The FLUXNET2015 dataset provides ecosystem-scale data on CO 2 , water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their data to create global datasets. Data were quality controlled and processed using uniform methods, to improve consistency and intercomparability across sites. The dataset is already being used in a number of applications, including ecophysiology studies, remote sensing studies, and development of ecosystem and Earth system models. FLUXNET2015 includes derived-data products, such as gap-filled time series, ecosystem respiration and photosynthetic uptake estimates, estimation of uncertainties, and metadata about the measurements, presented for the first time in this paper. In addition, 206 of these sites are for the first time distributed under a Creative Commons (CC-BY 4.0) license. This paper details this enhanced dataset and the processing methods, now made available as open-source codes, making the dataset more accessible, transparent, and reproducible.

Southwest Western Australia (SWWA) has experienced a 15–20% reduction in rainfall since the 1970s with severe reductions in inflows to Perth drinking water reservoirs. To quantify rainfall and runoff patterns, we used trend and change point analyses for a 50 year record (1950–2008) and in the last two decades (1989–2008). From 1950–2008, trend tests showed significant declines in annual rainfall and runoff with corresponding change points for both rainfall and flow in the late 1960s or mid‐1970s. In the more recent record (1989–2008), runoff declined in the majority of catchments, but rainfall did not show a significant downward trend. Rather, streamflow decline was observed as a step change in response to the occurrence of below‐average rainfall years. A shift from perennial to ephemeral streams and a decline in the runoff coefficient (runoff/rainfall) in the last decade suggests a new hydrologic regime has developed with important implications for future surface water supply.

Abstract. OzFlux is the regional Australian and New Zealand flux tower network that aims to provide a continental-scale national research facility to monitor and assess trends, and improve predictions, of Australia's terrestrial biosphere and climate. This paper describes the evolution, design, and current status of OzFlux as well as provides an overview of data processing. We analyse measurements from all sites within the Australian portion of the OzFlux network and two sites from New Zealand. The response of the Australian biomes to climate was largely consistent with global studies except that Australian systems had a lower ecosystem water-use efficiency. Australian semi-arid/arid ecosystems are important because of their huge extent (70 %) and they have evolved with common moisture limitations. We also found that Australian ecosystems had a similar radiation-use efficiency per unit leaf area compared to global values that indicates a convergence toward a similar biochemical efficiency. The two New Zealand sites represented extremes in productivity for a moist temperate climate zone, with the grazed dairy farm site having the highest GPP of any OzFlux site (2620 gC m−2 yr−1) and the natural raised peat bog site having a very low GPP (820 gC m−2 yr−1). The paper discusses the utility of the flux data and the synergies between flux, remote sensing, and modelling. Lastly, the paper looks ahead at the future direction of the network and concludes that there has been a substantial contribution by OzFlux, and considerable opportunities remain to further advance our understanding of ecosystem response to disturbances, including drought, fire, land-use and land-cover change, land management, and climate change, which are relevant both nationally and internationally. It is suggested that a synergistic approach is required to address all of the spatial, ecological, human, and cultural challenges of managing the delicately balanced ecosystems in Australasia.

In this study we examine the hydrological processes that underpin non‐stationarity in hydrological prediction. This is achieved by analysis of linkages between rainfall, groundwater storage, and runoff in Southwest Western Australia (SWWA), a region experiencing stream flow decline since the mid‐1970s. We find a close connection between rainfall and changes in catchment groundwater storage, with increases in storage in years with annual rainfall above a threshold (1050–1400 mm), and declines during low rainfall years. Where groundwater is in contact with the stream bed, runoff, as a proportion of rainfall, is highly correlated with groundwater storage. Recent drought years have reduced groundwater storage and runoff ratio. In the absence of replenishing wetter years, lower runoff ratios are subsequently maintained. Runoff from a given depth of annual rainfall is now far lower than that produced 15 years ago. In this way groundwater storage acts as the catchment's “memory”. This study highlights the importance of catchment groundwater storage that may be used to improve runoff prediction in a drying climate.