WETFEET: Mangrove growth responses to warming across a latitudinal gradient.csv

In the southeastern US, Avicennia germinans (black mangrove) is encroaching poleward due to warming temperatures and a decrease in annual freee events. To understand how warming will continue to impact mangrove encroachment, we deployed open-top passive warming chambers at three sites along the northeast coast of Florida encompassed by the Guana Tolomato Matanzas National Estuarine Research Reserve. Mangrove height and canopy widths were measured in each of the 36 plots (3 sites x 2 treatments x 6 replicates) at the outset of the experiment in May 2018 and then again in November 2018 (6 months) and in May 2019 (1 year). Plant height was measured to the tallest branch. Canopy width was measured at the widest dimension and then again at the dimension perpendicular from the first measurement.

In each plot, two PVC rings were placed over existing salt marsh vegetation. In August 2018, we measured the height and number of stems (stem density) of each species present in the biomass rings. All biomass was then cut at the base for allometric measurements in the lab. This process was repeated in August 2019.

To assess belowground root biomass, we took 30cm soil cores from each plot using a gauge auger in May 2018 and again in May 2019. Cores were split into two sections; 0-15cm depth, and 15-30cm depth. Each section was washed free from sediment, and remaining root biomass was dried in a 60 degree C oven and weighed.