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Insect populations decline, particularly in intensively managed agricultural landscapes. Insect communities are influenced by current agricultural practices, which are themselves determined by the economic, political and social frameworks. We highlight these direct and indirect drivers affecting insect communities, raise key research questions and discuss options for action to encourage a transformative change towards an economic, political and social system protecting biodiversity. ©2019 A.-C. Mupepele et al.; licensee oekom verlag.This article is distributed under the terms of th Creative Commons Attribution License CCBY4.0 (http://creativecommons.org/licenses/by/4.0).
Content may be subject to copyright.
GAIA 28/4(2019): 342– 347
342 FORUM342
Insect conservation in agricultural landscapes
An outlook for policy-relevant research
Insect populations decline, particularly in intensively managed agricultural landscapes. Insect communities are influenced by
current agricultural practices, which are themselves determined by the economic, political and social frameworks.
We highlight these direct and indirect drivers affecting insect communities, raise key research questions and discuss options
for action to encourage a transformative change towards an economic, political and social system protecting biodiversity.
Anne-Christine Mupepele, Katrin Böhning-Gaese, Sebastian Lakner, Tobias Plieninger, Nicolas Schoof, Alexandra-Maria Klein
Dr. Anne-Christine Mupepele | University of Freiburg | Faculty of Environment
and Natural Resources | Tennenbacher Str. 4 | 79106 Freiburg | Germany and
Senckenberg Biodiversity and Climate Research Center | Frankfurt am Main |
Germany | +49 7612033631 | anne-christine.mupepele@nature.uni-freiburg.de |
https://orcid.org/0000-0002-5671-0963
Prof.Dr. Katrin Böhning-Gaese | Senckenberg Biodiversity and Climate
Research Center | Frankfurt am Main | Germany and Goethe University
Frankfurt | Institute for Ecology, Evolution and Diversity | Frankfurt am Main |
Germany | katrin.boehning-gaese@senckenberg.de |
https://orcid.org/0000-0003-0477-5586
Dr.Sebastian Lakner | Thünen-Institute for Rural Studies | Braunschweig |
Germany and University of Göttingen | Agricultural Economics and
Rural Development | Göttingen | Germany | slakner@gwdg.de |
https://orcid.org/0000-0002-5122-8924
iological diversity is declining across the globe, resulting in the
loss of ecosystem functioning and services (IPBES 2019). For
insects, declining diversity has been shown in long-term studies,
especially in areas with intensive agricultural land use (Beckmann
et al. 2019, Homburg et al. 2019). A long-term record in Germany
measuring the biomass of flying insects indicated a dramatic loss
of flying insects in protected areas over the past 27 years (Hall-
mann et al. 2017).1Hallmann et al.’s publication has attracted world-
wide public attention and led to a societal and professional debate
on how to improve insect conservation. It supported conclusions
from the first report from the Intergovernmental Science-Policy
Platform on Biodiversity and Ecosystem Services(IPBES 2016) that
had stirred discussion on insect conservation internationally. In
Germany, these reports contributed to recent political action that
extends existing efforts to protect biodiversity by programs focus -
ing particularly on insect conservation, for example, the “action
program for insect conservation”(Aktionsprogramm Insektenschutz)
of the German Federal Government (BMU 2019).
Here we aim to give a perspective from a social-ecological and
economic research experience on future research that is required
to improve knowledge about declining insect populations in agri-
cultural landscapes and to develop effective conservation strate-
gies with a focus on Germany. To mitigate insect decline the driv-
ers responsible for these losses need to be addressed. As drivers
occur on different levels and manifest as direct or indirect influ -
ences on insect communities, we proceed as follows: first, we iden-
tify the potential drivers influencing insect communities and group
them according to their type of impact (direct or indirect). Second,
we raise research questions related to these drivers and define the
prerequisites to answer them (research approach). Lastly, we sug-
gest conservation measures based on knowledge that is currently
available. In the following, we start by introducing the conserva -
tion target: insect communities.
Insect communities
Insects fulfill manifold ecosystem functions and develop various
values for humans.2They provide ecosystem services, for example
pollinating crops or decomposing litter and excrements (Klein et
al. 2018). They can also harm human well-being, for example, as
crop pests or vectors of disease (Schäckermann et al. 2015). Their
decline can have tremendous effects on ecosystem functions and
services.
Insect conservation in agricultural landscapes. An outlook for policy-relevant research |GAIA 28/4(2019): 342 – 347
Keywords: biodiversity, drivers for change, insect decline, interdisciplinary, transdisciplinarity
B
Prof.Dr. Tobias Plieninger | University of Göttingen | Agricultural Economics
and Rural Development | Göttingen | Germany and University of Kassel |
Organic Agricultural Sciences | Witzenhausen | Germany |
plieninger@uni-goettingen.de | https://orcid.org/0000-0003-1478-2587
Nicolas Schoof,MSc | University of Freiburg | Faculty of Environment and Natural
Resources | Freiburg | Germany | nicolas.schoof@waldbau.uni-freiburg.de
Prof.Dr. Alexandra-Maria Klein | University of Freiburg | Faculty of
Environment and Natural Resources | Freiburg | Germany |
alexandra.klein@nature.uni-freiburg.de |
https://orcid.org/0000-0003-2139-8575
©2019 A.-C. Mupepele et al.; licensee oekom verlag.This article is distributed under the terms of the
Creative Commons Attribution License CCBY 4.0 (http://creativecommons.org/licenses/by/4.0).
https://doi.org/10 .14512/gaia.28.4.5
Submitted July 13, 2019; revised version accepted November18, 2019.
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1 This was recently confirmed by an insect survey in 150 grassland sites
covering ten years (Seibold et al. 2019).
2 Insects include very diverse taxonomic orders, such as beetles (Coleoptera),
butterflies and moths (Lepidoptera), bees, wasps and ants (Hymenoptera)
and flies (Diptera).
Insect communities are characterized by their diversity, num-
bers of individuals and community composition. While general
trends of diversity are known, there is less certainty about the long-
term trends of specific species and the community composition
(IPBES 2019, Basset and Lamarre 2019). It remains mostly un-
known whether insect species that are beneficial or damaging for
human well-being are more affected by decline(IPBES 2016). Be-
side changes in species diversity, traits and genetic diversity are
lost (Pereira et al. 2012). Insect communities and their character -
istic components are influenced by direct and indirect drivers (fig -
ure 1) – these are explained in the next step.
Direct drivers of insect losses
Direct drivers of insect losses comprise 1. habitat availability and
quality, and 2. land-use practices.
Habitat availability and quality (1)
To maintain stable populations, insects require habitats depend-
ing on their species-specific needs. On a landscape scale, two com-
ponents are important: first, the species-specific habitat needs to
be large enough to host a viable population, and second, with in-
creasing landscape diversity multiple species will find their habi-
tat requirements. Isolated habitat patches resulting from homo -
genization of landscapes and fragmentation of natural habitats
have negative effects on diversity (Rossetti et al.2017). Habitat re -
quirements for particular insect groups such as bees are known
especially in regard to landscape elements such as hedges, field
margins and extensively used meadows and pastures (Ponisio et
al. 2019, Sands and Wall 2017) (figure 2,p.345).Quantification of
how many and what kind of landscape elements are required for
conserving insects across taxa has been less investigated (e.g., Bat -
áry et al. 2017). Habitat availability and quality are themselves in-
fluenced by various drivers, such as climate change or land-use
practices. Land-use practices such as the application of pesticides
can also directly influence insects.
Land-use practices (2)
Most typically, the decline in insect diversity is related to multiple
processes of land-use intensification in agricultural landscapes
(Beckmann et al. 2019). Intensification increases cultivation or live-
stock husbandry outputs (e.g., via fertilizer inputs) and narrows
the variety of agricultural ecosystem services via specialization.
Intensification also leads to a decrease in landscape elements, such
as hedgerows (Van Vliet et al. 2015). Additionally, the abandon-
ment of landscape management can be an important driver of di-
versity decline, for example, if extensively managed grasslands are
given up and overgrown by scrub (Ernst et al. 2017). Location fac-
tors such as accessibility, soil quality or local climate explain why
some regions are more prone to agricultural intensification or
abandonment, while others have preserved higher shares of high
nature value farming (Van Vliet et al. 2015).
Indirect drivers: political, economic and social
factors
Agricultural practices are driven by economic, political, cultural
and natural factors (Plieninger et al. 2016). Economic drivers (3)
play an important role, as agricultural production is influenced
by local, European and global markets. Political drivers (4) influ -
ence land use either by shaping the economy with income subsi -
dies or support for production, or via laws for land consolidation
or directly regulating management. The most important Europe -
an Union policy is the Common Agricultural Policy (CAP) and the
way it is implemented in national policies (Heinrich et al. 2013).
Despite relating 30 percent of the direct payments to measures
Anne-Christine Mupepele et al.
FIGURE 1: Drivers influencing
insect communities in agricul-
tural landscapes. The flowchart
is giving broad categories
(bold), specified by a non-
exhaustive list with examples
within these categories (bullet
points). Numbers provide
a link to equally numbered
text sections.
a Food may be seen as part of ecosystem services, but here we emphasize the role of food as the main
purpose of agricultural production and therefore explicitly mention it beside other ecosystem services.
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intended to protect the environment (“greening”) and offering pay-
ments for voluntary measures (“agri-environmental schemes”),
the present CAP has shown substantial weaknesses in delivering
public goods and sustaining biodiversity (Pe’er et al. 2017, Pe’er
et al. 2019).
Society (5) influences political action and agricultural produc-
tion for example through consumer behavior (Seufert and Raman -
kutty 2017). Agricultural practices are also influenced by attitudes
and motivations of farmers. Farmers either focus on production,
emphasize their role in conserving biodiversity, or have a more ho-
listic understanding of being conservationists, primary producers,
and managers of a range of ecosystem services. Individual farm-
ers’ motivations have so far not been sufficiently considered for
the success of the implementation of some public policies (Dess -
art et al. 2019), although these policies are key to place farmland
biodiversity “in the hands and minds of farmers” (De Snoo et al.
2013). Motivations and practices of farmers are themselves influ -
enced by markets, social acceptance and the regulations set up by
the political frame. Effective insect conservation requires manage -
ment changes at the scale of landscapes, hence the degree of col-
laboration between farmers in a landscape is also an important
driver (Prager et al. 2012).
Research outlook
Successful conservation of insects requires strong knowledge per-
taining to the direct and indirect drivers as well as their complex
interactions, and about the design and implementation of com-
prehensive action as informed by transformation research. Based
on the experience of the authors, we suggest exemplary research
questions that would improve the understanding of these rela-
tionships in the following:
Research on direct drivers:
1. How does the above- and belowground insect community
composition and their traits in agricultural landscapes
change with quantity, quality and configuration of
landscape elements?
2. How does the management of permanent grasslands and
croplands affect insect communities and their diversity on
different landscape scales?
3. How do beneficial insects and pest species interact and
influ ence each other?
4. How does the equilibrium between beneficial insects and
pests change related to land use and various landscape
elements?
5. How do different pesticides and their combinations
(includ ing livestock medication) affect different insect
species and their ecological interactions?
6. How much of which pesticide is retained in the soils?
7. What are suitable indicators to monitor biodiversity on
farmland and how can the indicators successfully be linked
to drivers?
Research on indirect drivers:
1. How can we organize transformation processes within
industrialized societies to a more sustainable farming and
economic system, where externalities are priced into the
regular market?
2. How can we identify most effective leverage points to
transform a system of natural and social components
towards a more sustainable system?
3. How do different actors, such as farmers, consumers and
the civil society, influence each other in their direct or
indirect impacts on insect populations?
4. How can we organize or support collaborative actions
between farmers and citizens through, for example,
community-supported agriculture, which can also support
biodiversity-friendly systems?
5. How do political measures, including incentives
(subsidies) and obligations (regulations), lead to changes
in insect communities?
6. How will measures in the CAP, such as the eco-schemes
and conditionality, presumably replacing the “greening”
after 2020, impact insect conservation?
7. How can the link between incentive-based schemes and
conservation targets be improved while simultaneously
considering and leaving space to farmers’ intrinsic motivation?
8. How can agricultural policy incentivize a diversification of
farms regarding the provision of biodiversity as a regular
part of their business and support investments into farm
resources (labor, machinery, land) being necessary for such
diversification?
All the drivers mentioned interact in multiple ways, so that an
integrative research approach including production, economics,
politics, legislation, biodiversity and society is needed to accom-
modate the complexities among them (figure 1). So far, mainly
individual links, for example, between political activities and land
use, have been investigated (Batáry et al. 2015). An integrative ap -
proach requires an interdisciplinary research design, where differ -
ent disciplines collaborate in design, implementation and evalu -
a tion, such as in Rosa-Schleich et al. (2019). This can be achieved
by integrating socio-cultural, economic and ecological methodol -
ogies at the farm level offering the opportunity to gain valuable
in sights for sustainable production systems (Poudel et al. 2002,
Lakner and Breustedt 2017).3
Research approaches to gain knowledge
Research to fill the previously outlined knowledge gaps needs dif-
ferent approaches. Transdisciplinary research, linking science and
practice, is based on integrative approaches (Pohl et al. 2017). Giv-
en the complexity of the interaction of drivers, transformation re-
search can help navigate the process, including balancing trade-
offs between multiple stakeholders affected and monitoring and
evaluating the impact of measures undertaken (Loorbach et al.
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Anne-Christine Mupepele et al. FORUM 345
2017). Assessing and synthesizing the available knowledge relat -
ed to one research question can be best done by a systematic re-
view, as it was realized for example in an analysis on the effective -
ness of agri-environmental management on pollinators (Marja et
al. 2019) or the effects of schooling on farming practices (Wad -
dington et al. 2014).
Primary studies in research are most commonly based on short
funding phases. The link between particular species and the ef-
fect of a driver (e.g., pesticides) can be investigated in short term
at best through experimental studies, but changes in communi -
ties may be found only over longer time scales, and extinctions oc-
cur with a delay. Long-term social-ecological research can reveal
the long-term impact on species groups and communities result-
ing from an experimental manipulation. In Germany, long-term
(social-)ecological research is organized as part of a European and
global network, with most prominent sites being the Biodiversity
Exploratories4and the Jena Experiment5, both supported by Deut -
sche Forschungsgemeinschaft (DFG).
In addition to long-term social-ecological research, monitoring
is required as it provides information on a longer scale and with
a better coverage in space. It takes place to report the state of land -
scapes and society. So far, the coordination of comparable moni -
toring schemes covering a large space (across Germany, Europe
or even globally) and a broad range of taxonomic groups is miss-
ing (see also Geschke et al. 2019).
Insect conservation measures
Beside the identification of the drivers and their interaction re-
sponsible for insect decline, immediate changes need to and can
be instigated to reach a transformation towards a more favorable
environment for insect communities (Leopoldina et al. 2018, SRU
2018, Forister et al. 2019, BMU 2019). The current knowledge of-
fers multiple leverage points to foster insect conservation in agri-
cultural landscapes and each of them is ideally monitored and
evaluated.
Key arenas for action are:
Agricultural policy: In 2018, the European Commission launched
a new reform proposal for their CAP post 2020 (Pe’er et al. 2019).
To become a central instrument to mitigate biodiversity decline,
the link between subsidies and good practice prioritizing environ -
mental protection and the adaptability to local conditions needs
fundamental improvement, for example, by strengthening and
simplifying agri-environmental measures emphasizing specif-
ic targeted measures, instead of a one-size-fits-all approach like >
3 Ecosystem services provide a good common framework to investigate
trade-offs between ecological, economic and social interests.
4www.biodiversity-exploratories.de
5www.the-jena-experiment.de
FIGURE 2: An ivy bee (Colletes hederae) collecting pollen from ivy (Hedera helix) at Kaiserstuhl in Southern Germany. The ivy bee nests in coarse clay
and sandy soils and is mainly oligolectic, which means it requires particular plants as food source.
©Anne-Christine Mupepele
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3
2
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Anne-Christine Mupepele et al.346 FORUM346
“greening” (see Pe’er et al. 2017). This requires knowledge on spe-
cific relationships such as between agri-environmental practices
and resulting impacts on insect populations, and how to embed
measures in farming cultures to be sustained self-evidently as part
of conventional “good farming” practice (Burton and Paragahaw -
e wa 2011).
Law enforcement: The number of laws and regulations to sustain
biodiversity has substantially increased over the past decades, but
there is a lack of implementation of existing laws and controls, typ-
ically due to missing financial and staff resources (LANA 2016).
Especially at the level of local administration, a lack of priority and
financial means can hamper the implementation of regulations
(Haupt et al. 2010).
Trade and markets: Incorporating non-marketable services into
the market, for example, by taxing or subsidizing through payments
of ecosystem services, potentially protects habitats required for in-
sect conservation. Creating markets for regional products will sup-
port local value chains. The market for organic products with its es-
tablished certification system for a more environmental-friendly
farming process might serve as a guide to incorporate “biodiversi -
ty-friendly” products into respective certification systems. There
are some promising first approaches to develop and test such a cer-
tification scheme together with the food retailers (Stein-Bachinger
and Gottwald 2016). But here, particular social-ecological impacts
of different certification systems, direct and indirect land-use chang -
es resulting from certification, and a potential “consumer fatigue
regarding new certificates and labels need further investigation.n
Civil society: Civil society plays an important role to realize initia -
tives from bottom-up. These serve as multipliers and can influ-
ence public opinion and politics, such as recently seen in the pop-
ular petition to conserve biodiversity in Bavaria.6The engagement
of society in research activities (citizen science) can empower cit-
izens’ scientific competences and simultaneously support science
by voluntary labor and outreach. As a relatively new research area,
little is known about the mechanisms underlying a successful cit-
izen science initiative.
Sustaining insect diversity and mitigating losses of insect popu -
la tions requires a transformative change towards an economic,
political and social system protecting biodiversity. Transformative
change ideally starts at several leverage points simultaneously, and
the above-mentioned key arenas demand action from multiple
stakeholder groups. Action needs to be coordinated on a landscape
scale, while constantly monitoring the impact of change and act-
ing based on continuously updated, best available evidence.
We thank the German National Academy of Sciences Leopoldina, the Union of
the German Academies of Sciences and Humanities and the National Academy
of Science and Engineering (acatech) for initiating and funding the working
group Biodiversity in Agricultural Landscape providing the opportunity for the
authors to meet in workshops and share their ideas. We thank the members
of the working group for discussions and input. The first author was funded
by the STAY scholarship of the Neue Universitätsstiftung Freiburg.
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Tobias Plieninger
Born 1971 in Göppingen, Germany. Studies in forestry and en -
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2017 professor of social-ecological interactions in agricultural
systems at the Universities of Kassel and Göttingen, Germa -
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Sebastian Lakner
Born 1973 in Marburg an der Lahn, Germany. Studies in agri-
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Alexandra-Maria Klein
Born 1972 in Göttingen, Germany. Studies in biology, PhD in
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Katrin Böhning-Gaese
Born 1964 in Oberkochen, Germany. Studies in biology. 1993
PhD on continent-wide trends in bird populations. 2001 to 2010
professor for ecology at University Mainz. Since 2010 profes-
sor at Goethe University and Director of Senckenberg Biodi-
versity and Climate Research Centre, Germany. Research inter -
ests: impact of climate and land-use change on biodiversity,
ecosystem functions and services, social-ecological systems.
Anne-Christine Mupepele
Born 1985 in Konstanz, Germany. Studies in biology. PhD on
the evidence base of ecosystem services research. Since 2017
Postdoc in nature conservation and landscape ecology, Uni-
versity of Freiburg, Germany. Coordinater of the AG Biodiver-
sity in Agricultural Landscape funded by the German Academy
of Sciences Leopoldina. Research interests: evidence-based
conservation, arthropod ecology, ecosystem services, ecological statistics.
342_347_Mupepele 03.12.19 20:40 Seite 347
... Insects are currently declining in many parts of the world (Hallmann et al. 2021;Sánchez-Bayo and Wyckhuys 2021;Seibold et al. 2019;Wagner et al. 2021). The main explanations for insect decline are the loss of habitat through increasing urbanization, climate change, landscape homogenization, high use of pesticides and fertilization and intensive farming methods for example frequent mowing (IPBES 2019;Dicks et al. 2021;Mupepele et al. 2019;Potts et al. 2010). ...
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... Clearly, the new ICLS has the potential to protect the mentioned breeds and breed traits. The tasks of future research fit into an established field of research on the transformation of sustainability-deficient land use systems [34,35]. There are still some open questions in the implementation of the new ICLS. ...
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... The recent scientific literature confirms various threats for insects such as loss and fragmentation of habitats through agriculture and land usage/sealing, increased mortality through climate change, invasive species, and pollution through light, noise or chemicals pollution in water and soils (Wagner 2018;Cardoso et al. 2020). However, many studies identify the modern agricultural system with its current practices as one of the main drivers for the insect biodiversity decline (Mupepele et al. 2019;Cardoso et al. 2020). To obtain stronger evidence about the drivers of the insect biodiversity loss more empirical analyses have to be carried out. ...
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An alarming decrease of insects in number and variety calls for measures of protection and promotion, since insects are crucial for the functioning of ecosystems and provide multiple ecosystem services. Agricultural landscapes can provide vast insect habitats if they are managed accordingly. However, little is known about farmers’ problem awareness and attitudes toward insect biodiversity loss, related farming practises, or alternative acceptable insect-friendly solutions. To fill these research gaps, this paper aimed to reveal farmers’ perceptions and attitudes regarding these aspects in two German case studies. We conducted 23 semi-structured interviews with farmers in 2019 and qualitatively analysed them using semantic web analysis. Farmers mostly reported awareness of insects’ ecosystem services and disservices related to agricultural production rather than mentioning the holistic ecological importance of insects. About half of the farmers confirmed insect loss based on their own observations, whereas a similar number doubted there had been a decrease of insects. Most farmers are open-minded towards insect-friendly measures if financially compensated. The farmers also mentioned a joint societal responsibility for insects, economic pressure on farmers to use pesticides due to global market prices, and unbalanced agricultural policies. This study revealed in-depth insights into farmers’ thinking about insects and how farmers contextualise arguments. Our results identified overlaps in farmers’ mental models, which paves the way for co-designing insect-friendly farming practices in landscape labs. Local transformation efforts can also demonstrate new pathways for a shift on the higher levels.
... All of these studies point to the negative effects of agricultural intensification as a major reason to explain their findings. These reports even attracted media and public attention in Germany and worldwide, and fostered discussions in society and policy how to strengthen insect conservation (Mupepele et al., 2019). ...
Thesis
The rapid agricultural intensification during the last decades is among the main drivers of the dramatic and ongoing biodiversity loss on earth. The decline of species diversity and associated ecosystem services due to highly intensified farming practices and structural simplified agricultural landscapes includes the reduction of species richness and abundance of species. The loss of species and related shifts in species communities can also lead to altered functional traits within species communities. It can also include deteriorated population developments of single species known to be important ecosystem service suppliers for agricultural production. In Europe, billions of euros are spent each year to support farmers for applying environmentally friendly practices, but so far biodiversity continues to decline. This calls for the development of more effective biodiversity conservation measures on agricultural land. Within the framework of agri-environmental measures, agronomically non-productive measures exist such as the establishment of flowering fields, but there are also production integrated measures such as the organic farming of crops. Further, the growing of flowering lentil mixed-crops could be a valuable, but rarely studied option to further increase the biodiversity benefits of organic farming systems. Up to that, little is known about the relative effectiveness of non-productive flowering fields under conventional management and organically farmed mono- as well as lentil mixed-crops for the promotion of biodiversity on arable land. Within the scope of this thesis, i studied biodiversity effects in response to the establishment of annual flowering fields under conventional management, organically managed winter spelt as well as organic lentil mixed-crops. These three crop-use types were compared to conventional winter wheat (control). Besides, I took into account biodiversity effects of the within-field position (field edge versus interior) as well as the surrounding landscape complexity in 500 m around each study field. To get a comprehensive overview about potential biodiversity effects and related ecosystem functions in response to the four crop-use types, I assessed the abundance, species richness and community composition of wild plants (primary producers), carabids and spiders (ground-dwelling predators) as well as butterflies and wild bees (flower-visiting arthropods). I further assessed the functional diversity of carabids as an important species group for biological pest control. To quantify functional diversity in comparison between the four crop-use types, I used the community weighted means and functional divergence of three ecological traits – body size, feeding type, and flight ability. These traits can affect mobility (body size, flight ability) as well as pest and weed seed predation (feeding type, body size) of carabids. Last, I measured the population development of colonies of Bombus terrestris, I observed weight gain, foraging activity, worker body size, queen brood cell number and stored pollen types of colonies exposed at each study field in 2018. I found clear taxon-specific effects of the total abundance and species richness in response to the studied crop-use types. No distinct differences were found for the community composition, which was similar between crop-use types. Arable wild plants benefited most strongly from organic farming, in particular from lentil mixed-crops, but also from field edges. Ground-dwelling arthropods were also mainly promoted by field edges, whereas flower-visiting arthropods solely benefited from conventional flowering fields and organic lentil mixed-crops. Carabid functional diversity was higher at the field edge than the interior irrespectively of crop-use type. Feeding type diversity (carnivorous, ominovorous, herbivorous) of carabid assemblages did also profit from conventional flowering fields and organic winter spelt. Colonies of Bombus terrestries had higher foraging activity and larger body sizes, if exposed at organic winter spelt fields, whereas weight gain and queen brood cell numbers were unaffected by local crop-use type. Pollen stores within the colonies were dominated by Phacelia (Phacelia tanacetifolia) irrespectively of crop-use type. Phacelia was part of the sown seed-mixture in flowering fields, indicating a landscape-wide attraction of flowering fields as pollen source for Bombus terrestris. Over all studies i found only minor effects of the surrounding landscape, except the negative correlation between flower cover and pollen diversity of Bombus terrestris colonies. In summary, this thesis revealed that the establishing of annual flowering fields can be an appropriate measure to enhance biodiversity in conventional farming systems. Organic lentil mixed-crops are appropriate to further increase biodiversity benefits of organic farming systems. Within the conducted studies, different crop-use types promoted specific species groups and thereby different components of biodiversity. Hence, the results of this thesis reveal, that there is no single best measure for the promotion of biodiversity on arable land. Instead, the additive effects of non-productive and productive measures as well as field edge habitats underline, that a mosaic of different types of measures hold the greatest potential to benefit overall biodiversity in agricultural landscapes. Therefore, future agri-environmental schemes should provide particular incentives for individual farmers to apply a diversity of different measures on their farmland and should foster the collaboration and spatially coordinated implementation of complementary biodiversity measures between multiple farmers at the landscape scale.
... With several studies reporting alarming numbers (Hallmann et al. 2017;Seibold et al. 2019), the decline of insect populations in agricultural landscapes has gained considerable public attention in Germany in the past few years (Mupepele et al. 2019). In response to this, some groups in the federal state of Baden-Württemberg kicked off a public petition process for fostering insect conservation in September 2019. ...
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Values are considered an essential but ill-defined element in sustainability transformations. This perspective article explores: What kinds of values guide thinking and action in the context of caring for nature and engaging for landscape sustainability? How do these different values relate to each other? To frame our study, we discuss three basic principles in ethical reasoning. Prudence highlights the instrumental values of nature. Justice puts general moral obligations at the center. The Good Life focusses on relational values that are important to people in terms of personal life-goals. We show that all three types of values are expressed in landscape stewardship conceptualizations. As two case studies demonstrate, the relevance of these ethical claims may diverge among actors, which can lead to different goals and pathways. It is therefore crucial to develop multifaceted strategies that are tailored to the complexity of values at stake. A lack of communication on ethical claims may result in conflict and blockade of sustainability initiatives. For harnessing the full potential of values for sustainability transformations, the specific ethical dimensions of reasoning need to be made explicit and partial interests and common goods and rights need to be distinguished as arguments with different levels of legitimacy and power.
... Andere Maßnahmen lassen sich unter Umständen auch über Eco-Schemes in der I. Säule umsetzen. (Mupepele et al., 2019). ...
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Despite a substantial increase in scientific, public and political interest in pollinator health and many practical conservation efforts, incorporating initiatives across a range of scales and sectors, pollinator health continues to decline. We review existing pollinator conservation initiatives and define their common structural elements. We argue that implementing effective action for pollinators requires further scientific understanding in six key areas: (i) status and trends of pollinator populations; (ii) direct and indirect drivers of decline, including their interactions; (iii) risks and co-benefits of pollinator conservation actions for ecosystems; (iv) benefits of pollinator conservation for society; (v) the effectiveness of context-specific, tailored, actionable solutions; and (vi) integrated frameworks that explicitly link benefits and values with actions to reverse declines. We propose use of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) conceptual framework to link issues and identify critical gaps in both understanding and action for pollinators. This approach reveals the centrality of addressing the recognized indirect drivers of decline, such as patterns of global trade and demography, which are frequently overlooked in current pollinator conservation efforts. Finally, we discuss how existing and new approaches in research can support efforts to move beyond these shortcomings in pollinator conservation initiatives. This article is part of the theme issue ‘Natural processes influencing pollinator health: from chemistry to landscapes’.
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This paper reviews the findings from the last 20 years on the behavioural factors that influence farmers' decisions to adopt environmentally sustainable practices. It also proposes policy options to increase adoption, based on these behavioural factors and embedded in the EU Common Agricultural Policy. Behavioural factors are grouped into three clusters, from more distal to more proximal: (i) dispositional factors; (ii) social factors and (iii) cognitive factors. Overall, the review demonstrates that considering behavioural factors enriches economic analyses of farmer decision-making, and can lead to more realistic and effective agri-environmental policies.
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Insects make up the bulk of terrestrial diversity (1). Reports of insect declines, best documented in Europe and North America, suggest that 40% of insect species in temperate countries may face extinction over the next few decades (2), although this figure is probably inflated (3). Other studies have highlighted falling insect biomass in Germany and Puerto Rico (4, 5), as well as threats to many insect taxa in Europe (5) and insect pollinators worldwide (6) that support food production (7). To protect insects, it is crucial that they are considered as separate species with distinct responses to threats, with particular attention to tropical insects and their habitats. Bees and butterflies may serve as an initial focus, but conservation efforts must go far beyond these iconic species. Halting habitat loss and fragmentation, reducing pesticide use, and limiting climate change are all required if insect populations are to be preserved.
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Disconnected habitat fragments are poor at supporting population and community persistence; restoration ecologists, therefore, advocate for the establishment of habitat networks across landscapes. Few empirical studies, however, have considered how networks of restored habitat patches affect metacommunity dynamics. Here, using a 10‐year study on restored hedgerows and unrestored field margins within an intensive agricultural landscape, we integrate occupancy modelling with network theory to examine the interaction between local and landscape characteristics, habitat selection and dispersal in shaping pollinator metacommunity dynamics. We show that surrounding hedgerows and remnant habitat patches interact with the local floral diversity, bee diet breadth and bee body size to influence site occupancy, via colonisation and persistence dynamics. Florally diverse sites and generalist, small‐bodied species are most important for maintaining metacommunity connectivity. By providing the first in‐depth assessment of how a network of restored habitat influences long‐term population dynamics, we confirm the conservation benefit of hedgerows for pollinator populations and demonstrate the importance of restoring and maintaining habitat networks within an inhospitable matrix.
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• The drastic insect decline has received increasing attention in scientific as well as in public media. Long‐term studies of insect diversity trends are still rare, even though such studies are highly important to assess extent, drivers and potential consequences of insect loss in ecosystems. • To gain insights into carabid diversity trends of ancient and sustainably managed woodlands, we analysed data of carabid beetles from a trapping study that has been run for 24 years in an old nature reserve of Northern Germany, the Lüneburg Heath. We examined temporal changes in several diversity measures (e.g. biomass, species richness, functional diversity and phylogenetic diversity) and tested diverse species traits as predictor variables for species occurrence. • In contrast to recently published long‐term studies of insect diversity, we did not observe a decline in biomass, but in species richness and phylogenetic diversity in carabids at our study site. Additionally, hibernation stage predicted the occurrence probability of carabids: Species hibernating as imagines or both imagines and larvae and breeding in spring showed strongest declines. • We assume the detected trends to be the result of external effects such as climate change and the application of pesticides in the surrounding. Our results suggest that the drivers for the insect decline and the responses are multifaceted. This highlights the importance of long‐term studies with identification of the catches to, at best, species level to support the understanding of mechanisms driving changes in insect diversity and abundance.
Article
Most current research on land‐use intensification addresses its potential to either threaten biodiversity or to boost agricultural production. However, little is known about the simultaneous effects of intensification on biodiversity and yield. To determine the responses of species richness and yield to conventional intensification, we conducted a global meta‐analysis synthesizing 115 studies which collected data for both variables at the same locations. We extracted 449 cases that cover a variety of areas used for agricultural (crops, fodder) and silvicultural (wood) production. We found that, across all production systems and species groups, conventional intensification is successful in increasing yield (grand mean + 20.3%), but it also results in a loss of species richness (−8.9%). However, analysis of sub‐groups revealed inconsistent results. For example, small intensification steps within low intensity systems did not affect yield or species richness. Within high‐intensity systems species losses were non‐significant but yield gains were substantial (+15.2%). Conventional intensification within medium intensity systems revealed the highest yield increase (+84.9%) and showed the largest loss in species richness (−22.9%). Production systems differed in their magnitude of richness response, with insignificant changes in silvicultural systems and substantial losses in crop systems (−21.2%). In addition, this meta‐analysis identifies a lack of studies that collect robust biodiversity (i.e. beyond species richness) and yield data at the same sites and that provide quantitative information on land‐use intensity. Our findings suggest that, in many cases, conventional land‐use intensification drives a trade‐off between species richness and production. However, species richness losses were often not significantly different from zero, suggesting even conventional intensification can result in yield increases without coming at the expense of biodiversity loss. These results should guide future research to close existing research gaps and to understand the circumstances required to achieve such win‐win or win‐no‐harm situations in conventional agriculture. To determine the responses of species richness and yield to conventional land‐use intensification, we conducted a global meta‐analysis. Across all production systems (food, fodder, wood), intensification increases yield (+20.3%), but also leads to a loss of species (−8.9%). Within low intensity systems, intensification did not affect yield or richness, while within medium intensity systems, the highest yield increase (+84.9%) and largest richness loss (−22.9%) were found. Conventional intensification often drives a trade‐off between richness and production. However, this meta‐analysis also highlights that—even conventional—intensification can result in yield increases without coming at the expense of biodiversity loss.