managing land for food and biodiversity

Question 1

Aims of higher food production can conflict with biodiversity

Answer 1

food production: increase land for food production, intensification of agriculture, increased inputs, increased pressure from other land uses.
biodiversity: loss of natural habitat, increased habitat fragmentation, pollution, invasive species, increased roads.

Question 2

Consequences of changes in land use

Answer 2

croplands and pastures have become one of the largest biomes on Earth- covering 40% of terrestrial surface
agricultural expansion is one of the largest threats to biodiversity- primarily through loss of habitat- in the tropics over 80% of agricultural expansion that took place between 1980 and 2000 replaced forest
intensification of land-use compounds effects- leads to homogeneous landscape- a quarter of hedgerows in England and Wales were removed between 1946 and 1974 for the development of new drainage and machinery practices
Millennium Ecosystem Assessment (MEA) it was estimates that 23% of usable agricultural land was already degraded, 20% of the world’s pastures was damaged

Question 3

Different types of agriculture

Answer 3

High yielding: crops- oil palm, wheat, corn, sugar beet

Low yielding: mixed crop farms, organic, vegetables, coffee, cocoa

Question 4

Land sparing

Answer 4

separate land for conservation from land for farming
produce as much food as possible per unit of land
intensify agriculture
protect other land for: biodiversity, ecosystem services

Question 5

Land sharing

Answer 5

integrate biodiversity, conservation and food production on same land.
farm a greater total area
wildlife ‘friendly’ farming, which may impact yields (debate about this as long term can improve soil fertility)
agri-environment schemes

Question 6

Land sparing and Sharing case study

Answer 6

Phalan et al (2011) compared land sharing and sparing schemes in Southwest Ghana versus Northern India
“Assuming that they could be implemented properly, which would be the least harmful to biodiversity: land sharing or land sparing?”
measured crop yields and densities of 600 birds and tree species across gradients of agricultural intensity in both countries
used a variety of crops: oil palm, rice, wheat

Question 7

Outcomes- land sparing and sharing

Answer 7

more species were negatively affected by agriculture than benefited from it, particularly among species with small global ranges
same amount of food was produced in all scenarios but land sharing harmed wildlife more
best mix of crop yields and conservation occurred in a mix of high yield farms and plantations, combined with nature reserves alongside.
farms that retained some natural vegetation had more bird and tree species, but far less food energy per ha

Question 8

Sustainable intensification in agriculture

Answer 8

recognition of the need for increased yields, chiefly of arable crops, under current and future resource scarcity and environmental challenges.
increase food production from existing farmland
increases in production must come from increases in yield as increases in agricultural area has major environmental costs
attention on environmental sustainability
synergies between agricultural and landscape-wide system
SI is a policy goal, techniques and methods are context and location dependent