Floodplain hay meadows along the river Tisza in Hungary

extensive cattle farming, fishing (e.g. of the traditional species “csík”
(Barbatula spp.)), catching crabs and also by trading crops and livestock
(Andrásfalvy, 2007; Frisnyák, 1990).
In addition to the local farming system, transhumance also existed.
In the process of extensive livestock farming, the grey cattle were
driven from the summer pastures to the winter pastures of the
floodplain, which was covered by a more productive sward (Andrásfalvy,
2007). Pigs, living on the riverine meadows and marshes during
summer like “semi-wild” boars, spent the winter in the vast oak
woodlands of the upper reaches of the Tisza, where they fattened
on the acorns to reach their selling weight (Bellon, 2003). From the
neighbouring mountains, large herds were also transferred to the
Great Plain after the summer.
At the beginning of the 19 th century, the need for the expansion of
arable land increased as a result of the rise in crop prices and the
growth in population. This land was initially obtained by the prevention
of regular flooding of the meadows and marshes. This led to
the drying out and rapid salinisation of meadows in many areas. The
vast drained marshes and fens were ploughed. A negative effect of
keeping the water out of these fields was the increase of the annual
floods in the area close to the river.
Building high levees
Moreover, because of woodland clearance in the mountains catchments
of the river basin, the Great Plain received a greater volume
of water at a faster rate. To solve these problems, high levees were
built from 1884 onwards, with a final total length of 3000 km (Dunka
et al., 1996). These embankments divided the floodplain into a “floodfree”
area (inner-dike area) and the “floodway”(outer-dike area),
which is regularly inundated. Due to the levees being built close to
the riverbed and the isolation of the former meadows and marshes
from river floods, numerous habitats became considerably degraded
and, in addition, the biodiversity of these regions also substantially
decreased. Careless alteration of land use has led to the accumulation
of seemingly unsolvable economic and social problems (Mihók et al.,
2006; Rakonczay, 2002). As a result of water management, common
pastures had been parcelled by the end of the 19 th century and the
traditional transhumance in the floodplain meadows also ceased. The
extensive farming using the ancient grey cattle declined significantly,
and the “semi-wild” pig breeds also disappeared (Andrásfalvy, 2007).
Further draining and intensification
By the 1960’s, even the remaining inland waters on previous floodplains
beyond the levees had been drained. The arid grasslands,
having replaced the dried-out meadows, had been mostly ploughed
by that time. This situation was worsened with the introduction of
the single-crop system established on vast fields, together with the
increased use of chemicals and fertilizers. The replacement of the
floodplain meadows and native woodlands with plantations of alien
species (hybrids of Populus canadensis, Fraxinus pennsylvanica and
Acer segundo) and the establishment of large-scale cultivation on
the floodway also commenced at this time. However, an interesting
dualism can be observed concerning the utilisation of the floodway:
on floodplain meadows and pastures extensive, small-scale peasant
farming (grazing, mowing, etc.) survived until the 1980’s, simultaneously
with the socialist large-scale farming and forestry system. The
reason was that woodlands and wooded hayfields smaller than 50
ha were placed under the ownership of the farmers’ co-operatives
instead of forestry. Thus, their traditional, extensive utilisation may
have played a significant role in the preservation of riverine species
and biodiversity.
Although in the second half of the 20th century most floodplain
meadows lying in the floodway were converted into hayfields, grazed
pastures also remained until the 1980’s. The treeless grasslands, the
wooded pastures and hayfields and even the grass layer of the sparse
woodlands, were grazed and mown. The grazing and mowing pattern
of the grasslands was determined by the diverse topography, the
water regime and the climatic conditions.
Recent abandonment of the river valley
In the early 1990’s the socio-economic changes (re-privatisation,
decreased support for animal husbandry) considerably altered the
use of the floodway grasslands. Subsidisation of animal husbandry
reached its minimum level and as a consequence less milk, meat and
wool was produced. Since the local market system had not been developed
by that time due to the previous central control, the number
of livestock dramatically and rapidly decreased in the settlements
along the river. The management of the meadows and wooded pastures
of the floodway ceased and this has resulted in the slow invasion
by shrubs, which is consistent with their origin from woodland
clearance. At the same time, together with the abandonment of the
pastures, the cultivation of several arable fields also ceased, and
these areas were invaded in a few years by the previously introduced
Amorpha fruticosa. The sudden increase in the amount of propagules,
together with the high-level floods of the late 1990’s, led to the serious
infestation of all the grasslands, wooded hayfields and woodlands.
The swiftly spreading Amorpha fruticosa destroys the natural
vegetation by the deep shading of its dense population as well as by
means of allelopathy (Szigetvári and Tóth, 2002). When the individuals
invading a certain area reach the age of 4-5 years, they form a
closed canopy, and the grassland becomes featureless, the character
species disappear, and only species resistant to shading can survive.
The floodplain hay meadows of the region
Due to flood control, ancient floodplain hay meadows, with a nearnatural
water regime and water supply can only be found within the
floodway of the river Tisza. Floodplain meadows lying beyond the
levees have been either cultivated or have dried out, thus they have
become salinified and have changed into Achillea steppes. According
to recent studies, floodplain meadows isolated from the river totally
dry out and become salinised within 50-60 years. They are replaced
by dry, short grass-dominated steppes typically with Achilleo-Festucetum
pseudovinae vegetation (or Lythro-Alopecuraetum in regions of
lower elevation), the soil of which accumulates alkali salts at depth
(Molnár and Borhidi, 2003).
In the Pleistocene and lower Holocene, the meandering rivers of the
Great Plain deposited semi-circular point bars. These curved ridges
can be observed on hay meadows anywhere in the floodplain along
the Tisza. The narrow depressions between these ridges, which support
marshes and sedge-dominated communities, usually had a direct
connection with the river in past centuries. Today, these are covered
by smaller or wider patches of marsh vegetation dominated by
Glyceria maxima or Phalaris arundinacea large sedges such as Carex
gracilis, and beds of Phragmites australis or Typha latifolia. The top of
the curved ridges are covered by Peucedanum officinale dominated
meadow-steppes, while on their slopes and at lower elevations, tall
herb communities and different types of marshes have established.
The meadows have properly adapted to the rapidly changing water
supply and, with their dynamically changing species composition,
they tolerate both the longer humid and dry periods. Nowadays,
they are partially under nature conservation management, and the
authorities try to sustain their current state by mechanized mowing.
Under natural conditions, with the cessation of mowing or grazing,
the floodplain meadows are slowly encroached by the native riverine
trees (Salix alba, S. fragilis, S. purpurea, Populus alba, P. nigra, Quercus
robur, Fraxinus angustifolia ssp. pannonica, Ulmus campestris and U.
laevis) or shrubs (Viburnum opulus, Euonymus europaeus, Sambucus
nigra and Crataegus monogyna), as they originated from the cleared
woodlands. This tendency was utilised by humankind with the development
of wooded pastures and hayfields, where some young trees
were left to grow, establishing a special landscape characteristic of
the Tisza floodplain. Due to the cessation of management, the condition
of the wooded pastures and hayfields gradually declined and
they are replaced by thickets of introduced species over a relatively
short period of time. Though they have great value as examples of
traditional land-use supporting high biodiversity, their preservation
on the non-protected areas has not as yet been resolved.
Floodplain mesotrophic meadows
Floodplain mesotrophic meadows were once the most frequent
meadow type along the Tisza. Even today they serve as a matrix for
the floodplain hay meadows. Under natural conditions, they are wet
during the greater part of the year, and often inundated. They are
characterised by meadow and marsh species and dominated by Alopecurus
pratensis, Poa pratensis, Festuca pratensis, Dactylis glomerata
and Carex melanostachya. The average height of the sward is about
0,5-1 metre and species composition is determined by the duration
of water cover. The characteristic species are Clematis integrifolia,
Galium rubioides, Cardamine pratensis, Galega officinalis, Gratiola officinalis,
Viola elatior, Rumex confertus, Thalictrum flavum, Thalictrum
lucidum, Cirsium canum, Cichorium intibus, Symphytum officinale, Iris
pseudacorus, Galium palustre, Lysimachia vulgaris, Lythrum virgatum,
L. salicaria, Ranunculus repens, Pastinaca sativa and Lychnis flos-cucculi.
Sometimes they may have fen characteristics due to water logging.
This is indicated by the presence of species such as Serratula tinctoria,
Ophioglossum vulgatum and Gentiana pneumonanthe. In the meadows,
the characteristic colourful species include those that are often also
typical of the willow-poplar woodlands, such as Leucojum aestivum.
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