Structural attributes of a forest fragment under climber management

This is a dataset containing structural attributes of a degraded edge of a tropical seasonal semideciduous forest fragment in the Atlantic Forest of southeastern Brazil. We collected data in 36 plots of approximately 45 m x 44 m each, of which 12 had undergone climber cutting (cutting), 12 climber cutting in combination with planting of native tree species’ seedlings (cutting+planting), and 12 plots had not been managed (control). Climber cutting was conducted on a yearly basis since 2014 and data on trees, saplings, and climbers were collected at different moments in time along an eight-year period. We calculated tree basal area (m2.ha-1) using the stem diameter at breast height (DBH) measured for each large living tree (DBH ≥ 4.8 cm), tree density (ind.ha-1) using the number of large living trees, and percentage of large dead trees in relation to large living trees. We then calculated tree sapling (DBH < 4.8 cm and total height ≥ 50 cm) density (ind.ha-1) using the number of saplings and sapling richness (number of species). Last, we calculated climber density (ind.ha-1) using the number of climbers longer than 1 m and climber basal area (m2.ha-1) using the stem diameter measured 1 m away from the rooting point. Data on saplings and climbers were collected in 3 m x 15 m subplots positioned at the centre of each of the 36 plots. In the datafile, we present the variable values per plot.

Methods
We collected data of forest structural attributes in 36 plots of approximately 45 m x 44 m each installed on the edge of two stretches of the Vassununga State Park (Parque Estadual de Vassununga - PEV) (47º34’58” S and 21º42’58” W), municipality of Santa Rita de Passa Quatro, southeastern Brazil. The vegetation is the submontane seasonal semideciduous forest, which belonging to the Brazilian Atlantic Forest domain, and the edge studied borders a high-traffic road (Departamento de Estradas e Rodagem, 2024). From 2014 to 2021, 24 plots underwent climber cutting (cutting) on a yearly basis (except for 2018), of which 12 additionally had seedlings of native tree species planted (cutting+planting); the remaining 12 plots were kept unmanaged (control).

The following data were collected in the 36 plots: stem diameter at breast height (DBH, measured at 1.3 m from the ground) of every living tree with DBH ≥ 4.8 cm (large trees hereafter) and number of large dead trees, both obtained after the plots were installed in 2014 and before management began, and again in 2015, 2016, and between October 2022 and July 2023. We used a 3 m x 15-m subplot positioned at the centre of each of the 36 plots to collect tree sapling (DBH < 4.8 cm and total height ≥ 50 cm) data, namely number of saplings and saplings’ taxonomic identification. We also collected data on climbers longer than 1 m in the subplots, namely number of climbers and climber’s stem diameter, measured 1 m away from the rooting point. Data on saplings and climbers were collected between November 2021 and February 2022.

We calculated the density.ha-1 in each plot for large living trees, saplings, and climbers at the different moments in time. We also calculated the basal area of large living trees and climbers separately: we first calculated the basal area of each individual as BAind = π(DBH²)/40,000 (Soares, Paula & Souza, 2012), summed the BAind in the same plot (BAplot) and then calculated the basal area in m2.ha-1 considering the size of each plot. Last, we calculated the percentage of large dead trees in relation to large living trees per plot as (number of large dead trees/number of large living trees)*100.

References:

Departamento de Estradas e Rodagem, Traffic statistics, 2024. Available at: http://200.144.30.103/vdm/SFCG_Concessionaria.asp?CodRodovia=SP%20330. Accessed on 03/13/2024.

Soares, C. P. B., de Paula Neto, F. & de Souza, A. L. (2006). Dendrometry and forest inventory. [Dendrometria e inventário florestal]. UFV.