DOI: 10.5061/dryad.crjdfn3j8
title: Influence of tree height and age on leaf drip-tip morphology in lowland tropical rain forest trees

description: This dataset comprises leaf morphological measurements from 23 focal tree
 species within the Yasuní Forest Dynamics Plot in Yasuní National Park,
 Ecuador. It includes data from both saplings and adult trees, sampled in
 2022 and compared with herbarium specimens collected during the plot’s
 establishment (1995–1997). Each entry documents species identity,
 life-history strategy, developmental stage, and detailed leaf traits,
 including lamina dimensions, drip-tip presence and length, and drip-tip
 ratios. The dataset is structured across two components: (1) leaf-level
 measurements for over 1,400 samples, and (2) individual-level comparisons
 of leaf apex morphology over time. Data quality annotations (e.g.,
 herbivory, apex damage) are included. This resource supports trait-based
 ecological analyses, ontogenetic studies, and long-term morphological
 change assessments in tropical forest trees. Reuse potential includes
 comparative morphology and climate adaptation research.
description: # Influence of tree height and age on leaf drip-tip morphology in lowland
 tropical rain forest trees Dataset DOI:
 [10.5061/dryad.crjdfn3j8](https://doi.org/10.5061/dryad.crjdfn3j8) ##
 Description of the data and file structure This dataset was collected to
 examine variation in leaf apex morphology—specifically, drip-tip presence
 and dimensions—across developmental stages and tree maximum height
 categorizations over time in tropical tree species. Leaf samples were
 obtained from 23 focal species within the Yasuní Forest Dynamics Plot in
 Ecuador. For each species, leaf traits were measured from multiple
 individuals to assess drip-tip variation across life-history strategies
 and developmental stages. Measurements were also taken from both living
 trees in 2022 and herbarium specimens collected during the plot’s initial
 census (1995–1997), enabling individual-level comparisons of drip-tips
 across a ~25-year interval. ### Files and variables #### File:
 indiv_tree_study.csv **Description:** Contains metadata linking individual
 trees sampled in both 1995–1997 and 2022. Enables longitudinal comparisons
 of leaf morphology at the individual tree level across a ~25-year
 interval. Includes species identity, life-history strategy, tree tags, and
 herbarium/field sample IDs. ##### Variables * `family`: Taxonomic family -
 `genus`: Genus name - `species`: Species name - `spec_code`: Species code
 abbreviation - `life_history_strategy`: Growth form (e.g., treelet,
 mid-sized tree, tall tree) - `herb_ID`: Herbarium sample ID - `tree_tag`:
 Unique tree identifier - `date_coll_newspaper`: Date of herbarium
 collection - `field_ID`: Field sample ID (multiple leaves per tree) -
 `date_coll_field`: Date of field collection - `notes`: Observational notes
 on field sample collection  #### File: leaf_sample_data.csv
 **Description:** Contains leaf-level morphological measurements for all
 samples analyzed. Each row represents a single leaf sample with detailed
 trait data and observational notes. ##### Variables * `leaf_ID`: Unique
 leaf sample identifier - `date`: Date of sample collection - `spec_code`:
 Species code abbreviation - `family`, `genus`, `species`: Taxonomic
 classification - `life_history_strategy`: Growth form - `tree_tag_num`:
 Tree identifier - `DBH (mm)`: Diameter at breast height in millimeters -
 `devel_stage`: Developmental stage (adult or sapling) - `leaf_type`: Leaf
 shape (simple) - `margin`: Leaf margin type (entire or non-entire) -
 `trichome_presence`: Presence of leaf hairs (yes/no) - `lamina_length
 (cm)`: Length from base to apex - `lamina_width (cm)`: Maximum width
 perpendicular to midrib - `drip_tip`: Presence of drip-tip (yes/no) -
 `drip_tip_length (cm)`: Length of drip-tip - `drip_tip_ratio`: Ratio of
 drip-tip length to lamina length - `notes`: Observational notes (e.g.,
 damage, herbivory) ### **Missing Data Explanation** All missing data in
 the dataset are indicated by the value `"NA"`. These entries are
 not arbitrary; they reflect specific conditions encountered during data
 collection and processing. The reasons for `"NA"` values
 include: * **Leaf damage**: Physical damage to the leaf apex or lamina
 prevented accurate measurement. * **Scan limitations**: Poor scan quality
 or leaf positioning made trait assessment impossible. * **Trait absence**:
 In cases where a trait (e.g., drip-tip) was not present, related
 measurements (e.g., drip-tip length) were recorded as `"NA"` if
 the value could not be meaningfully assigned. * **Field constraints**:
 Some trees had fewer than the intended number of leaves available,
 resulting in incomplete data. * **Metadata gaps**: Occasionally, tree
 tags, tree DBH, and collection dates were not recorded or were ambiguous.
 No blank cells are present in the dataset; all missing or unavailable
 information is consistently marked as `"NA"` to ensure clarity
 and compatibility with downstream analysis. ## Code/software **Software
 Used:** * **R (version 4.2.1)** and **RStudio (version 2022.07.1)** were
 used for data cleaning, visualization, and statistical analysis. * **Fiji
 (ImageJ)**: Open-source image analysis software used to measure leaf
 traits from scanned images. * Fiji version: 2.9.0 * Key plugins: Angle
 Tool, Segmented Line Selection Tool **Workflow Summary:** * Leaf scans
 were imported into Fiji for measurement of apex angles and drip-tip
 lengths. * Measurements were exported to spreadsheets. * R was used to
 calculate derived metrics (e.g., drip-tip ratios), clean data, and perform
 statistical analyses. * Observational notes were manually annotated during
 fieldwork and image review. No custom scripts are included in this
 submission, but the workflow is reproducible using the software and
 methods described. ## Access information NA