Pimm et al. Biodiversity of species and their rates of extinction, distribution, and protection

Question 1

What is the scope of the paper

Answer 1

It reviews the biodiversity of eukaryote species, their extinction rates, distributions and protection

Question 2

How many land plant species do they estimate exist?

Answer 2

450,000 c.300,000 accepted, + an estimated 38% of the 260,00 unresolved species names =400,000 + 15% further discoveries predicted in models

Question 3

How many animal species are there?

Answer 3

1.9 Million are described estimates range from 5±3 M; 8.7 ± 1.3 M; to 11 M Some estimate 5-6M insects alone Estimates for marine species include 2.2 ± 0.18 million, and 0.7 to 1.0 million species

Question 4

What is the background rate of species extinctions? (i.e. without human influence?)

Answer 4

0.1 Extinctions / Million Species years

Question 5

How are background rates of species extinction calculated?

Answer 5

3 lines of evidence are used: Fossil record, molecular based phylogenetic studies, and data on net diversification. 1) The fossil record provides evidence at the level of genera extinctions / M Genera years, and this is assumed to be the same as species extinctions / M species years. 2) The phylogenetic studies assume that the number of species in a clade after a period of time is an exponential function St = S0 e((lamba - mu) x t)

lamba =speciation rate; mu = extinction rate

Recent taxa haven’t yet had time to go extinct, which allows seperate calculation of lamba and mu.

3) Data on net diversification is widespread (lamba -mu). There is evidence for widespread declines in diversity across taxa, so extinction rate is normally less than speciation rate!

Question 6

What is the current rate of extinctions?

Answer 6

Present extinction rates are ~100 E/MSY and there is strong suspicion that these rates miss extinctions even for well-known taxa. Therefore it is likely a thousand times higher than the background rate of 0.1 E/MSY

Question 7

What is the IUCN and what are the red list categories

Answer 7

International Union for Conservation of Nature Red List of Threatened Species, assesses species’ extinction risk as Least Concern, Near-Threatened, three progressively escalating categories of Threatened species (Vulnerable, En- dangered, and Critically Endangered), and Extinct

Question 8

What proportion of species are threatened

Answer 8

As of March 2014, the percentages of threatened terrestrial species ran from 13% (birds) to 41% (amphibians and gymnosperms) (13). For fresh- water taxa (26), threat levels span 23% (mam- mals and fishes) to 39% (reptiles)

Question 9

How is current extinction rate calculated?

Answer 9

the movement of species through the red list categories can be tracked. This would give an estimate of around 450 E/MSY. Taking a cohort analysis approach gives an estimate of around 100E/MSY. The authors follow cohorts from the dates of their scientific description, taxonomists described 1230 species of birds after 1900, and 13 of them are now extinct or possibly ex- tinct.

Question 10

What kind of species range size is most common? What sort of distribution is proposed to describe the distribution of species range sizes?

Answer 10

Small ranges dominate -

25% of most taxa have ranges 10⁵ km² and, for amphibians,10³ km².

This is probably a big overestimation as it assumes that species fill entire regions rather than just habitats within them

Question 11

Are large ranged or small ranged species more common LOCALLY?

Answer 11

small-ranged species are generally locally scarcer

This means they get described later (if at all).

Within a 6 million km² area of the Amazon 227 species comprised half of all trees. However, the sample contained nearly 5000 known species, and many unknown.

Quantifying sampling effort is vital in estimating how biodiversity varies biogeographically

Question 12

How useful are species richness maps?

Answer 12

These are dominated by large ranged species, and should be accompanied by a mapping out of small range species

Question 13

Where are small ranged mammals and amphibians, compared to threatened mammals and amphibians?

Answer 13

Big concentrations of small ranged mammals (smaller than median range) are found in madegascar, indonesia and papua new guinea

Question 14

Where are endemic flowering plant species found compared to all flowering plant species?

Answer 14

Question 15

How do the range maps differ between All, small range, threatened and data deficient marine snails of the Conus genus?

Answer 15

Question 16

what factors are being used to estimate future extinction rates? What are the problems?

Answer 16

There are few empirically tested predictions of future extinctions. Land use change, climate change, climate disruption have all been used by different authors.

We do not know whether these factors will impact different species or have a compound effect.

In freshwater ecosystems, flow rate modifications and fragementation are major drivers of extinctions.

Habitat suitability, population viability, mobility, ocean acidification are rarely considered.

Question 17

How can protection help reduce extinctions, and how has it helped already?

Answer 17

Habitat destruction is THE major cause of extinctions,

the rate at which mammals, birds, and amphibians have slid toward extinction over the past four decades would have been 20% higher were it not for conservation efforts

Question 18

How much protection is targeted?

Answer 18

Aichi Target 11 seeks protection of 17% of terrestrial lands, whereas the GSPC seeks to protect 60% of plant species.

The concentration of small-ranged species is such that were land protected efficiently to capture bio- diversity, the 17% so selected would encom- pass part of the ranges of 81% of plant species and all the ranges of 67%

These plant priorities match those for terrestrial vertebrates. Some 89% of bird species, 80% of amphibians, and 74% of mammals live within these plant priority areas

Question 19

How much protection has been achieved?

Answer 19

In 2009, 12.9% of the total land area was under some legal protection, up from <4% in 1985. Coverage varies between 4% and 25% protection of 14 major terrestrial biomes.

However

Protected areas are biased toward areas where there is little human pressure

Ocean protection lags behind that on land. A 2013 assessment (106) reported ~10,000 marine protected areas (MPAs) covering 2.3% of the oceans.

However , this includes areas not established for conservation.

Question 20

Do protected areas work?

Answer 20

Protected forests generally retain their forest cover (102), have far fewer anthropogenic fires than unpro- tected areas (103), and do not attract higher than expected human population growth to their perimeters.

Marine protected areas that are no-take, well-enforced, old, large, and isolated by deep water or sand are dis- proportionately successful in retaining their species

Globally, species with >50% of the sites of particular importance for them protected are sliding toward extinction only half as rapidly as those with <50% of their important sites protected

Question 21

Species of which ecosystem may prove to be the hardest to protect?

Answer 21

Protection of freshwater species will require managing landscapes and water use well beyond the fences of protected areas

Question 22

How may information on species improve in the future?

Answer 22

Large databases; taxonomists addressing synonymy; genetic barcoding; batch barcoding; amateur contributions

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