Integrating

biodiversity services

in agriculture

Teja Tscharntke

Agroecology, University of Göttingen, Germany

Research Training Group ESCALATE, Leipzig,

Helmholtz Centre for Environmental Research,

Seminar, June 14, 2018

Conflicting challenges

Halting the loss of biodiversity UN & EU Biodiversity strategy to 2020

Global food demand doubles until 2050 (10 billion people)

UN world population projections & FAO

UN & EU Biodiversity strategy to 2020 without success,

In Germany

1/3 of the 270 arable weed species endangered

41% of the 560 bee species endangered

30-70% decline in hoverflies (1989-2014)

50% of the common farmland bird species with population declines

(1980-2009)

65% of ecosystem types have disappered in most landscapes

BfN 2017, Agrar-Report

Biodiversity in agriculture:

spatial scale mismatch

Plant

Field

Landscape

Global

Integrating

biodiversity services

in agriculture

(1) Local management of biodiversity services

for sustainable agroecosystems

(2) Landscape design, combining land sparing with

land sharing and habitat connectivity

(3) At a global scale,

adapted solutions for smallholders

Tscharntke et al. 2005, Ecol Letters

Tscharntke et al. 2012, Biol Conserv

Tscharntke et al. 2012, Biol Reviews

Local management

of biodiversity services

for sustainable agroecosystems

FiB

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Local management of biodiversity services

for sustainable agroecosystems

Driven by socio-economic thinking at the household level

Agroecological intensification

with biodiversity-friendly farming practices

Implement crop diversification and legumes!

(crop rotation & mixture, undersowing, catch crop)

Reduce fertilizer applications!

Reduce pesticide applications!

Consider fallows with native plants!

Cap yield peaks with adapted, resilient varieties!

Maintain small fields and field boundaries!

Identify sustainable trade-offs!

Tscharntke et al. 2005, Ecol Letters; Tscharntke et al. 2011, Agric Ecosyst Environm;

Geertsema et al. 2016, Front Ecol Environ; Cunningham et al. 2013, Agr Ecosyst Environ;

Jackson et al. 2012, Global Environm Change

FiB

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Improves production of 75%

of the 115 most important crops globally,

influencing 35% of global human food supply

Pollination enhances crop yields & quality

Alexandra Klein et al. (2007)

Proc Roy Soc B

Annual monetary value of global pollination services:

US$ 235-577 billion, while 40% of invertebrate pollinators face extinction IPBS 2016

Bee wind self pollination

Pollination increases strawberry quality

Red colour & brightness

Acid-sugar ratio

Firmness & shelf life

Marketable yield by 39%-53%

Bjoern Klatt et al 2014, Proc Roy Soc B;

Bjoern Klatt et al. 2014, Agric Food Security

Bees richness/traits increases pumpkin seed set & yield

Multiple traits & functional groups

allow complementary resource use Vesna Gagic et al. 2015 Proc Roy Soc B

Patrick Hoehn et al. 2008, Proc Roy Soc London B

Pollination services – many species needed

Bee richness increases coffee yield

and decreases with forest distance: at 1500m, 55% yield Alexandra Klein et al. 2003, Proc Roy Soc B; Roland Olschewski et al. 2006,

Ecol Soc; Jörg Priess et al. 2006, Ecol Appl

Wild bees are more efficient crop pollinators than honeybees

Lucas Garibaldi et al. 2013, Science; Andrea Holzschuh et al. 2012, Conserv Biol

Experimental gradient in bee diversity:

functional groups & traits matter Fruend et al. 2014 Ecology

Response diversity to winter temperatures Jochen Fruend et al. 2013, Oecologia

Crop pollination mainly by common bee species,

David Kleijn et al. 2015 Nature Comm

Local management

enhancing biological pest control

Carsten Thies et al 2011, Ecol Appl

Excluding natural enemies

triplicates cereal aphid densities

Functional complementarity

(ground- & vegetation dwelling enemies)

Functional redundancy

Across EU regions, relative importance

of enemy group identity changes

Biocontrol of cereal aphids

across Europe

Ant exclusion or invasive ants: 27-34% reduced cocoa yield

Diverse and even ant communities needed!

Arno Wielgoss et al. 2014, Proc Roy Soc B; Wielgoss et al. 2012, J Appl Ecol

Bird and bat (day/night) exclusion: 31% cocoa yield reduction

Bea Maas et al. 2013, Ecol Letters; Maas et al. 2015, J Appl Ecol; Maas et al. 2015, Biol Rev

Bea Maas et al 2013, Ecol Letters

Biological pest control enhancing crop yield -

birds & bats & ants in cacao agroforestry

Indonesian

cacao agroforestry

Herbivore suppression

Enemy enhancement

Crop damage reduction

Crop yield drops

Reduced crop density

Resource competition

Crop quality

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Diversification of cropland

Identifying functionally important plants promoting yield Valuable crop combinations, trap or repellent crops

Optimized arrangement in space and time

Complementary resource use and interplant facilitation

(rooting depth, legume N, enemy attraction) Hooper et al. 2005, Ecol Mon

>95% of research investment into conventional agriculture Baret et al. 2015

High genetic crop diversity

enhances resistance against pathogens and pests

Mixtures of disease-susceptible & resistant rice varieties:

94% less rice blast, 89% greater yield

(than in monoculture, China) Zhu et al. 2000, Nature

Diversification of cropland: case studies

Multi-resistant wheat cultivars (in Europe)

allowing reduced fungicide use can be profitable but is little adopted Vanloqueren & Baret 2008, Ecol Entomol

Push-pull strategy for natural control of

maize pests in Kenya

Pushing away with repellent plants inside cropland

Pulling towards outside trap plants Cook et al. 2007, Ann Rev Entomol

Flavia Geiger et al. 2010, Basic Appl Ecol

Mark Emmerson et al. 2016, Adv Ecol Res

Yield-biodiversity trade-offs across Europe

9 EU regions, 1350 wheat fields

High yield reduces species richness

of plants, birds and beetles

as well as biological pest control

13 local & 9 landscape predictor variables

Pesticide application:

Consistent signal across Europe

Negative externalities of pesticides

Seed coating with neonicotinoids (neonics) contradicts IPM

& accumulation in soils affecting decomposition Bonmatin et al. 2015, Env Sci Pollut Res

Neonics affect homing ability of honeybees, bumblebee queen production,

wild bee survival and pollination;

high insect mortality indirectly affects bird declines Bjoern Klatt et al 2016, Front Ecol Evol; Hallmann et al. 2014, Nature

Beyond LD50 - sublethal exposure to pesticides

change reproduction, behavior, vitality etc. of beneficial insects Desneux et al. 2007, Annu Rev Entomol; Müller et al 2017, Env. Pollution, Müller 2018, BAAE

Disturbs and simplifies food-web interactions - ecologically a disaster Dudley et al. 2017 Biol Conserv

Jason Tylianakis et al.20017, Nature

Anne Ebeling et al. 2011, Basic Appl Ecol

Negative externalities of N fertilization

Eco-efficiency of agriculture

Efficiency = level of output per input (input-output risk)

Cereal yields doubled globally, but sevenfold N-fertilizer increase

(1960-1995) Efficiency declined form 70 to 25 kg grain per kg N

N over-fertilisation (by 45%) in China vs under-fertilization in Africa

Agriculture responsible for 30-35% of global greenhouse gas emission

(methane, nitrous oxide)

Environmental costs of all N losses in Europe:

€70-€320 billion per year (water, soil, air, human health);

higher costs than profits from fertilization

(Sutton and van Grinsven, 2011, CUP)

(Tilman 2001, Science; Keating et al. 2010, Crop Science;

Foley et al. 2011, Science)

Landscape design,

combining land sparing with land sharing

and habitat connectivity

Tscharntke et al. 2012, Biol Rev; Landis 2017, Basic Appl Ecol

Landscape design

Often decided on the political, consensus-oriented village level

Design landscapes with high configurational and compositional heterogeneity,

allowing spillover across (i) crops, (ii) crop boundaries and (iii) natural habitat Fahrig et al. 2011, Tscharntke et al. 2012, Biol Reviews; Baillod et al. 2017 J Appl Ecol

Landscape design so far neglected by EU policies and crop certification Tscharntke et al. 2014, Conserv Letters; Batary et al. 2017, Nature Ecol Evol

Hass et al. 2018, Proc Roy Soc B

Maintain 20% semi-natural habitat, sustaining large species pools Tscharntke et al. 2011, Agric Ecosyst Environ; Tscharntke et al. 2002, Ecol Appl

Consider landscape-wide community turnover (beta diversity) Tylianakis et al. 2005, Ecology; Clough et al. 2007, J Appl Ecol; Flohre et al. 2011, Ecol Appl

Manage simple (not complex) landscapes to have highest efficiency

(“the intermediate landscape complexity hypothesis”) Tscharntke et al. 2012, Biol Rev, Tscharntke et al. 2005, Ecol Letters

Combining land sharing and land sparing

in multifunctional landscapes

(1) Spillover from

natural habitats

to agroecosystems

(2) Spillover from

crop boundaries

to agroecosystems

(3) Landscape connectivity

for mutual benefits of natural &

boundary & crop habitats

Biodiversity services: common species of crop boundaries

Biodiversity conservation: rare species in protected reserves

Common and rare species need a connectivity matrix

Levins‘ metapopulation model

Local populations tend to go extinct with

P = 1 – e/m

(e = extinction rate, m= colonization rate)

Tscharntke & Brandl 2004, Ann Rev Entomol

Hence, in landscapes

without spillover across habitats,

extinction is the dominant process

Grassy field margin strips

enhance predator dispersal Andrea Holzschuh et al. 2009, Ecol Appl

Functional connectivity

via landscape configuration matters

Living fences: humminbirds Urs Kormann et al. 2016, Proc Roy Soc B

Crop-crop edges: bumblebees Hass et al. 2018, Proc Roy Soc B

Field margin strips enhance biological pest control

in oilseed rape

Damage

Complex landscapes:

reduced oilseed rape damage & increased parasitism

Thies & Tscharntke 1999, Science

Tscharntke et al. 2002, Ecol Appl

Field boundaries

to cope with edge effects

only efficient in simple landscapes!

Thies & Tscharntke 1999, Science

Tscharntke et al. 2002, Ecol Appl

Complex landscapes:

reduced rape damage & increased parasitism

Synanthropic species:

hares, hamsters, storks, arable “weeds“

Common farmland birds = endangered Whittingham 2011, J Appl Ecol

People love their countryside biodiversity

beyond any neoliberal monetary valuation Silvertown 2015 Trends Ecol Evol

Cultural ecosystem services

in agricultural landscapes

At a global scale,

adapted solutions for smallholders needed

At a global scale,

adapted solutions for smallholders needed

Often decided at the national governance level

Huge differences in wealth,

opportunities, governance, competition at food markets

Focus on smallholders:

90% of farms globally with <2 ha;

Smallholders are the backbone of global food security,

not western-style large-scale farms

Clough et al. 2011, PNAS,

Tscharntke et al. 2012, Biol Conserv

Graeub et al. 2016, World Developm

Trade-offs between food demand

and biodiversity conservation? Challenging the underlying assumptions!

Current global calorie production is much more than sufficient,

but not available to the 0.8 billion hungry (1.9 billion overweight)

Food usage is inefficient: >2/3 wasted or fed to livestock

Waste: retailer/consumer OR postharvest level

Feed: Cereal-fed cattle means 16 cal for 1 cal of meat (chicken: 3:1)

Biofuel hype, wasting food for energy;

land grabbing, violating land rights of indigenous populations;

speculation on food commodities Tscharntke et al. 2012, Biol Conserv

At a global scale,

adapted solutions for smallholders needed

Enhancing biodiversity services

may sustain resilient, agroecological production

and reduces vulnerability to social, economic and ecological shocks

Biodiversity services allow better

Biological pest control

Crop pollination

Erosion control, soil fertility

Higher profits if certified organic agriculture Bianchi et al. 2006, Proc Roy Soc B; Klein et al. 2007, Proc Roy Soc B; Batary et al. 2017 Nature Ecol Evol

Advancing small & adapted farms,

balancing ecological-economic needs (including education & health services, gender equality;

e.g. Crist et al. 2017, Science)

Tscharntke et al. 2012, Biol Conserv

Indonesian cacao yield & biodiversity in agroforestry not negatively related

Yann Clough et al. 2011 PNAS

Combining high crop yield with high biodiversity

Shade

quantity

Shade

quality

Clough et al. 2011, PNAS

Shade, cacao yield and biodiversity

High yields

High biodiversity

Combining high biodiversity with high yield

in tropical agroforestry

Clough et al. 2011, PNAS

Optimizing both yield and biodiversity!

Low economic costs - high ecological benefit

approaches for resilience

Landscape diversification

of crops & habitats

spatially, crop varieties

species, habitat types

temporally, crop rotation,

policy/market changes

Socio-ecomomic features

risk management, household

vulnerability, traditions

Tscharntke et al. 2012, Conserv Biol

Cumming et al. 2014, Nature

Jackson et al. 2012, Global Env Change

Bianchi et al. 2006 Proc Roy Soc B,

Letourneau et al 2011 Ecol Appl

Fahrig et al. 2011, Ecol Letters

Integrating biodiversity services

in agriculture: Challenges

(1) Consider the scale mismatch in agricultural management:

From economic-thinking households and consensus-oriented villages

to global competition at the national governance level

From local land-use practices and landscape species pools

to evolutionary patterns (beta-diversity of endemic species)

(2) On the local scale, develop effective crop diversification

in small fields, while minimizing agrochemical input and external costs

(3) On the landscape scale, combine land sharing with land sparing

in a connectivity matrix (with 20% habitat), enhancing pollination & biocontrol

(4) On the global scale, focus on adapted small-scale solutions

for smallholders

(5) Ecological-economic trade-offs with agroecological intensification,

to reduce household vulnerability and biodiversity losses

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