [C02]

EC

pH Cl HCO3 S042 I557 Ca2

Mg

Na

K

El 45 0.78 369 6.73 0.41 3.71 0.19 0.02 5.37 0.02

öä

1.5

153 0.59 543 6.9 1.21 4.06 1.24 0.05 7.16 0.05 0.13 0.02 0.OE

Si 121 0.58 526 7.01 0.65 4.5 0.91 0.16 6.76 0.02 0.17 0.01 0.0

S3 142 1.77 670 6.78 0.64 7.03 0.35 0.02 6.84 0.02 0.04 0.01 0.04 R6 94 1.24 249 6.47 0.52 2.49 0.11 0.01 2.92 0.01 0.07 0.01 0.01

R3 23 1.92 462 6.48 0.69 4.85 0.07 0.03 4.76 0.04 0.15 0.04 0.21

Rmin2 108 0.59 414 6.88 1.12 3.17 0.79 0.01 3.95 0.06 0.2 0.02 0.Of

'4

99 2.22 467 6.42 0.61 4.72 0.26 0.01 5.88 0.05 0.09 0.03 0.1

Outflow 0.34 485 7.43 0.35 4.75 0.29 0.01 5.35

— —

0.05

0.15

0.01

0.Of

* Outflow:water leaving the valley to converge with the river

33

(34)

Vegetation-map 'Pusta'-valley

Molinia comm.

Pbragmito-Molinietum mix.

Caricetum lasiocarpa Pbragmitetum

Equisetum palustre comm.

Meadow / ecotone

Meadow with Sphagnum Meadow with

Mix. Caithion

Carex fuscae comm./ass.

Caricetum rostrata Carex acuta comm.

Menyantho-Sphagnetum Carex diandra comm.

Caricetum acutiformis Carex paniculata comm.

E E

R

0 JV & 1W Pmductio

Thelypteris pal. corn

Forest River

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