Inbreeding depression affects the growth of seedlings of an African timber species with a mixed mating reproductive system, Pericopsis elata (Harms) Meeuwen

Selfing or mating between related individuals can lead to inbreeding depression (ID), which can influence the survival, growth and evolution of populations of tree species. As selective logging involves a decrease in the density of congeneric partners, it could lead to increasing biparental inbreeding or self-fertilization, exposing the population to higher ID. We assessed the influence of inbreeding on the growth of a commercial timber species, Pericopsis elata (Fabaceae), which produced about 54% of self-fertilized seedlings in a natural population of the Congo basin. We followed the survival and growth of 540 plants raised in a plantation along a gradient of plant density (0.07 to 15.9 plants per m2). Parentage analysis allowed us distinguishing selfed and outcrossed seedlings. The annual growth was higher for outcrossed than selfed plants, on average by 10.8% for diameter and 12.9% for height growth. Based on the difference in above ground biomass between selfed and outcrossed seedl..., Seeds were harvested between 17 September and 12 December 2016 in the 400 ha plot of Biaro forest, where all 196 Pericopsis elata trees (diameter at breast height ≥ 10 cm) had been inventoried. Seed trees were retained only if they produced mature seeds and were sufficiently isolated to avoid any confusion of seed provenance (19 seed trees eventually contributed to the seed pool used). One week after harvesting, seeds were sowed in polyethylene bags containing soil with natural manure, and an ID label indicating the seed tree. The nursery was located next to the botanical garden of the Science Faculty campus of the University of Kisangani (DR Congo), under mild shading. After germination, we randomized the positions of the seedlings in the nursery and followed their growth for one year before transplantation.
We installed three plantation trials in October 2017 according to the design Ia proposed by Nelder (1962), whereby plants are located along a set of concentric circles ensuring a g..., , # Inbreeding depression affects the growth of seedlings of an African timber species with a mixed mating reproductive system, *Pericopsis elata* (Harms) Meeuwen

[https://doi.org/10.5061/dryad.xwdbrv1nv](https://doi.org/10.5061/dryad.xwdbrv1nv)

This dataset contains data on the monitoring of seedlings of *Pericopsis elata*, a timber species from the African tropical zone, planted in the Nelder design in Kisangani, DR Congo. It includes diameter and height measurements of 540 seedlings planted in October 2017 and measured every 3 months until 2021. Each seedling was genotyped to distinguish outcrossed and selfed seedlings.

## Description of the data and file structure

The database (Angbonda_et_al._2024.xlsx) contains the numbers of each Nelder design (Nelder replicate; the words in brackets are the name of the column in the sheet), of each mother tree (Mother tree) that produced the seedlings, the number of each seedling (Num_plant) and the position of each seedling on the design with...