Tackling local ecological homogeneity: Finding intraspecific trait variability in local populations of Mediterranean plants

Local homogeneity, in ecology, is the often undisclosed assumption that variability within populations is negligible or mostly distributed evenly. In large areas, this can lead to the aggregation of different populations without regard for their unique needs and characteristics, such as drought sensitivity and functional traits distributions. Here we discuss whether this assumption can be justified, and we hypothesize that discerning the source of variation between plasticity and adaptation could be a feasible approach to formulate an informed decision. We test this hypothesis on plants, resorting to a common garden experiment to determine the source of variation of several plant functional traits at a local scale (~60 Km) of three wild species: Quercus ilex, Pistacia lentiscus and Cistus salviifolius. Individuals of each species were sourced from three key sites chosen along a local aridity gradient. Our approach led to the rejection of the local homogeneity assumption for Q. ilex and ..., This data were obtained over the course of two sampling campaigns.
The first campaign happened in June-August 2021 in situ, as samples were collected directly from adult individuals from three populations of the Latium region in central Italy, namely Castel Fusano (41°43'23.6\" N, 12°19'55.7\" E), La Farnesiana (42°11'38.9\" N, 11°52'33.1\" E) and Tivoli (41°57'51.5\" N, 12°48'54.9\" E).
The second campaign happened in June-August 2022 ex situ, as measurements were obtained from seedlings grown in a common garden from seeds collected at the original provenance sites.
We followed the same standard procedures described by Perez-Harguindeguy et al. (2016), \"Corrigendum to: New handbook for standardised measurement of plant functional traits worldwide.\" (Australian Journal of botany, 64(8), 715-716), to directly measure plant height (H), fresh leaf area (LA), and leaf thickness (LT). Leaf mass was measured at collection (FM), after 48h at 5 °C in the dark (SM) and after being kept at 90 °C until ..., , # Tackling local ecological homogeneity: finding intraspecific trait variability in local populations of Mediterranean plants

[https://doi.org/10.5061/dryad.hqbzkh1nv](https://doi.org/10.5061/dryad.hqbzkh1nv)

The dataset contains several plant functional traits from three populations of *Quercus ilex*, *Pistacia lentiscus* and *Cistus salviifolius* obtained both *in situ* and *ex situ*, from seedlings cultivated in a common garden. The included trait are total plant height (H), leaf mass per area (LMA), leaf dry matter content (LDMC), leaf tissue density (LTD), stomatal density (SD) and stomatal area index (SAI).
Traits were used to determine whether the intraspecific variability observed between the populations in situ would be inherited by seedlings cultivated *ex situ* in common conditions. Our results show significant variations for at least one trait between populations of *Q. ilex* and *C. salviifolius* but not *P. lentiscus* ex situ, and significant variations between populatio...