Measuring biodiversity

Dr RJ (Bob) ScholesChair, Global Terrestrial Observing System

CSIR Environmentek

PO Box 395, Pretoria 0001, South Africa

bscholes@csir.co.za

This paper will cover…

• Theory of biodiversity observations

• Existing approaches and systems

• Approaches that may satisfy the goals

Biodiversity: 3 aspects x 3 levels

(Noss 1994)

Fu

nction

al

Structural

Com

pos

itio

nal

Landscape patterns

Lan

dsca

pe

proc

esse

s/

dist

urba

nces

/

Population structure

Physiognomy/habitat structure

Landscape

type

Inte

rspe

cifi

c in

tera

ctio

ns

Genetic structure

Dem

ogra

phic

proc

ess

Species,

populations

Gene

sCom

munities/

ecosystems

Gen

etic

pr

oces

s

At any level, diversity has at least two components…

• How many different types of things are present– Elephant, rhino and lion is less diverse than– Elephant, rhino, lion, leopard and buffalo

• How evenly they are represented– 1000 elephants and 1 lion is less diverse than– 500 elephants and 500 lions

‘Academic’ ways of measuring biodiversity

Species level• Richness: Total number of species in an area (

diversity)• Species turnover along a gradient ( diversity)Ecosystem level• Number of different habitats or ecosystems (

diversity)Genetic level• Genetic homology• Cladistic distance

‘Policy’ ways of measuring biodiversity

• ‘Extinction based’ (IUCN)– Threatened species (Red Data Books)

• ‘Area based’ (Millennium goals)– Area under protection– Area of a key habitat (eg Forest cover)

• ‘Richness based’– Indicator groups or species eg CI Rapid Biodiversity

Assessment• Complementarity –based

– Various conservation optimisation tools, eg CPLAN• Various spatial representations

– Hotspots, last wild places

Royal Society Report2003

• ‘… no sound basis exists for assessing performance against these targets.’

• ‘The fate of organisms not yet recognised by science cannot be measured’

• Lack of baselines

• Biodiversity measures must be related to the objectives of measurement

Attributes of a good indicator

• Does it measure what it says it does?• Sensitive, but not oversensitive• Scale appropriate in time and space• Well-understood model• Reliable data available• Monitoring systems in place• Understandable by policymakers

(NRC 2000)

NCI = ecosystem quality x ecosystem quantity

Natural Capital IndexRIVM/UNEP-WCMC/GEO-3

Example: NCI for The Netherlands

SAMA* Biodiversity Intactness Index

• Based on impacts on populations, rather than extinctions

• Considers a range of impacts– Protected, sustainably used, unsust

used, partially transformed, transformed

• Scale independent• Applicable now, but amenable to

incremental improvement

Millennium Ecosystem AssessmentStrengthening Capacity to Manage Ecosystems Sustainably for Human Well-Being

*Southern Africa Millennium Ecosystem Assessment

SAMA Algorithm

B = biodiversity intactness indexCijk = populations of i under use k/ popn when protectedAjk= Area of land use k in ecosystem jRij = Richness of taxon i in ecosystem j

i= taxon, from 1 to t j= ecosystem, from 1 to m k= land use type, from 1 to n

)/()(11111

ijj

t

i

m

j

ijjkijk

n

k

t

i

m

j

RARACB

Needs: Land cover, richness, impact matrix

Worked exampleSouth Africa, biome resolution

Plants Mammals Birds Reptiles Amphibians Forest 0.772469 0.746174 0.926298 0.861815 0.780285118 0.789639 Fynbos 0.701956 0.683595 0.904151 0.825405 0.713922301 0.70769093 Grassland 0.688667 0.654478 0.899739 0.814188 0.698459825 0.70942015 Nama Karoo 0.93602 0.885709 0.975683 0.943799 0.936551519 0.93890049 Savanna 0.816195 0.76951 0.939368 0.88569 0.820343291 0.82664655 Succulent Karoo 0.923047 0.878428 0.972191 0.93975 0.92433773 0.92494938 Thicket 0.825957 0.774175 0.942372 0.886054 0.828344218 0.84208857

0.81082 0.768388 0.937475 0.880225 0.815859638 0.8087939

Taxa

Eco

syst

ems

WWF Ecoregion database

867 biodiversity-based regions of the worldBased on best available information

Species lists for birds, mammals, reptiles, plants,amphibia

Global land cover products

• Many are now available– DISCover, FAO-FRA, GLC 2000, Modis…

• Global coverage, resolution < 1 km– 20 m products available for key areas

• Methods and results convergence– GOFC/GOLD (a GTOS panel)

• Mid 1990s baselines feasible, year 2000 baseline in hand

• Reliable expectation of year 2010 repeat

What GTOS can offerGlobal Terrestrial Observing System

• Biodiversity is one of the five mandated topics covered by GTOS– Land, freshwater, cryosphere– Close collaboration with GOOS on coasts– GOOS covers open ocean

• TEMS database– ‘biodiversity module’

• Biodiversity network: methods harmonised• GOFC/GOLD

– Land cover dynamics, especially forests

Who, what, where

TEMS: Terrestrial Ecosystem Monitoring Sites

Web directory of 1,600 sites and 55 networks in 110 countries that carry out long-term terrestrial ecosystem monitoring of 110 variables

http://www.fao.org/gtos/tems

Variables specific to biodiversity:

•Colonization of habitat by invasive species•Habitat conversion•Habitat fragmentation•Indicator species•Pollinator species•Species Richness•Threatened Species

Many of the other 115 variables in TEMS are also directly linked to Biodiversity.

TEMS Biodiversity module

The CBD and WSSD goalsCBD CoP VII/26, WSSD Implementation Plan

• ‘..significantly reduce the rate of loss of biodiversity by 2010…’

• This is a ‘double differential’ problem– Change in a rate

• Requires at least 3 snapshots in time to solve

Rate 1

201020001990

Biodiversity

Rate 2

rate 2 < rate 1

Global strategy for plant conservationCBD CoP VI/9 April 2002

1. Accessible list of plant species…

2. Assess status of all species…

3. Understand conservation needs for threatened species…

4. 10% of each ecological region, 50% of species conserved in situ

5. 90% threatened species cons ex situ

6. 30% of production lands managed consistent with conservation goals

UN Millennium Goals

• ‘…reverse the loss of environmental resources…’

• Proposed indicators:– Proportion of land area covered by forest– Proportion of land area protected for

biodiversity conservation

• These indicators are measurable, but not necessarily sensitive to the goal

Pragmatic issues…

• For the purpose of evaluating progress towards the goals, biodiversity measurements– Don’t have to be perfect, just agreed– Need to be based on ‘activity’ rather than

‘stock’ measurements (cf UNFCCC)– Satellite-based land cover measurements,

coupled with ‘sparse’ in-situ information in an explicit way (a ‘model’) could do the job for terrestrial systems

A proposal

Agree to develop an approach based on1. Land cover/use in 1995, 2000, 2005 and 2100

[GOFC/GOLD + WCMC]

2. Richness within ecosystem units [WWF + Taxonomy initiatives+ NGOs + nations]

3. An impact matrix (land use x taxa, per biome) derived from site data, models and expert judgement [ Diversitas + GTOS]

For test by 2005, and retrospective application by 2010