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NEWS FROM THE DAINTREE RAINFOREST. Dr Mike Liddell Chemistry Department James Cook University. TWO STATION APPROACH.
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NEWS FROM THE DAINTREERAINFOREST Dr Mike Liddell Chemistry Department James Cook University
TWO STATION APPROACH • Station 1 : Cape Tribulation Based at the Australian Canopy Crane this station has been operating since 2001. Due to risk management decisions at JCU the station has been idle since June 2007 when tower access was removed for all JCU employees.In principle the Cape Trib station will restart later in February (or May!). • Station 2: Cow BayBased at the Daintree Discovery Centre this station is currently under construction and is due to go operational in March 2008.
THE LOCATIONS Satellite ImageryCape Tribulation LANDSAT80m resolution
THE FOREST • Pristine lowland rainforest at both stations. • Complex Type 1A mesophyll vine forest • Canopy height 25-35m – dependant on topography/soils. • Leaf area index Station 1 4 (Amazon 8-10) • High species diversity Station 1: 88 tree spp. in 1 Ha. • Moderate stand density Station 1: 680 stems >10cm dbh in 1 Ha • Significant species overlap between the two stations both in flora and fauna.
TOPOGRAPHY • Fetch: both stations have relatively flat topographic features for around 1-2 km in the prevailing wind direction at each site. • Behind both stations is an elevated Tablelands region which creates drainage flow at night.
THE SITES • The key question that we are looking for an answer for in this study: Is there a measureable change in carbon, water or sensible heat fluxes that can be attributed to climate change perturbing the rainforest? • Both sites are in complex terrain. • Only daytime flux data will be used for long term analyses. • Microclimate : T essentially identicalStation 1 wetter and less solar (pyran.)Station 2 drier and lower RH • Soils : Station 1 fertile clay-loam / colluvial gravels Station 2 deep basalt derived soils
1m 1m temp probes Gypsum blocks CS616-L 0.1m 0.75m 1.5m SOIL CHARACTERISTICS • Cape Trib station : water availability is likely to bea key driver of productivity in these seasonally dryrainforests. A sensor pit was dug – initially by hand! • Rock : Soil ratio : around 40%
FOREST PRODUCTIVITY Cape Trib station above ground productivity • Dendrometry: 171 trees have been banded. • Litter: 25 traps have been monitored fortnightly.
ALLOMETRY • Species specific allometric equations have been developed along with general species equations allowing calculation of site biomass = 270 t ha-1 • Detailed measurements of crown dimensions allows theforest architecture to be monitored quanititatively.
PHENOLOGY • Aim: is to look for early warning signs of the Daintree rainforest being influenced by climate change by studying forest phenology. • Long term project : 10 years + • Select species will be chosen that have a sensitivity to extinction, along with pioneer species, iconic species and species of cultural significance (Kuku Yalanji). • Around 700 – 900 trees will be monitored on amonthly basis using binoculars and traps. • Site and species selection is currently underway using existing detailed soil and species maps.
DISCOVERY CENTRE TOWER • Daintree Discovery Centre : located near Cow Bay pub, welcomed its 1 millionth visitor in 2007. • Tower : 23m walk-up tower (3 abreast!) • Mast : 10m above the top platform
RAINFALL Annual average rainfall approx. 3900m. Strongly seasonal 70% falls between December and April. The low rainfall in 2002 has happened only once in the last 40 years - <2500mm.- 2003 was a repeat event! 2006 was 5944mm
CARBON FLUXES Station 1: Cape TribulationAverage values of daytime carbon flux. (mmol/m2/s-1)
CONCLUSIONS • The carbon flux data indicates that this ecosystem is acting as a sink for carbon in years with normal wet and dry seasons.Where one of these periods has reduced precipitation the forest shifts to become a source of carbon. • The Daintree region is predicted to have significantly longer and dryerdry seasons (CSIRO) indicating potential problems for the viability of this type of rainforest.
ACKNOWLEDGEMENTS Prof. Steve Turton (ATFI)Dr Peter Franks (JCU Botany)Dr Paul Nelson (JCU Earth Sciences)Cassandra Nichols (JCU ACCRF)David Blake (UQ)Nicolas Nieullet (ENGREF, FRANCE)Otavio Campoe (UNESP, BRAZIL ) Australian Crane Research FacilityDick Cooper (late), R. Rader, K. Goodall. Research Assistants: T. Shmueli, C. Fairweather, T. Fischer Funding: MTSRF,ARC (RIEF), CRC-TREMState Government – Premiers Dept. JCU (Program, MRG) , Discovery Centre.