The role of forest biodiversity in the sustainable use of ecosystem goods and services in agriculture, agro-forestry, and forestry

Transcription

1 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

2 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

3 Ecosystem goods and services from the MEA

4 Sustainable vs. unsustainable management and the concept of thresholds

5 Resilience is the capacity of an ecosystem to recover after major disturbance Reorganization of functional species Stable mature forest state Disturbance

6 Ecosystem state Stability of an ecosystem is a concept related to resistance to change Stability within bounds = no recognizable major changes in vegetation community over time System is resistant to change over time time

7 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

8 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

9 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

10 Biodiversity continues to be lost: we did not meet the CBD 2010 target MSA = mean species abundance

11 Change of Land Use (area coverage) across all biomes Global Total (TEEB, 2010) Actual Difference Area million km2 million km to 2050 Natural areas % Bare natural % Forest managed % Extensive agriculture % Intensive agriculture % Woody biofuels % Cultivated grazing % Artificial surfaces % World Total Natural areas loss is 7.5m M km2 - broadly equivalent to the area of the Australia. Losses: 11 natural, bare natural areas & extensive agriculture broadly equals the USA

12 Biodiversity and ecosystem functioning Literature summaries of studies on the effect of biodiversity loss on ecosystem function: Schlapfer and Schmid 1999 Cardinale et al Balvanera et al Thompson et al effect 19/23 108/ /771 30/35 No effect 4/23 0/ /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

13 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

14 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.)

15 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

16 Loss of function Functional niche complementarity among pumpkin pollinators in Indonesia. Hoehn, Tscharntke, Tylianakis & Steffan-Dewenter (2008) Proc. Roy. Soc. Lond. B

17 Forest ecosystem near an agricultural field contributes crop production an example of native pollinators Taki et al (submitted)

18 Numbers of individuals(per trap) Parasitoids: biological control Plantation (Jpn cedar) Secondary forest (deciduous) Stand age(years after clear cutting) Maleque et al (2010)

19 Loss of function Biodiversity loss can reduce ecosystem process rates, particularly in natural environments. Tylianakis, Rand, Kahmen, Klein, Buchmann, Perner & Tscharntke (2008) PLoS Biol.

20 Loss of plant diversity correlated with insect diversity Bees: F 1,77.6 = 23.09, P < Wasps: F 1,67.0 =10.46, P < Tylianakis, Klein, Lozada & Tscharntke (2006) J. Biogeogr.

21 Agroforestry Agroforest intensification: shade-sun grown From: Tylianakis, Tokyo, April 2010

22 Bee diversity Agroforestry: positive effects of pollination Cacao intensification reduces bee biodiversity in Sulawesi = reduced crop A AB AB B Tscharntke et al. (2008) Ecology High Med Low Forest Cacao Management Intensity

23 Cacao agroforest intensification The yellow crazy ant Anoplolepis gracilipes in cacao agroforests in Sulawesi. Forest spp. Other spp. Probability of crazy ants being present Effects on other ant species Bos, Tylianakis, Steffan-Dewenter & Tscharntke (2008) Biological Invasions

24 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

25 Basis for evaluating ecosystem services (TEEB, 2010) OECD Baseline scenario International Policies Change in Land use, Climate, Pollution, Water use Change in Change Economic in Value Biodiversity Change In Ecosystem Services Change in Ecosystem functions (Kumar, TEEB, Tokyo, 2010) TEEB estimates that G&S from global tropical forests are worth US$ 11 Trillion ($6000/ha)

26 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

27 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

28 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

29 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