Dataset for: Population decline in a Pleistocene refugium: stepwise, drought-related dieback of a South Australian eucalypt

Refugia can facilitate the persistence of species through long-term environmental change, but it is not clear if Pleistocene refugia will remain functional under anthropogenic climate change. Dieback of species within refugia therefore raises concerns about their long-term persistence. Using repeat field surveys, we investigate dieback patterns of an isolated population of Eucalyptus macrorhyncha during two droughts and discuss prospects for its continued persistence in a Pleistocene refugium. We first confirm that the Clare Valley in South Australia has constituted a long-term refugium for the species, with the population being genetically highly distinct from other conspecific populations. However, the population lost >40% of individuals and biomass through the two droughts, with mortality being just below 20% after the Millennium Drought (2000–2009) and almost 25% after the Big Dry (2017-2019). The best predictors of mortality differed after each drought. While the north-facing as..., The data contains three datasets derived from analysing data from multiple surveys of a red stringybark population (Eucalyptus macrorhyncha) in Spring Gully Conservation Park (SGCP), Clare Valley, Australia. These are the Tree Health Index (THI), Biomass and Drivers datasets, which are used in the analyses of the associated paper. Below I explain how each dataset was obtained.
The South Australian Department of Environment and Water (DEW) initiated a tree health monitoring program in 2009, during which four North-South oriented transects were established in SGCP. Each transect (between 1.2 and 1.8 km long) had sampling sites every 50 m. At each sampling site, the four closest canopy trees within a 10 m radius were marked with a permanent aluminum tag, their location recorded with a handheld GPS (brand and model unknown), and various measurements relating to their health status taken (see below). In total, 471 trees were surveyed, 30 of which were South Australian blue gums (Eucalyptus l..., , # Dataset for: \"Population decline in a Pleistocene refugium: stepwise, drought-related dieback of a South Australian eucalypt\"

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The data contains three datasets derived from analysing data from multiple surveys of a red stringybark population (*Eucalyptus macrorhyncha*) in Spring Gully Conservation Park (SGCP), Clare Valley, Australia. These are the Tree Health Index (THI), Biomass and Drivers datasets, which are used in the analyses of the associated paper. The Methods section under 'Data Description' explains how each dataset was obtained.

## Description of the Data and file structure

**Biomass dataset**: Excel spreadsheet with 3 sheets (formulas have been retained).

* Sheet 1: for each surveyed stem it has the ID number applied to the site, tree and stem and the following information: treeDead (is the tree dead (d) or alive (a), stemDead (is the stem dead (d) or alive (a), D (diameter at breast height, in cm), H (tree height, in m), and estimates of wood density (WD) and abo...