The food-biodiversity challenge: biodiversity

Question 1

What is the definition of biodiversity?

Answer 1

The variability among living organisms from all sources including inter alia, terrestrial, marine and other aquatic systems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems.

Question 2

What are the three levels/scales of biodiversity?

Answer 2

• Genetic
• Organismal
• Ecological

Question 3

What are some crucial ecosystem services for agroecosystems (agricultural ecosystems)?

Answer 3

• Pollination
• Biological pest control
• Maintenance of soil structure and fertility
• Nutrient cycling
• Hydrological services

Question 4

How much is pollination worth in term of an agricultural ecosystem service?

Answer 4

~US$267–$657 billion annually (2020)

Question 5

What ecosystem services can the agroecosystems themselves provide?

Answer 5

• Regulation of soil and water quality
• Carbon sequestration
• Support for biodiversity

Question 6

What are some of the disservices produced by agroecosystems if managed incorrectly?

Answer 6

• Loss of wildlife habitat
• Nutrient runoff
• GHG emissions
• Pesticide poisoning

Question 7

How does modern intensive farming impact biodiversity?

Answer 7

Negative impact on farmland biodiversity
E.g., farmland birds declined by 56% between 1970 and 2015

Question 8

How does modern intensive farming negatively impact the environment itself?

Answer 8

• Accelerated soil erosion
• Habitat change and management (e.g., loss of UK hedgerows)
• Farm waste - fertilisers, pesticides, organic waste

Question 9

How does modern intensive farming negatively impact communities biologically/genetically?

Answer 9

• Increased resistance to pesticides
• Increased prevalence of diseases (e.g., BSE, foot and mouth, salmonella etc.)

Question 10

How is food production increased (four factors)?

Answer 10

• Increased land use
• Intensification of agriculture
• Increased inputs (fertilisers etc.)
• Increased pressure from other land uses (e.g., urban)

Question 11

What are the main impacts of increasing food production on biodiversity?

Answer 11

• Loss of natural habitat
• Increased habitat fragmentation
• Pollution
• Invasive species
• Increased roads

Question 12

What is responsible for the majority of global land use?

Answer 12

Agricultural production

Question 13

What is more important: food security or biodiversity?

Answer 13

• Debateable – both are important
• Is it possible to have both?

Question 14

What are the five stages in land use transitions to increasingly intensive use?

Answer 14

1. Pre-settlement
2. Frontier
3. Subsistence
4. Intensifying
5. Intensive

Question 15

How much of the world’s (ice-free) land surface do croplands and pastures cover?

Answer 15

38% - one of the largest biomes

Question 16

What is one of the largest threats to biodiversity?

Answer 16

Agricultural expansion, causing habitat loss

Question 17

How much of farmland is already degraded according to the FAO and what consequence does this have?

Answer 17

1/3 - affects production

Question 18

What is habitat fragmentation in the context of agriculture?

Answer 18

The breaking up of continuous habitats (like forests) into smaller, isolated patches due to agricultural expansion or land-use change.

Question 19

How does fragmentation relate to habitat loss?

Answer 19

Fragmentation often coincides with habitat loss, compounding the ecological impact by reducing both the quantity and quality of habitat.

Question 20

How does fragmentation affect community structure in ecosystems?

Answer 20

It leads to changes in species composition — some species decline or disappear due to isolation or smaller patch sizes, while others may increase (e.g., generalists or edge species).

Question 21

What happens when a forest becomes partially fragmented?

Answer 21

Loss of rare forest species and specialists

Increase in fast-colonising, open-habitat species

Question 22

Describe the stages of community structure upon fragmentation of a forest.

Answer 22

1. Continuous forest
2. Partially fragmented (rare species lost, increasing numbers of open-habitat species)
3. Fragmented and edge effects
4. Fragmented at equilibrium (community structure altered fundamentally)

Question 23

What is land sparing?

Answer 23

Separating land for nature from the land used for farming.
Therefore:
- Farmland is higher yielding
- Other land is protected for biodiversity and ecosystem services

Question 24

What is an example of land sparing?

Answer 24

California Almond Orchards:
- Farming on a vast scale
- Spare areas for wildlife allow key ecosystem services to promote this vast farming (e.g., 1.5 million honeybee hives required for pollination)

Question 25

What is land sharing?

Answer 25

Use of the same land for both biodiversity conservation and food production. Therefore: - Agriculture less high yielding but more biodiverse - More farmland may be needed to provide food (as less intense) - Less land solely for nature conservation

Question 26

What is an example of land sharing?

Answer 26

Agroforestry

Question 27

What is a good case study to compare land sparing/sharing? What is the main aim of this study?

Answer 27

The Phalan et al. (2011) study in southwest Ghana and Northern India: Aim: to compare how crop yields (oil palm, rice, and wheat etc.) and species densities (600 bird and tree species) relate across gradients of agricultural intensity, and determine whether land sparing or land sharing better conserves biodiversity.

Question 28

What do density-yield curves tell us in the context of land use?

Answer 28

They show how individual species' population sizes vary with yield and help identify whether land sparing or land sharing would better support each species.

Question 29

Was land sparing or land sharing found to benefit species more at the same food production level (case study: Phalan et al. (2011)). What did they recommend for conserving biodiversity in tropical forests?

Answer 29

Land sparing benefited more species than land sharing at the same food production level. Recommendation for tropical forests: Protecting forest reserves (land sparing) while investing in high-yield agriculture on smaller areas of land.

Question 30

What are some caveats or limitations of the Phalan et al. (2011) study comparing land sparing/sharing?

Answer 30

- Focused on a limited number of taxa, sites and habitats - Based on correlational data - Results (population densities) may be influenced by adjacent habitats - May not account for extinction debts from past land conversion - Governance is crucial for land sparing to succeed

Question 31

What are five problems with land sparing?

Answer 31

- Implies that biodiversity in agroecosystems is functionally negligible – not true (some prefer to be in agricultural areas) - Environmental cost of intensification is high - Assumes that "spared land" will be protected (often isn't) - Oversimplification of debate into production vs biodiversity - Focuses on food production not security

Question 32

How can "land sparing" be optimised?

Answer 32

Intensive agriculture can occur in areas where biodiversity loss will be the least (using vertebrate info to support this)

Question 33

What approach is now considered more effective than choosing between land sparing or sharing?

Answer 33

A context-specific combination of land sharing and land sparing in well-connected landscape mosaics, also called "land-sharing/-sparing connectivity landscapes".

Question 34

What does the new conceptual framework known as "land-sharing/-sparing connectivity landscapes" focus on?

Answer 34

It categorizes landscapes into four archetypes of social-ecological system states and emphasizes dynamic transitions between them.

Question 35

What are the four archetypes of "social-ecological system states" in the new framework known as "land-sharing/-sparing connectivity landscapes"?

Answer 35

Win–win (e.g. agroecology) Win–lose (e.g. intensive agriculture) Lose–win (e.g. fortress conservation) Lose–lose (e.g. degraded landscapes)

Question 36

What does the new land-use approach known as "land-sharing/-sparing connectivity landscapes" help researchers and policymakers do?

Answer 36

- Compare landscapes - Analyse transitions between different system states - Identify opportunities for improving both biodiversity and human outcomes