Characterisation of Neotropical Savanna Ecosystems by their Modern Pollen Rain

Huw Jones

Institute of Geography

University of Edinburgh

Importance of understanding vegetation dynamics during the Quaternary

• Global carbon cycle

• Responses to global environmental changes

• Speciation and biogeographic theories

Amazonian palaeoecology• What type of ecosystems existed during the last glacial maximum?

Savanna

Seasonally dry tropical forest

Evergreen Rainforest

Noel Kempff Mercado National Park, Bolivia

From Burbridge et al., 2004

Savanna ecosystems in NKMNP

Upland savanna Lowland seasonally-flooded savanna

Interpreting the grass pollen signal (ThePoaceae family)

• Only identifiable to family level.

• Several studies infer that an increase in grass pollen is due to increased aridity. However…

• Increase in grass pollen in lake sediment could result from

1. Increase in extent of upland savannas

2. Changes in lake surface area

3. Increase in extent of seasonally- flooded savannas

Grass pollen. Photo by Will Gosling

Sampling and analysis

• Modern pollen rain sampled by analysis of pollen traps and lake sediment samples

• Pollen trap and sediment samples will be prepared by standard methods (Gosling et al., 2003 and Faegri & Iverson, 1989, respectively), to allow production of pollen slides.

• Vegetation plot data will allow modern pollen-vegetation relationships to be defined

• Statistical methods will be used to assess variability in pollen rain and degree to which ecosystems may be differentiated.