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 as described by Isaac et al. (2017) for the quality control and post-processing steps. The final, gap-filled product containing Net Ecosystem Exchange (NEE) partitioned into Gross Primary Productivity (GPP) and Ecosystem Respiration (ER) has been produced using the ONEFlux software as described in Pastorello et al. (2020). This data set has been produced as part of the FLUXNET Shuttle project. The Tumbarumba flux station is located in the Bago State forest in south eastern New South Wales (GPS coordinates: -35.6566, 148.1517)
The forest is classified as wet sclerophyll, the dominant species is alpine ash (Eucalyptus delegatensis), and average tree height is 40m. Elevation of the site is 1200m and mean annual precipitation is 1000mm. The Bago and Maragle State Forests are adjacent to the south west slopes of southern New South Wales and the 48,400 ha of native forest have been managed for wood production for over 100 years.
The instrument mast is 70m tall. Fluxes of heat, water vapour and carbon dioxide are measured using the open-path eddy flux technique. Supplementary measurements above the canopy include temperature, humidity, wind speed, wind direction, rainfall, incoming and reflected shortwave radiation and net radiation. Profiles of temperature, humidity and CO2 are measured at seven levels within the canopy. Soil moisture content is measured using Time Domain reflectometry, while soil heat fluxes and temperature are also measured. Hyperspectral radiometric measurements are being used to determine canopy leaf-level properties. Bushfire Disturbance
On New Year's Eve 2019 (31/12/2019) a bushfire swept through the Bago State Forest with a moderate severity burn (full understorey consumption but no canopy consumption). Prior to the fire, the forest had been growing without major disturbance over a period of almost 40 years, enabling study of its response to ongoing smaller disturbances such as insect outbreaks, droughts, normal weather fluctuations and internal stand dynamics.
The regrowth forest is structurally and functionally different to pre-fire conditions. The fast ground-fire caused nearly 100% mortality of the ash tree species, where the mountain gum (Eucalyptus dalrympleana) species resprouted with epicormic growth. There are high levels of ash regenerating from seedlings and other eucalypt trees (mountain gum and peppermint) are rapidly re-sprouting. There were around 10 months of data gap after the fire.
Credit
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.
Purpose
The purpose of the Tumbarumba flux station is: - to study the ecophysiological processes and rates of C accumulation of a commercially important, high-productivity forest - to measure the exchanges of carbon dioxide, water vapour and energy between the forest and the atmosphere using micrometeorological techniques - to develop new data analysis and interpretation methods for micrometeorology in complex terrain. This work will contribute significantly to the discipline of micrometeorology since much of the world's forests are located in complex terrain, where classical techniques may not be suitable - to utilize the ecophysiological and micrometeorological measurements to test models of plant and canopy function, such as the acclimation of photosynthetic capacity to temperature variations with season and the response of stomata to drought - to utilize the measurements to test land surface models such as the Community Atmosphere Biosphere Land Exchange model CABLE - 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.
Lineage
Data collected using standard eddy covariance and meteorological instrumentation on a 70m tower at the Tumbarumba 1 site. The data were quality controlled using the PyFluxPro software package, see Isaac et al (2017), which is available at
https://github.com/OzFlux/PyFluxPro. Gap filling and partitioning has been done using the ONEFlux software package, see Pastorello et al 2020, which is available at
https://github.com/fluxnet/ONEFlux.
Procedure Steps1.
Data is measured using standard micro-meteorological instrumentation on a flux tower.
2.
Data is recorded on a data logger and is collected by the site PI.
3.
Data quality control including removal of data outside plausible ranges, removal of spikes, exclusion of particular date ranges and removal of data based on the dependence of one variable on another is done using PyFluxPro.
4.
Filtering for low-ustar conditions, gap filling and partitioning of NEE into GPP and ER are done using ONEFlux.