1. Preserving biodiversity and soil
Professor Jim Harris
structure and function
School of Applied Sciences
Cranfield University
Bedfordshire UK

2. Talk outline
• Global challanges
• Life in the soil and soil function
• Effects of land use
• Ecosystem service framework for monitoring and
decision support
• Options for the future to maintain and enhance
soil resources
• Conclusions

3. Challenges
• Global climate change
• Sea level rise
• Agricultural intensification
• Food and water security
• Loss of biodiversity

4. Ellis and Ramankutty 2008

6. Life in the soil/soil
function
Soils are remarkably complex
•Physically
•Chemically
•Biologically

7. 5 cm 5 mm

8. HOW MUCH LIFE IS
THERE ?
SOIL BIOMASS
• handful of arable soil
(c. 200g)
• approximately
0.5 g of fresh biomass
(mainly ‘microbial’)
• Over 10,000 species per
gram (conservative
estimate)

9. 5 tonnes per hectare –
equivalent to 100 sheep
grassland – 20 times greater = 2000 sheep per hectare

11. THE WORKING SOIL
ENGINE
FOOD WEBS:
SOIL ORGANIC
PLANT MATERIAL
CARBON MATTER
BACTERIA
THE FUEL OF FUNGI
THE SOIL
ENGINE PROTOZOA
NEMATODES
INSECTS
ARACHNIDS
MOLLUSCS
WORMS
MAMMALS

12. C storage
Regulated by
Soil •Structure
C biota
•Chemistry
•C input quality & quantity
•Community phenotype
C loss

13. Effects of land use on
soil biodiversity, function
and carbon

14. Organic Matter losses due to land-use
600
500
OM loss kg/ha/yr
400
300
200
100
0
Forest Bare Agriculture Agroforestry
Land-use type
Redrawn from McDonald et al (2002)

15. Change in soil carbon in response to change in
land use (redrawn from Guo and Gifford 2002)
Crop to secondary forest
Crop to plantation
Crop to pasture
Percentage change
Native forest to pasture
Pasture to crop
Native forest to crop
Native forest to plantation
Pasture to plantation
Overall
-80 -60 -40 -20 0 20 40 60

16. Hendrix et al 1986

17. Increasing susceptibility to disturbance

18. Cumulative perennial ryegrass yields with and without
earthworms, in organically and inorganically fertiliser regimes
Redrawn from Boyle et al (1997)

19. Soil type
Susceptibility
To each
Degradation
Pressure
Degradation
Pressures
Actual Lost
Land Use •Physical
degradation Services Costs
•Chemical
•Biological
Resultant
Ecosystem
Service flow
Benefits

20. Ecosystem services
approach for
monitoring what is
going on
•Framework for assessment
•Natural Capital

21. Land Use Change
•Deforestation
•Urbanization
•Agricultural Expansion
•Conversion to grazing
•Agricultural intensification
Ecological knowledge
Ecosystem consequences
•Food, fibre, timber for human consumption
•Climate feedbacks
•Disease
•Water quantity and quality
•Biodiversity
Societal values
Assessment of
trade-offs

23. Soil-dependent
ecosystem services

24. Critically, these are
RENEWABLE services

25. Options for the future
to maintain and
enhance soil resources
•No/min till
•Land sparing
•Mixed landscapes
•Reserves and hydroponics

26. Effect of soil management on soil microbial biomass-C
(redrawn from Feng et al 2003)
250
Conventional
No-till
200
Biomass-C (ug/g)
150
100
50
0
Feb May October
Month

27. Effect of soil managment on soil organic matter
40
Conventional
35
No-till
30
Organic matter (g/kg)
25
20
15
10
5
0
0 to 1 1 to 3 3 to 7.6 7.5 to 15.2
Depth (cm)

28. Location of straw residues dependant on tillage type
100
90 Conventional
80 Reduced
No-till
Percentage of total
70
60
50
40
30
20
10
0
0-5 5-10 10-15 15-20 20-25
Depth (cm)
Redrawn from Tebrugge and During 1999

29. Effect of conventional and no-till managment on
aggregate stability (redrawn from Rhoton et al
2002)
60
Percentage of soil by weight
50 Conventional
No-till
40
30
20
10
0
0 to 1 1 to 3 3 to 7.6 7.5 to 15.2
Depth (cm)

30. Effect of land-use on sediment losses
Grass ley
Direct sowing
Stubble
Buffer strip
Winter wheat (no added P)
Winter wheat
Stubble tillage
Cultivation
Cross-ploughing
Normal Ploughing
0 200 400 600 800 1000
mg/litre
Redrawn from Puustinen et al 2004

31. Economic return (redrawn from Al-Kaisi and Xin 2004)
250
200
Economic return (USD/ha)
150
100
50
0
No-till Chisel-plough Ploughed
Tillage type

32. Redrawn from Hodgson et al (2010) Ecol.Lett

33. Combining land-use
can lead to significant
biodiversity gains –
Butterfly abundances
in different land use
types
Redrawn from Hodgson et al (2010) Ecol.Lett

34. Conclusions
• Achieving food security and soil health is a complex
issue requiring careful consideration and quantification
of trade-offs
• The Ecosystem Services approach offers a sound
framework to analyse options
• The options for land use require a greater
understanding of our soils, and a higher resolution to
make decisions resulting in sustainable landscapes.

35. Thank you for listening!

37. Methodology
Potential Ecosystem Map
• Digital Terrain Model
• Soil Maps
• Geology Maps
• Climate data
• Land-use data
• Hydrological function
• Socio-economic models
• Climate change scenarios

38. One model to bind
them all…….

39. Ecosystem service map

40. Ecosystem service map

41. Ecosystem service map

42. Ecosystem service map