1. Passively regenerating native vegetation presents a cost-effective opportunity to sequester carbon and reinstate habitat in heavily cleared agricultural landscapes.

2. However, in some cases a few woody species recolonise in dense, low-diversity stands that are slow to self-thin.

3. Restoration thinning of over-dominant species has been proposed to accelerate ecosystem recovery, but its longer-term efficacy remains uncertain, and is likely to depend strongly on rainfall.

4. This study focuses on a restoration thinning experiment established in 2007 in dense brigalow (Acacia harpophylla) regrowth in Queensland, Australia. Using variation in rainfall between 2007 and 2017, we examined the interactive effects of neighbourhood density and moisture availability on the growth and survival of A. harpophylla.

5. We also compared the strength of A. harpophylla density effects on itself to its effects on a sparsely distributed co-occurring tree species (Casuarina cristata) that was codominant in the original forest.

6. Our results provide clear evidence that thinning permits A. harpophylla to grow rapidly during periods of high rainfall, and that interspecific competition between A. harpophylla and C. cristata is relatively weak. As such, thinning of dense A. harpophylla could be combined with seeding or planting of co-occurring tree species with complementary niches to further accelerate forest recovery in this extensive regrowth ecosystem.

See Towers, I. R. & Dwyer, J. M. (2020). Restoration thinning permits stems to capitalise on high-rainfall years in a regenerating endangered forest ecosystem. Ecological Solutions and Evidence for methods.

Brig_growth_2020.Rproj - R project file, open first before opening brig_growth_model_2020_revised.R
brig_growth_model_2020_revised.R - R code used for analyses

Data/ - contains all datafiles

all_brig_and_others_2015_no_multis.csv - measurements of stem diameter (including multiple diameters per individual if joined below-ground)
and spatial position in coordinates in 2007 and 2015 for all woody stems > 1.5 cm in established 
quadrats and adjacent remnant

Bulli_daily_climate.csv - Daily climate informaiton for Bulli weather station from end of 2006 to 2017

stem_growth_bottom_2017 - Circumference measurements of focal A. harpophylla stems from 2007 to 2017 and survival recors

Outputs/ - contains outputs from R code, will be saved there automatically via the Rproj file.

R/ - contains R_functions.R, R functions written specifically for this project, accessed by the Rproj file.