http://www.fao.org/about/meetings/agroecology-symposium-china/en/ Key note presentation of Steve Gliessman, from University of California Santa Cruz, on agroecology as the foundations for food system sustianability. The presentation was prepared and delivered in occasion of the International Symposium on Agroecology in China, held in Kunming, China on 29-31 August 2016.

1. Agroforestry: a trend in global land use
International Symposium on Agroecology for Sustainable Agriculture and Food Systems
Kunming, Yunnan, China, 29th - 31st August, 2016
Jianchu Xu PhD
Principal Scientist, World Agroforestry Center
Distinguished Professor, Institute of Animal Science, Chinese Academy of Agricultural Sciences
Distinguished Professor, Kunming Institute of Botany, Chinese Academy of Sciences

2. What landscape do we want?

3. Tree cover loss globally: 42-51%, 2.4-3.4 billion ha
Tree cover loss in China: 59-67%, 0.19-0.27 billion ha
Ahrends, Xu et al. 2016 (unpublished)
How much tree cover has been lost in human history?

4. Significantly increasing tree cover on agricultural land
http://www.nature.com/articles/srep29987

5. The contribution of
agroforestry to global and
national carbon budgets
http://www.nature.com/articles/srep29987

6. Change in Amount of Agricultural
Area with Tree Cover
From 2000-2002 to 2008-2010
• Globally, proportion of land under
at least 10% tree cover increased
from 40% to 43%
• The amount of land with at least
10% tree cover increased in
almost all regions
• South America showed the
largest increase
• Only decrease was in North and
Central Asia
• South Asia increased from 21% to
28%, East Asia from 43% to 48%
• In Central America, agricultural
land with at least 10% tree cover
increased to 96%

7. Change in Population of
Agricultural Area with Tree Cover
From 2000-2002 to 2008-2010
• The share of the global population
living in agricultural areas with at
least 10% tree cover increased from
41% to 46%: more than 90 million
more people
• In almost all regions, the population
living in areas with at least 10% tree
cover increased
• South Asia showed the largest
increase: 44 million more people;
increased to 34% of all persons in
ag area
• The only region which showed a
decrease was North and Central
Asia
• In Central America, the population
living on agri. land with at least 10%
tree cover increased to 95%

8. Average Tree Cover
by Population Density
2000-2002 & 2008-2010
• Central America has the overall
highest ratio of tree cover vs pop.
density, which increased during
the period 2008-2010
• South Asia and Sub-Sahara Africa
have high levels of tree cover at
low pop. densities, but low levels
of tree cover at higher pop.
densities, lower than the global
average
• South America and SE Asia both
show increased levels of tree
cover at higher pop. densities

12. The area of planted trees across China has exceeded 46
million hectares, ranking it first in the world
Forest Land: Average Tree Cover in 2000 was 35%; by 2010, this had increased by 3.3% to 38%
Agricultural Land: Average Tree Cover in 2000 was 12%; by 2010, this had increased by 2% to 14%

13. Significant opportunities for up-scaling of agroforestry
Although China increased tree cover overall, including on agricultural land, more than 30%
of all agricultural land was found to have lost tree cover

14. SylvopastureRiparian buffer
Alley cropping
Windbreaks
Mixed planting
Trees as hotspots for biodiversity and ecosystem services

15. More people, more trees and more productivity:
Almost all production land equivalency ratios in agroforestry are greater than 1
Graves et al. (2007b)
Mead & Willeay (19080)

16. Nodules
Roots
During the N-fixation process, C
acts as both an energy source
and a substrate for amino acid
production, incorporating the
fixed N into an organic form
N-fixation draws CO2
below ground, acting
as a C sink
CO2Pump model
Mortimer, Hyde, Xu Jianchu, Biology Letter (under review)
Tree as carbon pump

17. Trees in Nutrition Cycle
Mortimer et al. 2015 Applied Soil Ecology 96:25-32

18. The honey bee genus—nine Apis species in the world, of which six species are present in China
Trees in land sharing and land
sparing landscape management
Teichroew J., Xu J, et al. 2016. Biological Conservation
http://dx.doi.org/10.1016/j.biocon.2016.05.023

19. Bracing trees, bracing life
Thank you!
Contact email: j.c.xu@cgiar.org