Common pastures as biodiversity refuges in the pre-alpine agricultural landscape - From relict to future model?
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Introduction 1
From relict to future model?
Common pastures as biodiversity refuges
in the pre-alpine agricultural landscape
C INJA S CHWARZ
Front & back cover Front: Pre-alpine landscape with the common pasture Mühlenberger Viehweide and the characteristic species (from left to right) Stethophyma grossum (Photo: Gregor Stuhldreher), Tree Pipit (Photo: Joachim Fünfstück) and Minois dryas (Photo: Thomas Fartmann). Back: Common pasture Echelsbach Gschwend.
First supervisor: Apl. Prof. Dr. Thomas Fartmann Second supervisor: Apl. Prof. Dr. Günter Purschke Date of disputation: 11.03.2022
From relict to future model?
Common pastures as biodiversity refuges in
the pre-alpine agricultural landscape
A thesis submitted for the degree of
Doctor rerum naturalium
Osnabrück University
Faculty of Biology/Chemistry
Department of Biodiversity and Landscape Ecology
submitted by
C I NJ A S C H W A RZ
2021
Contents
Chapter I
Introduction ................................................................................................................................. 1
Chapter II
Comparison of common pastures and control plots ............................................................. 11
Paper I
Common pastures are important refuges for a declining passerine bird in a pre‐alpine
agricultural landscape
SCHWARZ C, TRAUTNER J, FARTMANN T (2018)
Journal of Ornithology 159: 945–954. ................................................................................... 12
Paper II
Conservation of a strongly declining butterfly species depends on traditionally managed
grasslands
SCHWARZ C, FARTMANN T (2021)
Journal of Insect Conservation 25: 255–271. ........................................................................ 14
Paper III
Traditional grazing management creates heterogeneous swards and fosters
grasshopper densities
SCHWARZ C, FARTMANN T (2021)
Insect Science (accepted) ....................................................................................................... 16
Chapter III
Summary and Synopsis .............................................................................................................. 20
References .................................................................................................................................. 27
Danksagung ................................................................................................................................ 38
Curriculum Vitae ....................................................................................................................... 39
Publications ................................................................................................................................ 40
Erklärung über die Eigenständigkeit der erbrachten wissenschaftlichen Leistungen ........... 41
Chapter I Introduction
2 Chapter I
Global biodiversity crisis Agricultural land in Europe
Humans have altered the physical en-
vironment of the earth at an unpreceden- GENESIS OF TRADITIONAL LANDSCAPES
ted rate since the beginning of the indus- The agricultural landscape in Europe is
trial era 200 years ago (Foley et al. 2005, the result of a long-lasting land-use histo-
Rockström et al. 2009). As a result, bio- ry with different stages that overlay, re-
diversity is declining sharply, with current fine and replace each other (Plieninger et
rates of species extinction 1,000 times al. 2006). Humans began to form the
higher than the natural background rate landscape by introducing grazing systems
and this trend is increasing (De Vos et al. with domestic animals and arable cultures
2014). Previous efforts to delay biodiver- during the Palaeolithic (Bouma et al.
sity loss have been inadequate, with a 1998). Over time, this human impact on
growing mismatch between increasing the landscape increased and became
pressure on biodiversity (e.g., resource large-scale during antiquity (Vos & Mee-
consumption, overexploitation and clima- kes 1999). From the Middle Ages to the
te change impacts) on the one hand, and Renaissance, the entire European agricul-
slowing responses to this development tural landscape was gradually exploited,
on the other (Butchart et al. 2010). Ar- with a high degree of diversity in man-
guably, humans have triggered a sixth agement systems (Bouma et al. 1998,
global mass extinction (Barnosky et al. Vahle 2001). What we see as the tradi-
2011). tional agricultural landscape was formed
For terrestrial biomes, land-use change mainly between the Renaissance and the
is assumed to be the main driver of the 19th century: Multifunctional land-use
biodiversity crisis (Sala et al. 2000, Foley systems such as mixed agriculture, in-
et al. 2005, Rockström et al. 2009). In tegrated forests, tree pastures and rough
Europe, biodiversity is strongly connect- grazing lands, varied strongly on a small
ed to agricultural land due to a long histo- scale, where they adapted to climate, phy-
ry of cultivating land and a diminution of siography and local cultures (Bouma et al.
natural habitats (Beaufoy et al. 1994, Phil- 1998, Vos & Meekes 1999). Remnants
lips 1998, Vos & Meekes 1999, Plieninger from this traditional landscape still exist
et al. 2006, Donald et al. 2006, Henle et today, but a large proportion has been
al. 2008, Kleijn et al. 2009). At present, drastically re-shaped into an industrial
agricultural land covers more than 40% agricultural landscape since the industrial
of the European surface (EU-28, Euro- revolution during the second half of the
stat 2017) and is very important for bio- 18th century (Vos & Meekes 1999).
diversity conservation (BMU 2007, Henle
et al. 2008). However, this is also where LAND-USE CHANGE
we see the largest decrease in biodiversity Since the industrial revolution, Europe
across different taxa such as plants, in- has entered a new era of agricultural
sects and birds, and most farmland spe- management practices (Rockström et al.
cies are highly threatened (Vickery et al. 2009): Land-use systems are predomi-
2001, Donald et al. 2006, Flohre et al. nantly monofunctional on a large scale,
2011). with similar production systems imple-
Introduction 3
mented using the same industrial meth- creasing depopulation of marginal areas
ods (Vos & Meekes 1999). The majority (Cocca et al. 2012).
of society is alienated from agricultural
land use, which is increasingly dominated VALUE OF THE REMAINING TRADITIONAL
by external markets and governmental LAND-USE SYSTEMS
planning procedures (Bouma et al. 1998, Nowadays, traditional land use is often
Vos & Meekes 1999). synonymous with low intensity farming
Thus, land-use change had two oppos- because characteristics of both are (i) low
ing effects for the agricultural landscape external input (e.g., nutrients, agrochemi-
in Europe (Foley et al. 2005, Henle et al. cals), (ii) sparse land drainage, (iii) low
2008, Kleijn et al. 2009, Plieninger et al. mechanisation, (iv) slow rate of land-use
2016): On the one hand, agricultural land change and (v) low output per hectare
use was intensified on productive land with minimised nutrient emission, water
which resulted in an expansion of arable loss and reuse of production waste (e.g.,
land (Bakker 1989, Höchtl et al. 2005). dung as fertilizer) (Beaufoy et al. 1994,
On the other hand, in more marginal Velthof et al. 2014, Plieninger et al. 2016).
farming areas with physical or socio- Often, spatially and temporally differenti-
economic obstacles, agricultural land fell ated rotational principles exist with alter-
into disuse (Plieninger et al. 2016). Both nating periods of human impact and of
intensification and abandonment led to a regeneration (Plieninger et al. 2016).
dramatic decline of traditional land-use Livestock farming is usually performed
systems and promoted the homogeniza- with regional heritage livestock breeds in
tion of the landscape with severe negative low stocking density and with a limited
effects on nature conservation and biodi- use of concentrate feeds (Beaufoy et al.
versity (Beaufoy et a. 1994, Bouma et al. 1994, Velthof et al. 2014).
1998, Kleijn et al. 2009). Consequently, most traditional land-
Today, few traditional land-use sys- use systems (i) are rich in structures,
tems remain in Central Europe, especially (ii) offer many ecological niches, (iii) sup-
in areas where land-use change is imped- port a well-adapted wildlife due to long
ed due to marginal environmental condi- continuity of management systems and
tions (e.g., in uplands, mountains and (iv) have a high biodiversity with many
wetlands) or specific socio-economic, rare species (Pykälä 2000, Lederbogen et
cultural, or political causes (e.g., land al. 2004, Hampicke 2006). Thus, tradi-
property conditions) (Beaufoy et al. 1994, tional land-use systems have a high prior-
Brown 2006, Plieninger et al. 2006). The ity and a special importance for Europe-
co-development of land use, ecosystems an nature conservation (Bakker 1989,
and species over such a long period of Stenseke 2006). Although there is a gen-
time is globally unique (Pykälä 2000, eral desire to preserve traditional land-use
Hampicke 2006, Stenseke 2006). Howev- practices and cultural landscape, only a
er, the remaining systems are decreasing small proportion of area is protected or
rapidly because of the increasing eco- funded nowadays and thus preserved for
nomic importance of off-farm labour for the future (Beaufoy et al. 1994). Due to
descendants of the farmers and an in- the great regional variation in traditional
4 Chapter I
land use, each system has evolved its one of the main areas of common pas-
own characteristics and diversity that tures in Central Europe.
requires differentiated considerations
(Beaufoy et al. 1994). Study area
The study area – a stronghold for com-
Common land mon pastures in Central Europe – is situ-
For many centuries, the use of common ated in the pre-alpine region (hereafter
land was a central element of traditional called pre-Alps) of southern Germany in
agriculture in Europe (Brown 2006). In the Federal State of Bavaria (Figure 1)
the past, most of the pasturelands were (Pille et al. 2003, Lederbogen et al. 2004).
commonly used under the condition of For my dissertation, I have chosen twelve
equality for all members of a community traditionally managed, large-scale com-
(Helfrich 2009, EFNCP 2021). Sharing mon pastures in that region (Table 1).
land ensured a livelihood especially for The study area is located between
small farms with little land ownership 750–900 m a.s.l. at the northern edge of
because the costs could be reduced e.g., the Alps (LfU 2020a). There, a molasse
by sharing the construction and upkeep basin formed during the alpine orogene-
of fences, or the herding of livestock sis since the Cretaceous and received the
(Lederbogen et al. 2004). ablated fine sediments, sands and gravel
As part of the land-use change, com- from the Alps (Doppler et al. 2004). In
mon pastures have sharply decreased in interaction with sea-level fluctuation until
value and extent over the past two centu- the Miocene, this led to two great shifts
ries (Lederbogen et al. 2004, Brown between marine and freshwater molasse
2006). Fundamental changes in social and (Doppler et al. 2004). The molasse basin
political conditions led to the increasing is divided into the folded molasse, which
pursuit of private property and thus to a forms part of the alpine nappe structure
separation and fragmentation of common and the foreland molasse (LfU 2020a,
land (Beaufoy et al. 1994, Brown 2006). Doppler et al. 2004).
One of the major changes made in this During the Würm – the last glacial pe-
context was the distinction of open- and riod in the Alps – glacier advances
woodland (Lederbogen et al. 2004). The formed a young moraine landscape: Gla-
consequences for agricultural biodiversity cial erosion and accumulation of mo-
were devastating because structure, com- raines, tills and meltwater sediments de-
position and functioning across different veloped a small-scale heterogeneous land-
scales became more and more homoge- scape (LfU 2020a). Special features of the
neous (Cardinale et al. 2012). study area are drumlins: Large hills facing
Today, only remnants of the historical north-east/south-west, streamlined with
common pastures with their traditional the glacier flow (LfU 2020a).
management have survived, most of The climate of the pre-Alps is cool
them in agriculturally marginal areas and wet with a mean annual temperature
(Brown 2006, Plieninger et al. 2006). Due of 7.7 °C and an annual precipitation of
to the vulnerability of this land-use type 1,336 mm (meteorological station Bad
and its potential for the conservation of Kohlgrub 742 m a.s.l.; period: 1992–
biodiversity, I focus my dissertation on 2019; DWD 2020). The sunshine dura-Introduction 5
Figure 1: Location of the study area and common pastures in Upper Bavaria (southern Germany). For the
abbreviation of the common pastures see Table 1.
tion is comparatively high for Germany scale mosaic of land use, which is particu-
with an average of 1,600 to 2,000 hours larly impacted by dairy farming (BfN
per year (period: 1961–2019; DWD 2012). In the past, pastures included the
2020). In the pre-Alps, small-scale climate whole range from subjacent mires to pro-
differences prevail based on relief and truded woodlands, which usually covered
altitude (Lederbogen et al. 2004). Fur- the glacial deposits, so a wide range of
thermore, extreme weather events like semi-natural habitats developed (BfN
summer thunderstorms, winter fog, late 2012). For a long time, the rural popula-
frost and snowfall through until May are tion relied on farming on such rather
characteristic of this region (Lederbogen low-yield land at low costs because of a
et al. 2004). lack in transport possibilities and long-life
Due to the climate and landscape food preservation, and a generally low
morphology, the area is characterised by a productive capacity in the agricultural
small-scale mosaic of different soil types: sector (Beaufoy et al. 1994, Lederbogen
The most common soil types are brown et al. 2004). Some of the once extensive
earth, luvisol and pararendzina on morai- common pastures still exist, with relative-
ne accumulations and drumlins, and stag- ly stable livestock pasturing in the study
nosol, gley and mire in valleys and de- area (BfN 2012). These common pastures
pressions (LfU 2020b). The scale and are characterised by fluent transitions
variety of mires make the pre-Alps the between open and forest landscapes and
most important stronghold for mires in the presence of extended mire (Scholle et
Central Europe (Succow & Jeschke 1990, al. 2001).
Ackermann et al. 2012). However, land-use change has not
In this region, small-scale alternating failed to leave its marks: Until the 19th
environmental conditions led to a small- century, pastures were used predominant-6 Chapter I
Table 1: Overview of common pastures and research content of the three papers in this thesis: Fieldwork
took place on patches of 25 ha (Paper I) and plots of 500 m 2 (Paper II, III). HA and MO are remaining areas
of a former common pasture, which is currently managed with traditional methods by one shareholder.
District: GAP = Garmisch-Partenkirchen, OAL = Ostallgäu, TÖL = Bad Tölz-Wolfratshausen, WM =
Weilheim-Schongau; management: R = Rotational grazing system, P = Permanent grazing system (May–
October).
Mühlenberger
Lettigenbichl
Moosreitner
Bernbeurer
Steingädele
Urspringer
Echelsbach
Hachegger
Gschwend
Viehweide
Viehweide
Viehweide
Viehweide
Viehweide
Viehweide
Viehweide
Viehweide
Viehweide
Berghofer
Söldner
Premer
Holzer
Rieder
Abbreviation BS BE EG HA HO LE MO MV PV RV UR ST
District OAL WM GAP WM WM GAP WM OAL WM TÖL WM WM
Area (ha) 68 27 80 15 32 56 5 54 121 56 53 34
Management R R R R P R P P/R R P R R
Paper I: Common pastures are important refuges for a declining passerine bird in a pre-alpine agricultural landscape.
Tree Pipit
Territorial mapping1
Environmental parameters
Biotope types2
Borderline density3
Landscape diversity4
Paper II: Conservation of a strongly declining butterfly species depends on traditionally managed grasslands.
Minois dryas
Oviposition-site mapping5
Territorial mapping6
Environmental parameters
Grazing pressure7
Nectar plants8
Sunshine duration9
Vegetation structure10
Vegetation types11
Paper III: Traditional grazing management creates heterogeneous swards and fosters grasshopper densities.
Grasshoppers
Assemblage mapping12
Environmental parameters
Grazing pressure7
Sunshine duration9
Vegetation structure10
Vegetation types11
1 According to Bibby et al. (2000)
2
According to Riecken et al. (2006)
3 Between open and forest landscape
4 Shannon Index according to O’Neill et al. (1988)
5 Sampled in a radius of 30 cm around oviposition and random sites
6 Sampled with a standardized transect walk (Pollard & Yates 1993, Weking et al. 2013)
7 Measured as number of cow and horse droppings
8 Method according to Krämer et al. (2012), based on Leopold (2001) and Corwell & Futuyuma (1971)
9
Measured with a horizontoscope after Tonne (1954)
10 Included different vegetation layer covers, density and height
11 Using character and differential plant species according to Oberdorfer (1992), Dierßen & Dierßen (2008)
12 Sampled with box quadrat of 2 m2 placed randomly 10 × per patch (Gardiner et al. 2005, Gardiner & Hill 2006, Fartmann et al. 2008)Introduction 7
ly in summer, with daily movement of in ecosystems, (v) are declining or threat-
livestock (oxen, horses, dairy and young ened and in need of protection and
cattle) and ancillary uses (peat working, (vi) are determinable with standardised,
removal of timber, firewood, leaves for proven and practicable methods (Dale &
bedding and grasses for winter feed) Beyeler 2001, Lederbogen et al. 2004,
(Lederbogen et al. 2004). Since the indus- Siddig et al. 2016). Based on these crite-
trialisation, some productive mineral soils ria, I selected indicator species from the
have been drained, levelled and fertilised classes of birds (e.g., Donald et al. 2006,
in contrast to less productive mires Lederbogen et al. 2004, Gregory et al.
(Lederbogen et al. 2004). Furthermore, 2004, Graham et al. 2017, Newton 2017)
ancillary uses were largely discontinued and insects (e.g., Lederbogen et al. 2004,
(Lederbogen et al. 2004). Fartmann & Hermann 2006, Poniatowski
However, the dominant form of land & Fartmann 2008, Krauss et al. 2010,
management has been maintained until Schirmel et al. 2010) because they cover a
today: Common pastures are still used for wide span of ecological demands on dif-
raising dairy cattle in low stocking capaci- ferent spatial scales and avoid an over-
ties of 0.5–2.0 livestock units per hectare simplified understanding of interactions
on extensive rotational or permanent (Dale & Beyeler 2001).
pastures throughout the summer (Leder-
bogen et al. 2004). This land use is of BIRDS
existential importance for the majority of Birds respond to environmental changes
shareholders of the pastures in the study at moderate spatial and temporal scales
area (Lederbogen et al. 2004). (Gregory et al. 2004). They are mainly
sensitive to changes in breeding habitats
Indicator species and food supply (Vickery et al. 2001,
Using indicator species is an established Benton et al. 2002, Newton 2004). Due
method in environmental research to to their position on top of the food
(i) assess the abiotic and biotic state of an chain, their assemblages reflect alterations
environment, (ii) identify key information of producers or consumers (Gregory et
about complex ecosystems and (iii) depict al. 2004).
the impacts of environmental change on A suitable indicator bird for this thesis
habitats, communities and ecosystems is the Tree Pipit (Anthus trivialis): It is
(Dufrêne & Legendre 1997, McGeoch strongly specialised in semi-open habitats
1998, Dale & Beyeler 2001, Siddig et al. with fluent transitions between open and
2016). forest landscapes that are key elements of
Therefore, in my thesis I chose to the traditional used systems in the study
work with indicator species that (i) repre- area (Loske 1987a, Gregory et al. 2004,
sent the community of valuable open and Südbeck et al. 2005). Furthermore, it is
semi-open habitats on common pastures representative for other species which
in the study area, (ii) are sensitive to envi- need the same habitat (e.g., other farm-
ronmental changes, (iii) respond to these land birds like the endangered Red-
changes in a known and predictable Backed Shrike [Lanius collurio]) (Leder-
manner, (iv) indicate an impeding change bogen et al. 2004).8 Chapter I
INSECTS all threatened species in Germany
Insects are excellent indicator species for (Lederbogen et al. 2004).
grasslands because they are short-lived
and respond rapidly to environmental Knowledge gaps
changes (Schirmel et al. 2010, Ponia- The main reasons for current levels of
towski et al. 2018). In less fragmented biodiversity loss are habitat destruction
landscapes like the study area, habitat and habitat loss as result of land-use
quality has been mentioned as a major change (Sala 2000, Jantz et al. 2015).
driver for insect distribution and diversity Thus, one of the main tasks for mitiga-
(Krämer et al. 2012, Löffler & Fartmann ting the global biodiversity crisis now is
2017, Münsch et al. 2018, Poniatowski et to identify and conserve agricultural sys-
al. 2018). Habitat quality depends largely tems with high biodiversity. This thesis
on the availability of sufficient host, contributes to this by analysing the bio-
nectar or food plants, sufficient vegetati- diversity value of traditionally used com-
on structure and microclimate (Ponia- mon pastures in the pre-Alps. Carefully
towski & Fartmann 2008, Munguira et al. selected indicator species show the rele-
2009, Stuhldreher & Fartmann 2018). In vance of this habitat for the threatened
this thesis, I focussed on the less mobile community of farmland species in Cen-
group of Orthoptera (hereinafter termed tral Europe (Quinger et al. 1995, Leder-
‘grasshoppers’) and the highly mobile bogen et al. 2004, van Swaay et al. 2006,
butterfly species Minois dryas. Grasshop- Streitberger et al. 2012). Knowledge
pers have a high functional significance in gained from this thesis should contribute
grasslands due to their key role as her- to conserving existing biodiversity hot-
bivores and prey (Samways 2005). spots.
Consequently, I chose them to gain in- A further task for the mitigation of
sights into the state of the whole ecosys- biodiversity loss is to outline processes
tem. and functional connections between land-
Butterflies – with their exceedingly use practice and biodiversity. Despite the
complex habitat requirements – are de- once global distribution of common pas-
clining more strongly than many other tures, not much is known about the rela-
taxonomic groups (Thomas et al. 2004, tionship between this farming system and
Thomas 2005). They are a major model the demands of most species living in it
group in ecology and biodiversity conser- (Beaufoy et al. 1994). To contribute to
vation (Watt & Boggs 2003, Ehrlich & closing this gap, I focussed on how rela-
Hanski 2004). Particularly M. dryas is tionships between plants, invertebrates
severely affected by land-use change due and birds have developed and the result-
to its specialisation on the nutrient-poor ing dependence of many highly specialist
open mires that are a key element of the species on a relatively stable, albeit hu-
common pastures in the study area man-modified environment (Beaufoy et
(Ebert & Rennwald 1991, van Swaay et al. 1994). A detailed area-wide systematic
al. 2006). It is representative for other analysis of the habitat preferences of
species of secondary usage-dependent farmland species like Tree Pipit, M. dryas
open habitats that make up a large part of and grasshoppers on common pasturesIntroduction 9
compared to the surrounding landscape is bility concerning land use and the special
still missing. Thus, the relevance of graz- role of the pre-Alps for their conserva-
ing for their conservation on common tion. Further, I focus on transitions be-
pastures in general and on different grass- tween forest and open landscapes be-
land and mire types in particular is largely cause they are sharply separated as a con-
unknown. sequence of land-use change. With my
This thesis is the first study using a research and the knowledge gained, I
systematic and quantitative approach on a hope to raise attention for the common
multi-taxa level considering vertebrate pasture as a valuable land-use type.
and invertebrate species and drivers for Hence, I address the following research
biodiversity for common pastures in the questions:
pre-Alps. Furthermore, the ecological
research presented here contains the larg- Importance of common pastures in the modern
est number of common pastures with the agricultural landscape of the pre-Alps
largest spatial extent conducted so far in - How does land-use change affect land-
this area. The few existing studies are scape, habitats and biodiversity?
mostly descriptive (Lederbogen et al. - Are common pastures important
2004) or consider only one common pas- refuges for farmland species and biodi-
ture (Bhattarai et al. 2004, Rosenthal & versity hotspots?
Lederbogen 2008), or a single taxon (An-
thes et al. 2003, Grüneberg 2003, Harry Grazing influence on the habitat quality of
et al. 2005, Rosenthal 2010, Fumy et al. common pastures
2020). Therefore, generalisations can only - How does grazing affect habitat quality
be made to a limited extent. Studies for farmland species and biodiversity?
which are comparable in scope to this - What are the key drivers for farmland
thesis in other parts of Central Europe species and biodiversity in the study
are exceptions so far (Kostrzewa 2004, area?
Sutcliffe 2013).
Implications for conservation
Aims of the thesis - Which management recommendations
The main aim of my thesis is to examine for the conservation of farmland species
whether and to what extent common and biodiversity can be derived from
pastures contribute to biodiversity con- the findings?
servation in the modern agricultural land-
scape of Central Europe. There is some Outline of the thesis
evidence which indicates that they serve This thesis consists of three papers, each
as refuges for declining wildlife (Leder- of which focuses on the aforementioned
bogen et al. 2004) – but to date, quantifi- questions for one indicator species or
able research is missing group, i.e., (i) Tree Pipit (A. trivialis),
In addition, I examine how traditional (ii) dryad (M. dryas) and (iii) grasshoppers.
long-time grazing affects habitat quality In the first paper, I quantify Tree Pipit
for declining farmland indicator species. territories on common pastures and
In this context, I pay particular attention compare them to the surrounding land-
to mire ecosystems due to their vulnera- scape. I analyse in detail which key fac-10 Chapter I
tors determine habitat quality for the management recommendations for the
Tree Pipit. Territories and home-range conservation of M. dryas.
scale are regarded separately due to diffe- The third paper addresses the impacts
rent demands. In addition, I discuss the of common pasturing on grasshopper
importance of common pastures for the assemblages. For a comparison between
conservation of this species. common pastures and the surrounding
The second paper focuses on the habi- landscape, I consider species richness,
tat and oviposition-site preferences of M. density and indicator species. I analyse
dryas in common pastures and the sur- drivers for the composition of grasshop-
rounding landscape (land-use types: Fal- per assemblages and give implications for
low, mown once, mown twice or more conservation.
often). I differentiate between grasslands In the last chapter, I draw together the
on mineral soil, fens, transition mires and findings from the three papers to provide
raised bogs within the land-use types. I a synthesis of my research on a multi-taxa
then discuss the relevance of common level. Finally, I develop perspectives for
pastures and give, where appropriate, management and biodiversity conserva-
tion.Chapter II Comparison of common pastures and control plots
12 Chapter II
Paper I
Common pastures are important refuges for a d eclining
passerine bird in a pre‐alpine agricultural landscape
S C HW AR Z C, T R A UT N E R J, F A RT M AN N T (2018)
Journal of Ornithology 159: 945–954.
doi.org/10.1007/s10336 -018-1561-0
Abstract
Agricultural landscapes play an important role in biodiversity conservation. The Tree
Pipit (Anthus trivialis) was formerly a widespread breeding bird in European farm-
lands. However, today, its numbers are sharply declining in most European coun-
tries. The aim of our study was to compare territory densities of Tree Pipits in com-
mon pastures and control plots in the surrounding pre-alpine agricultural landscape
in southern Bavaria (Germany). Additionally, we determined the drivers of territory
and home-range establishment in Tree Pipits.
Habitat composition in common pastures and control plots reflected distinct dif-
ferences in land-use intensity. Common pastures had larger areas of nutrient-poor
habitats and higher landscape diversity compared to control plots. In line with this,
we detected a clear response of Tree Pipits to differences in habitat composition.
Territories were nearly exclusively found in common pastures. Within the common
pastures, Tree Pipits preferred those parts that had a higher landscape diversity and,
additionally, at the territory scale, larger areas of groups of trees.
The common pastures are important refuges for the threatened Tree Pipit in the
pre-alpine agricultural landscape of the study area. In contrast to the control plots,
the common pastures provided (i) sufficient suitable song posts and (ii) heteroge-
neous vegetation with appropriate nesting sites and a high availability of arthropod
food resources. Our study corroborates findings from other studies across Europe
highlighting the prime importance of traditionally used wood pastures for the Tree
Pipit and biodiversity in general.Comparison of common pastures and control plots 13 Common pastures are important refuges for the threatened Tree Pipit in the agricultural landscape of the pre-Alps (Photo: Joachim Fünfstück). Characteristic habitat for Tree Pipits with sufficient song posts in a diverse landscape on the common pas- ture Lettigenbichl.
14 Chapter II
Paper II
Conservation of a strongly declining butterfly species depends
on traditionally managed grasslands
S C HW AR Z C, F AR TM A N N T (2021)
Journal of Insect Conservation 25: 255 –271.
doi.org/10.1007/s10841 -020-00288-2
Abstract
Introduction: Due to land-use intensification at productive soils and abandonment
of marginal farmland, biodiversity has dramatically declined throughout Europe. The
dryad (Minois dryas) is a grassland butterfly that has strongly suffered from land-use
change across Central Europe.
Aims/Methods: Here, we analysed the habitat preferences of adult M. dryas and the
oviposition-site preferences in common pastures located in mire ecosystems of the
German pre-Alps.
Results: Our study revealed that plot occupancy was equal at common pastures and
control plots. However, the abundance of M. dryas was higher at common pastures,
although the composition of vegetation types did not differ between the two plot
types.
Discussion: Open fens and transition mires traditionally managed as common pas-
tures or litter meadows (= meadows mown in autumn to obtain bedding for live-
stock) were the main habitats of M. dryas in our study area. They offered (i) sufficient
host plants (Carex spp.), (ii) had a high availability of nectar resources and (iii) a vege-
tation that was neither too sparse nor too short. In contrast, both abandonment and
intensive land use had negative impacts on the occurrence of the endangered butter-
fly species.
Implications for Insect Conservation: Based on our study and other recent re-
search from the common pastures, we recommend to maintain the current grazing
regime to foster biodiversity in general and M. dryas in particular. Additionally, where
possible, abandoned fens and transition mires adjacent to common pastures should
be integrated into the low-intensity pasture systems. The preservation of traditionally
managed litter meadows is the second important possibility to conserve M. dryas
populations.Comparison of common pastures and control plots 15 Minois dryas strongly prefers fens and transition mires on common pastures (here on Serratula tinctoria) (Photo: Thomas Fartmann). Characteristic oviposition habitat of M. dryas: The stick marks the position of the egg in a fen on the Mühlenberger Viehweide (left). The egg was dropped during flight between sedges and rushes on the moss layer (right) (Photo: Gregor Stuhldreher).
16 Chapter II
Paper III
Traditional grazing management creates heterogeneous
swards and fosters grasshopper densities
S C HW AR Z C, F AR TM A N N T (2021)
Insect Science (accepted)
doi.org/10.1111/1744 -7917.13041
Abstract
Common pastures were once the dominant type of land use in many European re-
gions. However, during the past 150 years, they have declined dramatically. Recent
studies have shown that they are hotspots for rare plant, butterfly and bird species in
the study area, the Bavarian pre-Alps (southern Germany). However, studies on the
value of these pastures for Orthoptera (hereinafter termed ‘grasshoppers’) have been
scarce. Here, we studied the effects of traditional summer grazing in common pas-
tures on grasshopper assemblages.
Our study revealed that grasshopper species richness did not differ between
common pastures (N = 57) and controls (N = 57). By contrast, density of all and
threatened species varied between common pastures and controls in all plots and
within the two vegetation types with the highest grasshopper abundance, grasslands
on mineral soil and fens. Two threatened species, Pseudochorthippus montanus and
Stethophyma grossum, were identified as indicators for common pastures; controls had
no indicative species. Traditional low-intensity grazing in common pastures has re-
sulted in open and heterogeneous swards with some bare ground, a low cover of lit-
ter and an intermediate vegetation height favouring high densities of grasshopper
species in general and threatened species in particular. This is especially true for the
two most productive vegetation types, grasslands on mineral soil and fens.
To promote biodiversity in general and grasshopper densities in particular, we
recommend maintaining traditional cattle grazing (stocking capacities: 0.5–2.0 live-
stock units/ha) in common pastures. Where possible, this grazing regime should also
be introduced in the surrounding landscape.Comparison of common pastures and control plots 17 The vegetation type ‘grassland on mineral soil’ on the common pasture Echelsbach Gschwend. The vegetation type ‘fen’ on the common pasture Mühlenberger Viehweide.
18 Chapter II The vegetation type ‘transition mire’ on the common pasture Berghofer Söldner. The vegetation type ‘raised bog’ on the common pasture Echelsbach Gschwend.
Comparison of common pastures and control plots 19 Pseudochorthippus montanus (left) and Stethophyma grossum (right) are indicator species for common pastures in the pre-Alps (Photos: Thomas Fartmann, Gregor Stuhldreher).
Chapter III Summary and Synopsis
Summary and Synopsis 21
Importance of common pastures in the insects and (iv) unsuitable for biodiversity
modern agricultural landscape of the conservation. Exceptions are other low-
pre-Alps intensity land-use systems that make up
only a marginal part in the pre-Alps now-
HOW DOES LAND-USE CHANGE AFFECT adays. In the context of this thesis, these
LANDSCAPE, HABITATS AND BIODIVERSITY? systems comprise exclusively traditionally
The biodiversity crisis which is driven by managed hay and litter meadows that are
land-use change is clearly present in the closely linked to the existence of com-
pre-alpine agricultural landscape: Bavari- mon pastures providing fodder and litter
an grasslands declined by about 3.9% as bedding for cattle and horses in the
between 2003 and 2012, which is above winter-season.
the German average of 3.6% (BfN 2014).
In addition, only 5–13% of the current ARE COMMON PASTURES IMPORTANT
grasslands in the study area have a high REFUGES FOR FARMLAND SPECIES AND
nature value (HNV), i.e., are rich in spe- BIODIVERSITY HOTSPOTS?
cies and ecological valuable due to low- The results from this study show that the
intensity management (Matzdorf et al. modern agricultural landscape in the pre-
2010). This proportion is below the na- Alps is largely unsuitable as a habitat for
tionwide average of 16.8% (Matzdorf et farmland species, threatened species and
al. 2010). species- and individual-rich assemblages.
Traditionally used common pastures With its systematic approach at a multi-
in the pre-Alps are one form of such low- taxa level, this thesis demonstrates the
intensity farmland with century-long value of common pastures as refuges in
management continuity (Lederbogen et the modern agricultural landscape. Thus,
al. 2004). But they decreased sharply as a the few remaining common pastures in
result of land-use change (personal mes- the study area are of outstanding im-
sages, Waldherr 2000): The Mühlenberger portance for the conservation of wildlife
Viehweide (MV), for example, declined species and farmland biodiversity as a
by 62% between 1818 and 2004 (Leder- whole in the pre-Alps. My findings are in
bogen et al. 2004). Areas excluded from line with other studies across Europe,
the original pasture were directly affected which emphasise the crucial relevance of
by land-use change and either went fal- traditionally used pastures for wildlife
low or became intensively used grasslands conservation (e.g., Moga et al. 2009, Diaz
(own observation). et al. 1997, Pinto-Correia & Mascarenhas
The comparison between remaining 1999, Lederbogen et al. 2004, Streitberger
common pastures and surrounding grass- et al. 2012, Helbing et al. 2014).
lands in this thesis clearly shows the con- Specifically, I show that farmland
sequences of land-use change in our birds, represented by the Tree Pipit, reach
modern agricultural landscape: Surround- significantly higher abundances on com-
ing grasslands – no matter whether inten- mon pastures compared to the surround-
sified or abandoned – are largely (i) ho- ing landscape (Paper I), where their oc-
mogeneous on both landscape and habi- currence is alarmingly low. Equally,
tat scale, (ii) poor in nutrient-poor habi- common pastures meet the complex de-
tats, (iii) sparsely populated by birds and mands of threatened butterfly species like22 Chapter III
M. dryas throughout their life cycle (Paper not be considered without looking at
II, see below). They occur with high grasslands on mineral soils, as they make
abundances on common pastures and up large parts of most common pastures
allocated hay and litter meadows. More- and have a special value for the overall
over, I show for the entire assemblage of foraging behaviour of livestock.
grasshoppers that abundances of all spe- Fens make up the largest part of the
cies – and particularly of those under mire types on common pastures consid-
threat – are significantly higher on com- ered in this thesis. Among the mire types,
mon pastures in contrast to the surround- grazing pressure is highest in fens; how-
ing landscape (Paper III). ever, it is significantly lower than in grass-
land on mineral soil (Figure 11). In fens,
Grazing influence on the habitat quali- the grazing regime results in (i) higher
ty of common pastures covers of shrubs and Cyperaceae and
(ii) a rather denser and higher field layer
HOW DOES GRAZING AFFECT HABITAT than in surrounding fens. Fens are
QUALITY FOR FARMLAND SPECIES AND strongly preferred by Tree Pipits due to
BIODIVERSITY? the fluent transition between open and
Although the importance of traditional woodland habitats that provide (i) suffi-
low-intensity farmlands for biological cient song posts and (ii) heterogeneous
conservation is increasingly coming to vegetation with appropriate nesting sites
the force, there is still a gap in knowledge and a high availability of arthropod food
about how different forms of manage- resources (Paper I), such as grasshoppers
ment in distinct areas concretely affect (Pätzold 1990). Grasshopper densities are
habitats, species and assemblages (Bun- twice as high on common-pasture fens
zel-Drüke et al. 2009). One of the most compared to surrounding fens (Paper
controversially discussed aspects in this III). Grasshoppers favour fens due to
context is the influence of grazing on (i) the high covers of Cyperaceae as food
mire ecosystems (e.g., Küchler et al. 2009, and (ii) the vegetation structure with high
Groom & Shaw 2015). Livestock grazing and dense parts as shelter. In addition,
affects habitats not only through
browsing, but also through lying, wallo-
wing, trampling and urine or fecal deposi-
tion (Milchunas et al. 1988). Studies pro-
vide different insights depending on mire
type, local site conditions and idiosyn-
crasies of grazing regimes, amongst
others. Consequently, a carefully differen-
tiated systematic consideration is necessa-
ry, which has largely been missing for my
study area and my study taxa. Due to the Figure 2: Number of cow droppings (mean value
± SE) in open and semi-open habitat types on
regional specifics, a differentiation in the common pastures based on data of Paper II and
mire types of fen, transition mire and III. Differences were tested using Generalized
Linear Mixed-effect Models (GLMM) with subarea
raised bog is necessary. The grazing in- as a random factor. Different letters indicate
fluence on the different mire types can- significant differences between vegetation types.Summary and Synopsis 23
fens are strongly preferred habitats for M. ates good germination conditions for
dryas because they provide (i) sufficient shrubs like Picea abies and Pinus x rotundata
host plants (Carex spp.), (ii) a high availa- (own observation, Lederbogen et al.
bility of nectar resources and (iii) a vege- 2004). The analyses in Paper II and III
tation that is neither too sparse nor too confirm that grazed raised bogs have
short (Paper II). (i) more shrubs, (ii) less cover of herbs
Transition mires are the second largest and (iii) a lower vegetation density. In
mire ecosystems on common pastures. contrast to the other mire types, grazing
Grazing pressure is rather low (Fig- leads neither to an improvement of the
ure 11). They clearly differed from transi- habitat quality for farmland species nor to
tion mires outside the common pastures an increase in biodiversity. Only few and
due to (i) more heterogeneous structures predominantly highly specialised species
with a mosaic of open soil and high vege- (e.g., Metrioptera brachyptera) prefer raised
tation, (ii) higher covers of Cyperaceae bogs anyway; in the study area, they have
and shrubs and (iii) lesser cover of herbs. been shown to prefer disused raised bogs
Additionally, transition mires on com- (Paper III).
mon pastures are frequently closely inter- Grassland on mineral soil occupies a
locked with fens (own observation, Le- special position within the common pas-
derbogen et al. 2004). Thus, a range of tures because here traditional manage-
species – even those with less mobility – ment has partially changed as a conse-
can benefit from the offer of both habitat quence of the land-use change. Leder-
types. This is particularly favourable for a bogen et al. (2004) already observed that
species like M. dryas, which has complex nearly half of the common pasture on
and changing requirements during its life mineral soil within their study area (pre-
cycle and whose main habitat are both Alps and calcareous fringe of the North-
vegetation types on common pastures ern Alps) had been fertilised and drained
(Paper II). to improve productivity. My observations
Raised bogs have large extents on a confirm this development and that graz-
few common pastures but are completely ing pressure on mineral soil is significant-
missing on others. In contrast to fen and ly higher than in the mire types as a con-
transition mire, they are less interlocked sequence (Figure 11). Yet even on miner-
with other mire types and grazing pres- al soil, the current management creates a
sure is very low due to inadequate fodder structural heterogeneity with both
values (Figure 11) (own observation, Le- (i) open soil and sparse vegetation and
derbogen et al. 2004). Sphagnum mounds (ii) ruderal patches with tall rushes and
build up a nearly closed surface on raised herbs that are largely missing in the sur-
bogs, both on common pastures and in rounding area. There, mineral soil grass-
the surrounding area. All surrounding lands are predominantly intensively
raised bogs discussed in this thesis are mown. This thesis shows that especially
disused. Due to the low grazing pressure, grasshoppers prefer grazed grasslands on
there are only few differences between mineral soil, which is evident from high
pastures and surrounding fallows: On densities of all and threatened species
pastures, the surface is occasionally inter- (Paper III). Conversely, threatened farm-
rupted by livestock trampling, which cre- land species like M. dryas prefer predomi-24 Chapter III
nantly nutrient-poor habitats, but benefit are widespread habitats of all common
to some extent from grassland on mineral pastures in the study area; however, they
soil if it is closely connected to main ha- are largely missing in the surrounding
bitats in fen or transition mires. agricultural areas. These habitats are
strongly preferred by insects due to their
WHAT ARE THE KEY DRIVERS FOR FARMLAND (i) high abundances of nectar sources,
SPECIES AND BIODIVERSITY IN THE STUDY (ii) high covers of sedges that are fre-
AREA? quently needed as a food source and
The high landscape diversity on common (iii) structural heterogeneity with a small-
pastures is a key driver for the existence scale mosaic of high and dense field layer
of farmland species in the pre-Alps. Birds vegetation and of sparse plant cover with
like the Tree Pipit and butterflies like M. open soil (Paper II, III). Biodiversity is
dryas can satisfy the complex demands particularly high in parts with higher graz-
during their life cycle there. My thesis ing pressure that supresses the accumula-
shows that Tree Pipits benefit strongly tion of litter and the emergence of too
from the fluent transition between open many shrubs. Because of these favourable
habitats and woodland on common pas- habitat conditions for insects, fens and
tures, which offers suitable song posts, transition mires are extremely valuable
lookouts and sites for nesting and fora- for foraging of insectivorous farmland
ging (Paper I). In the agricultural lands- birds.
cape of Central Europe, the radical sepa- In view of climate change, landscape
ration of forest and open habitats is a and structural heterogeneity within habi-
major threat to farmland birds (Moga et tats become even more important: They
al. 2009). Also lesser mobile species like serve as buffers during extreme climate
butterflies benefit from the high lands- events and as an opportunity for claiming
cape diversity with small-scale mosaics of new habitats (Fartmann et al. 2021).
habitat types on common pastures. It In summary, the key drivers for farm-
facilitates the use of diverse resources: M. land species and biodiversity on multi-
dryas, for example, has its main habitats in taxa scale in this thesis are (i) a high land-
fen and transition mire, but it benefits scape diversity with some but not too
strongly from nectar resources on ad- many trees and shrubs in smooth transi-
jacent grassland on mineral soil (Paper tion to semi-open and open habitats, (ii) a
II). In the modern agricultural landscape high availability of open and semi-open
of Central Europe, however, transitions nutrient-poor habitats – particularly fens
and close connections of habitats are and transition mires – and (iii) a high
largely missing (Benton et al. 2003, Babai structural heterogeneity on habitat scale
& Molnár 2014, Wielgolaski et al. 2017). due to an appropriate grazing regime that
A further key driver that fosters farm- favours Cyperaceae and flowering plants
land species and biodiversity on common but suppresses accumulation of litter as
pastures in the pre-Alps is the high avail- well as vegetation that is too high and
ability of nutrient-poor open and semi- dense.
open habitats. Fens and transition miresSummary and Synopsis 25
Implications for conservation transition mires and (iii) the shape of
each pasture that affects accessibility (cf.
WHICH MANAGEMENT RECOMMENDATIONS Lederbogen et al. 2004).
FOR THE CONSERVATION OF FARMLAND Furthermore, I recommend integrat-
SPECIES AND BIODIVERSITY CAN BE DERIVED ing fens and transition mires adjacent to
FROM THE FINDINGS? common pastures when they are either
My thesis revealed the high importance fallows or intensively managed. The inte-
of common pastures for the conservation gration of adjacent grasslands on mineral
of farmland species and biodiversity in soil should be carefully vetted: If they are
the pre-alpine agricultural landscape. improved, livestock may prefer grazing
Consequently, my main recommendation mainly in these parts, whereas less nutri-
is to protect the remaining common pas- ent-rich parts become abandoned (see
tures with their traditional management. above). However, it is advisable to moni-
Despite the predominantly century-long tor the grazing behaviour of livestock
continuity in management, the pressure carefully with each change in the form of
on common pastures through land-use management.
change is already visible today: Several While this thesis makes the positive
parts of mineral soil grasslands are being influence of grazing on fen and transition
improved through fertilization and drai- mire on common pastures obvious, a
nage to enhance productivity and fodder positive influence on raised bogs has not
value for livestock (own observation, been detected. Raised bogs are extreme
Lederbogen et al. 2004). Consequently, habitats which are poor in species and
the grazing regime changes on the entire individuals – and also in livestock (Fig-
pasture, and the vulnerable balance ure 11). The only characteristic species
between grazing pressure, vegetation for raised bogs was the grasshopper
development and wildlife animals is at Metrioptera brachyptera that prefers fallows
risk of being disturbed. While improved in contrast to grazed bogs (Paper III).
grassland is more frequented by livestock, Otherwise, I found no differences be-
other parts – especially mires – are less tween grazed and abandoned raised bogs
frequented (Figure 11). with regard to study species and assem-
As my thesis shows, grazing is particu- blages. To conclude, grazing on raised
larly necessary to avoid succession and to bogs does not seem to be relevant for
conserve the extraordinary biodiversity of biodiversity conservation and should not
fens and transition mires. Therefore, I be prioritised. Yet where grazing intensity
recommend stopping the improvement changes and a higher grazing pressure is
of grassland on mineral soil. Where this is to be feared for raised bogs, the conse-
not possible, the development of grazing quences for highly adapted assemblages
behaviour in connection with the influ- have to be monitored so that actions can
ence on farmland species and biodiversity be taken rapidly where needed (e.g., fenc-
should be monitored. A suitable extent of ing off raised bogs, reducing stocking
grazing in mires is individual for each capacity).
common pasture, depending on (i) the In view of the consequences of cli-
proportion of improved mineral soil mate change, it is particularly beneficial to
grassland, (ii) the proportion of fens and maintain and restore high water levels on26 Chapter III
common pastures. Hydrologically intact traditionally used grasslands are usually
mires are more resilient to climate change highly fragmented which obstructs the
and thus habitats can be conserved (Essl spreading and exchange of flora and fau-
et al. 2012). na (EEA 2011). In addition to common
Finally, an aim for conserving farm- pastures, traditionally managed hay and
land species and biodiversity is to pre- litter meadows – as part of the traditional
serve and enlarge a network of large and livestock farming in the pre-Alps –
well-connected traditionally used areas. In should be preserved, enlarged and con-
the modern agricultural landscape of nected within the habitat network.
Central Europe, ecologically valuableReferences 27
References
Ackermann W, Balzer S, Ellwanger G, Gnittke I, Bayerisches Geologisches Landesamt (eds.) (1996)
Kruess A, May R, Riecken U, Sachteleben J, Geologische Karte von Bayern 1 : 500 000. 4. ed.
Schröder E (2012) Hotspots der biologischen LfU, München.
Vielfalt in Deutschland. Auswahl und Abgren-
Bazelet CS, Samways MJ (2012) Grasshopper and
zung als Grundlage für das Bundesförderpro-
butterfly local congruency in grassland rem-
gramm zur Umsetzung der Nationalen Strate-
nants. Journal of Insect Conservation 16: 71–85.
gie zur biologischen Vielfalt. Natur und Land-
schaft 87: 289–297. Beaufoy G, Baldock D, Dark J (1994) The Nature
of Farming. Low intensity farming systems in nine
Akeboshi A, Takagi S, Murakami M, Hasegawa
European countries. Institute for European En-
M, Miyashita T (2015) A forest-grassland
vironmental Policy, London.
boundary enhances patch quality for a grass-
land-dwelling butterfly as revealed by dispersal Bellmann H (2006) Der Kosmos Heuschreckenführer.
processes. Journal of Insect Conservation 19: 15– Franckh-Kosmos Verlag, Stuttgart.
24.
Beneš J, Konvička M, Dvořák J, Fric Z, Havelda
Anthes N, Fartmann T, Hermann G, Kaule G Z, Pavlíčko A, Vrabec V, Weidenhoffer Z
(2003) Combining larval habitat quality and (2002) Butterflies of the Czech Republic: Distribu-
meta-population structure – the key for suc- tion and Conservation I, II. SOM, Prague.
cessful management of pre-Alpine Euphydryas
Benton TG, Bryant DM, Cole L, Crick HQR
aurinia colonies. Journal of Insect Conservation 7:
(2002) Linking agricultural practice to insect
175−185.
and bird populations: a historical study over
Babai D, Molnár Z (2014) Small-scale traditional three decades. Journal of Applied Ecology 39:
management of highly species-rich grasslands 673–687.
in the Carpathians. Agriculture, Ecosystems &
Benton TG, Vickery JA, Wilson JD (2003) Farm-
Environment 182: 123–130.
land biodiversity: is habitat heterogeneity the
Baillie SR, Marchant JH, Leech DI, Massimino D, key? Trends in Ecology and Evolution 18 (4): 182–
Sullivan MJP, Eglington SM, Barimore C, Da- 188.
dam D, Downie IS, Harris SJ, Kew AJ, New-
Berg Å (2008) Habitat selection and reproductive
son SE, Noble DG, Risely K, Robinson RA
success of ortolan buntings Emberiza hortulana
(2014) BirdTrends 2014: Trends in numbers,
on farmland in central Sweden – The im-
breeding success and survival for UK breed-
portance of habitat heterogeneity. Ibis 150:
ing birds. British Trust for Ornithology, Thetford.
565–573.
Bakker JP (1989) Nature Management by Grazing
BfN (Bundesamt für Naturschutz) (2012) Land-
and Cutting. Geobotany 14: 3–17.
schaftssteckbriefe. https://www.bfn.de (accessed
Barnosky AD, Matzke N, Tomiya S, Wogan 05 April 2021).
GOU, Swartz B, Quental TB, Marshall C,
BfN (Bundesamt für Naturschutz) (2014) Grün-
McGuire JL, Lindsey EL, Maguire KC, Mer-
land-Report: Alles im Grünen Bereich? Unpub-
sey B, Ferrer EA (2011) Has the Earth’s sixth
lished report.
mass extinction already arrived? Nature 471:
51–57. Bhattarai KR, Vetaas OR, Grytnes JA (2004)
Relationship between plant species richness
Bartón M (2016) Package MuMIn. Available from
and biomass in an arid sub-alpine grassland of
https://www.r-project.org.
the central Himalayas, Nepal. Folia Geobotanica
Bauer HG, Bezzel E, Fiedler W (2012) Das 39: 57–71.
Kompendium der Vögel Mitteleuropas. Alles über
Bibby CJ, Burgess ND, Hill DA, Mustoe SH
Biologie, Gefährdung und Schutz: Passeriformes –
(2000) Bird census techniques, 2. ed. Academic
Sperlingsvögel, 2. ed. AULA-Verlag,
Press, London.
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