Effects of Organic Farming on Biodiversity

Abstract

Changes in farming practices over the past century have had negative influence on farmland biodiversity. Organic farming excludes most agrochemicals, such as inorganic fertilisers and synthetic pesticides, and can be an alternative to conventional farming. A recent meta-analysis indicates that there is on average 30% higher species richness on organically managed farmland compared to conventionally managed farmland. There are, however, large variation between organism groups, with a positive influence on plants and pollinators and possibly predators and birds, but less influence on and insufficient knowledge for other groups. Using more formal experimental design, focusing on understudied organism groups and aspects of biodiversity, such as genetic and ecosystem diversity, and evaluating effects on rare species would advance our knowledge. The yield reduction under organic farming, resulting in more land needed to produce the same amount, could offset some of the biodiversity benefits of organic farming. Agricultural landscapes are both used to produce food and other agricultural products and as habitat for farmland biodiversity.Agricultural intensification, with increased use of agrochemical, mechanisation, crop breeding and conversion of land, is a threat to biodiversity.Organic farming is aimed at ecosystem management and reduction of agrochemical use.Organic farming results in around 30% higher biodiversity compared to conventional farming.The effects of organic farming vary between organism groups owing to their ecological traits.The effect of organic farming on biodiversity can be modified by landscape heterogeneity, land use intensity and time since conversion to organic farming.There are remaining gaps in the knowledge about how to combine agricultural production and biodiversity conservation.

Full text

Effects of Organic
Farming on Biodiversity
Maj Rundlöf, Department of Biology, Lund University, Lund, Sweden
Henrik G Smith, Department of Biology & Centre for Environmental and Climate
Research, Lund University, Lund, Sweden
Klaus Birkhofer, Department of Biology, Lund University, Lund, Sweden
Advanced article
Article Contents
•Introduction
•Organism-dependent Effects of Organic Farming
•Landscape and Scale-dependent Effects of
Organic Farming
•Organic Farming and Biodiversity Conservation
•Conclusions, Knowledge Gaps and Future
Studies
Online posting date: 15th December 2016
Changes in farming practices over the past century
have had negative influence on farmland biodiver-
sity. Organic farming excludes most agrochemicals,
such as inorganic fertilisers and synthetic pesti-
cides, and can be an alternative to conventional
farming. A recent meta-analysis indicates that
there is on average 30% higher species richness
on organically managed farmland compared to
conventionally managed farmland. There are, how-
ever, large variation between organism groups,
with a positive influence on plants and pollinators
and possibly predators and birds, but less influence
on and insufficient knowledge for other groups.
Using more formal experimental design, focusing
on understudied organism groups and aspects of
biodiversity, such as genetic and ecosystem diver-
sity, and evaluating effects on rare species would
advance our knowledge. The yield reduction under
organic farming, resulting in more land needed to
produce the same amount, could offset some of
the biodiversity benefits of organic farming.
Introduction
Several key ecosystem processes in agricultural landscapes have
been replaced by mechanical and chemical practices in conven-
tional farming, often with negative consequences for biodiversity
(Stoate et al., 2001). Organic farming, which aims at ecosystem
management and excludes agrochemicals such as inorganic fer-
tilisers and most pesticides (Stockdale et al., 2001), can be an
alternative to conventional farming. Organic farming can inu-
ence biodiversity directly and indirectly. Given the regulations
eLS subject area: Ecology
How to cite:
Rundlöf, Maj; Smith, Henrik G; and Birkhofer, Klaus (December
2016) Effects of Organic Farming on Biodiversity. In: eLS. John
Wiley & Sons, Ltd: Chichester.
DOI: 10.1002/9780470015902.a0026342
of organic farming, direct effects include reduced exposure to
pesticides and inorganic fertilisers. For example, a large Euro-
pean study has shown that increased use of pesticides reduced
the diversity of plants, carabids and birds (Geiger et al., 2010a).
Indirect effects include effects of changed farming practices that
results from the restrictions on agrochemical use, such as the use
of organic manure and changed crop choice (Stockdale et al.,
2001), which can result in increased local habitat diversity on
organic farms (Hardman et al., 2016, but see Schneider et al.,
2014). There are however remaining gaps in the knowledge about
how different aspects of farming practices inuence biodiver-
sity. In this article, we aim to review the effects of organic
farming on biodiversity based on relevant literature, put this
work into perspective and identify knowledge gaps. See also:
Biodiversity– Threats;Conservation of Biodiversity
The effects of organic farming on biodiversity, most often
dened as species richness, have been assessed in a large num-
ber of studies (see examples in Tab l e 1) and summarised in
review articles (e.g. Hole et al., 2005) and meta-analyses (e.g.
Bengtsson et al., 2005). In the latest and largest meta-analysis
assessing the impacts of organic farming on biodiversity, Tuck
et al. (2014) concluded that organic farming increases the local
biodiversity with on average about 30% but that there is large
variation between studies and organism groups. This variation
can be attributed to differential responses of organisms to changes
in farming practice (Fuller et al., 2005), modifying effect of the
heterogeneity of the surrounding landscape (Rundlöf and Smith,
2006), variation in the time since conversion to organic farm-
ing (Jonason et al., 2011) and the scale at which organic farm-
ing is applies: eld, farm or whole landscape (Gabriel et al.,
2010). The spatial distribution of organic farming could also con-
tribute to the variation; organic farming is often more common in
extensively managed agricultural areas with a larger proportion
of permanent habitats such as grasslands (Rundlöf and Smith,
2006; Gabriel et al., 2009). Comparing biodiversity between
organically and conventionally managed farmland, without con-
sidering this, would make it difcult to separate the inuence
of the farming practice from that of for example soil condi-
tions or landscape structure. Rather than comparing different
farms with and without organic management, ideally biodiversity
should be evaluated before and after conversion, for example in a
before-after-control-impact (BACI) design (Figure 1). However,
to our knowledge, such studies do not exist. See also:Species
Richness: Small Scale
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Effects of Organic Farming on Biodiversity
(a)
1
2
Organic
farms
Conventional
farms
Simple
landscapes
Complex
landscapes
1
2
1
2
3
4
3
4
3
4
(b)
1
3
Time 1
(before)
Time 2
(after)
5
6
2
1
3
2
4
5
6
4
Figure 1 Experimental designs useful for evaluating effects of organic farming on biodiversity. (a) A paired design, where organic farms are paired with
conventional farms, for example by taking the landscape context and geographical location into consideration, is useful in space-for-time substitution
studies. (b) The BACI (before-after-control-impact) design can also be used, where half of the selected farms (or fields) are converted to (or from) organic
farming. Biodiversity is assessed on the farms (or fields) both before and after the conversion. Farms (or fields) should preferably be randomly assigned to
the treatment and control groups. In both the cases, it is important to include sufficient replication to be able to detect any difference in the measured
parameter(s) between the farming systems.
Organism-dependent Effects of
Organic Farming
Different organism groups can be positively, negatively or not at
all affected by organic farming (Bengtsson et al., 2005; Fuller
et al., 2005; Winqvist et al., 2011; Birkhofer et al., 2014a; Schnei-
der et al., 2014;Tucket al., 2014;Tabl e 1). These different
responses have partly been attributed to how mobile organisms
are; it could be more difcult to detect effects on mobile organ-
isms, moving over large areas, if only a small area is organically
managed (Fuller et al., 2005). Differences could also be due to
how strong organisms respond to the changes that conversion
to organic farming entails, such as the reduction in pesticide
use and crop choice. Local factors such as agrochemical input
are probably more important for sedentary organisms such as
plants, while landscape factors, such as the amount of permanent
habitat, are more important for mobile organisms. The effect of
organic farming on biodiversity can also depend on which aspects
of biodiversity that are considered, such as taxonomic related-
ness or community or trait composition (Andersson et al., 2013;
Birkhofer et al., 2014a,2015).
For some organism groups, such as mammals, reptiles, amphib-
ians and protozoa, there are very few studies about the effects
of organic farming (Tuck et al., 2014). With such limited data,
it is hard to draw general conclusions. Here we summarise the
knowledge for organism groups for which we have sufcient
information, based on Tuck et al. (2014) and some more recent
publications.
Microbes and decomposers
The biomass of soil bacteria and fungi can be negatively affected
by conventional compared to integrated or organic farming (Kong
et al., 2011) with often pronounced effects of the farming sys-
tem on community composition (reviewed in Birkhofer et al.,
2012). In soil animals, it is noticeable that effects of organic farm-
ing on species richness are weak to absent compared to other
functional groups (Tuck et al., 2014). The review by Tuck et al.
(2014), however, explicitly excludes all data about a range of
important soil animal groups due to low numbers of publications.
Among the excluded taxonomic groups are annelids (earthworms
and pot worms) and nematodes (roundworms). On the basis of
the few available publications, pot worms (Enchytraeidae) and
earthworms (Lumbricidae) show less consistent responses to dif-
ferences in farming practices compared to some trophic groups
of nematodes (Birkhofer et al., 2012; Schneider et al., 2014).
Soil arthropods (meso- and macrofauna) are also not consistently
affected by organic farming, with effects that range from higher
abundance and species richness to no difference or even oppo-
site patterns under conventional farming (Birkhofer et al., 2008;
Diekötter et al., 2010).
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Effects of Organic Farming on Biodiversity
Tabl e 1 Effects of organic farming on the species richness of different organism and functional groups relative to conventional farming,
with examples for case studies and additional reviews.
Effect of organic
farming
Examples
Organism group (n)
Microbes (6) =Kong et al. (2011); Birkhofer et al. (2012)
Plants (62) +Aude et al. (2003); Roschewitz et al. (2005); Rundlöf et al. (2010); Winqvist et al.
(2011); Schneider et al. (2014)
Arthropods (89) +Feber et al. (1997); Weibull et al. (2000); Clough et al. (2007); Diekötter et al.
(2010); Ekroos et al. (2010); Rusch et al. (2014); Birkhofer et al. (2015); Inclán
et al. (2015)
Birds (17) =Batary et al. (2010); Geiger et al. (2010b); Smith et al. (2010a); Winqvist et al.
(2011)
Functional group (n)
Decomposers (19) =Birkhofer et al. (2008, 2012); Diekötter et al. (2010); Schneider et al. (2014)
Producers (plants) (62) +Aude et al. (2003); Roschewitz et al. (2005); Rundlöf et al. (2010); Winqvist et al.
(2011); Schneider et al. (2014)
Herbivores (6) =Birkhofer et al. (2015)
Pollinators (21) +Holzschuh et al. (2008); Rundlöf et al. (2008b); Andersson et al. (2013); Schneider
et al. (2014)
Predators (49) +Birkhofer et al. (2008, 2012, 2014a, 2015); Diekötter et al. (2010); Ekroos et al.
(2010); Winqvist et al. (2011); Rusch et al. (2014); Schneider et al. (2014);
Inclán et al. (2015)
Effect direction and sample size are based on results in Tuck et al. (2014): +, higher species richness on organic farmland; =, no signicant difference
in species richness between organic and conventional farmland (i.e. when the 95% credible interval overlap 0); n, number of studies included in the
meta-analysis.
Plants
Plants are the organism group that usually shows the most con-
sistent results when comparing organic and conventional farming
(reviewed in Bengtsson et al., 2005;Holeet al., 2005;Tucket al.,
2014). The relatively strong effect of organic farming on plant
diversity is primarily due to the direct negative effects of her-
bicides in conventional farming (Geiger et al., 2010a), reducing
noncrop plant diversity in elds (Roschewitz et al., 2005; Win-
qvist et al., 2011; Schneider et al., 2014) and adjacent habitats
(Aude et al., 2003; Rundlöf et al., 2010). Organic cereal elds
generally have higher plant diversity compared to conventional
elds (Roschewitz et al., 2005; Winqvist et al., 2011), both on
cereal farms and on farms with both cereal and animal produc-
tion (Ekroos et al., 2010). The difference can be particularly
pronounced in landscapes devoid of seminatural habitats, while
approaching similar levels between farming systems in more
complex and heterogeneous landscapes (Roschewitz et al., 2005;
but see Winqvist et al., 2011). The management of elds can also
inuence plant diversity in adjacent habitats. Plant diversity was
higher in uncultivated eld borders (Rundlöf et al., 2010)and
hedges (Aude et al., 2003) adjacent to organically managed elds
compared to adjacent to conventional elds.
Herbivores
The effect of organic farming on the diversity of herbivores
is not well known (Tuck et al., 2014), partly because many
applied studies rather focus on effects of organic farming on abun-
dances of single pest species instead of community level analyses
(Birkhofer et al., 2016). The few available studies suggest that
local farming practices have a very variable effect on herbivore
species richness and that landscape-scale intensication may be
a stronger driver of herbivore diversity compared to organic farm-
ing practices (Tuck et al., 2014). True bug communities (mainly
consisting of herbivorous species) have higher species richness
on organic farmland and in addition have a lower functional and
taxonomic distinctness under conventional farming (Birkhofer
et al., 2015). The later effect suggests that reduced species num-
bers due to intense, conventional farming may simultaneously
result in a loss of phylogenetically and trait-wise unique species
from local herbivore communities. Interestingly, even if positive
effects of organic farming on herbivore diversity in crop elds
are observed compared to conventional farming, the number of
species will still be much lower than in adjacent seminatural habi-
tats (Birkhofer et al., 2014b).
Pollinating arthropods
Pollinators, such as bees and hoveries, and other ower visitors,
such as butteries, have been the focus of many studies compar-
ing diversity on organic and conventional farmland (Tuck et al.,
2014). These organism groups generally have higher species rich-
ness on organic compared to conventional farmland (Rundlöf
and Smith, 2006;Feberet al., 1997; Holzschuh et al., 2008;
Rundlöf et al., 2008a,b; Andersson et al., 2013; Birkhofer et al.,
2014a; Schneider et al., 2014). As they are all dependent on
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Effects of Organic Farming on Biodiversity
nectar and/or pollen from owering plants, their diversity prob-
ably benets from the higher abundance of owering plants in
and around organically managed elds (Gabriel and Tscharn-
tke, 2007; Rundlöf et al., 2008b). High pollinator diversity on
organically managed farmland could contribute to support insect
pollinated plants, both wild (Gabriel and Tscharntke, 2007)and
cultivated (Environmental Impacts of Organic Farming). The
use of insecticides to control pest insects in conventional farming
can have negative effects also on nontarget organisms (Desneux
et al., 2007; Rundlöf et al., 2015), so the limited use of such agro-
chemicals in organic farming may contribute to the often-found
higher pollinator diversity.
Predaceous arthropods
The main groups of arthropod generalist predators (predaceous
beetles and spiders) seem to benet from organic farming in terms
of abundance (reviewed in Bengtsson et al., 2005; Fuller et al.,
2005;Holeet al., 2005; see also Birkhofer et al., 2008). Effects
on the diversity of these taxonomic groups are less predictable
(Schneider et al., 2014, reviewed in Birkhofer et al., 2012), as
predaceous species groups within this functional groups can be
negatively affected by organic farming (Birkhofer et al., 2014a).
Organic farming also alters the composition of ecological traits in
generalist predator communities compared to that in convention-
ally managed elds (Rusch et al., 2014; Birkhofer et al., 2015).
These diversity changes in the functional composition of predator
communities together with effects of organic farming on predator
abundance can affect the functional role of predator communi-
ties in organically compared to conventionally managed elds
(Birkhofer et al., 2016). Studies on the effect of organic farm-
ing on parasitoid communities traditionally focus on parasitism
rates and not on taxonomic richness or other measures of diver-
sity. Inclán et al. (2015) recently documented positive effects of
organic farming on tachinid parasitoid species richness across
local to landscape scales.
Birds
Bird are generally positively affected by organic farming (Win-
qvist et al., 2011;Tucket al., 2014), but effects vary between
studies and species (Wilcox et al., 2014) and species richness
may even be higher on conventional farms (Gabriel et al., 2010).
The latter results may be because organic farms were associated
with habitats favouring corvids, which are important nest preda-
tors. Although attempts to determine what causes organic farming
to benet birds are few, there are indications that it is related
to lower use of pesticides and higher availability of seminatu-
ral habitat (McKenzie and Whittingham, 2009), both which may
benet food availability. Positive effects of organic farming on
bird species richness are found on both arable elds and in mead-
ows (Batary et al., 2010). In addition, organic farming has been
found to have larger effects on bird species richness in landscape
with low amounts of seminatural habitat (Smith et al., 2010a,but
see Winqvist et al., 2011). Organic farming may benet birds also
in winter (Fuller et al., 2005), at least in simplied agricultural
landscapes (Geiger et al., 2010b). In general, landscape structure
may be a more important determinant of bird species richness
than farm management (Gabriel et al., 2010).
Landscape and Scale-dependent
Effects of Organic Farming
Several studies have shown that effects of organic farming on
plants and more mobile biodiversity can be landscape depen-
dent (Roschewitz et al., 2005; Rundlöf and Smith, 2006). In
heterogeneous landscapes, with a high proportion of uncultivated
habitats such as eld borders and seminatural grasslands, sim-
ilar levels of diversity can be expected on organic and conven-
tional farmland because the complexity of the landscape and high
habitat availability promote biodiversity and the local manage-
ment becomes less important (Tscharntke et al., 2005). In con-
trast, simple and homogeneous landscapes dominated by arable
farming are suggested to have an intermediate species pool that
responds to improved local habitat quality by management, such
as organic farming (Tscharntke et al., 2005). Another factor
that can inuence the effect of organic farming on biodiver-
sity is how large portions of the landscape are that are man-
aged organically (Rundlöf et al., 2008a,b; Diekötter et al., 2010;
Gabriel et al., 2010). This could be because effects on mobile
organisms become more detectable when organically managed
habitat is more agglomerated or because of nonadditive effects
on populations. As a result, there can be additive biodiversity
benets of managing farmland organically beyond the single
farm (Gabriel et al., 2010). However, other studies found no
landscape-dependent effect of organic farming (Weibull et al.,
2000; Winqvist et al., 2011). In the meta-analysis by Tuck et al.
(2014), the difference in diversity between organic and conven-
tional farming increased with increasing proportion of arable land
and a multicountry study concludes that the species richness ben-
ets of organic farming increased with increasing regional nitro-
gen input (Schneider et al., 2014). There is however considerable
variation in the results, which is partly attributed to different
responses between organism groups to local farming practices
and varying land-use intensity in different landscapes. See also:
Species Richness: Small Scale
Organic Farming and Biodiversity
Conservation
Given that the difference in local biodiversity between organic
and conventional farmland is most pronounced in simple and
intensively farmed landscapes (Roschewitz et al., 2005; Rundlöf
and Smith, 2006;Tucket al., 2014), the biodiversity gain would
be largest if farms in such areas would convert to organic farming
(Tscharntke et al., 2005). However, as this landscape dependency
cannot be generalised over organism groups and the knowledge of
how organic farming inuence rare and threatened species, which
are predominantly occurring in heterogeneous landscapes (Kleijn
et al., 2011), is insufcient (but see Birkhofer et al., 2014a), the
optimal location of organic farming to support biodiversity needs
further investigation.
Although the overall effect of organic farming on biodiver-
sity appears to be positive (Tuck et al., 2014), there is some
uncertainty if this positive inuence on local biodiversity can con-
tribute to higher regional diversity (Schneider et al., 2014). This
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Effects of Organic Farming on Biodiversity
pattern could be expected if organic farming had a stronger inu-
ence on common species compared to more rare species. There
are however studies that indicate that organic farming can con-
tribute to larger diversity also at regional scales (Clough et al.,
2007). Biodiversity conservation is not always an outspoken goal
of organic farming and the design and implementation of this
farming practice is not optimised for such purpose. Using the eco-
logical requirement of the organisms in focus as starting points
when designing the rules governing organic farming, its effect on
biodiversity would most likely be enhanced.
There is an ongoing debate on the optimal way to conserve
biodiversity and at the same time increase agricultural produc-
tion (Phalan et al., 2011; Fischer et al., 2014). Although organic
farming has an overall positive effect on biodiversity (Tuck et al.,
2014), the increased land area needed to compensate for the
lower yields in organic farming systems (Ponisio et al., 2015)
leaves less land that could be used for biodiversity conservation.
Because of the lower yields and a suggested higher diversity per
unit production under conventional farming, it has been argued
that there may be no overall benet of organic farming (Hodg-
son et al., 2010). This approach to standardise biodiversity by
yield that is for example commonly used in comparing emissions
of greenhouse gases between organic and conventional farming
however suffers from major logical aws for diversity. In contrast
to CO2levels, species richness is not measured on a simple addi-
tive scale where all units are easily exchangeable because each
species is a unique entity. In Europe, there are for example many
rare species that depend on extensively managed farmland and
thus are directly supported by low-intensity agriculture such as
organic farming (Sutcliffe et al., 2015). See also:Environmental
Impacts of Organic Farming
Conclusions, Knowledge Gaps and
Future Studies
We conclude that there is strong support for an overall posi-
tive effect of organic farming compared to conventional farming
on biodiversity, measured as species richness over all organism
groups (Tuck et al., 2014), but that there remain several knowl-
edge gaps. Plants are one of the most well-studied organism group
and that is strongest inuenced by organic farming, probably due
to direct effects of herbicide use in conventional farming, and
this effect can cascade up to affect higher trophic levels in the
food chain. The effect of organic farming differs between organ-
ism groups, with positive inuence on plants and pollinators and
possibly also predators and birds, but less inuence on microbes,
herbivores and decomposers and insufcient knowledge about for
example mammals and amphibians (Tuck et al., 2014). In fact,
most organism groups apart from plants, arthropods and birds
appear to be understudied in relation to effects of organic farming
and conclusions apply to common rather than rare species.
The higher biodiversity on organic farmland, for example of
pollinators, could contribute to ecosystem services, but there is
still a limited understanding about how organic farming inu-
ences such services (Environmental Impacts of Organic Farm-
ing). We have focused on species-based measures of biodiversity,
but biodiversity also includes genetic and ecosystem variation.
These aspects of biodiversity have not been addressed prop-
erly in relation to organic farming. See also:Ecosystem Ser-
vices;Convention on Biological Diversity;Diversity of Life;
Environmental Impacts of Organic Farming
Current studies of biodiversity effects of organic farming are
predominantly conducted as ‘space-for-time’ studies, where bio-
diversity is compared between areas with already established
organic and conventional farmland at the same point in time
(Figure 1). In such studies, it is essential to consider multiple
factors that can modify the effect of organic farming on biodi-
versity, for example the heterogeneity and land-use intensity in
the landscape surrounding the organic farmland. Another type
of study that would be useful is the BACI design, that is studies
where biodiversity is evaluated before and after conversion to or
from organic farming (Figure 1). Such formal experiments could
help to disentangle some of the inconclusive results in the litera-
ture. It is, however, logistically and nancially very challenging to
conduct experiments at a landscape scale, which is often needed
for mobile organisms. One solution would be to integrate such
experimental evaluation in policies that include agri-environment
schemes to support organic farming (Smith et al., 2010b). The
conclusions we draw here are applicable to Western and Northern
Europe and North America because these are the regions where
most studies on organic farming and biodiversity have been con-
ducted (Tuck et al., 2014). There are very few studies from other
regions, so knowledge about the effects of organic farming on
biodiversity elsewhere is limited.
References
Andersson GKS, Birkhofer K, Rundlöf M and Smith HG (2013)
Landscape heterogeneity and farming practice alter the species
composition and taxonomic breadth of pollinator communities.
Basic and Applied Ecology 14: 540–546.
Aude E, Tybirk K and Pedersen MB (2003) Vegetation diversity
of conventional and organic hedgerows in Denmark. Agriculture,
Ecosystems and Environment 99: 135–147.
Batary P, Matthiesen T and Tscharntke T (2010)
Landscape-moderated importance of hedges in conserving
farmland bird diversity of organic vs. conventional croplands and
grasslands. Biological Conservation 143: 2020–2027.
Bengtsson J, Ahnström J and Weibull A-C (2005) The effects
of organic agriculture on biodiversity and abundance: a
meta-analysis. Journal of Applied Ecology 42: 261–269.
Birkhofer K, Bezemer TM, Bloem J, et al. (2008) Long-term organic
farming fosters below- and aboveground biota: implications for
soil quality, biological control and productivity. Soil Biology and
Biochemistry 40: 2297–2308.
Birkhofer K, Bezemer TM, Hedlund K and Setälä H (2012) Commu-
nity composition of soil organisms under different wheat farming
systems. In: Cheeke T, Coleman DC and Wall DH (eds) Microbial
Ecology in Sustainable Agroecosystems. Advances in Agroecology,
pp. 89–112. Boca Raton: CRC Press.
Birkhofer K, Ekroos J, Corlett EB and Smith HG (2014a) Win-
ners and losers of organic cereal farming in animal communities
across Central and Northern Europe. Biological Conservation 175:
25–33.
eLS © 2016, John Wiley & Sons, Ltd. www.els.net 5

Effects of Organic Farming on Biodiversity
Birkhofer K, Wolters V and Diekötter T (2014b) Grassy margins
along organically managed cereal elds foster trait diversity and
taxonomic distinctness of arthropod communities. Insect Conser-
vation and Diversity 7: 274–287.
Birkhofer K, Smith HG, Weisser WW, et al. (2015) Land-use effects
on the functional distinctness of arthropod communities. Ecogra-
phy 38: 889–900.
Birkhofer K, Arvidsson F, Ehlers D, et al. (2016) Landscape com-
plexity and organic farming independently affect the biological
control of hemipteran pests and yields in spring barley. Landscape
Ecology 31: 567–579.
Clough Y, Holzschuh A, Gabriel D, et al. (2007) Alpha and beta
diversity of arthropods and plants in organically and conventionally
managed wheat elds. Journal of Applied Ecology 44: 804–812.
Desneux N, Decourtye A and Delpuech J-M (2007) The sublethal
effects of pesticides on benecial arthropods. Annual Review of
Entomology 52: 81–106.
Diekötter T, Wamser S, Wolters V and Birkhofer K (2010) Land-
scape and management effects on structure and function of soil
arthropod communities in winter wheat. Agriculture, Ecosystems
and Environment 137: 108–112.
Ekroos J, Hyvönen T, Tiainen J and Tiira M (2010) Responses in
plant and carabid communities to farming practises in boreal land-
scapes. Agriculture, Ecosystems and Environment 135: 288–293.
Feber RE, Firbank LG, Johnson PJ and Macdonald DW (1997) The
effects of organic farming on pest and non-pest buttery abun-
dance. Agriculture, Ecosystems and Environment 64: 133–139.
Fischer J, Abson DJ, Butsic V, et al. (2014) Land sparing versus land
sharing: moving forward. Conservation Letters 7: 149–157.
Fuller RJ, Norton LR, Feber RE, et al. (2005) Benets of organic
farming to biodiversity vary among taxa. Biology Letters 1:
431–434.
Gabriel D and Tscharntke T (2007) Insect pollinated plants benet
from organic farming. Agriculture, Ecosystems & Environment
118: 43–48.
Gabriel D, Carver SJ, Durham H, et al. (2009) The spatial aggregation
of organic farming in England and its underlying environmental
correlates. Journal of Applied Ecology 46: 323–333.
Gabriel D, Sait SM, Hodgson JA, et al. (2010) Scale matters: the
impact of organic farming on biodiversity at different spatial scales.
Ecology Letters 13: 858–869.
Geiger F, Bengtsson J, Berendse F, et al. (2010a) Persistent negative
effects of pesticides on biodiversity and biological control potential
on European farmland. Basic and Applied Ecology 11: 97–105.
Geiger F, de Snoo GR, Berendse F, et al. (2010b) Landscape com-
position inuences farm management effects on farmland birds
in winter: a pan-European approach. Agriculture, Ecosystems and
Environment 139: 571–577.
Hardman CJ, Harrison DPG, Shaw PJ, et al. (2016) Supporting local
diversity of habitats and species on farmland: a comparison of
three wildlife-friendly schemes. Journal of Applied Ecology 53:
171–180.
Hodgson JA, Kunin WE, Thomas CD, et al. (2010) Comparing
organic farming and land sparing: optimizing yield and buttery
populations at a landscape scale. Ecology Letters 13: 1358–1367.
Hole DG, Perkins AJ, Wilson JD, et al. (2005) Does organic farming
benet biodiversity? Biological Conservation 122: 113–130.
Holzschuh A, Steffan-Dewenter I and Tscharntke T (2008) Agri-
cultural landscapes with organic crops support higher pollinator
diversity. Oikos 117: 354–361.
Inclán DJ, Cerretti P, Gabriel D, et al. (2015) Organic farming
enhances parasitoid diversity at the local and landscape scales.
Journal of Applied Ecology 52: 1102–1109.
Jonason D, Andersson GK, Öckinger E, et al. (2011) Assessing the
effect of the time since transition to organic farming on plants and
butteries. Journal of Applied Ecology 48: 543–550.
Kleijn D, Rundlöf M, Scheper J, et al. (2011) Does conservation on
farmland contribute to halting the biodiversity decline? Trends in
Ecology & Evolution 26: 474–481.
Kong AYY, Scow KM, Cordova-Kreylos AL, et al. (2011) Microbial
community composition and carbon cycling within soil microen-
vironments of conventional, low-input, and organic cropping sys-
tems. Soil Biology and Biochemistry 43: 20–30.
McKenzie AJ and Whittingham MJ (2009) Why are birds more
abundant on organic farms? Journal of Food, Agriculture and
Environment 7: 807–814.
Phalan B, Onial M, Balmford A and Green RE (2011) Reconciling
food production and biodiversity conservation: land sharing and
land sparing compared. Science 333: 1289–1291.
Ponisio LC, M’Gonigle LK, Mace KC, et al. (2015) Diversication
practices reduce organic to conventional yield gap. Proceedings of
the Royal Society B 282: 20141396.
Roschewitz I, Gabriel D, Tscharntke T and Thies C (2005) The
effects of landscape complexity on arable weed species diversity
in organic and conventional farming. Journal of Applied Ecology
42: 873–882.
Rundlöf M and Smith HG (2006) The effect of organic farming
on buttery diversity depends on landscape context. Journal of
Applied Ecology 43: 1121–1127.
Rundlöf M, Bengtsson J and Smith HG (2008a) Local and landscape
effects of organic farming on buttery species richness and abun-
dance. Journal of Applied Ecology 45: 813–820.
Rundlöf M, Nilsson H and Smith HG (2008b) Interacting effects of
farming practice and landscape context on bumblebees. Biological
Conservation 141: 417–426.
Rundlöf M, Edlund M and Smith HG (2010) Organic farming at
local and landscape scales benets plant diversity. Ecography 33:
514–522.
Rundlöf M, Andersson GK, Bommarco R, et al. (2015) Seed coat-
ing with a neonicotinoid insecticide negatively affects wild bees.
Nature 521: 77–80.
Rusch A, Birkhofer K, Bommarco R, et al. (2014) Management
intensity at eld and landscape levels affects the taxonomic and
functional structure of generalist predator communities. Oecologia
175: 971–983.
Schneider MK, Luscher G, Jeanneret P, et al. (2014) Gains to species
diversity in organically farmed elds are not propagated at the farm
level. Nature Communications 5: 4151.
Smith HG, Dänhardt J, Lindström Å and Rundlöf M (2010a) Con-
sequences of organic farming and landscape heterogeneity on
species richness and abundance of farmland birds. Oecologia 162:
1071–1079.
Smith HG, Öckinger E and Rundlöf M (2010b) Biodiversity and
the landscape ecology of agri-environment schemes. Aspects of
Applied Biology 100: 225–232.
Stoate C, Boatman ND, Borralho RJ, et al. (2001) Ecological impacts
of arable intensication in Europe. Journal of Environmental Man-
agement 63: 337–365.
Stockdale EA, Lampkin NH, Hovi M, et al. (2001) Agronomic and
environmental implications of organic farming systems. Advances
in Agronomy 70: 261–327.
6eLS © 2016, John Wiley & Sons, Ltd. www.els.net

Effects of Organic Farming on Biodiversity
Sutcliffe LM, Batáry P, Kormann U, et al. (2015) Harnessing the bio-
diversity value of Central and Eastern European farmland. Diver-
sity and Distributions 21: 722–730.
Tuck SL, Winqvist C, Mota F, et al. (2014) Land-use intensity
and the effects of organic farming on biodiversity: a hierarchical
meta-analysis. Journal of Applied Ecology 51: 746–755.
Tscharntke T, Klein AM, Kruess A, et al. (2005) Landscape perspec-
tives on agricultural intensication and biodiversity – ecosystem
service management. Ecology Letters 8: 857–874.
Weibull A-C, Bengtsson J and Nohlgren E (2000) Diversity of butter-
ies in the agricultural landscape: the role of farming system and
landscape heterogeneity. Ecography 23: 743–750.
Wilcox JC, Barbottin A, Durant D, et al. (2014) Farmland birds and
arable farming, a meta-analysis. In: Lichtfouse E (ed) Sustainable
Agriculture Reviews,vol.13, pp. 35–63. Cham: Springer.
Winqvist C, Bengtsson J, Aavik T, et al. (2011) Mixed effects of
organic farming and landscape complexity on farmland biodiver-
sity and biological control potential across Europe. Journal of
Applied Ecology 48: 570–579.
Further Reading
Benton TG, Vickery JA and Wilson JD (2003) Farmland biodiversity:
is habitat heterogeneity the key? Trends in Ecology & Evolution 18:
182–188.
Bommarco R, Kleijn D and Potts SG (2013) Ecological intensica-
tion: harnessing ecosystem services for food security. Trends in
Ecology & Evolution 28: 230–238.
Ekroos J, Ödman AM, Andersson GKS, et al. (2016) Sparing land
for biodiversity at multiple spatial scales. Frontiers in Ecology and
Evolution 3: 145.
Gabriel D, Sait SM, Kunin WE, et al. (2013) Food production
vs. biodiversity: comparing organic and conventional agriculture.
Journal of Applied Ecology 50: 355–364.
Green RE, Cornell SJ, Scharlemann JPW and Balmford A (2005)
Farming and the fate of wild nature. Nature 307: 550–555.
Kleijn D and Sutherland WJ (2003) How effective are European
agri-environment schemes in conserving and promoting biodiver-
sity? Journal of Applied Ecology 40: 947–969.
Köhler H-R and Triebskorn R (2013) Wildlife ecotoxicology of
pesticides: can we track effects to the population level and beyond?
Science 341: 759–765.
Tscharntke T, Clough Y, Wanger TC, et al. (2012) Global food
security, biodiversity conservation and the future of agricultural
intensication. Biological Conservation 151: 53–59.
Winqvist C, Ahnström J and Bengtsson J (2012) Effects of organic
farming on biodiversity and ecosystem services: taking landscape
complexity into account. Annals of the New York Academy of
Sciences 1249: 191–203.
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