Dataset DOI: 10.5061/dryad.sn02v6xmk

Description of the data and file structure

This dataset contains litterfall, leaf litter chemistry, canopy imagery, and climate data collected from a wet montane forest in Hawai'i. Data were collected over a 12-year period beneath two dominant native tree species: Metrosideros polymorpha ('ōhi'a lehua) and Acacia koa (koa). The dataset includes leaf litterfall rate by species and season, leaf litter chemistry (Carbon and Nitrogen) by species and season, PhenoCam image classifications from machine-learning-derived canopy classes from time-lapse camera images; and climate data corresponding to the study location and sampling periods. These data were used to examine seasonal leaf turnover timing, foliar nutrient investment, canopy greenness dynamics, and environmental drivers of leaf phenology in a tropical montane forest.

Files and variables

File: litter_chemistry.csv

Description of variables:

• species: ACAKOA = Acacia koa; METPOL = Metrosideros polymorpha
• month: (1-12)
• year: 4-digit year (2009-2021)
• season: wet = months 11-4 (Nov-Apr); dry = months 5-10 (May-Oct)
• %C: leaf litter percent Carbon
• %N: leaf litter percent Nitrogen
• C:N: leaf litter Carbon to Nitrogen ratio

File: litter-turnover-climate.csv

Description of variables: 

• date_range: leaf litterfall collection dates
• days: number of days within "date_range"
• season: wet = months 11-4 (Nov-Apr); dry = months 5-10 (May-Oct)
• metpol_rate_gdm2: Metrosideros polymorpha leaf litterfall rate - grams per square meter per day
• acakoa_rate_gdm2: Acacia koa leaf litterfall rate - grams per square meter per day
• Tair_C_mean: Average air temperature (Celsius) over "date_range"
• RH_%_mean: Average relative humidity (percent) over "date_range"
• Tsoil_C_mean: Average soil temperature (Celsius) over "date_range"
• SHF_Wm2_mean: Average soil heat flux (Watts per square meter ) over "date_range"
• SM_%_mean: Average soil moisture (percent) over "date_range"
• PAR_mmolm2s_mean: Average photosynthetically active radiation (micromoles per square meter per second) over "date_range"
• WS_ms_mean: Average wind speed (meters per second) over "date_range"
• P_mm_sum: Cumulative sum of precipitation (millimeters) over "date_range"

File: roi_summary.csv

Description of variables:

• year: 4-digit year
• month: (1-12)
• day: day of month

PhenoCam canopy classification variables follow the naming convention:

region[N]_[class]pct[stat]

where:

N = region of interest (ROI) number (1–6)

class = classification group:

• sunlit – sunlit green leaves
• shaded – shaded green leaves
• nonphoto – non-photosynthetic vegetation
• bark – bark
• understory – understory vegetation

stat = summary statistic:

• mean – average percent of pixels in that category across daily images
• sd – standard deviation
• se – standard error

Example: region2_sunlit_pct_sd = standard deviation of the percent of pixels classified as sunlit green leaves within region of interest (ROI) 2.

Access information

Other publicly accessible locations of the data:

• NA

Data was derived from the following sources:

• NA