Cape Tribulation Flux Data Release 2024_v1 

This release consists of flux tower measurements of the exchange of energy and mass between the surface and the atmospheric boundary-layer using eddy covariance techniques. Data were processed using PyFluxPro (v3.4.15) as described by Isaac et al. (2017). PyFluxPro produces a final, gap-filled product with Net Ecosystem Exchange (NEE) partitioned into Gross Primary Productivity (GPP) and Ecosystem Respiration (ER).

The Cape Tribulation flux station was located in the land that is adjacent to the Daintree National Park which is part of the Wet Tropics World Heritage Area (WTWHA). The site is flanked to the west by coastal ranges rising to more than 1400 m and to the east by the Coral Sea. The red clay loam podzolic soils are of metamorphic origin and have good drainage characteristics. The metamorphic rocks grade into granite boulders along Thompson Creek which runs along the northern boundary of the site. The crane site itself is gently sloping but the fetch area makes the site one of very complex terrain. The forest is classed as complex mesophyll vine forest (type 1a) and has an average canopy height of 25m. The dominant canopy trees belong to the Apocynaceae, Arecaceae, Euphorbiaceae, Lauraceae, Meliaceae, Myristicaceae and Myrtaceae families. The forest is continuous for several kilometres around the crane except for an area 300 m due east of the crane, which is regrowth forest. Annual average rainfall at the site is around 5180 mm and is strongly seasonal, with 66% falling between January and April (wet season). Mean daily temperature ranges from 26.6 °C in February to 21.2 °C in July.

Tropical cyclones are a frequent occurrence in Far North Queensland. These severe tropical storm systems are natural phenomena which play a major role in determining the ecology of Queensland's tropical lowland rainforests. In March 1999 Tropical Cyclone Rona (Category 3) passed over the Cape Tribulation area causing widespread damage (gusts >170 km/h). At the site several large trees fell, nearly all of the remaining trees were stripped of leaves and the lianas towers were torn to ground level.

The flux station was mounted at the 45 m level on the tower of the Australian Canopy Crane external link. The canopy crane is a Liebherr 91 EC, freestanding construction tower crane. The crane is 48.5 m tall with a radius of 55 m enabling access to 1 hectare of rainforest. Fluxes of heat, water vapour and carbon dioxide were measured using the open-path eddy covariance technique. Supplementary measurements above the canopy included temperature, humidity, rainfall, total solar; these measurements have continued post the flux system decommissioning. Heat flux, soil temperature and water content (time domain reflectometry) were measured in proximity to the flux station; these measurements have continued post the flux system decommissioning. Detailed biometric measurements are made at the crane site and all trees have regular (5 yearly) dbh measurements and canopy mapping carried out. Monitoring bores (3) are located on site. Leaf litter measurements are carried out on a monthly basis. 

We at TERN acknowledge the Traditional Owners and Custodians throughout Australia, New Zealand and all nations. We honour their profound connections to land, water, biodiversity and culture and pay our respects to their Elders past, present and emerging.
The Cape Tribulation flux station is managed by the James Cook University as part of the TERN (DIISR funded) FNQ Rainforest Supersite. Equipment was provided by grants from the ARC external link (RIEFP) and JCU.
Past support was from the Rainforest CRC and Department of Environment and Heritage - Marine and Tropical Sciences Research Facility Project 5ii.2. Climate Change: Scaling from trees to ecosystems. 

The purpose of the Cape Tribulation flux station is to:

• measure exchanges of carbon dioxide, water vapour and energy between the tropical rainforest and the atmosphere using micrometeorological techniques
• quantify the changes in carbon and energy balances of an Australian tropical rainforest during the course of post-cyclone canopy recovery. Closely linked to the micrometeorological ecosystem-level studies are leaf-level studies of the major tree and liana species at the site (Dr Owen Atkin, ANU; Dr Peter Hietz, Vienna) and water balance and soil carbon studies (Drs P. Nelson, Marc Le Blanc, JCU)
• recommend management strategies for the conservation of carbon stores in tropical rainforest ecosystems that are subject to relatively frequent cyclone disturbance.

 

All flux raw data is subject to the quality control process OzFlux QA/QC to generate data from L1 to L6. Levels 3 to 6 are available for re-use. Datasets contain Quality Controls flags which will indicate when data quality is poor and has been filled from alternative sources. For more details, refer to Isaac et al. (2017).