River Red Gum Tree Size and Growth Data

These data were collected as part of the River Red Gum Ecological Thinning Trial.

Data were collected for eight tree size and growth parameters, as described below:

Tree Diameter at Breast Height: Within each 9 ha plot, 30 trees with >10 cm diameter at breast height (DBH) were randomly selected along a north–south transect in the centre of the plot and permanently marked. Where trees died, replacement trees of a similar DBH were subsequently marked and measured. The DBH of each tree was measured to the nearest mm six times over seven years.

Tree Crown Size: The crown size of each of the 30 permanently marked trees was measured three times over seven years. Crown size was measured by estimating the distance between the canopy edges in 2 perpendicular planes in metres.

Tree Crown Extent: The crown extent of each of the 30 permanently marked trees was measured six times over seven years. Crown extent is defined as the percentage of the potential crown that contains live foliage and was visually estimated to the nearest 5%.

Tree Mortality: Tree mortality was surveyed by assessing the living or dead status of 50 trees with ≥10 cm DBH along a north-south transect within a 2 ha subplot in each 9 ha plot. Dead trees were defined as those with no live foliage. Tree mortality was surveyed six times over seven years.

Large Trees: Large trees were surveyed by traversing a central 2 ha subplot in each 9 ha plot and measuring and recording all trees with a DBH of 80 cm or more. Surveys were conducted three times over seven years.

Hollow-bearing Trees: Hollow-bearing trees were surveyed by traversing a central 2 ha subplot in each 9 ha plot and visually assessing the presence of hollows in living and dead trees. Surveys were conducted three times over seven years.

Tree Size Classes: Tree size class distribution data were collected on ten 0.1 ha subplots per 9 ha plot. Within each subplot, each living tree >1.37 m in height was counted and allocated to a size class. Multi-stemmed trees were counted as a single individual, with data recorded for each stem. Size class data was surveyed in the 2021-22 survey year.

Coppice: New shoots (coppice regrowth, also known as resprouts) may emerge from cut stumps or pushed over saplings of Eucalyptus camaldulensis. Data on coppice regrowth following thinning were recorded in ten 0.1 ha subplots in each 9 ha plot in the 2021-22 survey year. The number of coppice stems >1.37 m in height emerging from stumps and pushed over or damaged saplings was recorded. Only recent coppice arising from stumps and saplings that resulted from the thinning trial were counted.

Further information is provided in the reference guide for each dataset.

Data for tree diameter, large trees, hollow-bearing trees, and tree size classes are not publicly available. Contact data.broker@environment.nsw.gov.au for more information.