Download The role of forest biodiversity in the sustainable use of ecosystem

The role of forest biodiversity in the
sustainable use of ecosystem goods and
services in agriculture, agro-forestry, and
forestry
Ian Thompson (et al.)
Canadian Forest Service
Great lakes Forest Research Centre
December, 2010
Some background
information
• this presentation is from an OECD
funded symposium held in Tokyo,
April 2010
• organizers:
- Dr. Kimiko Okabe, Japanese
Forest and Forest Products
Research Institute (FFPRI), and
- Dr. Ian Thompson, Canadian
Forest Service
• 18 presentations over 2 days
• >200 attendees
• published as an FFPRI research
report and on their website
• summary paper ready for
submission to BioScience
Ecosystem goods and services – from the MEA

Sustainable vs. unsustainable management
and the concept of thresholds
Resilience is the capacity of an ecosystem
to recover after major disturbance
Reorganization
of functional
species
Stable mature
forest state
Disturbance
Stability of an ecosystem is a concept
related to resistance to change
Ecosystem state
Stability within bounds = no
recognizable major changes in
vegetation community over time
System is resistant
to change over time
time
Resilience is an emergent ecosystem property
• resilience of a system is a function of biodiversity at
many scales: genes, species, and regional diversity
among ecosystems
• biodiversity underpins ecosystem resilience and the
ecological goods and services from ecosystems
• loss of biodiversity may alter the ecosystem resilience
and will result in reduced goods and services
• loss of resilience means increased uncertainty about
future ecosystem condition
Thresholds exist where the resilience capacity is
overcome and the system moves to a new state that
will differ in appearance and services
• e.g., if a forest becomes dry, it loses species, is
subject to increased frequency of fire, and moves to a
savannah or grassland state
• this new state is stable and will require considerable
change to move to another state
• the forest biodiversity has been lost and so have
most of the goods and services from the ecosystem
Tropical dry forest
Drier climate
savannah
Two examples of invasive species forming highly
resilient but highly degraded ecosystems
Removing invasive acacia
forest in California
Invasive black wattle (Acacia
mearnsii) in South Africa - a very
stable and resilient system
Biodiversity continues to be lost: we
did not meet the CBD 2010 target
MSA = mean species abundance
Change of Land Use (area coverage)
across all biomes – Global Total (TEEB, 2010)
Actual
2000
2050
Difference
Area
million
km2
million
km2
2000 to 2050
Natural areas
65.5
58.0
-11%
Bare natural
3.3
3.0
-9%
Forest managed
4.2
7.0
67%
Extensive agriculture
5.0
3.0
-40%
Intensive agriculture
11.0
15.8
44%
Woody biofuels
0.1
0.5
400%
Cultivated grazing
19.1
20.8
9%
Artificial surfaces
0.2
0.2
0%
108.4
108.4
World Total
 Natural areas loss is 7.5m M km2 - broadly equivalent to the area of the Australia.
 Losses:
natural, bare natural areas & extensive agriculture broadly equals the USA
11
Biodiversity and ecosystem functioning
Literature summaries of studies on the effect
of biodiversity loss on ecosystem function:
Schlapfer and
Schmid 1999
+ effect
No effect
Cardinale et
al. 2006
Balvanera et
al. 2006
Thompson et
al. 2009
19/23
108/108
485/771
30/35
4/23
0/108
286/771
5/25
• various ecosystems, various measures
• shapes of curves differ among response variables (primary
production, C storage, transpiration, etc.)
• depended on number of species removed
• effects are strongest at the community level
Functional species in ecosystems
• functional species play disproportionately important roles
in ecosystem
• pollination: many insects, some birds, some bats
• pest reduction: many birds, many bats, predatory insects
• decomposition: insects, fungi, micro-organisms
Functional redundancy - insurance hypothesis
• from: Walker (1995); Yachi and Loreau (1999); others
• hypothesis: multiple species perform the same function in
many ecosystems
• loss of one species results in the role filled by another with
no change in goods and services
• that is….biodiversity enables the system to be resilient to
some level of species loss
• evidence clear that diversity supports stability in ecosystems
- exact mechanism is unclear
(populations, food webs, etc.)
Many biodiversity-related ecosystem
services are not recognized as important
• role of biodiversity in:
• mitigating climate change
• prevention of disease and pest outbreaks
• crop production (e.g., pollination, soil processes)
• water flow and purification
• ecosystem resilience and stability
• complexity that is overlooked by managing single
resources rather than considering ecosystem effects
Loss of function
• Functional niche complementarity among
pumpkin pollinators in Indonesia.
Hoehn, Tscharntke, Tylianakis & Steffan-Dewenter (2008) Proc. Roy. Soc. Lond. B
Forest ecosystem near an agricultural field contributes
crop production – an example of native pollinators
Taki et al （submitted）
Numbers of individuals（per trap）
Parasitoids: biological control
Plantation (Jpn cedar)
Secondary forest (deciduous)
Stand age（years after clear cutting）
Maleque et al （2010）
Loss of function
• Biodiversity loss can reduce ecosystem process rates,
particularly in natural environments.
Tylianakis, Rand, Kahmen, Klein, Buchmann, Perner & Tscharntke (2008) PLoS Biol.
Loss of plant diversity correlated with insect diversity
Bees: F1,77.6 = 23.09,
P < 0.0001
Wasps: F1,67.0 =10.46,
P < 0.002
Tylianakis, Klein, Lozada & Tscharntke (2006) J. Biogeogr.
Agroforestry
Agroforest intensification: shade-sun grown
From: Tylianakis, Tokyo,
April 2010
Agroforestry: positive effects of pollination
Bee diversity
• Cacao intensification reduces bee biodiversity in
Sulawesi = reduced crop
B
A
High
AB
Med
AB
Low
Forest
Cacao Management Intensity
Tscharntke et al. (2008) Ecology
Cacao agroforest intensification
The yellow crazy ant Anoplolepis
gracilipes in cacao agroforests in
Sulawesi.
Probability of crazy ants being
present
Forest spp.
Other spp.
Effects on other ant species
Bos, Tylianakis, Steffan-Dewenter & Tscharntke (2008) Biological Invasions
Many examples of how biodiversity has
positive effects on ecosystem services
• increase natural forest in agro-forest systems to
increase pollination and natural control of pest species
• increase landscape heterogeneity to increase richness
of pollinator community, decrease pests, and increase
stability in biological communities
• reducing monocultures on a landscape will improve total
goods and services
• reforestation and recovery in tropical systems is fully
possible
• improving plantations for multiple values can result in
greater value to local communities
Basis for evaluating ecosystem
services (TEEB, 2010)
OECD
Baseline
scenario
International
Policies
Change
in
Land use,
Climate,
Pollution,
Water use
Change
in
Biodiversity
Change
in
Ecosystem
functions
Change
In
Ecosystem
Services
Change in
Economic
Value
(Kumar, TEEB, Tokyo , 2010)
• TEEB estimates that G&S from global tropical forests
are worth US$ 11 Trillion ($6000/ha)
Failure by scientists to enable policy
makers/politicians/public to understand issues
• indicators:
• forest loss continues at a rate of 13 million ha/year
• 61% of Japanese and EU public do not know the word
„biodiversity‟
• climate change continues unabated
• many foresters still consider biodiversity to be a forest product,
instead of actually being the forest
• continued clearing of forest near agricultural lands
• SFM criticized as an excuse to conduct „business as usual‟
• biodiversity often considered as a preservation issue rather than a
sustainability issue
• emphasis is still on non-declining, even flow of limited goods
Problems faced by scientists
• few believe that ecology issues are urgent – translates to
funding
• need to embrace other points of view and other methods
• no training in public communications and dealing with the
media
• „biodiversity‟ is often referred to as an „ecosystem service‟
• not everyone has the same expectations
• “monoculture of the mind”
Improving biodiversity considerations in decision
making and policy: the role for scientists
• improve the understanding of mechanisms by which
biodiversity supports ecosystem goods and services
• identify and improve valuation of these services
• improve communication with policy makers and convey key
messages on how biodiversity improves ecosystem function
• enabling the capacity to manage sustainably, instead of
making mistakes and then having to react
• indicators may be useful, but not in the absence of
thresholds and meaningful quantifiable values
• communicate better: lose the jargon
Key science messages from Tokyo
OECD-funded symposium
• biodiversity supports ecosystem functioning and enhances resilience
• biodiversity is higher in natural forests >secondary forests
>plantations
• increasing biodiversity increases goods and services
• diversity in pollinators increases crop yields
• diversity in landscapes that include natural forests (at close
distances to crops) increases pollinators and reduces pest species
• on the other hand: intensifying land use drives extinctions
• loss of biodiversity means huge economic losses; unrecognized until
after the damage is done
• consider/manage the ecosystem, not individual resources
• valuation of ecosystem services can be a strong tool for influencing
policy