Carbon and Water fluxes in a tropical lowland rainforest in Far North Queensland

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1 Insert your logo here Carbon and Water fluxes in a tropical lowland rainforest in Far North Queensland Presented by : Associate Professor Mike Liddell James Cook University michael.liddell@jcu.edu.au ph:

2 DAINTREE OZFLUX SITES Pristine lowland rainforest at both stations. Elevation: m Complex Type 1A mesophyll vine forest (cyclone scrub) Canopy height 25-35m Stems/ha 700 (10cm dbh) Species Leaf area index 4 T mean : 24 o C (daily min-max o C) Rainfall: 5730mm Daintree Rainforest Observatory (Australian Canopy Crane) Daintree Tower

3 DAINTREE TOWER TERN Ozflux Standard system. Running since December 2008.

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5 DAINTREE RAINFOREST OBSERVATORY Cape Tribulation Ozflux station. Australian Canopy Crane Running since December TERN Ozflux Standard system since March 2012.

6 MONITORING OZFLUX SITES Real time monitoring.

7 FNQ SUPERSITE OZFLUX SITES THE RELEVANCE OF LOCATIONS Regional Ecosystem (1:25 000) BVG (1:1 million) BVG (1:2 million) BVG (1:5 million) Robson Creek upland Daintree Rainforest upland 340 ha [7.3.36a] 4,000 ha [7.3.17] 30,000 ha [1b:CMVF-NVF on Tablelands] 30,000 ha [1a: CMVF-NVF in very wet locations] 60,000 ha [complex mesophyll to notophyll vine forests] 700,000 ha [type 1: rainforests, scrub] Vertebrate fauna : 28% Native flora : 10% Landmass : 0.2%

8 FUTURE CLIMATE High-end (90th percentile) projected increases in seasonal average T(ºC) and rainfall under high (SRES A1FI) emissions scenarios for (Source: CSIRO CMAR Suppiah 2010) Month JFM AMJ JASO ND

9 DAINTREE OZFLUX SITES Season Rainfall changes (mm/day) from downscaled simulations from the Mk 3.5 GCM to a 14km grid. (Source: Suppiah 2010)

10 Flux Carbon Gap Filled ( mol m -2 s -1 ) CARBON FLUXES AND DRIVERS Daintree Tower Rainfall, solar radiation and temperature are the big drivers of the carbon fluxes. The drought of 2002, 2003 reduced the photosynthetic output of the forest DRO Tower Photosynthesis Time (hrs) FC_WPL ( mol m -2 s -1 ) FLUX 2001 FLUX 2002 FLUX 2003 FLUX 2004 FLUX 2005 FLUX Time (30min intervals) X Axis The wet year of 2010 influenced both respiration and photosynthesis.

11 CARBON AND WATER FLUXES PAR and temperature have strong seasonal trends Hour Hour DRO (Crane) 12 Discovery Tower Day of Year FC_WPL (mmol m-2 s -1) LE_WPL (W m -2 ) DOY

12 Jan 7-Feb 27-Feb 19-Mar 8-Apr 28-Apr 18-May 7-Jun 27-Jun 17-Jul 6-Aug 26-Aug 15-Sep 5-Oct 25-Oct 14-Nov 4-Dec 24-Dec Daily Precipidation (mm) RAINFALL THE BIG DRIVER This is a seasonally dry tropical rainforest. But... it is at the wet end of lowland rainforests. This is the BOM data, the DRO is much wetter (around 1.5m) and it is 1.5km away! Y Axis Mean D N O S A J J X Axis M A M J F Mean 2011

13 20/9/07 27/9/07 4/10/07 11/10/07 18/10/07 25/10/07 1/11/07 8/11/07 15/11/07 22/11/07 29/11/07 6/12/07 13/12/07 17/12/07 24/12/07 Soil water content (m3/m3) Rainfall (mm/hour) SUB-SURFACE WATER STORAGE Water storage m (mean) 0.75 m (mean) 1.5 m (mean) Rain Sensors: Temperature (thermocouple) Water content (TDR probes) Water potential (Gypsum blocks)

14 8/04/ /04/2008 6/05/ /05/2008 3/06/ /06/2008 1/07/ /07/ /07/ /08/ /08/2008 9/09/ /09/2008 7/10/ /10/2008 4/11/2008 Daily change in water content (m3/m3) Soil profile water content (mm) WATER UPTAKE vs DEPTH Wet soil: Greatest water extraction 900 from topsoil (most negative change in water content) m 0.75 m 1.5 m Soil profile Dry soil: 500 Least water extraction from topsoil

15 Depth to water table (mm) GROUNDWATER Installed 3 bores to measure uptake from groundwater Bedrock at m depth Very little variation in depth to watertable at the end of the Water table dry season /09/ /10/2011 7/01/2012 Date

16 BIOMETRIC BALANCE We are looking at the change in the above-ground tree biomass AGB. There have been 3 census intervals 2000, 2005, In addition dendrometer bands have been placed on 270 trees. During the census period the forest has increased in AGB by 9.1 t/ha.

17 AGB increase Species specific allometric equations have been developed along with general species equations allowing calculation of site biomass = 271 t ha e+5 2.0e+5 1.5e+5 1.0e+5 5.0e Apocynaceae Lauraceae Meliaceae Myrtaceae Family Proteaceae ALLOMETRY Sterculiaceae Detailed measurements of crown dimensions allows the forest architecture to be monitored quantitatively crown height [m]

18 Total dry litter (t/ha/mo) CARBON IN PLOTS Other components of the biomass flux are measured such as fine leaf litter. Turnover around 3%of AGB/yr. Water is not a major driver of changes in this flux. Unless there are drought conditions. Instead the main driver is wind events Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec LIDAR surveys have been carried out.

19 QUANTIFYING AQUATIC CARBON FLUX How much dissolved and particulate carbon (DOC &POC) are transported from wet-dry rainforest at the Daintree Rainforest Observatory? (ph, turbidity, temp, conductivity) STARFLOW (depth, velocity) (DOC &POC)

20 DISCHARGE EFFECT ON THE SOURCE OF DOC molar C:N Preliminary data shows molar C:N and δ 13 C DOC increase with increasing discharge. This suggests during flood events organic carbon from the surface soil layers is mobilised and dominates export. During low flow groundwater export dominates C DOC Discharge (L/s)

21 ACKNOWLEDGEMENTS Nico Weigand (JCU) David Blake (JCU) Cassandra Nichols (JCU ACCRF) Nicolas Nieullet (ENGREF, FRANCE) Otavio Campoe (UNESP, BRAZIL ) Prof Michael Bird (JCU EES) Dr Paul Nelson (JCU EES) Australian Crane Research Facility Dick Cooper (late), R. Rader, K. Goodall, P. Byrnes Funding: DIISRTE (EIF), DEEDI (Qld), Discovery Centre, MTSRF, ARC (RIEF), CRC-TREM Qld Premiers Dept., JCU (Program, MRG),