 | The
following articles are summaries from the handbook: Protection and development
of limestone grasslands in the Swabian Alb - Schutz und Entwicklung der Kalkmagerrasen
der Schwäbischen Alb (ISSN 0342-6858) - Beiheft 83 - Veröffentlichungen
für Naturschutz und Landschaftspflege in Baden-Württemberg, Karlsruhe
1995. - The limestone
grasslands of southwest germany - a model for conservation and development of
anthropo-zoogenic types of ecosystems
- Chances
and limits of conservation managment of dry grasslands
- Conservation
managment of calcereous grasslands
- Limestone
grasslands and poor meadows: endangered biotopes of the Schwäbischen Alb
- Investigations to
the fauna of frequently grazed limestone grasslands
- The
potential vulnerability of plant populations in limestone grasslands on the Middle
Swabian Alb by succession and afforestation - a coenotical approach
- The importance of
transhumance for the interchange of species between isolated limestone grasslands
- Succession induced
changes in the invertebrate fauna of limestone grasslands on the „Schwäbische
Alb“
- Natural
succession - an alternative development to limestone grassland of the „Schwäbische
Alb“
- Economical
aspects of nature conservation measures in limestone grasslands and low-productive
meadows
- Economics
of conservation and re-establishment of limestone grassland and low-productive
meadows
- The
importance of structural and surrounding area parameters for calcareous grassland
- Strategies for preservation
and development of dry, nutrient-poor limestone grasslands.
(13-30) Plachter et Schmidt, 1993 : The
limestone grasslands of southwest germany - a model for conservation and development
of anthropo-zoogenic types of ecosystems In the European and Anglo-American
societies nature and human culture are understood to be strictly opposite. This
is reflected in the basic concept of nature conservation as well, as the crucial
goal is the protection of „untouched“ nature against human influence. Adopting
this, man is compulsatorily the intruder, disturbing the ideal order of nature
by whatever activity he carries out there, thus lowering the intrinsic value of
the natural elements of the biosphere. In the light of actual scientific data
this puritanical attitude has to he questioned. Even in historic periods man’s
influence on nature had been more extensive than it was believed for a long time.
Untouched nature nearly no longer exist on eatth. This comes especially obvious
in the Central European cultural landscapes. Here the substantial influence of
man on the landscapes not only dates back for at least 6,000 years. Moreover:
the mass of the native fauna and flora is linked to anthropo-zoogenic types of
ecosystems, which owe theirs existence to very specific kinds of landuse. Many
of those landuse techniques became unusual or economically unprofitable in recent
times. By this the question has to been asked, whether and how far it is a task
of nature conservation itself to protect and encourage those historic landuse
practises. Alternatives could be the substitution of landuse by a specific nature
conservation management or the renunciation of any use or management in favour
of a undisturbed semi-natural succession. In Central Europe various grassland
ecosystems are very characteristic types of anthropo-zoogenic habitats. Although
the losses had been immense during the last 150 years, even nowadays they are
wide-spread in many areas thus determinating the visual quality of the landscape
and are still persisting in spatial connectivity of adjacent areas. In historic
landuse systems those ecosystems usually had been sources for nutrients (grazing
of lifestock; taking off biomass by harvesting without adequate substitution by
fertilizers). They therefore actually belong to the most nutrient-poor ecosystems
in the commonly over-fertilized landscapes of Central Europe, which - together
with a huge amount of endangered species -justifies their high protective value.
Recent losses are either due to a chance to modern kinds of landuse including
fertilization or conversation to fallow land, often followed by reforestation.
In the past nature conservation normally seeked to compensate those landuse changes
by substitutional management carried out by or for account of the nature conservation
agencies (in Germany: socalled „biotope-care“) or contracts with farmers which
guarantee financial compensation for the maintenance of unprofitable kinds of
historic landuse. Despite of the fact that a statical, conserving management ignores
the intrinsic dynamics of populations and ecosystems, the number of fallowed areas
has grown to an amount in recent days which exceeds the financial and organisatorical
capabilities of nature conservation agencies and NGOs by far. Among the grassland
ecosystems of Central Europe dry meager types, especially those on limestone,
play an extraordinarily role. In several regions they clearly determine the feature
of the landscapes. One of those regions is the „Schwäbische Alb“, a mountainous
region in southwest Germany (State of Baden-Württemberg), elevating to 700 to
900 meters above sealevel. Most of the dry nutrient-poor grassland there owes
its origin to traditional sheep keeping, which was carried out by shifting grazing
during the whole year. Summer and winter pastures were often separated by hundreds
of miles. The flock of sheep normally stayed only some hours or days on one specific
area, than turning to a neighboring one. It is obviously that this landuse system
is no longer very attractive regarding the international market as well as regional
economic and social features. Linked to this system of pastures are several types
of dry meadows which delivered fodder for sheep and cattles within the traditional
agricultural systems. Those ecosystems are at least as endangered as the dry pastures.
For the comparative evaluation of different types and successional states of this
nutrient-poor grassland and for the development of strategies for protection and
management of those stands the Ministry of the Environment of the State of Baden-Württemberg
placed a scientific research project in 1991. The results ought to be applicable
to other regions and to similar types of grassland ecosystems. The project
was carried out in close cooperation by nature conservation scientists and economists.
A permanent working group of officials, practical experts and scientists took
care of the implication of the results in practical work and the specification
of methodological regulations in the fields of évaluation and planning. Important
questions of the scientific work had been among others: - Are the normal
kinds of habitat management effective?
- Is a static protection of those
man-made ecosystems possible at all?
- Which methodologies are adequate
for the comparative assessment of areas and various kinds of landuse?
- What
is the history of landuse in this region in detail? Can historic states of landuse
be a reference for the future development of those grassland ecosystems?
- What
types of succession occur on fallow land?
- Will there be again valuable
stages within the successional course, which justify the decision to use certain
areas not any longer?
- Is therefore semi-natural succession an equally
worth alternative to persisting landuse?
- Is it possible to restitute
the historic pathes between the pastures for the flocks of sheep, also to improve
biological conductivity ?
- What are the social and economic key factors,
which cause the growing unattractiveness of sheep keeping?
- Are there
ways to improve these factors?
- Are there possibilities to reduce the
proportion of public subsidies in the income of the enterprises by offering new
chances on the public market?
-
back to top (31-36)
Petermann, 1993 : Chances and limits of conservation managment of dry grasslands
In the past 30 years measures of mechanical biotope care have been regarded to
be the sole option in order to prevent further loss of limestone grasslands in
the swabian alb region. It is the current goal of conservation managment to preserve
the remaining sites in face of a continuing decline of sheep herding and other
uses of meager grasslands. Site preservation is limited by the amount of funding
and personal available for managment purposes. Thus, even in large nature preserves,
sucession still takes its toll, further reducing the spatial reducing of limestone
grasslands. There is reason to believe that replacement of sheep grazing through
mowing is not a desirable general strategy, as it will lead to a shift in floral
and faunal composition and ultimately is bound of increase the degree of uniformity
between different grassland sites. Therefore, managment of limestone grasslands
should aim towards a mixture of pastoral use and mechanical managment. In this
context and for economical reasons, large unfragmented grasslands are best suited
for sheep grazing. Active mechanical managment should be concentrated on small,
isolated sites and the occasional removal of shrubs in large pastures. In spite
of numerous attempts to re-establish pastoral use of limestone grasslands sucess
has been sparse. Currently, only a increased effort in mechanical managment can
secure the present status of the remaining grasslands. Such efforts are necessary
to at least maintain the basis for a future re-emergence of the pastoral use of
these grasslands. - back
to top (37-63) Schumacher
et al : Conservation management of calcereous grasslandsThe Central
European calcareous grasslands are almoust all man made and when not being cultivated
anymore, a constant maintenance is necessary in order to preserve them. The respective
maintenance programs should be developed in such a way that a considerable integration
of agricultural use and maintenance is achieved. Keeping up or reintroducing an
extensive form of land use should be prefered to pure maintenance because of reasons
concerning the economy of nature, the ecosystem and agricultural structures. Generally,
maintenance through utilization (keeping up an old form of land use that isn`t
profitable anymore by directed financial aid) and maintenance without any form
of land use are distinguished. Reconditioning is understood to be the regeneration
of a poor grassland that has been lying fallow or been left to turn to scrubland
since a considerable amount of time. It is a measure that is only carried out
out once and is especially intended to rapidly remove the dead grass covering,
in addition to the scrub removal. On the other hand maintenance through utilization
(tending or paddock grazing, with sheep or other livestock) should preferably
by organized. -
back to top (109-126)
Beinlich und Klein : Limestone grasslands and poor meadows: endangered biotopes
of the Schwäbischen Alb The limestone grasslands (mesobromion) are
to be found on former forest sites and only evolved over the centuries after forest
clearing and subsequent grazing. Two types are distinguished: the mowed mesobrometum
(limestone meadows) and gentiano-koelerietum (limestone pasture). Especially in
this century the once widespread areas of limestone grasslands have diminished
to a great extent: about 50% have disappeared from the Alb since the beginning
of the century, outside the alb the losses are about 80-90%. In Baden-Wuerttemberg
supposedly about 150 km² of poor grasslands are still to be found. The dry and
economically poor meadows on limestone, which are closely related to the above
mentioned biotopes, are to be found within the alb area in three different forms:
the valley and mountain oat-grass meadows and the "Mittelgebirgs" or cranesbill-yellow
oat-meadows. Just as the actual poor grasslands, the dry and economically poor
meadows are also diminishling rapidly. The losses since the beginning of the 20th
century are estimated to be around 90%. All above mentioned types of grasslands
are extremely colorful flowered habitats. The importance of limestone grasslands
is due to their great number of drought and heat resistant plant and animal species
and of warmth needing species with a main area of distribution further south.
Additionally, many species have found a refuge here from the intensively used
modern agricultural landscape where no other richly flowered habitats can be found.
- back
to top (159-180)
Walther : Investigations to the fauna of frequently grazed limestone grasslandsThe
Swabian Alb (South-Western Germany) is one of the last centres of transhumant
sheperding in Central Europe. Frequently grazed (Grazing intervall about three
weeks) and adjacent little or ungrazed limestone grassland sites were compared
by inventorying four invertebrate taxa: Carabid beetles (Coleoptera), land snails
(Gastropoda), grasshoppers (Saltatoria) and butterflies (Lepidoptera). The largest
part of the land snail coenosis is made up of thermophilous and subthermophilous
species, of which even the most abundant ones are considered to be endangered.
Most of these species prefer short grass with a high proportion of bare ground.
Trochoidea geyeri has a disjunct range in central Europe. One of its largest populations
is found on the limestone grasslands of the Swabian Alb studied here. Sites with
little vegetation cover regularly harbour geophilus grasshopper species. In general
species favouring xerothermophilous conditions are rarely found in these parts
of the Swabian Alb for climatic reasons. Stenotopic carabid beetle species prefer
short grass in open areas. But, by far the most abundant species is Clathus fuscipes,
an euryoecious species of open areas. It makes up almost two thirds of all individuals.
Percentage of specialists that require the close interconnection of grazed and
ungrazed tracks at the edge of limestone grassland sites is high in the Lepidoptera
fauna. Diversity is higher on less grazed patches. Species typical for open areas,
like Lysandra coridon or Melanargia galathea are most abundant on short grass.
• High intensity of grazing does not necessarily lead to the degradation of a
limestone grassland site for nature conservation. This type of land use can create
essential habitat structures for specialized species if it is part of a mosaic
of similar habitats on a landscape level. - back
to top (199-226)
Poschlod et al: The potential vulnerability of plant populations in limestone
grasslands on the Middle Swabian Alb by succession and afforestation - a coenotical
approach In the region of the „Middle Swabian Alb“ the potential vulnerability
of plant populations of calcareous (limestone) grasslands to succession or afforestation
was investigated. A data base for all 187 species, occuring in the calcareous
grasslands of this region, was constructed. The collected data were life and growth
form parameters, the persistence of the shoot and generative diaspore population
along the successional sere (investigated by field observations and experiments)
and the dispersability. Dispersability was studied by a morphological classification
and by field observations of dispersal by sheep. Pollination also was classified
to look for a possible viability by missing or reduced geneflow. The greatest
part of the total species pool seems to have a low vulnerability to succession
and afforestation. Shoot or generative diaspore populations can still survive
in older succession stages. But for many species the dispersal by sheep is the
only possibility to survive by recolonizing suitable sites. Between 30 and 40
species are strongly endangered by succession and afforestation because the shoot
population cannot survive in older succession stages and the generative diaspore
bank is transient. Also dispersability is very low. Most of the species are already
in the Red Data Book of Baden-Württemberg, but some not yet like Anthyllis vulneraria,
Asperula cynanchica a. o. lf the trend of fallowing of liniestone grasslands is
still going on populations of these species will diminish and partially die out.
Therefore succession as an aim of nature conservation should be only a part of
the management of calcarcous grasslands. An extensive management concept could
be a „directed mosaic-cycle“. An afforestation as a management tool to avoid colonization
by clonal shrubs should be only an exceptional case. - back
to top (229-256)
SABINE F. FISCHER, PETER POSCHLOD und BURKHART BEINLICH : The importance of transhumance
for the interchange of species between isolated limestone grasslands
During the vegetation period 1993 a transhumant flock of sheep on the Swabian
Alb was examined concerning the question which plants and animals are transported
in the wool, hooves and the digestive tract of sheep within a calcareous grassland.
Furthermore, experiments on dispersal using marked diaspores and grasshoppers
on two tame sheep were carried out in order to find out their retention time on
sheep. During the time of research 108 vascular plants and 27 animal species were
discovered in the wool, hooves and excrement of the Münsingen flock. The wool
proved to be the most significant medium for the transportation of plants: during
16 intensive examinations of the fleece of a single sheep over 8500 diaspores
of 85 vascular plant species were found. The experiments with marked diaspores
showed that diaspores, once attached to the fur, can be transported over months
and consequently over the entire roaming area of the sheep. However, many plant
species are transported in the hooves and digestive tract of sheep. The hooves
of 30 sheep contained over 380 diaspores of 48 vascular plant species and in the
excrement of 105 acts of defecation 270 diaspores capable of germination from
27 plant species were fotind. Amongst the animals which are transported by sheep
only grasshoppers (13 species) and snails (7 species) were found frequently in
the fur and hooves respectively. During the experiments with marked grasshoppers
the average period of time the grasshoppers stayed on the sheep was 14 minutes.
Over this period of tame sheep cover a distance of over 100 m when grazing and
well over 500 m when roaming. Most of the snails were transported in the mud stuck
under the hoover. In the hooves of 30 sheep 18 shells of mainly srnall species
and juvenile snails were discovered. The results of this research prove that the
importance of shepherding, especially of transhumance, is more diverse than first
assumed. Sheep did not only shape the calcareous grasslands by trai-npling and
browsing, they are also responsible for an interchange of species between the
grazing through transportation of plants and animals. In this way the spreading
isolation effects in our greatly fragmented landscape of today, which are increasingly
endangering those organisi-ns with a weak capability of dispersal, can be reduced.
Additionally, this Transport is also essential for the regeneration of grasslands
having been left fallow over a tonger period of tii-ne: plants and animals with
weak capability of dispersal, which have meanwhile disappeared from the feillow
land can be reintroduced to these areas by sheep.- back
to top (283-310)
BURKHARD BEINLICH: Succession induced changes in the invertebrate fauna of
limestone grasslands on the „Schwäbische Alb“ The effects of fallowing
and the intrusion of shrubby vegetation on selected invertebrate groups (butterflies,
grasshoppers, snails, ground beetles and ants) was studied. As succession proceeds,
the number of species characteristic for limestone grasslands declines. This includes
threatened and endangered species. Intensively grazed limestone grasslands provide
suitable habitats for 50-60 endangered species, as compared to about 20-30 endangerd
species found to be associated with different successional stages. Depending on
the invertebrate group considered, maximum species richness is associated with
different successional stages. As shrubby vegetation cover surpasses 30 % of the
grassland area, a rapid decline of species numbers was observed in the ground
beetles. In contrast, species numbers were found to increase as succession proceeds
from early to medium stages in the butterflies and ants. The presence of meager,
short grass successional stages is particularly imponant for grasshoppers, snails
and ground beetles. In these groups 40 % of all the species in limestone grasslands
are associated with early successional stages. As succession proceeds to the final
beech-forest stage, the number of taxa with close habitat ties is bound to increase
again in the snails and ground beetles. From a conservation perspective, the communities
associated with late successional stages are, however, less valuable than those
associated with intensively grazed grasslands or early successionalstages.- back
to top (311-336)
BURKHARD BEINLICH, DANIEL HERING und H. PLACHTER: Natural succession - an
alternative development to limestone grassland of the „Schwäbische Alb“
Limestone grasslands have always been influenced by changes in land use. Consequently,
fallow land and the spreading of bush is not only an occurrence of the present.
However, the continuous intensification of cultivation in the form of ley farming
seems to have played a more essential role throughout the history of limestone
grasslands than the abandonment of land use followed by development of bushland
or respectively forest. Today, succession to forest constitutes the main cause
of endangerment to the existence of limestone grasslands. The course of succession
is determined by numerous factors (e.g. former land use, soil depth, water balance,
degree of bush covering, propagation and dispersal mode of occurring plants or
the behavior of certain animals) and can therefore proceed differently on similar
sites. Ultimately, the different courses of succession all proceed toward a collective
stage. This being one ofthe different types of beech forests depending on the
respective site. In the Schwäbisehe Alb-area the courses of succession on the
escarpment ridge differ distinctively from those of the Alb highlands. On the
escarpment ridge deciduous trees predominate the succession. Of great importance
in this case is blackthom, Prunuss spinosa, which spreads over polycormones, tends
to form a pure stand and as a result is difficult to be rid of through maintenance
measures. The succession processes on the Alb highland, on the other hand, are
mainly determined by conifers (esp. Pinus, Picea and Juniperus). Prunus spinosa
grows poorly here and consequently only plays a subordinate role. After ceasing
land cultivation bush generally spreads essentially slower on mowed limestone
and pooreconomic grassland than on abandoned pastures. This is mainly due to the
absence ofbare ground, which serves as a germinating bed for the seeds, and due
to the land becoming matted after cultivation stop. Considering that under the
conditions of the Alb highlands no sequel stage would even approximately attain
the value of regularly sheep-grazed open limestone grasslands and in addition
considering the possible implementation of similar succession processes on other
fallow areas, succession can not be contemplated as an altemative development
to limestone grasslands from a nature conservation perspective. Also the large
portion of succession forests in comparison to the areas of intact limestone grasslands
on the Alb speak against this thought - acoording to evaluations of five forestry
departments this portion lies at an average of about 57 %. - back
to top (349-358)
KLAUS TAMPE: Economical aspects of nature conservation measures in limestone
grasslands and low-productive meadows To conserve historical landscapes
in regions characterized by calcareous grassland and other types of low-productive
pastureland requires cost-intensive measures to be taken. These comprise both
reconditioning measures and, once the desired state of the landscape is attained,
provisions suited for its maintenance. Reconditioning measures have to be taken
only once at the start of a conservation programme and are necessary whenever
the areas lack the required properties due to former neglect. In general, trees,
shrubs and other woody material have to be removed. The maintenance measures subsequent
to reconditioning have to be taken continuously, and a distinction has to be drawn
between what might be termed „pure maintenance“ and „maintenance through utilization“.
While in the former case no (or almost no) goods are produced for the marketplace,
the latter are to be characterized as traditional land-use practices aiming at
producing agricultural goods, although at a very extensive level by to-day’s standards.
In general, „maintenance through utilization“ schemes are to be preferred to those
based on „pure maintenance“ for various reasons. „Pure maintenance“ measures should
only be taken in special cases or temporarily. They comprise the mowing of meadows
without utilizing the vegetable matter as fodder (although it might be necessary
that it must be removed from the areas and disposed of), the grazing of pastureland
without the animals achieving any significant economic value, and the regular
removal of woody plant material. Measures characterized as „maintenance through
utilization“ imply traditional haymáking and, especially on limestone grassland,
sheep grazing which is a case in point. Obviously, „pure maintenance“ measures
must be paid. Additionally however, prevailing conditions preclude any economic
profitability of extensive land-use schemes, if they receive payments only from
the sale of their marketable products. Therefore, „maintenance through utilization“
measures must receive an additional remuneration for their ecological services,
too. In both types of measures, annual costs can be calculated without difficulty.
However, if the total cost of land developement schemes are to be calculated on
an annual basis, costs incurring only once (such as for reconditioning measures)
or at regular intervals (such as for capital goods like machinery and buildings)
have to be transposed into rents respectively annuities, according to the rules
of financial accounting. In addition to the settlement of real costs involved
in landscape development, further payments may be necessary if certain land-users
are both physically capable and legally entitled to apply practices not in accordance
with regional conservation objectives. For instance, they may be willing to crop
their land intensively, applying high amounts of fertilizer and pesticides. They
are persuaded to abstain from intensive land-use and to cooperate in conservation
schemes only if they receive compensation payments which make them at least as
well-off as if they did not cooperate. Although the necessity to resort to compensation
payments such as these may also emerge in the region regarded here, it is advocated
that land-use conflicts of this kind must be resolved in other ways. The parties
not willing to cooperate in conservation should be offered areas outside the region
in exchange, where they may continue their intensive land-use.- back
to top (361-388)
KLAUS TAMPE und ULRICH HAMPICKE : Economics of conservation and re-establishment
of limestone erassland and low-productive meadows In search for strategies
for the conservation and ecological development of limestone grassland, other
pastureland and low-productive meadows in South-west Germany (Schwäbische Alb),
reference has to be made to human activities which have generated these ecosystems
in past centuries. The case in point are sheep-breeding and extensive haymaking.
Both utilization schemes are analyzed from an economic point of view, focussing
on two aspects: Firstly, costs and revenues from the sale of marketable products
are elicited. Secondly, their usual financial deficit is established in order
to estimate the necessary funding which these activities must receive in order
to make them economically sustainable. This funding can be interpreted as a remuneration
for valuable ecological services. Today, sheep-breeding is run both by migratory
and stationary herdsmen. Seasonal migration being increasingly on the decline
due to various obstacles such as missing cattle-tracks and pasturages utilizable
during the winter, the strategies suggested here focus on stationary systems.
Sheep-breeding in the region „Schwäbische Alb“ is centred around two military
training areas near the towns of Münsingen and Albstadt. Save exceptionally favourable
circumstances (for instance the possibility to sell products at the farm to tourists
or restaurants), both migratory and stationary systems perform poorly in economic
terms if all cost components are considered properly in the calculation. This
is true even allowing for current subsidies. Since 1993, sheep-farms grazing their
droves on chalk grassland classified by the Nature Conservation Law (§ 24a NatSchG)
of the land Baden-Württemberg, improve their income considerably by receiving
DM 200 per hectare and year from the land’s conservation programme (MEKA). Yet
this improvement fails to assure a complete coverage of all costs in stationary
sheep-breeding. For the latter system to be sustainable, provision has to be made
not only for a winterproof sheepshed but also for a well-designed scheme of fodder
supply implying sufficient areas of energy-rich supplemental green food in addition
to the poorer material growing on the limestone grassland. Further requirements
concern pasturages utilizable during autumn and, of course, sufficient hay resources
for the winter half-year. If, on the average, four ewes graze on one hectare of
limestone grassland, one hectare of summer pastureland requires the addition of
0,08 hectare of supplemental green food, 0,17 hectare of autumn pastureland and
0,44 hectare for meadows for haymaking. It is assumed here that lowly-productive
haymeadows are used in order to conserve their ecological qualities. According
to the economic analysis carried out here, the stationary sheep-breeding system
is, under normal conditions, characterized by the fact that the disproportional
or ftx costs exceed the receipts from sales of meat and wool, calculated in pure
market prices (less proportional costs), by DM 1048 per hectare and year. The
most important cost components are wages, annuities for the sheepsheds and the
reconditioning measures (removal of shrubs and trees from the pasturages) although
the latter accrue to the public rather than to the sheep-farm. If society wishes
sustainable sheep-breeding to be continued in order to conserve the countryside
in the region, roughly DM 1000 per hectare and year must be made available in
one form or another, additionally to the earnings from product sales, calculated
in market prices. All subsidies already in existence, such as payments per ewe
or per hectare, resulting from landscape preservation programmes organized by
the EC or by the land BadenWürttemberg and from other sources, sum up to roughly
DM 600 per hectare and year, so that the remaining deficit totals about DM 400
per hectare and year, of which DM 240 are allotted to reconditioning measures.
The economic analysis of haymaking on low-productive meadows yields a somewhat
different result. Assuming a wage rate of DM 15 per hour and allowing for all
fix and proportional costs, the system yields an economic deficit of about DM
300 per hectare and year if the hay is marketed at current prices (1993). In most
farms, this deficit is fully covered by current subsidies so that no further funding
appears necessary, assuming that the economic circumstances do not deteriorate
in the future. An important contribution in this respect is the provision for
consolidated hay-markets which can be assisted efficiently by the establishment
of a sustainable sheep-breeding system in the same region and its continuous demand
for hay during the winter season. - back
to top (391-406)
DANIEL HERING & BURKHARD BEINLICH The importance of structural and surrounding
area parameters for calcareous grassland The composition of calcareous
grassland biocoenoses depends to a great extent on different structural and surrounding
area parameters. The area size and the distance to other calcareous grasslands
influence the probability ofpopulation survival and consequently also the species
inventory. Additionally, the habitat conditions and the occurrence of certain
animal species are greatly determined by the exposure and the vegetation structure.
Further factors that contribute to the forming of calcareous grassland biocoenoses
are the density of shrubs, the soil structure and the occurrence of typical special
sites. The effect of the mentioned parameters on calcareous grassland biocoenoses
is documented in the literary references and our own research data. These effects
are further clarified by examples. - back
to top (441-463)
HARALD PLACHTER UND BURKHART BEINLICH Strategies for preservation and development
of dry, nutrient-poor limestone grasslands Even in historic time man
has had a decisive impact on nature. This resulted in the creation of new ecosystem
types. The human impact is particularly striking in the Central European cultural
landscapes, where historic landuse systems created a fine-grained mosaic of natural,
semi-natural and anthropo-zoogenic ecosystems. Historic landuse practises are
essential for the continued existence of many specific ecosystems but they are
increasingly replaced by modern landuse techniques. Recently, not only intensification
but cease of use as well has tumed out to be a problem for conservation. Fallow
land is often preserved through substitutive management by nature conservation
institutions. But the capacities for this kind of management are limited and its
impact frequently differs significantly trom the historic one. Thus, in spite
of the management efforts, the anthropogenic ecosystems change. Dry, nutrient-poor
limestone grasslands (Mesobromion) are still common in several parts of Central
Europe, considerably shaping the visual qualities of the landscapes and providing
habitat for many species. Originally these grasslands either had provided hay
(meadows) or they had served as pastures. The pastoral use mainly was tied to
migrating herdes. The pastures served as nutrient sources within the complex historic
landuse systems and thus owe their existence to unsustainable practices. For several
reasons dry, nutrient-poor calcareous grassland can serve as a very delicate model
for a future management and development of anthropo-zoogenic ecosystems which
is in line with the goals of nature conservation. In this context a study was
carried out in limestone grasslands of South-west Germany (State of Baden-Württemberg).
The historic landuse types are no longer profitable. Therefore, to preserve their
high degree of biodiversity an increasing number of areas has to be managed by
nature conservation institutions. Even today the number of areas exceeds the capacities
of these institutions. Therefore the frequency and degree of management impacts
is considerably lower than in historic times. It is not sufficient to preserve
a specific state of succession in a long-time perspective. Recently, the protection
of natural ecological processes has been identified to be an imponant, independant
goal of nature conservation. Natural succession is such a process. However, it
is doubtful whether for limestone grasslands succession would be a general acceptable
alternative to historical usage patterns. In fact there is not one single strategy
which is applicable to all grassland ecosystems types but a series ofalternatives
ofprimarily equal importance. The decision for one of these alternatives has to
be made on a local level, taking into account general landscape scenarios for
the future development of the region. For dry, nutrient-poor limestone grassland
in South-west Germany those alternatives are: 1. Promotion and restitution
of sheep keeping under a grazing regime, where the flocks are kept in stables
during winter while they are herded between pastures during the rest of the year.
In this scenario winter stable and the winter feed are economically sensible factors.
Improving profitability therefore means to lower the costs for these factors within
the economic balance of the entire enterprises. 2. Promotion of adequate
agricultural practices for nutrient-poor grassland. This strategy especially -
but not only - refers to nutrient-poor and mesophilic meadows. Measures include
governmental subsidies as well as regional marketing strategies. By linking strategies
I and II, winter feed can be provided to sheep keepers from nutrient-poor grassland
thereby increasing profit margins for an extensive landuse system. 3.
Preservation and management of out standing areas which lost their historic types
of use. Due to limited capacities and general ecological considerations this strategy
must be confined to few areas. 4. Preservation of the regional set species
diversity. In many regions nutrient-poorgrassland is already restricted to small
and isolated areas. If these areas are lost, many species will vanish from large
regions. In this case, even if the situation improves in future, re-colonization
is not very probable. Thus the persistance of those relict areas is highly important.
5. Succession. If none of the above strategies turns out to be useful
for a specific area, succession can be an appropriate alternative. But a decision
in favour of succession must take into account, that in South-west Germany a considerable
part of former grassland has been left to succession in the past decades.
The resulting forests are excellent starting points for the implementation
of „process reserves“, but an inventory of those areas is still laking and the
knowledge concerning their actual state is still poor. Some military training
areas prove to be outstanding staIting points for the implementation of those
strategies. This is particularly true for the strategies I and II. Management
of those vast areas depends on sheep grazing, this being a promising basis for
economically profitable enterprises. |