EE Lecture 34: The State of Biodiversity Flashcards
what went down at the 2002 Convention on Biological Diversity
made a 2010 target to:
significantly reduce the rate of biodiversity loss by 2010
need indicators of the state of global biodiversity
name some species that have had very sharp popn declines
leatherback turtle hippo elegant fat-tailed possum mauritius kestrel red howler monkey
describe popn trends in temperate regions
increase by 29% on average
describe popn trends in tropical regions
decreased by 70%
which regions show greatest increase in popns
temperate
what is the living planet index
indicator of the state of global biological diversity, vertebrate popn trends
how does LPI vary wrt. to income of country
low income countries have greater reduction in biodiversity where more people rely on local biodiv
how much have vertebrate pops declined by? since when?
declined by 30% since 1970
name some early attempts at categorising extinct pops
The Red Book -1969
why were earlier attempts at categorising endangered pops not successful
informal
subjective - low repeatability and easy to challenge
were the targets set by the CBD (convention biological diversity) in 2002 for 2010 met?
no
rate of decline is steady at best and pressures are worsening
what scheme is in place currently to determine threatened species
IUCN Red List
give order of categories for IUCN Red List
NE -not evaluated DD - data deficient LC -Least Concern NT-Near Threatened VU- vulnerable EN-endangered CR-Critically endangered EW-Extinct in Wild EX-Extinct
what does NT and CR and EW stand for
LC
Near threatened
Critically endangered
Extinct in Wild
least concern
what are the criteria for Red List
A) Pop reduction B) Geographic Range distribution C)Small pop size+decline D)V small + restricted pop E)Quantitative Analysis
what determines whether a pop is CR on Red List
A)pop reduction»_space;90% in 10yrs
B)extent of occurrence >50% in 10yrs
what is criteria A for IUCN species list
pop reduction
what is criteria B for IUCN
geographic range and distribution
what is criteria C for IUCN
small pop size and decline
what is criteria D for IUCN
v small and restricted pop
what is criteria E for IUCN
quanitative analysis
if a species had pop reduction of»_space; 50%, which category would it be
vulnerable under criteria A of popn reduction
if a species had an estimated pop continuing declince of 20% in 3yrs what category would it be in
Endangered under category C of IUCN small pop size and decline
if a species had a 5000km2 extent of occurence and
Endangered, under criteria B of distribution of geographic range
if a species had an extinction rate of»_space;50% in 10yrs/3 gen what cateogry would it be in
Critically Endangered under criteria E of IUCN stating quantitative analysis
what criteria does a species need to make it endangered
pop reduction»_space;70%
extent occurence >20%
what criteria does a species need to make it vulnerable
A)50% decline already
B)20000km2 range & 2000km2 area of occupancy
C)10% predicted to decline
D)>10% probability extinction
give an example of a vulnerable species
hippo
give an example of endangered species and what makes it so
western leopard toad
range =1750km2
fragmented habitat
declining pop
give an example of endangered species and what makes it so
African Wild dog
pop size
give example of critically endangered pigeon
silvery wood pigeon
pop
give an example of a vulnerable species and why
aldabra flying fox
one location
why is western leopard toad threatened
its endangered
only has range = 1750km2
fragmented habitat
declining pop
why is african wild dog threated
endangered
pop size
why is silvery wood pigeon v threated
critically endangered
pop
why is aldabra flying fox threatened
its vulnerable
only one location where it can live
what two ways of measuring range size are there
- extent of occurrence
2. area of occupancy
how can you measure range size via extent of occurrence
point the localities and range is dot to dot of outside perimeter
how can you measure range size using area of occupancy
point localities, then do bar through each suggesting where range of each locality is (looks like a score through a point)
which percentages species are threatened with extinction
11% birds
25% mammals
33% amphibians
how many species are critically endangered
3879
what does the number of species critically endangered suggest about how many extinctions there are per year
what can you assume about the number of species that will die out
3879 CR
may be ~20 extinctions per year - assuming half will die out in 10 years
what are the pros of the Red Listing approach
easy to use
practical
applicable
makes allowance for rough data rather than requiring a single number
what are the cons of the Red List approach
% boundaries mean orgs close to threshold could be put in the wrong category
use of multiple criteria and no statistical method
looks @ species as a whole but could be variations among different pops
still reliant on being able to catch enough data
How is the Red List Index calculated
for groups that have been asessed multiple times:
calculate % species going ujp ladder and % down
express as Red List Index - steepness of sloe = rate of change
what is the Red List Index
based on the IUCN Red List and indicates the changing state of global biodiversity. It defines the conservation status of major species groups, and measures trends in extinction risk over time.
