DOI: 10.3886/e239733v1
title: Experimental Soil Warming Impacts Soil Moisture and Plant Water Stress and Thereby Ecosystem Carbon Dynamics (Blodgett, CA)

description: This dataset contains data on daily soil temperature, moisture and flux,
 and soil carbon stock and root biomass across a soil profile down to 
100 cm depth at Blodgett Forest Research Station, CA, USA. These data 
were generated to determine if modeling of an experimental soil warming 
of 4C showed increased soil CO2 emissions and changes in bulk soil 
carbon stocks with depth consistent with field observations, as part of 
the study: Riley et al. (2025) Experimental Soil Warming Impacts Soil 
Moisture and Plant Water Stress and Thereby Ecosystem Carbon Dynamics in
 Journal of Advances in Modeling Earth Systems. This research was 
performed within the framework of the TES Belowground Biogeochemistry 
SFA project, in particular association with a 1 m-deep experimental soil
 heating experiment at the University of California Blodgett Forest 
Research Station, California (120 ° 39′40′′W; 38 ° 54′43′′N). Continuous
 data were collected at the plot level, and bulk soil carbon and root 
biomass were sampled once a year from each plot from 0-100 cm, in 10 cm 
intervals. <br>Measurements relevant to the current study include soil 
temperature and soil volumetric water content measured continuously at 
multiple depths in the top meter; fine root biomass and SOC stocks 
measured from annual soil cores. Soil flux was continuously monitored 
using a LI-8100 Automated CO2 Flux System in conjunction with the 
LI-8150 Multiplexer (Licor, Nebraska, USA). Soil flux was determined 
using SoilFluxPro software, with flux values showing an R² fit of less 
than 0.9 being excluded from the analysis. Data were collected from each
 paired plot (1-3): one control (C) and one heated (H).
description: We use observations from a 1 m deep soil heating experiment at the 
University of California Blodgett Forest Research Station, California 
(120 ° 39′40′′W; 38 ° 54′43′′N, 1370 m above sea level (Hicks Pries et 
al., 2017). The site is located in the foothills of the central Sierra 
Nevada, has a Mediterranean climate with a mean annual precipitation of 
1660 mm (most as snow fromNovember through April) and mean annual air 
temperature of 12.5°C. The area’s mixed-conifer forest includes 
ponderosa pine, sugar pine, incense cedar, white fir, Douglas fir, and 
oak; most of the trees around our experimental manipulation plots are 
conifers, so we assumed plant functional traits consistent with a 
temperate evergreen conifer tree. The soil is of granitic origin with a 
well-developed O horizon and is classified as a fine-loamy, mixed, 
superactive, mesic Ultic Haploxeralfs in the Holland series. <br><br>The soil heating method is described in detail in Hicks Pries et al. 
(2017). Briefly, three plot pairs, each with a 3 m diameter control and 
heated plot, were established in 2013 and heating began January 2014. 
Twenty-two 2.4 m steel pipes were installed vertically into the soil 
around each plot boundary, and heating cables were placed in the pipes. 
Two concentric rings (1 and 2 m diameter) of heater cables were 
installed 5 cm deep to compensate for surface heat loss to the 
atmosphere. In each heated plot, power was supplied to the vertical and 
surface heaters to maintain a 4 °C temperature differential with its 
paired control plot. <br>This dataset contains data on daily soil temperature, moisture and 
flux, and soil carbon stock and root biomass across a soil profile down 
to 100 cm depth. Continuous data were collected at the plot level, and 
bulk soil carbon and root biomass were sampled once a year from each 
plot from 0-100 cm, in 10 cm intervals. <br>Measurements relevant to the current study include soil temperature 
and soil volumetric water content measured continuously at multiple 
depths in the top meter; fine root biomass and SOC stocks measured from 
annual soil cores. <br>We measured soil temperature in each plot with custom-made 
temperature probes with thermistors at 5, 15, 20, 30, 50, 70, 75, and 
100 cm. Further, we recorded volumetric soil water content in each plot 
with one moisture probe (Sentek EnviroSCAN, Australia) at 10, 30, 50, 
and 90 cm. Soil temperature and moisture were collected and graphed as 
30-minute averages, and were reported as annual averages. <br>Volumetric water content was converted to water filled pore space, 
WFPS, using measured soil bulk density and inferred porosity. Porosity 
was inferred using estimated bulk density (g cm -3) and an assumed 
particle density of 2.66 g cm -3; was estimated from measured soil mass,
 water content, and volume. <br>We used dataloggers (CR1000, Campbell Scientific, Utah, USA) to 
record soil temperature and moisture values continuously and created a 
program that adjusted the power to the heaters every 10 min based on 
soil temperatures in the control plots to maintain a targeted 4°C 
warming in the paired heated plots. Temperature sensors at 15 and 20 cm 
were queried to control the power supply to the shallow heaters, while 
temperature sensors at 70 and 75 cm were queried to control power supply
 to deep heaters. <br>Soil flux was continuously monitored using a LI-8100 Automated CO2 
Flux System in conjunction with the LI-8150 Multiplexer (Licor, 
Nebraska, USA). Air from the headspace of each closed chamber (20 cm 
diameter), which was permanently installed 10 cm into the mineral soil 
across the six plots, was circulated through the multiplexer via a 
diaphragm pump.Soil flux was determined using SoilFluxPro software, with
 flux values showing an R² fit of less than 0.9 being excluded from the 
analysis. Data were collected from each paired plot (1-3): one control 
(C) and one heated (H).<br><br><br>