Managing farming to reduce biodiversity loss Flashcards
Global expansion of agriculture
- Oil palm 56% expansion from 1999 - 2008
- Soya bean 33%
- Cocoa bean 32%
- Bamboo 26%
1980-2012
154 Mha converted, 77 x Wales
Global imbalance in deforestation
mainly in southern hemisphere, in tropical regions
Massive loss of biodiversity
Threats to IUCN status of species in the tropics are higher than elsewhere
Cultivated lands are vastly simplified systems
And human population is rapidly expanding (will reach 11 billion by 2100)
1.5 billion overweight and obese people
More meat consumption per capita as population increases
Usable protein per acre of farmland
18x more protein per hectare from soy than from beef
More biofuel use boosts agriculture
More US corn grown for biofuel than for animal feed in 2010
In the next 40 years agricultural production could grow by
60-100%
Agriculture is key driver of extinction crisis
Growing demand for food and biofuels
Future of global biodiversity in hands of agricultural policymakers
How best to manage agriculture expansion to minimize biodiversity loss?
(1) “Land-sharing” or “land-sparing” farming
(2) Expand in low biodiversity areas
Land-sharing
Farm at lower intensity Organic farming Set-aside strips Hedgerows Woodlots / fragments Biodiversity protected within agricultural matrix
land-sparing
Farm at high intensity
‘Industrial’ farming
Use less land to meet demand
Biodiversity protected within remaining natural forest
Which strategy (sharing or sparing) is best for species?
plot a density-yield curve for total abundance of each species across landscapes
A convex relationship between yield of food and species abundance means land-sparing is best.
A concave relationship means land-sharing is best.
Sharing or sparing for oil palm?
Trees are all “losers”, but land-sparing is best, especially for species with small ranges.
But previous work has ignored potential role of surrounding landscapes
- Species could disperse into test landscapes from forest elsewhere
- Species could use resources from outside test landscape
Land-sparing is best for biodiversity
More species have higher abundance
Higher landscape-level species richness
Land-sparing is increasingly better further from contiguous forest edge
Land-sparing also best for carbon
Need to intensify existing tropical farmland
Many areas have already been degraded across the tropics
Burned multiple times
Erosion
Converted to farmland
Imperata grasslands in SE Asia
What if Imperata is the focus of new farmland?
Can meet 2020 oil palm demand without forest loss if focus on degraded lands
Predictions from coarse-grain species layers
Can overlook important habitat for conservation at smaller scales
Two habitats dominate in the Llanos:
Anthropogenic / semi-natural grassland
Natural forest patches
Can oil palm develop at minimal cost to biodiversity in either of these two habitats?
Effect of oil palm on biodiversity
1) Species richness differs
2) Species composition differs
3) Forest species decline
Forest patches have most species
Oil palm more species rich than pasture
Forest species have higher occurrence in oil palm than in pasture
Minimal biodiversity impacts of converting intensive Llanos pasture to oil palm
But vital to preserve forest patches
How can we persuade the oil palm industry to direct development to such areas?
Sustainability (‘green’) labelling
Sustainability labelling
Media and consumer pressure
Greenpeace vs
400 global retailers ($2.8 trillion) cut all deforestation from supply chains by 2020
Cost of removing deforestation?
Simulate where to put new oil palm to avoid deforestation: Meet 2025 production Calculate rent of current land use Predict oil palm rent Choose most profitable cells
Additional Price of a Mars?
Deforestation-free palm oil increases cost of production by $30 t-1
Translates into a Mars price increase of: £0.0001p
Demand deforestation-free products!!!
Caveat: not enough forest-free areas to meet demand beyond 2025
Expansion of tropical farmland is the biggest driver of global extinction crisis
Growing demand means production may double by 2050
Land sharing vs land sparing paradigm
Sparing best, but need adequate safeguards
Degraded (non-forest) areas can be used
Sustainability to access western markets
Effective land zoning to stop deforestation
Use higher yielding varieties
Sime Darby’s “super palms” variety increases yields from 4»_space; 10 tCPO ha-1
Genome sequencing opens way for producing pest and drought resistance
Big potential for saving forest with yield increases…
The danger of yield increases
Markets are globally interconnected
Buyers can substitute one crop for another
53% oil palm yield increase > price falls 4.3% Villoria et al. 2013 Am J Agri Econ
Transfer food production from temperate to tropics»_space; more deforestation
Governments must zone areas for high-yielding crops coupled with forest estates
Without this safeguard, land sparing could be in the temperate zone
