encouraging on farm biodiversity
TRANSCRIPT
Encouraging on-‐farm biodiversity
Paul Manning, BSc. Ag DPhil Candidate, University of Oxford
Farmland associated species in widespread decline.
What we know.
Ranges of farmland birds decline under more intensive agricultural management.
Donald et al., 2001
PopulaLons of birds decline when agriculture is intensified.
Donald et al., 2001
At naLon level, more intensive producLon linked to the number of rare, threatened, or exLnct species.
Storkey et al. 2011
Post-‐war intensificaLon of agricultural systems has resulted in widespread decline in soil seed banks.
Robinson and Sutherland, 2002
We see a huge increase in the frequency of exLncLons during periods of agricultural intensificaLon.
Ollerton et al. 2014
Organic producLon can play an important role in restoring and conserving farmland biodiversity.
What we know.
Organic farming supports biodiversity
Meta-‐analysis by Tuck et al.
• Screened all published literature on how organic farming affects species richness.
• Evaluated the findings of changes in diversity in 184 cases.
Organic farming systems support 30% more species than convenLonal farms.
Plants respond more strongly to organic management than any other taxa.
For Farming Systems Typical of AtlanLc Organic ProducLon Systems, data are sparse!
Organic farming has a stronger posiLve effect on biodiversity in more intensively farmed landscapes.
1. What are the most effec/ve ways of promo/ng on-‐farm biodiversity?
What we need to learn
Hedgerows
Longer hedges support greater number of bird species. Effect is stronger in simple landscapes.
Batary et al., 2010
Inclusion of trees within hedgerows increases Pipistrelle bat densiLes on agroecosystems.
Kelm et al. 2014
Bats suppress corn earworm, meaning less damage from Aspergillus flavus and Fuserium (ear rot).
Maine and Boyles. 2015
All hedgerows are not created equal
Use of non-‐crop habitat
Pywell et al. 2015
• Large 900 ha farming estate • Randomised blocked design. • Does the inclusion of agri-‐environmental schemes affect yield?
Per acre yield increased with proporLon of land ‘spared’
Pywell et al. 2015
When considering land lost, overall yields found to be the same across sparing strategies.
Pywell et al. 2015
Good stewardship of natural habitat w/in agroecosystems can have significant conservaLon value. James et al. 2015
Use of naLve plants means more than four Lmes the abundance of buberflies!
James et al. 2015
SupporLng pollinators
CauLon
• Bee hotels might not help naLve biodiversity and could have negaLve consequences for species living in agricultural landscapes.
• Greater numbers of less aggregated nesLng sites could be of greater benefit.
Studied the fate of 600 ‘bee-‐hotels’ set in urban gardens across Toronto.
Non-‐naLve bees make beber use of nest boxes than naLves.
MacIvor et al. 2015
We need to be wary of ‘bee-‐washing’
Recommended ways of benefiAng bees: 1. Use fewer/no insecLcides 2. Plant a diversity of flowers 3. Offer less aggregated nesLng sites.
1. What are the most effec/ve ways of promo/ng on-‐farm biodiversity?
2. Does more biodiversity support greater delivery of ecosystem services?
What we need to learn
Biodiversity – Ecosystem FuncLoning relaLonships are like a box of chocolates.
Biodiversity – Ecosystem FuncLoning
Biodiversity
FuncLo
ning
Biodiversity – Ecosystem FuncLoning FuncLo
ning
Biodiversity
Biodiversity ecosystem funcLoning relaLonships are complicated!
Is there an economic argument to conserving pollinator diversity in agroecosystems?
Large yield benefits are mostly provided by the most common species
Kleijn et al., 2015
Crop visiLng species only represent a Lny fracLon of overall bee diversity
Kleijn et al., 2015
Does greater predator diversity mean more or less pest regulaLon?
Snyder et al. 2006
Greater predator diversity suppresses herbivore populaLons!
Snyder et al. 2006
A couple of examples from my research.
Dung decomposiLon
Dung decomposiLon
Dung decomposiLon
Improving hydrological properLes of soil Brown et al.(2002)
Improved forage growth Bang et al. (2005)
Enhancing feeding acLvity of soil mesofauna
Manning et al. (In press )
Suppression of pasture weeds? Manning et al. (In Progress)
Improved soil permeability Bang et al.(2005)
Alleviate drought stress Johnson et al. (2015)
Suppression of faecal pathogens on produce Jones et al. (2015)
Slows pasture fouling Anderson et al. (1984)
Controlling spread of gastrointesLnal parasites Bryan (1973)
Dung beetles provide mulLple ecosystem services
Biology can be subtle. This means we might someLmes overlook interesLng phenomena.
1. Dung oviposi/ng endocoprid
Aphodius ater
2. Soil oviposi/ng endocoprid
Aphodius fossor
3. Paracoprid
Onthophagus joannae
Small differences in dung removal across all treatments. Significant effects probably not biologically so.
We can see how feeding is verLcally straLfied within the soil.
3. Paracoprid beetles seem to drive higher levels of feeding ac/vity by soil fauna.
Clear paberns of funcLonal idenLty on bait consumpLon.
Clear paberns of funcLonal idenLty on bait consumpLon.
Clear paberns of funcLonal idenLty on bait consumpLon.
The importance of diversity can be higher when you consider mulLple ecosystem services.
Improving hydrological properLes of soil Brown et al.(2002)
Improved forage growth Bang et al. (2005)
Enhancing feeding acLvity of soil mesofauna
Manning et al. (In press )
Suppression of pasture weeds? Manning et al. (In Progress)
Improved soil permeability Bang et al.(2005)
Alleviate drought stress Johnson et al. (2015)
Suppression of faecal pathogens on produce Jones et al. (2015)
Slows pasture fouling Anderson et al. (1984)
Controlling spread of gastrointesLnal parasites Bryan (1973)
Dung beetles provide mulLple ecosystem services
Dung beetles are suscepLble to stressors.
Whether diversity meant higher grass growth depended on whether system was disturbed.
Soil fauna feeding acLvity isn’t significantly influenced by diversity or perturbaLon.
Feed
ing acLvity
(%)
Bulk den
sity (kg·∙m
−3)
Bulk density isn’t significantly influenced by diversity or perturbaLon.
Dung beetles exposed to ivermecLn consume significantly less dung. No effect of diversity.
Higher dung beetle diversity means much higher funcLoning. This relaLonship is lost under ivermecLn exposure.
How percepLve are the public to biodiversity?
“Would you like to see more biodiversity?”
89%
83%
57%
23% Schwartz et al. 2014
IntervenLons were made to increase biodiversity.
Schwartz et al. 2014
Biodiversity manipulaLons successful
27%
49%
Schwartz et al. 2014
Respondents did not noLce any of the changes in species richness in birds, pollinators. InformaLve posters, and interpretaLon meant visitors became aware of parkland biodiversity.
Schwartz et al. 2014
What does this mean for the organic industry?
• Important to CHAMPION the benefits of organic agriculture in supporLng farmland diversity.
• People care. This can become a really important way of engaging supporters, and the public on the benefits of organic producLon systems.
In summary
• Organic producLon supports biodiversity. • Many intervenLons can support on-‐farm biodiversity. Experiment with management. Find out what works for you.
• Data are noisy! Large experiments, collaboraLon key to discovering paberns.
• Biodiversity can support greater delivery of ecosystem services. BUT, it’s complicated.
Thanks.