Warra Flux Data Release 2021_v1 

This data release consists of flux tower measurements of the exchange of energy and mass between the surface and the atmospheric boundary-layer in semi-arid eucalypt woodland using eddy covariance techniques. It been processed using PyFluxPro (v3.3.0) as described in Isaac et al. (2017), https://doi.org/10.5194/bg-14-2903-2017. PyFluxPro takes data recorded at the flux tower and process this data to a final, gap-filled product with Net Ecosystem Exchange (NEE) partitioned into Gross Primary Productivity (GPP) and Ecosystem Respiration (ER). For more information about the processing levels, see https://github.com/OzFlux/PyFluxPro/wiki.

Eucalyptus obliqua forests dominate the vegetation below 650 m where they exist as fire-maintained communities. On fertile soils these forests attain mature heights in excess of 55m: the tallest E. obliquareaches a height of 90m. The flux station is installed in a stand of tall, mixed-aged E. obliqua forest (77 and >250 years-old) with a rainforest understorey and a dense man-fern (Dicksonia antarctica) ground-layer, on a small flat of elevation 100 m adjacent to the Huon River. The understorey vegetation progresses from wet sclerophyll (dominated by Pomaderris apatala and Acacia dealbata) to rainforest (dominated by Nothofagus cunninghamii, Atherosperma moschatum, Eucryphia lucida and Phyllocladus aspleniifolius) with increasing time intervals between fire events. The site supports prodigous quantities of coarse woody debris as is characteristic of these fire-maintained eucalypt forests on fertile sites in southern Tasmania.
The soil at the flux site is derived from Permian mudstone and has a gradational profile with a dark brown organic clayey silt topsoil overlying a yellow brown clay.
The climate of Warra is classified as temperate with a mild summer and no dry season. Mean annual precipitation is 1700 mm with a relatively uniform seasonal distribution. Summer temperatures peak in January (min. 8.4°C – max 19.2°C) with winter temperatures reaching their lowest in July (min 2.6°C – max 8.4°C).

The instruments are mounted at the top of an 80m tall guyed steel lattice tower. Supplementary measurements above the canopy include temperature, humidity, windspeed, wind direction, rainfall, incoming and reflected shortwave radiation and net radiation. An open-path gas analyser (EC150) was replaced by a closed-path gas analyser (EC155) at the end of Jan 2015.Soil moisture content is measured using Time Domain Reflectometry, while soil heat fluxes and temperature are also measured. Micro-meteorology (CO₂, H₂O, energy fluxes), meteorology (temp, humidity, wind speed and direction, rainfall) taken from the Warra Flux Site from 2013 to late 2016. Data incomplete due to ongoing problems since changing the open-path IRGA to a closed path system (CPEC200) during 2015. Soil data (moisture, heat flux, temp) complete for time period. For additional site information, see https://www.tern.org.au/tern-observatory/tern-ecosystem-processes/warra-tall-eucalypt-supersite/ . 

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 site is managed by the University of Tasmania and funded by TERN. 

The purpose of the Warra flux station is:
to study the ecophysiological processes and rates of C accumulation and decomposition in a mixed-aged, tall, wet Eucalyptus obliqua forest originating from past natual wildfires
to measure the exchanges of carbon dioxide, water vapour and energy between the forest and the atmosphere using micrometeorological techniques
to link ecophysiological processes and rates of C accumulations and decomposition with the biota.
to utilize the measurements in combination with remote sensing data and land surface models to upscale estimate the net exchanges of carbon and water at regional scale. 

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) in the Publications section, https://doi.org/10.5194/bg-14-2903-2017 .