what to conserve? conservation units (lecture 2)

Question 1

Why select conservation units?

Answer 1

• essential for effective and efficient planning given limited resources
• the aim is to protect biodiversity
• biodiversity = variability among living organisms: within species/between species/ecosystems
• have to select from these units

Question 2

What is yearly required versus actual spend on conservation?

• James et al., 2001
• McCarthy et al., 2012

Answer 2

• James et al: required $27.5B, actual $6B (20%)

- McCarthy et al: required $78B, currently at 10% of this

Question 3

What units of conservation do taxonomic and ecosystems approaches encompass?

Answer 3

Taxonomic:

• genetic diversity
• populations
• sub-species
• species

Ecosystems:

• habitats
• ecosystem services

Question 4

Why use genetic diversity as a conservation unit?

Answer 4

• important for population resilience (small population paradigm)
• in plants may be useful for improving yields in closely related crop species
• varies spatially

Question 5

What are problems with genetic diversity as a conservation unit?

Answer 5

• focus on genetic diversity or genetic uniqueness?
• is it practical?
• are there more practical surrogates for genetic diversity?

Question 6

Why use populations as a conservation unit?

Answer 6

Multiple populations = higher probability of:

• maximising genetic diversity
• protecting local adaptations
• insurance against local disasters

Question 7

What are problems with populations as a conservation unit?

Answer 7

• while some distributions are obvious others are less clear
• is each isolated distribution a distinct population?
• populations can be difficult to define
• based on rarely tested assumptions of genetic divergence between populations
• often there are multiple populations, rarely pragmatic to save them all
• focus on local concerns instead of global priorities
• can lead to narrow outlooks and inefficient conservation

Question 8

Example of the problems with populations as a conservation unit:

• great cranes project

Answer 8

• common cranes extinct in UK circa 1600
• cranes recolonised ~ 1980
• 2009 great cranes project started
• £400,000 per year on trying to increase UK common crane population
  BUT
• common crane populations in Europe have seen large increases since the 1990s
• common cranes are “least concern”
• 11 other crane species globally threatened with extinction
• e,g, siberian crane is critically endangered, black-necked crane is vulnerable, neither is getting enough spent on them

Question 9

Why use subspecies as a conservation unit?

Answer 9

• surrogate for genetic diversity

- idea that conserving a species genetic diversity is more likely if you conserve all its subspecies

Question 10

What are problems with subspecies as a conservation unit?

Answer 10

• subspecies doesn’t mean genetic distinctiveness
• Zink (2004) 97% continentally distributed avian species lack genetic distinctiveness
• subspecies based conservation problematic bc
  a) incorrectly assumes subspecies always represent genetic variation
  b) promotes parochial conservation

Question 11

Example of the problems with subspecies as a conservation unit:

• dusky seaside sparrow

Answer 11

• subspecies restricted to florida
• $2.5 million investment
• declared extinct 1990
• another non-threatened subspecies was genetically identical

Question 12

Why use species as a conservation unit?

Answer 12

• traditional conservation unit
• species are irreplaceable
• pragmatic:
  
  • public understand it
  • unit at which biological data is most frequently
    gathered
  • relatively easy to recognise & define (legally
    important)

Question 13

What are problems with species as a conservation unit?

• unstable taxonomy: shearwaters, inflation

Answer 13

Shearwaters:

• 2 species were split in the early 1990s
• manx shearwater = least concern
• balearic shearwater = critically endangered, declining 7.4% a year, will be extinct in 40 years

Taxonomic inflation/progress?:

• albatross: now 21 species, used to be 13
• lemurs: 33sp in 1994, 70 in 2006, now about a hundred
• Philippines may have more than 100 more avian endemics than currently defined

Question 14

What are problems with species as a conservation unit?

Answer 14

• unstable taxonomy
• most species not described
• especially true for non-charismatic species

Question 15

Why use habitats as a conservation unit?

Answer 15

• response to accusations that species based conservation ignores many species
• pragmatic:
  
  • reasonably good data on habitat loss
  • protecting habitats gives a good chance of
    protecting species that live there
  • habitat loss is a major driver of extinction risk
  • 80% of terrestrial vertebrates threatened with
    habitat loss
• protect ecosystem services e.g. watershed management relying on intact forest (utilitarian approach)

Question 16

What are problems with habitats as a conservation unit?

Answer 16

• broad-scale habitat definitions (e.g. forest type) and loss are pretty easy to define but it is more difficult at finer scales
• some species have such small ranges that broad habitat conservation won’t do it

Question 17

What are ecosystem services?

Answer 17

• benefits of ecosystems to human wellbeing

- humans are buffered by technology/culture but ultimately rely on ecosystem services

Question 18

What are supporting ecosystem services?

Answer 18

• necessary for production of other ecosystem services
• e.g. primary production, nutrient cycling, soil formation
• often excluded from economic evaluations to prevent double counting

Question 19

What are provisioning ecosystem services?

Answer 19

• resources obtained from ecosystems

- e.g. wood, fibre, food, freshwater

Question 20

What are regulating ecosystem services?

Answer 20

• benefits obtained from the regulation of ecosystem processes
• e.g. climate regulation, flood regulation, disease regulation, water purification

Question 21

What are cultural ecosystem services?

Answer 21

• non-material benefits to human wellbeing

- e.g. aesthetic, mental well-being, recreational activities like fishing and ecotourism

Question 22

Provisioning ecosystem services:

• pollination
• productivity

Answer 22

Pollination:

• $27B dollars a year globally
• (Klein et al., 2007)

Productivity:

• debate as to whether it increases with plant species richness or if only a few really contribute
• when various conditions accounted for however most species enhance service provision in one or more scearios

Question 23

Regulating ecosystem services:

• flood defence

Answer 23

• super-cyclone, India Orissa 1999

- mangrove forests significantly reduced death in villages less than 10km from the coast (Das and Vincent, 2009)

Question 24

Cultural ecosystem services:

• well-being

Answer 24

• children in high-rise flats have better concentration levels when views of green spaces are availability (Taylor et al., 2002)
• people in parks with more plant species have higher mental wellbeing scores (Fuller et al., 2007)

Question 25

Why use an ecosystem services approach to conservation?

Answer 25

• provides financial incentive for conservation

BUT

Question 26

What are problems with ecosystem services as a conservation approach?

• ecosystem disservices

Answer 26

• ecosystem disservices: e.g. mosquitos carrying malaria in africa cost $12B USD in healthcare, lost work days, tourism, investment

Question 27

What are problems with ecosystem services as a conservation approach?

• lack of data

Answer 27

• lack of data: only 4 services have been mapped (Naidoo, 2008) using inadequate proxies
• where there is data shows lack of congruence between biodiversity and ecosystem service provision except in few win-win areas

Question 28

What are problems with ecosystem services as a conservation approach?

• biodiversity ignored

Answer 28

• biodiversity ignored:
• limited info on relationship b/w biodiversity and ecosystem services
• some may be be more reliant on biomass than biodiversity
• cultural services may be more reliant on perceived than actual biodiversity
• service provision can be largely dependent on number of people