Lecture 12 - Reserve design

Question 1

a, B, y diversity

Answer 1

alpha = within sites
Beta = turnover across sites
gamma = total biodiversity

Question 2

single large vs several small

Answer 2

if species richness increases with area, larger block would support more species

Question 3

all small reserves have same species

Answer 3

single large = more sites doesn’t add more species

Question 4

small reserves differ in composition

Answer 4

several small = protects more if there is turnover

• complementary communities
• allows escape from diminishing return

Question 5

Quinn said …

Answer 5

many small accumulate species faster than single largest

Question 6

Lomolino …

Answer 6

examined small - large, large - small, complementarity (optimal choice), random pick

• optimal choice = less land to represent all sp.
• small - large = comparable, but often no better than random pick

Question 7

several small better for max diversity if…

Answer 7

sites complementary

Question 8

Global conservation strategies - protected areas

Answer 8

11. 5% land surface

- many sp. not protected = 20% terrestrial verts, 1500 amphibians

Question 9

conservation areas opportunistically set up

Answer 9

unwanted land

• US reserves = high elevation, poor productive soils
• choosing a-diversity (local richness) ignores B (community dissimilarity)
• should be sites that protect complementary sets

Question 10

conservation international biod hotspots

Answer 10

34 - 2.3% land surface

• 50% plants, 42% t.verts
• complementarity more effective = more species in smaller area

Question 11

edge area ratio

Answer 11

more several small, elongated shapes

- single large better = protects core, avoid fragmentation

Question 12

persistence

Answer 12

presence doesn’t ensure future persistence

• Allee effects = v small pops at risk, death > birth
• single large better

Question 13

disturbance

Answer 13

unpredictable events may drive extinction

• spatial distribution of disturbance relative to SLOSS
• depends on whether probabilities in small reserves in independent
• probability theory = events independent, probability of both occurring is a x b

Question 14

simple models - parameters (disturbance)

Answer 14

1. logistic growth in patches
2. carrying capacity K proportional to patch area
3. each year, probability of fire wiping out pop
4. if several small far enough apart = probabilities independent

Question 15

role of dispersal

Answer 15

indvs may disperse between sites

• fire - can be recolonized
• increase persistence = allows recolonisation, recovery

Question 16

spacing between reserves

Answer 16

• far enough so disturbances independent

- close enough for dispersal and recolonisation

Question 17

several small best for

Answer 17

max diversity

persistence if disturbances independent and dispersal happens

Question 18

single large best for

Answer 18

minimise edge effects

supports larger pops, longer term persistence