Have you wondered
how the numerous species in the ecosystems are quantified? How do you know that
the grasscutter- in West Africa, a large rodent used for food- population in an
ecosystem is dwindling? How does one monitor population of the species
scientifically, to sustain the required balance?
Some
international organisations are applying their resources to tackle these issues
as follows:
LPI
The Living Planet Index (LPI) is an indicator of the state of global
biological diversity, based on trends in vertebrate populations of species from around the world.
The LPI
provides the general public, scientists and policy-makers with information on
trends in the abundance of the world’s vertebrates and offers
insights into which habitats or ecosystems have species that are declining most
rapidly. This information can be used to define the impact humans are having on
the planet and for guiding actions to address biodiversity loss.
The World
Wide Fund for Nature (WWF) is
working in collaboration with the Institute
of Zoology (IoZ), the
research division of the Zoological
Society of London (ZSL), to
further develop the project which began in 1997.
The Living
Planet Index was originally developed by WWF in collaboration with UNEP-WCMC, the biodiversity assessment and policy implementation
arm of the United Nations Environment Programme. UNEP-WCMC collected much of the data
for the index in the first few years of the project.
Results are
presented biennially in the WWF Living Planet Report, on the
World Wide Web, and in publications such as the Millennium
Ecosystem Assessment and the UN Global
Environment Outlook. National and
regional reports are now being produced to focus on relevant issues at a
smaller scale. The 2012 edition of the Living
Planet Report was released
in May 2012 (LPR 2012). In a world first, the LPR 2012 was launched from space
by astronaut André
Kuipers in the International
Space Station, in
collaboration with the European
Space Agency.
Between 1970
and 2007, the index fell by 28%. This global trend suggests that natural
ecosystems are degrading at a rate unprecedented in human history.
CALCULATION
The current Living
Planet Database (LPD) maintained by ZSL, contains over 10,000
population trends for more than 2,500 species of fish, amphibians, reptiles,
birds and mammals.
The global LPI
is calculated using over 7000 of these population time-series which are
gathered from a variety of sources such as journals, online databases and
government reports.
A generalised
additive modelling framework is used to determine the underlying trend in each
population time-series. Average rates of change are calculated and aggregated
to the species level.
Each species
trend is aggregated to produce an index for the terrestrial, marine and
freshwater systems. The three system indices are weighted equally within
tropical and temperate regions which are then aggregated to produce the global
LPI.
CONVENTION
In April 2002,
at the Convention on Biological Diversity (CBD), 188
Nations committed themselves to actions to: “… achieve, by 2010, a
significant reduction of the current rate of biodiversity loss at the global,
regional and national levels…”
The Living
Planet Index is one of the indicators designated for immediate testing by the CBD as a
means of measuring progress towards the 2010 target, specifically for trends in
abundance and distribution of species. The work at ZSL is concerned with
ensuring the most rigorous and robust methods are implemented for the measurement
of population trends, expanding the coverage of the LPI to more broadly
represent biodiversity, and disaggregating the index in meaningful ways (such
as assessing the changes in exploited or invasive species).
BUILDING A NETWORK
Population data
invariably comes from the better monitored regions of the world; however a
network of organisations collecting species population data is currently being
developed. With the regular addition of high quality data to the LPD the LPI
will provide greater coverage of species from poorly known taxonomic groups and
regions. In addition, ZSL and WWF have recently begun forming partnerships to
develop LPIs for Invertebrates and plants.
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