Dataset DOI: 10.5061/dryad.z34tmpgsk

Description of the data and file structure

The dataset was collected in 2013 and 2021 from Kibale National Park, Uganda, East Africa. Vegetation surveys were done in a large-scale tropical forest restoration area (ca. 10,000 ha) in compartments that were planted between 1995 and 2017, and in old-growth forest (reference primary forest). Compartments that we surveyed were planted in 1995, 1999, 2000, 2005, 2007, 2008, 2011, and 2017 (2011 and 2017 were surveyed only in 2021). The area was previously encroached, and the forest was not able to regenerate naturally in parts of the deforested area. We studied how forest structure, tree community and diversity have started to recover along the chronosequence (55 study sites).

We used a nested plot design to record:
(1) large trees (20 x 40 m plot, diameter ar breast height (DBH) ≥ 20 cm),
(2) medium trees (20 x 20 m plot, DBH ≥ 10 and < 20 cm)
(3) small trees (20 x 10 m plot, DBH ≥ 5 and < 10 cm), and
(4) saplings (10 x 10 m plot, DBH < 5 cm; including seedlings).
Plots shared one corner. We identified each stem to the species or genus level (if possible) and measured the DBH of small, medium and large trees. We calculated the estimated total basal area (m2/ha), the estimated total stem density (stems/ha), the taxa richness (count of the total tree taxa per study site), and the community similarity of the study site to the mean community similarity of primary forests (%). In 2021, we also recorded the mean tree height (m), canopy cover (%), and understorey vegetation covers (%) of Acanthus pubescens, Lantana camara, Cenchurus purpureus and Marantochloa spp. from the 20 x 40 m plots.

Please, consult our conditionally accepted article, Korkiatupa et al. (2025) "Chronosequence resampling elucidates tree community and forest structure recovery patterns in restored tropical rainforest" Ecology and Evolution 15, no. 8: e72033. https://doi.org/10.1002/ece3.72033, for detailed description of the methods and analyses.

This file describes the datasets used in the above article.
The files consist of three .csv files containing:
(1) the tree community data (total estimated stem density / ha).
(2) univariable data for each study site (forest structure and diversity variables, and metadata of the study sites)
(3) DBH data for planted trees.
The methods used for obtaining the data, the analyses, and the terminology used in the data files are described in detail in the article (https://doi.org/10.1002/ece3.72033).

Files and variables

File: planted_trees_DBH.csv

Description: In each study plot (site), we recorded if the stem was planted (located in 5x5m grid) or not (located outside the grid or the planting status was not clear). This file has record of all the planted tree stems and their diameter at brest height (DBH) in cm. Please consult our paper for detailed definitions of the terms and methods used.

Variables

• Studysite: The code of the study site.
• PLANTING_YEAR: A year when restoration planting with native trees occurred. Planting years were 1995, 1999, 2000, 2005, 2007, 2008, 2011, and 2017.
• Survey_time: A year (2013 or 2021) when the vegetation survey was conducted.
• Species: Recorded species or genus.
• DBH_cm: Diamerer at breast height in centimeters: measured 1.3 m up from the highest point of ground at the tree's base.

File: tree_univariables.csv

Description: Metadata of the study sites, as well as forest structure and diversity variables for each study site. Please consult our paper for detailed definitions of the terms and methods used.

Variables

• studysite: The code of the study site. "_old" ending = 2013 data. Wihtout ending = 2021 data.
• study_site_code: The code of the study site.
• Latitude: Study site's latitude.
• Longitude: Study site's longitude.
• dist_to_PF: Distance to nearest border of primary forest (m) from each study site.
• elevation: Study site's elevation (m) derived from digital elevation model in QGIS
• group: Grouping used for our study sites: young = younger restored (planted in 2011, 2012), mid = intermediate restored (planted in 2005, 2007, 2008), old = older restored (planted in 1995, 1999, 2000), primary = primary forest.
• Plantingyear: The year when restoration planting occured. Planting years were 1995, 1999, 2000, 2005, 2007, 2008, 2011, and 2017. For primary forests the value is "primary_forest".
• Survey_time: The year (2013 or 2021) when the vegetation survey was done.
• Age: Forest age since planting during the survey year. For primary forest we gave an arbitrary age of 150, since they have not experianced any disturbances at least for ca. 150 years.
• canopy_cover: The mean canopy cover (%) based on five measurements per plot. Measured from the four corners and center of the plot.
• mean_height_m: The mean tree height (meters) based on three measurments of planted trees per plot (in restored sites) or litterature based mean of the height of the primary forest.
• restored_or_primary_forest: The status, i.e., restored or not, of the study site.
• Acanthus_pubescens: The vegetation cover estimation of Acanthus pubescens (%) in 40x20m plot.
• Lantana_camara: The vegetation cover estimation of Lantana camara (%) in 40x20m plot.
• Marantochloa: The vegetation cover estimation of Marantochloa ssp. (%) in 40x20m plot.
• Cenchurus_purpureus: The vegetation cover estimation of Cenhchurus purureus (%) in 40x20m plot.
• BA_ha: The total estimated basal area (m2/ha).
• Stems_ha: The total estimated stem density (stems/ha)
• total_n_taxa: The taxa richness, i.e., count of the total tree taxa per plot.
• simtoPF: The community similarity of the study site to the mean community similarity of primary forests.

Missing data codes: NA (data not available).

File: tree_community_data_estimated_stems_ha.csv

Description: Tree community data. Rows present the study sites and columns present the species, genus or unidentified species. The nomenculture of the taxa uses KEW's Plants of the World Online database (https://powo.science.kew.org/). The values are total estimated stem density (stems/ha) for each taxon in each study site. Please consult our paper for detailed definitions of the terms and methods used.

Variables

• studysite: The code of study sites in the 2013 (with "_2013" ending in the code) and the 2021 (without ending) survey times.
• Species names in columns: First comes all taxa that has been identified to species or genus level. At the end is five unidentified species. Unidentified tree species were listed as “Unknown 1”, “Unknown 2”, etc., for each study site, which means that Unknown1 in one study site could be a different plant species in other study site.

Code/software

The .csv files can be viewed with any spreadsheet program.