<b>Intraspecific variation of </b><b><i>Pterocarpus erinaceus</i></b><b> Poir. along an aridity gradient: Insights into its response to drier conditions</b>

Description of the studyIntraspecific phenotypic variation is widespread in nature, and understanding its causes and consequences is key to predict the evolutionary trajectories of plant populations and their adaptive responses to environmental stressors. Widely distributed species often encounter broad environmental gradients, imposing differential selective pressures across populations. If there is sufficient genetic variation and the effects of natural selection are stronger than those from neutral evolutionary processes, differences in patterns of selection may lead to adaptive population differentiation. Thus, understanding how species adapt to environmental changes is crucial for effective conservation and habitat restoration. In this regard, our study examines morphological and functional trait variability in <i>Pterocarpus erinaceus</i> Poir., a species with a wide distribution range along the South-North aridity gradient prevailing in Benin.This study was conducted in the Republic of Benin, West Africa, and covered the entire environmental gradient from south to north. Benin is located in the intertropical zone, between latitude 6°30' and 12°30' North and longitude 1° and 3°40' East (Figure 1). The country includes three climate zones, defined based on phytogeographic data and climatic gradient: (i) the Sudanian zone (SZ) in the north (semi-) arid zone (9°45'-12°25'N and 0°45’-3°50’E), (ii) the Sudano-Guinean zone (SGZ) in the sub-humid zone (7°30'-9°45'N and 1°30’ – 3°50’E), and (iii) the Guinean zone (GZ) in the south humid zone (6°25'-7°30'N and 1°45’-2°50’E). Annual rainfall ranges from 800 to 1400 mm from north to south (Adomou, 2005). This rainfall gradient has resulted in the presence of dense deciduous forests in the south and woodlands and savannas in the north (Table 1).We included the data file and the r script.<b>Variables</b> <b>Id : </b>Plot identification code<b>Climate_Zone :</b> Climate Zone<b>Population :</b> Population selection by climate zone<b>TLL:</b> Total Leaf length (cm)<b>PEL: </b>Petiole Length (cm)<b>LEL: </b>Leaflet length<b>LW:</b> Leaflet width (cm)<b>PeL: </b>Petiolule length<b>NL:</b> Number of Leaflet<b>LRCC:</b> Chlorophyll content (%)<b>LM: </b>Leaflet mass (g)<b>LA:</b> Leaflet area (cm²)<b>SLA: </b>Specific leaf area (m²/g)<b>LMA:</b> Leaf mass per area (g/m²)<b>DBH: </b>Diameter at breast height (cm)<b>TH: </b>Total height (m)<b>NB: </b>Number of branches<b>bio_1:</b> Annual mean temperature<b>bio_11:</b> Mean Temperature of Coldest Quarter<b>bio_16:</b> Precipitation of Wettest Quarter<b>bio_2:</b> Mean Diurnal Range (Mean of monthly (max temp - min temp))<b>bio_3:</b> Isothermality<b>bio_12: </b>Annual Precipitation<b>Index_of_Aridity:</b> Aridity Indexe<b>Ele :</b> Altitude<b>GZ :</b> Guinean Zone<b>SGZ : </b>Sudano-Guinean Zone<b>SZ : </b>Sudanian Zone

研究概况：种内表型变异在自然界中广泛存在，解析其成因与效应是预测植物种群演化轨迹及其对环境胁迫适应性响应的关键所在。广布物种通常会经历大范围的环境梯度，进而在不同种群间施加差异化的选择压力。若种群具备充足的遗传变异，且自然选择的作用强度高于中性演化过程，则选择模式的差异可引发适应性种群分化。因此，阐明物种适应环境变化的机制，对于实施高效保护与生境修复工作至关重要。为此，本研究聚焦于刺猬紫檀（*Pterocarpus erinaceus* Poir.）——一种沿贝宁境内南北走向的干旱梯度广泛分布的物种。

本研究于西非贝宁共和国开展，覆盖了该国全境南北完整的环境梯度。贝宁地处热带间地带，位于北纬6°30′至12°30′、东经1°至3°40′之间（图1）。依据植物地理学数据与气候梯度特征，该国可划分为三个气候区：
(i) 北部苏丹气候区（Sudanian Zone, SZ）：半干旱区，地理范围为北纬9°45′至12°25′、东经0°45′至3°50′；
(ii) 中部苏丹-几内亚气候区（Sudano-Guinean Zone, SGZ）：亚湿润区，地理范围为北纬7°30′至9°45′、东经1°30′至3°50′；
(iii) 南部几内亚气候区（Guinean Zone, GZ）：湿润区，地理范围为北纬6°25′至7°30′、东经1°45′至2°50′。
年降雨量自北向南介于800至1400毫米之间（Adomou, 2005）。该降雨梯度塑造了南部茂密的落叶阔叶林与北部的稀树灌丛、草原群落（表1）。

本研究附带数据文件与R脚本。

**变量**
**Id**：样地识别编码
**Climate_Zone**：气候区
**Population**：基于气候区选取的种群
**TLL**：叶片总长度（cm）
**PEL**：叶柄长度（cm）
**LEL**：小叶长度
**LW**：小叶宽度（cm）
**PeL**：小叶柄长度
**NL**：小叶数量
**LRCC**：叶绿素含量（%）
**LM**：小叶质量（g）
**LA**：小叶面积（cm²）
**SLA**：比叶面积（Specific Leaf Area, m²/g）
**LMA**：单位叶面积质量（Leaf Mass per Area, g/m²）
**DBH**：胸径（Diameter at Breast Height, cm）
**TH**：植株总高度（m）
**NB**：分枝数量
**bio_1**：年平均气温
**bio_11**：最冷季度平均气温
**bio_16**：最湿季度降水量
**bio_2**：气温日较差均值（月最高温与最低温差值的平均值）
**bio_3**：等温性
**bio_12**：年降水量
**Index_of_Aridity**：干旱指数
**Ele**：海拔
**GZ**：几内亚气候区
**SGZ**：苏丹-几内亚气候区
**SZ**：苏丹气候区

搜集汇总

背景与挑战

背景概述

该数据集聚焦于Pterocarpus erinaceus Poir.在贝宁南-北干旱梯度下的种内表型变异，包含形态、功能性状及环境变量，用于分析植物对干旱条件的适应机制。数据集覆盖贝宁三个气候带，支持生态适应和可持续管理研究。