Mangrove above-ground biomass and production are related to forest age at Low Isles, Great Barrier Reef

Above-ground biomass contributes a large proportion of mangrove carbon stock; however, spatio-temporal dynamics of biomass are poorly understood in carbonate settings of the Southern Hemisphere. This influences capacity to accurately project the effects of accelerating sea-level rise on this important carbon store. Here, above-ground biomass and productivity dynamics were quantified across mangrove age zones dominated by Rhizophora stylosa, spanning a tidal gradient atop a reef platform at Low Isles, Great Barrier Reef, Australia. Above-ground biomass was extrapolated across the forest using field plot data, allometry, a canopy height model derived from remotely piloted aircraft (RPA) LiDAR and regression analyses. Above-ground biomass production was calculated as mean annual biomass increments and canopy production was determined using RPA-derived multispectral imagery and a Normalised Difference Vegetation Index. Mangrove above-ground biomass was estimated at 519.7 ± 3.11 t ha-1 ..., Collection and analysis of field data
A total of 18 field plots (10 × 10 m) were established in the *R. stylosa-*dominant forest to collect tree measurements. Plots were positioned to span mangrove age zones and varying forest structures, assessed using historic mapping and field observations, respectively. Plots 1A–D and 2A–D are positioned in the 1848–1928 forest and plot 3 are in the 1928–1945 forest but close to the margin of the 1945–1973 forest. Plots 4A–D are in the 1945–1973 forest but also overlap with the 1973–2012 forest. Plots 5A and 5B are in the 1945–1973 forest and plots 6, 7 and 8 are in the 1973–2012 forest.
To calculate field plot AGB, tree trunk circumference at breast height (at 1.3 m) was measured and converted to DBH (cm). If trees were multi-stemmed, each stem was treated as a separate tree. For leaning trees, DBH was measured at 1.3 m along the natural height of the trunk, or above the highest prop root when this arose from the stem at a height above 1.3 m and th..., # Data from: Mangrove above-ground biomass and production are related to forest age at Low Isles, Great Barrier Reef

Dataset DOI: [10.5061/dryad.5tb2rbpfg](10.5061/dryad.5tb2rbpfg)

## Description of the data and file structure

### Files and variables

#### File: AGB_89_calib_logistic_t.tif

**Description:** AGB model of the mangrove forest at 10 m resolution, developed using field plot data, CHM from LiDAR (Matrice 300 RTK Zenmuse L1, 2023) and logistic regression (detailed in manuscript).

#### File: LI_CHM_filled_10m_pos_calib.tif

**Description:**  Canopy height model (CHM) at 10 m resolution, clipped to the mangrove extent. Calibration of the CHM was performed by linear regression analysis between field plot mean tree height where all tree heights were measured (n = 7) and the corresponding CHM pixel value to improve accuracy of the models. 

#### File: LowIsles_DEM_10m_clip.tif

**Description:**  Digital elevation model (DEM) LiDAR (Matrice 300 RTK Zenmuse L1, 2023) at 10 m reso...,