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...生态学中的局部同质性（Local homogeneity）是一种常未被明确阐释的假设，即种群内部的变异可忽略不计，或大致呈均匀分布。在大尺度区域中，该假设会导致对不同种群进行聚合分析时，忽视其独特的生存需求与特征，例如干旱敏感性与功能性状分布格局。 本研究探讨该假设是否成立，并提出假说：区分表型可塑性（plasticity）与适应性（adaptation）的变异来源，可为该假设的验证提供可行路径。我们以植物为研究对象，借助同质园实验（common garden experiment），在约60千米的局域尺度上，探究冬青栎（Quercus ilex）、乳香黄连木（Pistacia lentiscus）和岩蔷薇（Cistus salviifolius）这3个野生物种的多种植物功能性状（plant functional traits）的变异来源。每个物种的个体均采自沿局域干旱梯度选取的3个关键样点。本研究方法否定了冬青栎和……的局部同质性假设，本数据集来源于两次采样工作。 第一次采样于2021年6-8月以原位（in situ）方式开展，直接从意大利中部拉齐奥大区的3个种群的成年个体采集样本，样点分别为卡斯特尔富萨诺（41°43'23.6'' N，12°19'55.7'' E）、拉法尔涅西亚纳（42°11'38.9'' N，11°52'33.1'' E）与蒂沃利（41°57'51.5'' N，12°48'54.9'' E）。 第二次采样于2022年6-8月以迁地（ex situ）方式开展，对取自原生源地种子并在同质园中培育的幼苗进行性状测定。 本研究遵循Perez-Harguindeguy等人（2016）在《<全球植物功能性状标准化测定新手册>勘误》（发表于*Australian Journal of Botany*，64(8)，715-716）中描述的标准流程，直接测定株高（H，plant height）、鲜叶面积（LA，fresh leaf area）与叶厚度（LT，leaf thickness）。叶质量分别于采集时（FM，fresh mass）、黑暗条件下5℃放置48小时后（SM，stored mass）以及置于90℃烘烤至……时进行测定。 # 破解局域生态同质性：探寻地中海植物局域种群的种内性状变异 [https://doi.org/10.5061/dryad.hqbzkh1nv](https://doi.org/10.5061/dryad.hqbzkh1nv) 本数据集涵盖冬青栎、乳香黄连木与岩蔷薇3个种群的多项植物功能性状，数据分别来自原位与迁地采样，其中迁地样本为在同质园中培育的幼苗。本次测定的性状包括：总株高（H）、叶质量面积比（LMA）、叶干物质含量（LDMC）、叶组织密度（LTD）、气孔密度（SD）与气孔面积指数（SAI）。 研究利用这些性状，旨在明确原位观测到的种群间种内变异，是否会在同质园的统一培养条件下由幼苗继承。研究结果显示：迁地培育的冬青栎与岩蔷薇种群间至少存在一项性状的显著差异，但乳香黄连木种群间未出现该情况；且种群间的显著变异在……