Download Impacts of Climate Change on Mediterranean Biodiversity and

Impacts of Climate Change on Mediterranean Biodiversity
and Challenges of Adaptation
Margarita Arianoutsou - Farangitaki
Department of Ecology and Systematics,
Faculty of Biology, University of Athens, Greece
http://uaeco.biol.uoa.gr
Mediterranean climate regions of the world
One of the biodiversity hotspots
Defined on the basis on high endemism and high threat of destruction
Concept of Biodiversity Hotspots
•critical areas of the world for conservation
>1500 endemic plant species
< 30% of their area remaining natural
•16% of the world land surface, but the remnant natural
areas form only 2.3% of the world’s area
•50% of all world plant species are endemic to these
regions, and
•77% of all terrestrial vertebrate species are present.
Diverse landscapes rich in plant and animal species
Biodiversity hotspots within the Mediterranean Basin
Area: 1.12 x 106 km2
Plant species: 25,000
Heterogeneity
Topographic: high
Climatic:
high
Global change has four interacting components: climate,
atmospheric composition, land use and ecological diversity
Not only do climate, atmospheric and land use changes modify
diversity at all levels of organization, but biodiversity may also have
an important role in the capacity of the ecological systems to
respond to those changes.
Changes in land use and climate as foreseen in the
four Millennium Ecosystem Assessment scenarios
project to a reduction of habitats by year 2050
which will result in a loss of global vascular plant
diversity ranging from 7-24% relative to 1995.
Unprecedented change: Ecosystems
 5-10% of the area of five
regions of the
Mediterranean biome
was converted between
1950 and 1990
 More than two thirds of
the area of two biomes
and more than half of
the area of four others
had been converted by
1990
MA
Direct drivers growing in
intensity
MA
Most direct drivers of
degradation in
ecosystem services
remain constant or are
growing in intensity in
most ecosystems
Map of one scenario of the expected change in biodiversity for the year 2100.
Scenario C implies that interactions among the drivers are synergistic;
consequently, total change is calculated as the product of the changes resulting
from the action of each driver. Different colors represent expected change in
biodiversity from moderate to maximum for the different biomes of the world
ranked according to total expected change. Numbers in parentheses represent
total change in biodiversity relative to the maximum value projected for each
scenario
[Sala et al. 2000, Science 287]
Spatial sensitivity of plant diversity in Europe ranked by biogeographic
regions. Mean percentage of current species richness (Left) and
species loss(Center) and turnover (Right) by environmental zones
under the A1-HadCM3 scenario
The northern Mediterranean (52%), Lusitanian (60%) and Mediterranean
mountain (62%) regions are the most sensitive regions; the Boreal (29%),
northern Alpine (25%), and Atlantic (31%) regions are consistently
less sensitive. (Thuiller et al. 2005, PNAS 102).
Global change!
How is it affecting biodiversity?
The present global biota has been affected by fluctuating Pleistocene
(last 1.8 million years) concentrations of atmospheric carbon dioxide,
temperature, precipitation, and has coped through evolutionary changes,
and the adoption of natural adaptive strategies.
Such climate changes, however, occurred over an extended period of
time in a landscape that was not as fragmented as it is today and with
little or no additional pressure from human activities.
Habitat fragmentation has confined many species to relatively small
areas within their previous ranges, resulting in reduced genetic
variability.
evidence
Rapid urbanization reaching into natural
areas is also increasing habitat
fragmentation
Invasive species & disturbed areas
evidence
Warming beyond the ceiling of
temperatures reached during the
Pleistocene will stress ecosystems
and their biodiversity far beyond the
levels imposed by the global climatic
change that occurred in the recent
evolutionary past and possibly
beyond the tolerance limits of many
narrow niche species.
Coral reefs
evidence
Polar bear
Flagship
species
evidence
Aloe dichotoma / Quiver tree
Studies performed by SANBI strongly suggest that the range of the Quiver tree has
begun to respond to climate-induced stress. Observations from over 50 sites in
the trees range noted two trends. Firstly, where populations were found on slopes,
mortality was much higher at lower elevations than at higher ones (where it
would be warmer). Secondly, there were higher mortality rates in the north of the
tree's range (towards the equator), than those found in the south -again, trees
survived better where the climate was cooler.
Dynamic Models Predictions
Low elevations conifer forests are expected
to expand their cover by 2% (B2) - 4% (A2)
Conifers of the higher elevations are
expected to be reduced by 4% (B2) – 8%
(A2).
Experimental
data used for
parameririzing
models of
species
dynamics
Fyllas et al.
submitted
Fyllas et al. submitted
Simulations under three different
climate scenarios suggest a
relative greater vulnerability of
forests dominated by higher
altitude species, and particularly
the endemic to Greece Abies
cephalonica fir, to climate change.
Pinus nigra was simulated to
retreat and being replaced by low
altitude pines at dry areas, but
increased its dominance at the
expense of Abies cephalonica at
wetter places.
Typical low altitude
Mediterranean pines (P.
halepensis and P. brutia), seem to
be able to maintain their
populations under moderate
climate warming scenarios and are
projected to expand their
distribution ranges at higher
altitudes.
In all cases fire frequency
increased following a drying trend
imposed by the global warming
scenarios.
Although fires are projected to be
more frequent in our simulations,
viable forest stands are
simulated to be established at
our study sites, with however
significant shifts in species
composition.
Fyllas et al. submitted
Abies cephalonica does not posses
any active regeneration mode to cope
with fire (e.g. serotinous cones or
thick bark).
Its regeneration is foreseen to be
dependent on seed dispersal and
colonization from unburned patches
Mt Parnitha National Park
(declared at 1961; 25,800 ha)
Pinus nigra forests is a
priority habitat type included
in the Habitats Directive
92/43 of EU
Impacts and
Challenges to adaptation
Maintain /
Enhance
resistance
and
resilience
Preventive
measures
e.g. prevent
the
expansion of
exotic
species
Restore
degraded
areas
Prober et al. 2012
Ameliorating
ecological
processes
Enhancing
resistance
Exotic species
management
Prevention measures
Ameliorating ecological processes
Fire management
Initiatives on pre-fire management may include a systematic application
of risk assessment, fire safety, fire prevention and fire hazard reduction
techniques
Initiatives on post-fire management may include proper decisions on
restoration of burned areas (natural regeneration, reforestation,
selection of species etc)
Hydrological engineering
Enhancing resistance
Designing refugia for preserving terrestrial biodiversity
Microreserve 'Portell de l'Infern', Pobla de Benifassar, Castellón ©Emilio Laguna
The particular placement of areas devoted to restoration of native vegetation
at various scales is a primary approach to climate adaptation for biodiversity. It
may facilitate the maintenance of smaller (microreserves) or larger populations
(landscape reserves) and shifts in species distributions, both of which should
help native species adjust to changing climates
Exotic species management
On the basis of the available literature – a total of 37
eradication programmes have been recorded. Thirtythree eradications were carried out on islands and four on
the mainland. The rat (Rattus spp.) has been the most
common target (67%), followed by the rabbit. In many
cases, these eradications determined a significant
recovery of native biodiversity. Differently to other regions
of the world, no eradications of alien invertebrates and
marine organisms have been recorded; regarding
invasive alien plants, it appears that only some very
localized removals have been completed so far in
Europe.
The limited number of eradications carried
out in Europe so far is probably due to the
limited awareness of the public and the
decision makers, the inadequacy of the legal
framework, and the scarcity of resources
(IUCN, P. Genovesi, 2004)
Prevention measures
Control emissions
Regulate tourism
Regulate grazing
Manage water points
Minimize road constructions
Minimize mining
Overall,
Ecosystem-based adaptation uses biodiversity and ecosystem
services in an overall adaptation strategy. It includes the sustainable
management, conservation and restoration of ecosystems to provide
services that help people adapt to the adverse effects of climate
change.
Examples of ecosystem-based adaptation activities include:
•Coastal defence through the maintenance and/or restoration of
mangroves and other coastal wetlands to reduce coastal flooding and
coastal erosion.
•Sustainable management of upland wetlands and floodplains for
maintenance of water flow and quality.
•Conservation and restoration of forests to stabilize land slopes,
regulate water flows, enhance CO2 absorption.
•Apply proper fire management plans
•Preserve/establish habitats connectivity
•Establishment of diverse agroforestry systems to cope with
increased risk from changed climatic conditions.
•Conservation of agrobiodiversity to provide specific gene pools for
crop and livestock adaptation to climate change
Biodiversity
is part of
the solution
to climate
change
Thank you