Dataset from: Functional traits explain both seedling and adult plant spatial patterns in gypsum annual species

1. Ecological processes such as seed dispersal or plant–plant interactions
and environmental constraints such as climate or soil heterogeneity are
known to influence establishment, and thus the spatial patterns of plant
communities and populations. In this study, we hypothesized that key
functional traits such as the specific leaf area (SLA), reproductive ratio
(reproductive/vegetative biomass), seed mass, and maximum plant height
would influence the spatial patterns of individual species in annual,
gypsophilous plant communities, and that these effects would be modulated
by both the soil surface structure (biocrust) and climate (precipitation)
conditions. 2. We mapped the spatial patterns of all plants found in six 1
x 1 m plots (more than 1000 individuals per plot) in both the seedling
(autumn) and adult stages (spring) under two biocrust experimental
conditions (intact vs disturbed biocrust) during two consecutive years
which were contrasted in term of precipitation (dry year and wet year). To
assess the spatial patterns of seedlings and adults, we fitted four
different spatial point pattern models (i.e., Poisson, inhomogeneous
Poisson, Poisson cluster, and inhomogeneous Poisson cluster processes) to
each of the 242 populations of the 27 most abundant species that had more
than 15 individuals per plot. 3. Most seedling populations exhibited
clustered spatial patterns that persisted in the adult stage, which
suggests that short-distance dispersal is an adaptive trait for soil
specialists such as gypsophilous plants. One-third of the populations
fitted an inhomogeneous model best, but the physical structure of the
biocrust was not related to them. More importantly, we found a connection
between the functional strategies of species and the spatial distribution
of plants. In particular, during the dry year, irrespective of the
biocrust conditions, species with a high SLA and high Rep/Veg mainly
exhibited clustered spatial patterns, whereas low SLA and low Rep/Veg were
associated with random distributions. Species with heavy and light seed
masses had random and clustered patterns, respectively. In both the dry
and wet years, species with lower maximum heights had clustered patterns,
whereas taller species exhibited random patterns. In addition, species
with heavier seeds and greater maximum heights had the largest cluster
sizes. 4. Our results confirm that the spatial patterns of seedlings and
adult plants are significantly determined by the functional strategy of
each species.