Lecture 13: Agriculture and sustainability Flashcards
there has been a _____ of agriculture
global expansion of agriculture
–> 1999-2008 (increase 25-50%)
____ of tropical agriculture
expansion
–v rapid expansion of many tropical crops
tropical forests: conversion to agriculture between 1980 and 2012
~154 Mha converted
theres a global ___ in deforestation
imbalance
cost of agriculture expansion in tropics
- massive loss of biodiversity
- vastly simplified systems
why do we not see this expansion ending?
continuing expansion in population (11 billion by 2100)
- greedy people! (1.5 billion overweight/obese)
- more meat consumed / capita
- more BIOFUEL use
__ X more protein / ha from soy than beef
18 times
more/less US corn grown for biofuels than for animal feed in 2010
MORE
in the next forty years, agriculture production could grow by
60-100%
agriculture is key driver of
extinction crisis
future of global biodiversity in hands of
agriculture policymakers
how best to manage agriculture expansion to minimise biodiversity loss?
1) land sharing/ land sparing
2) expand in low biodiversity areas
land sharing:
- farm at lower intensity
- organic farming
- set aside strips
- hedgerows
- woodlots/fragments
- biodiversity protect WITHIN agricultural matrix
land-sparing
- farm at high intensity
- ‘industrial’ farming
- use lead land to meet demand
- biodiversity protected within remaining natural forest
determine land sharing/sparing which graph?
- Density yield curve
- L-sharing on top (concave relationship)
- L-sparing under (convex relationship)
in oil palm, sharing / sparing?
SPARING
- especially for spp with small ranges
land sparing/sharing
sparing is best for:
- biodiversity (more app have higher abundance, higher landscape level species richness)
- better further from contagious forest edge
- best for carbon
option 2 expand in low biodiversity areas
- many areas ave been degraded across the tropics
- -burned multiple times
- -erosion
- -converted to farmland
can we meet the 2020 demand of oil palm demand without forest loss IF we focus on degraded lands??
YES
llanos pasture good for oil palm??
- forest patches have most species
- minimal biodiversity impacts converting intensive llanos pasture to oil palm
- but vital to preserve forest patches
- -> sustainability (‘green’) labelling answer to persuade industry to use such areas
sustainability labelling:
- media & consumer pressure
- greenpeace vs nestle
- 400 global retailers cut all deforestation from supply chains by 2020
cost of removing deforestation?
$30/t –> one prob there are to enough forest free areas to meet demand beyond 2025
using higher yielding varieties
=more crop / hectare on existing land
- genome sequencing opens way for producing rough and pest resistance
- sime drabs super palms increase yield from 4->10 tCPO/ha
