Project allocation NGEN03 2014 Long-term Holocene increases in - - PowerPoint PPT Presentation

Project allocation NGEN03 2014

Long-term Holocene increases in atmospheric CO2 and CH4 concentrations: natural or anthropogenic? (Mats Rundgren)

• In 2003 William Ruddiman, a respected palaeoclimatologist, published a paper in which he argued

that the increasing atmospheric CO2 and CH4 concentrations recorded over the past 8000 and 5000 years, respectively, were caused by human land use. The rise in carbon dioxide was suggested to result from early agriculture and deforestation in Eurasia, and the methane increase was attributed to rice irrigation. According to Ruddiman, the high greenhouse gas concentrations in the late Holocene relative to earlier interglacials has prevented ice accumulation in northeastern Canada and postponed the transition into the next glacial period. This ‘outrageous’ hypothesis has become highly debated within the scientific community. This project should present and discuss the evidence and arguments put forward by Ruddiman and the contra-evidence and arguments that challenge his hypothesis. References to start with:

• Ruddiman, W.F. 2003. The anthropogenic greenhouse era began thousands of years ago. Climatic Change 61,

261-293.

• Claussen, M. et al. 2005. Did humankind prevent a Holocene glaciation? Climatic Change 69, 409-417.
• Olofsson, J. & Hickler, T. 2008. Effects of human land-use on the global carbon cycle during the last 6,000 years.

Vegetation and Archaeobotany 17, 605-615.

• Vavrus, S. et al. 2008. Climate model tests of the anthropogenic influence on greenhouse-induced climate change:

the role of early human agriculture, industrialization, and vegetation feedbacks. Quaternary Science Reviews 27, 1410-1425.

• Elsig, J. et al. 2009. Stable isotope constraints on Holocene carbon cycle changes from an Antarctic ice core.

Nature 461, 507-510.

• Kutzbach, J.E. et al. 2010. Climate model simulation of anthropogenic influence on greenhouse-induced climate

change (early agriculture to modern): the role of ocean feedbacks. Climatic Change 99, 351-381.

• Stocker, B.D. et al. 2011. Sensitivity of Holocene atmospheric CO2 and the modern carbon budget to early human

land use: analyses with a process-based model. Biogeosciences 8, 69-88.

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Stable isotope composition of CH4 in ice cores spanning the last glacial and the Holocene: what does it reveal about the relative importance of different, natural and anthropogenic, methane sources? (Mats Rundgren)

• Ice core records spanning several glacial-interglacial cycles show that atmospheric CH4 levels are tightly coupled

to orbitally-controlled insolation variations. A strong climatic influence on atmospheric methane concentrations is also indicated on centennial timescales for the last glacial-interglacial transition. In contrast, the Holocene methane record is more difficult to directly relate to climate-related processes and, at least during recent centuries, anthropogenic processes are likely to have been important. One way to better understand the relative importance

• f different, natural and anthropogenic, processes for the observed CH4 changes is to analyse the stable carbon

(δ13C of CH4) and hydrogen (δD of CH4) isotope compositions of methane preserved in ice cores. Because the isotopic composition of different methane sources, e.g. wetlands, soils, lakes, biomass burning, fossil fuels and marine clathrates, is relatively well known, CH4 isotope and concentration records can be used as input in model calculations to estimate the relative contribution of these processes. A number of recent studies adopting this approach have provided interesting information about carbon cycle dynamics during the last glacial, the last glacial-interglacial transition and the Holocene (both before and during the recent period of strong anthropogenic influence).

• References to start with:
• Ferretti, D.F. et al. 2005. Unexpected changes to the global methane budget over the past 2000 years. Science

309, 1714-1717.

• Schaefer, H. et al. 2006. Ice record of δ13C for atmospheric CH4 across the Younger Dryas-Preboreal transition.

Science 313, 1109-1112.

• Sowers, T. 2006. Late Quaternary atmospheric CH4 isotope record suggests marine clathrates are stable.

Science 311, 838-840.

• Fischer, H. et al. 2008. Changing boreal methane sources and constant biomass burning during the last
• termination. Nature 452, 864-867.
• Mischler, J.A. et al. 2009. Carbon and hydrogen isotopic composition of methane over the last 1000 years. Global

Biogeochemical Cycles 23, GB4024, doi:10.1029/2009GB003460.

• Sowers, T. 2010 Atmospheric methane isotope records covering the Holocene period. Quaternary Science

Reviews 29, 213-221.

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Present and future impacts of anthropogenic CO2 increase on ocean chemistry and marine ecosystems (Mats Rundgren)

• Ocean CO2 uptake in response to the anthropogenic increase in atmospheric CO2 concentrations over the past

decades has been larger than the ocean buffering capacity, resulting in an ocean pH decrease. Since 1800 A.D.,

• cean pH has decreased from 8.16 to 8.05. A further drop to around 7.8 is estimated by the end of the century

(Feely et al. 2009), and within a few hundred years ocean pH may reach levels not experienced in the last 20 million years or more. Because many marine organisms, both planktonic and benthic, are known to be sensitive to changes in pH, human CO2 emissions are likely to have important consequences for marine ecosystems. For example, experiments in artificially acidified waters show that organisms with carbonate shells have difficulties maintaining their shells at lower than present pH. In addition to this pH effect, ocean CO2 uptake results in changes in the chemistry of the oceans that reduce their ability to absorb additional atmospheric CO2. This project should describe and discuss the likely effects of the anthropogenic CO2 increase on ocean chemistry and marine ecosystems, both at present and in the future.

• Caldeira, K. & Wickett, M.E. 2003. Anthropogenic carbon and ocean pH. Nature 245, 365.
• Feeley, R.A. 2004. Impact of anthropogenic CO2 on the CaCO3 system in the oceans. Science 305, 362-366.
• Feely, R.A., Doney, S.C., and Cooley, S.R. 2009. Ocean acidification: present conditions and future changes in a

high CO2 world. Oceanography 22, 36-47.

• Kerr, R.A. 2010. Ocean acidification unprecedented, unsettling. Nature 328, 1500-1501.
• U. Riebesell, K. G. Schulz, R. G. J. Bellerby, M. Botros, P. Fritsche, M. Meyerhöfer, C. Neill, G. Nondal, A.

Oschlies, J. Wohlers & E. Zöllner. 2007 Enhanced biological carbon consumption in a high CO2 ocean. Nature 450, 545-548.

• Ridgwell, A. & Zeebe, R.E. 2005. The role of the global carbonate cycle in the regulation and evolution of the Earth
• system. Earth and Planetary Science Letters 234, 299-315.
• Orr, J.C. et al., 2005. Anthropogenic acidification over the twenty-first century and its impact on calcifying
• rganisms. Nature 437, 681-686.
• Sunda, W.G. 2010. Iron and the carbon pump. Science 327, 654-655.
• Ruttimann, J. 2006. Sick seas. Nature 442, 978-980.
• Ruttimann, J. 2006. Sick seas. Nature 442, 978-980.

III

Has ancient DNA helped understanding of animal ecology during the Quaternary? (Richard Bradshaw)

• Recovery and sequencing of ancient DNA from extinct and surviving

fauna have altered understanding of the combined effect of climate change and human impact on population dynamics and ecology. In this project you will assess the strengths and limitations of this new analytical technique, including the issues of contamination. You will review selected studies to highlight how they have contributed to our knowledge of past community dynamics and extinction.

• Willerslev, E. et al. (2014) Fifty thousand years of Arctic vegetation

and megafaunal diet. NATURE 506, 47-51.

• Haile, J. et al. (2009) Ancient DNA reveals late survival of mammoth

and horse in interior Alaska. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Volume: 106 Issue: 52 Pages: 22352-22357

• Hofreiter, M. et. (2012) Ancient biomolecules in Quaternary
• palaeoecology. QUATERNARY SCIENCE REVIEWS 33, 1-13.

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The Holocene spread of spruce and beech in Europe. Climatic control, human influence or migration biology? (Richard Bradshaw)

• The establishment of large populations of spruce and beech in northern

Europe occurred during the late Holocene, long after the establishment

• f pine, oak, elm alder and other tree species. Why was this the case?

In this project you will review the evidence for climatic control, migration biology and disturbance processes on the dynamics and distribution of spruce and beech in Europe during the Holocene.

• Magri, D. (2008) Patterns of post-glacial spread and the extent of

glacial refugia of European beech (Fagus sylvatica). JOURNAL OF BIOGEOGRAPHY 35, 450-463.

• Lehsten, D. et al. (2014) Modelling the Holocene migrational dynamics
• f Fagus sylvatica L. and Picea abies (L.) H. Karst. GLOBAL

ECOLOGY AND BIOGEOGRAPHY 23, 658-668.

• Bialozyt, R. et al. (2012) Modelling the spread of Fagus sylvatica and

Picea abies in southern Scandinavia during the late Holocene. JOURNAL OF BIOGEOGRAPHY 39, 665-675.

• Bradshaw, R.H.W. & Lindbladh, M. (2008) Regional spread and stand-

scale establishment of Fagus sylvatica and Picea abies in Scandinavia. ECOLOGY 86, 1679-1686.

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Global change effects on biodiversity (Dörte Lehsten)

• There are multiple pressures on the biodiversity within ecosystems, independent of

climate change. Among these pressures are land use change, direct effects of CO2, N deposition and exotic plant invasions. Rapid climate change may increase or decrease these pressures. The idea would be to examine (probably in selected ecosystems) in the context of climate change how these other drivers of change either alone, or in combination, might influence both biodiversity and ecosystem processes.

• Bradshaw C.J.A. et al. 2007. Global evidence that deforestation amplifies flood risk

and severity in the developing world. Global Change Biology 13, 2379-2395

• Brown, R.L. & Peet, R.K. 2003 Diversity and invisibility of southern Appalachian plant
• communities. Ecology 84, 32-39
• Dukes, J.S.& Mooney H.A. 1999. Does global change increase the success of

biological invaders ? Trends in Ecology & Evolution 14 135-139

– IPCC 2007 www.ipcc.ch

• Kienast, F., Wildi, O & Brzeziecki, B. 1998 Potential impacts of climate change on

species richness in mountain forests: an ecological risk assessment. Biological Conservation 83 291-305

• Ramankutty, N. et al. 2007. Challenges to estimating carbon emissions from tropical

deforestation Global Change Biology 13, 51-66

• Rounsevell, M.D.A et al. 2006 A coherent set of future land use change scenarios for

Europe Agricultural Ecosystems & Environment 114 57-68. Tetiana & Gustav

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What will the direct physiological effects of increasing atmospheric CO2 be? (Dörte Lehsten)

• Elevated CO2 does not only affect the climate; it also enhances photosynthesis and affects

stomatal conductance and thereby the water balance of ecosystems. Model experiments have suggested that the so-called CO2 fertilization effect could be crucial for the fate of the future of the global carbon cycle, but how large will these effects really be?

• Bonan, G. (2008) Carbon cycle: Fertilizing change. Nature Geoscience, 1, 645-646.
• Cramer, W., Bondeau, A., Woodward, F.I., Prentice, I.C., Betts, R.E., Brovkin, V., Cox, P.M.,

Fisher, V., Foley, J.A., Friend, A.D., Kucharik, C., Lomas, M.R., Ramankutty, N., Sitch, S., Smith, B., White, A. & Young-Molling, C. (2001) Global response of terrestrial ecosystem structure and function to CO2 and climate change: results from six dynamic global vegetation models. Global Change Biology, 7, 357-373.

• Hickler, T., Smith, B., Prentice, I.C., Mjöfors, K., Miller, P., Arneth, A. & Sykes, M.T. (2008) CO2

fertilization in temperate FACE experiments not representative of boreal and tropical forests. Global Change Biology, 14, 1531-1542.

• Finzi, A.C., Norby, R.J., Calfapietra, C., Gallet-Budynek, A., Gielen, B., Holmes, W.E., Hoosbeek,

M.R., Iversen, C.M., Jackson, R.B., Kubiske, M.E., Ledford, J., Liberloo, M., Oren, R., Polle, A., Pritchard, S., Zak, D.R., Schlesinger, W.H. & Ceulemans, R. (2007) Increases in nitrogen uptake rather than nitrogen-use efficiency support higher rates of temperate forest productivity under elevated CO2. Proceedings of the National Academy of Sciences, 104, 14014-14019.

• Körner, C., Morgan, J.A. & Norby, R. (2007) CO2 fertilisation: when, where, how much?

Terrestrial ecosystems in a changing world (ed. by S.G. Canadell & D.E. Pataki & L.F. Pitelka). Springer, Berlin Heidelberg.

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Biodiversity in changing landscapes – In what way can the history of semi-natural grassland habitats be of importance? (Dörte Lehsten)

• Unimproved semi-natural grasslands have developed as a result of low-

level human management (grazing and haymaking) over thousands of years and show high levels of species richness. In Europe, rapid changes in agricultural practices during the last half century have led to the loss of semi-natural grasslands (pastures) accompanied by the local extinction of grassland plants, the isolation of the remaining populations and the loss of species diversity. Many theories have been proposed to explain the pattern

• f species and the maintenance of diversity in plant communities. Recently,

the importance of habitat history as potential determinants of local or regional species diversity has been emphasised. When focussing on plant species the historical factors should be paid extra attention, as the respons

• f change in the species can occur generations after the actual event and

current habitat changes can have future ecological costs.

• In this project you will focus on associations between habitat history

(including landscape history) and species diversity in semi-natural

• grasslands. Can present day diversity (in genes and species) be explained

by landscape history? What is the state of knowledge?

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• S. A. O. Cousins and O. Eriksson (2001): Plant species occurrences in a rural hemiboreal landscape: effects of remnant habitats, site

history, topography and soil. Ecography 24, 4, 461-469

• S. A. O. Cousins and O. Eriksson (2002): The influence of management history and habitat on plant species richness in a rural

hemiboreal landscape, Sweden. Landscape Ecology 17, 6, 517-529

• S. A. O. Cousins, H. Ohlson and O. Eriksson (2007): Effects of historical and present fragmentation on plant species diversity in semi-

natural grasslands in Swedish rural landscapes. Landscape Ecology 22, 5, 723-730

• A. Dahlstrom, S. A. O. Cousins and O. Eriksson (2006): The history (1620-2003) of land use, people and livestock, and the relationship to

present plant species diversity in a rural landscape in Sweden. Environment and History 12, 2, 191-212

• F. de Bello, M. Vandewalle, T. Reitalu, J. Leps, H. C. Prentice, S. Lavorel and M. T. Sykes (2013): Evidence for scale- and disturbance-

dependent trait assembly patterns in dry semi-natural grasslands. Journal of Ecology 101, 5, 1237-1244

• O. Eriksson, S. A. O. Cousins and H. H. Bruun (2002): Land-use history and fragmentation of traditionally managed grasslands in
• Scandinavia. Journal of Vegetation Science, 13, 5, 743-748
• E. Gustavsson, T. Lennartsson and M. Emanuelsson (2007): Land use more than 200 years ago explains current grassland plant

diversity in a Swedish agricultural landscape. Biological Conservation 138, 1-2, 47-59

• L. J. Johansson, K. Hall, H. C. Prentice, M. Ihse, T. Reitalu, M. T. Sykes and M. Kindstrom (2008): Semi-natural grassland continuity,

long-term land-use change and plant species richness in an agricultural landscape on Oland, Sweden. Landscape and Urban Planning 84, 3-4, 200-211

• M. Partel, A. Helm, T. Reitalu, J. Liira and M. Zobel (2007): Grassland diversity related to the Late Iron Age human population density.
• Journal of Ecology 95, 3, 574-582
• J. Pykala, M. Luoto, R. K. Heikkinen and T. Kontula (2005): Plant species richness and persistence of rare plants in abandoned semi-

natural grasslands in northern Europe. Basic and Applied Ecology 6, 1, 25-33

• T. Reitalu, H. C. Prentice, M. T. Sykes, M. Lonn, L. J. Johansson and K. Hall (2008): Plant species segregation on different spatial scales

in semi-natural grasslands. Journal of Vegetation Science 19, 3, 407-416

• T. Reitalu, L. J. Johansson, M. T. Sykes, K. Hall and H. C. Prentice (2010): History matters: village distances, grazing and grassland

species diversity. Journal of Applied Ecology 47, 6, 1216-1224

• T. Reitalu, O. Purschke, L. J. Johansson, K. Hall, M. T. Sykes and H. C. Prentice (2012): Responses of grassland species richness to

local and landscape factors depend on spatial scale and habitat specialization. Journal of Vegetation Science 23, 1, 41-51

• T. Reitalu, M. T. Sykes, L. J. Johansson, M. Lonn, K. Hall, M. Vandewalle and H. C. Prentice (2009): Small-scale plant species richness

and evenness in semi-natural grasslands respond differently to habitat fragmentation. Biological Conservation 142, 4, 899-908

• M. Vandewalle, O. Purschke, F. de Bello, T. Reitalu, H. C. Prentice, S. Lavorel, L. J. Johansson and M. T. Sykes (2014): Functional

responses of plant communities to management, landscape and historical factors in semi-natural grasslands. Journal of Vegetation Science 25, 3, 750-759

References for: Biodiversity in changing landscapes – In what way can the history of semi-natural grassland habitats be of importance?

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What does biodiversity do for us? (Dörte Lehsten)

• What are ecosystem services? What is the link between biodiversity and

ecosystem services? What would be the effects to create substitutes for ecosystem services?

• Examples of references:
• Balvanera, P., G.C. Daily, P.R. Ehrlich, T.H. Ricketts, S.Bailey, S. Kark, C. Kremen and H. Pereira. 2001.

Conserving biodiversity and ecosystem services. Science 291: 2047.

• Kremen, C. (2005). Managing ecosystem services: what do we need to know about their
• ecology? Ecology Letters, 8, 468-479.
• Balvanera, P., Pfisterer, P.A., Buchmann, N., He, J-S., Nakashizuka, T., Raffaelli, D. and
• Schmid, B. (2006). Quantifying the evidence for biodiversity effects on ecosystem
• functioning and services. Ecology Letters, 9, 1146-1156.
• Boyd, J. and Banzhaf, S. (2007). What are ecosystem services? The need for standardized
• environmental accounting units. Ecological Economics, 63(2-3), 616-626.
• Capistrano, D., Samper K.C., Lee, M.J. and Raudsepp-Hearne, C. (eds.) (2005). Ecosystems and Human Well-

being: Multiscale Assessments, Volume 4. Island Press, Washington DC, 388 pp.

• Carpenter, S.R., DeFries, R., Dietz, T., Mooney, H.A., Polasky, S., Reid, W.V. and Scholes, R.J. (2006).

Millennium ecosystem assessment: research needs. Science, 314, 257-258.

• Costanza, R., d’Arge, R., de Groot, R., Farber, S., Grasso, M., Hannon, B., Limburg, K.
• Naeem, S., O’Neill, R.V., Paruelo, J., Raskin, R.G., Sutton, P. and van den Belt, M.
• (1997). The value of the world’s ecosystem services and natural capital. Nature, 387,
• 253-260.
• Daily, G.C. (ed.) (1997). Nature’s Services: Societal Dependence on Natural Ecosystems.
• Island Press, Washington DC.

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Technical development and its impact on ecosystems. (Dörte Lehsten)

• Technical developments which aim to reduce human efforts are often

underestimated in their impacts on ecosystems. Hence, in the end they may cause more damage than pay off.

• Examples are channels between oceans, rivers and lake, irrigation systems,

water power plants. Due to the systems they have different impacts on the

• A) describe the impacts of the Suez channel and Panama channel on

marine ecosystem in the connected water bodies. Did physical or chemical impacts occur? How did these impact species diversity. How do these channels act as migrating corridors? How sensitive are these water bodies to immigratng species in respect of occuring invading species?

• B) describe the impact of irrigation systems in aride zones to river and

discharge water bodies? How does the irrigation system affects the irrigated ecosystems? How changes the hydrology of that region and in the rivers and or lake? How did these changes effect physical and chemical characteristics of the discharge water body? What impacts had these changes on species and the biodiversity. Choose an example ancient or currently occuring.

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Technical development and its impact on ecosystems. (Dörte Lehsten)

• C) Water power plant have an impact on the ground water level. The

pressure of the water column has in impact on the surrounding region and increases ground water level. The often (semi-) natural valley used for water storage changes dramatically from terrestrial to aquatic environment. Further, accompiened dams act as artificial barriers for migration path ways. Decide for two examples (case studies). Discuss impacts on the hydrological regime of the river, impacts on ecosystem in river, changes in sediment transport and impacts on lower side of the river ecosystem, artificial filled valley, species migration and biodiversity. Describe similarities and differences in the impacts what causes differences?

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Changes in fire regimes over the Holocene and their potential driving forces. How can a knowledge of the past help to predict the future? (Chiara Molinari)

• Fire is a global phenomenon affecting ecosystems, land-surface properties,

the carbon cycle, atmospheric chemistry, aerosols and human activities at all spatio-temporal scales (ranging from days to centuries and from microsites to biomes). Despite that, comparatively little is known about the patterns and driving forces of fire activity through time. Historical records, remotely sensed data, tree rings data and sedimentary charcoal records provide information about the linkage of fire, climate variability, vegetation dynamics and human activities. A better understanding of the role of fire in terrestrial biosphere is essential in order to protect and manage present and future ecosystems for the provision of ecological services and the conservation of biological diversity.

• This project should describe fire dynamics during the Holocene at a global
• r continental scale and discuss the potential drivers of these changes.

Particular attention should be paid to the importance of palaeo- environmental researches in the prediction of future fire increase in response to future global warming.

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References for: Changes in fire regimes over the Holocene and their potential driving forces. How can a knowledge of the past help to predict the future? (Chiara Molinari)

• Bowman, D.M.J., Balch, J.K., Artaxo, P. et al. (2009) Fire in the Earth System. Science, 324, 481–

484.

• Carcaillet, C., Almquist, H., Asnong, H. et al. (2002) Holocene biomass burning and global

dynamics of the carbon cycle. Chemosphere, 49, 845–863.

• Daniau, A.-L., Bartlein, P.J., Harrison, S.P. et al. (2012) Predictability of biomass burning in

response to climate changes. Global Biogeochemical Cycles, 26, G–4007.

• Galanter, M., Levi, H., II & Carmichael, G.R. (2000) Impacts of biomass burning on tropospheric

CO, NOx, and O3. Journal of Geophysical Research: Atmospheres, 105, 6633-6653.

• Marlon, J.R., Bartlein, P.J., Daniau, A.-L. et al. (2013) Global biomass burning: a synthesis and

review of Holocene paleofire records and their controls. Quaternary Science Reviews, 65, 5–25.

• Molinari, C., Lehsten, V., Bradshaw, R.H.W. et al. (2013) Exploring potential drivers of European

biomass burning over the Holocene: A data-model analysis. Global Ecology and Biogeography, 22: 1248–1260.

• Power, M.J., Marlon, J., Ortiz, N. et al. (2008) Changes in fire regimes since the Last Glacial

Maximum: an assessment based on a global synthesis and analysis of charcoal data. Climate Dynamics, 30, 887–907.

• Pyne, S.J. (2000) Vestal fire: an environmental history, told through fire, of Europe and Europe’s

encounter with the world. University of Washington Press, Seattle, WA.

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Reducing emissions from deforestation and degradation (REDD): opportunities and obstacles (Dan Metcalfe)

• REDD is a strategy gaining increasing ground in climate policy

circles to encourage sustainable resource and carbon storage, mainly in developing tropical countries. While the strategy offers a potentially powerful tool to achieve multiple positive environmental

• bjectives simultaneously there exist multiple practical, scientific,

cultural and ethical obstacles.

• What are the major obstacles to successful implementation of REDD

and what can be done to overcome these obstacles?

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Effects of animals on ecosystem structure and dynamics (Dan Metcalfe)

• Trophic interactions between predators and herbivores are affected by, and

in turn affect, a wide range of ecosystem processes. However, most predictive models of ecosystem functioning under present and potential future climate largely ignore animals. To what extent is this a problem and what can realistically be done about it?

• Are there any consistent shifts in trophic interactions across ecosystem

types and with climate. What might this tell us about future ecosystem processes under projected climate change?

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