skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • NSF Public Access
  • Search Results
  • Water loss through evapotranspiration after precipitation events in bioenergy crops grown in similar climatic conditions
Title: Water loss through evapotranspiration after precipitation events in bioenergy crops grown in similar climatic conditions
The relationship between precipitation and evapotranspiration (ET) is critical to understanding water cycle related dynamics in ecosystems, including crops. Existing studies of bioenergy crops have primarily focused on annual or seasonal ET rates, with less attention given to the immediate ET response following precipitation events. This study examines the variation in ET rates in the days subsequent to precipitation events across various bioenergy crops—corn, switchgrass, and prairies—utilizing 13 years (2010–2022) of growing season data. Meteorological and eddy covariance flux data were collected from seven eddy covariance flux towers as part of the GLBRC scale-up experiment at the Kellogg Biological Station Long Term Ecological Research sites. The analysis revealed that average ET peaked the day after precipitation and declined linearly over the following days, with a statistically significant relationship (p-value = 0.00027, R2= 0.96). Neither the type of biofuel vegetation nor the historical land use significantly influenced ET post-precipitation events (p-values = 0.53 and 0.153, respectively). Key predictors of ET following precipitation events include shortwave radiation, season, day of the year, ambient temperature, vapor pressure deficit (VPD), long-wave radiation, precipitation amount, soil moisture, and annual variability. These findings enhance our comprehension of ET responses in bioenergy crop systems, with implications for water management in sustainable agriculture.  more » « less
Award ID(s):
1832042
PAR ID:
10565563
Author(s) / Creator(s):
; ; ; ; ; ; ;
Publisher / Repository:
Frontiers Media
Date Published:
Journal Name:
Frontiers in Environmental Science
Volume:
12
ISSN:
2296-665X
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. (, ProQuest)
    This study proposes a new method for computing transpiration across an eddy covariance footprint using field observations of plant sap flow, phytomorphology sampling, uncrewed aerial system (UAS) digital image processing, and eddy covariance micrometeorological measurements. The method is applied to the Jornada Experimental Range, New Mexico where we address three key questions: (1) How do daily summer transpiration rates of Mesquite (Prosopis glandulosa) and Creosote (Larrea tridentate) individuals of different ages compare? (2) How can the contributions of plants of varying sizes and ages be integrated for terrain-wide transpiration estimates? (3) What is the contribution of transpiration to total evapotranspiration within the eddy covariance footprint? Data collected from June to October 2022, during the North American Monsoon season, include hourly evapotranspiration and precipitation rates from the Ameriflux eddy covariance system (US Jo-1 Bajadasite) and sap flux rates from heat-balance sensors. We used plant biometric measurements and supervised classification of RGB imagery to upscale from the patch- to footprint-scale estimations. Our results show that Mesquite’s average daily summer (JJAS) transpiration is about 2.9 mm/day, while Creosote’s is 1.7 mm/day. A proportional relationship between the plant’s horizontal projected area and the number of water flow conduits was extended to the eddy covariance footprint via UAS data. The summer transpiration to evapotranspiration ratio (T/ET) was 0.52, increasing to 0.83 following significant precipitation in September 2022. Further testing of this method is needed in different regions to validate its applicability. With appropriate adjustments, it could be relevant for other areas with similar ecological conditions. 
    more » « less
  2. ; (, Hydrological Processes)
    ABSTRACT Evapotranspiration (ET) from temperate forests plays a significant role in the regional and global water cycles. However, extreme weather events such as heat and drought are affecting the water use and water use efficiency (WUE) of these forests. Climate change impacts may be more severe in plantation forests where the age of the forest plays a significant role, causing differences in their responses to environmental stresses. This study presents 14 years (2008–2021) of water flux data measured using the eddy covariance technique in an age sequence (83, 48 and 20 years as of 2021) of eastern white pine (Pinus strobusL.) forests in the Great Lakes region in southern Ontario, Canada. The mean annual ET was 465 ± 41, 466 ± 32 and 403 ± 21 mm year−1in the 83‐, 48‐ and 20‐year‐old stands, respectively, with the highest annual water flux observed in the 83‐year‐ old stand, which was similar to that of the 48‐year‐old stand. Mean annual gross ecosystem productivity (GEP) was 1585 ± 100, 1660 ± 115 and 1634 ± 331 g C m−2 year−1in the 83‐, 48‐ and 20‐year‐old stands, respectively, while mean annual WUE was 3.4 ± 0.4, 3.6 ± 0.4 and 4.0 ± 0.8 g C kg H2O year−1in the respective stands. Lower ET and relatively higher GEP resulted in the highest WUE in the youngest stand, even though the highest GEP was observed in the middle‐aged stand. Air temperature (Tair) was the dominant control on ET, GEP and WUE in all three different‐aged stands, while drought, characterised as the relative extractable water (REW) in the soil, had a significant impact on ET in the late summer. The results of this study further showed that forest age significantly influenced how forests responded to drought stresses. The younger stand was more efficient in carbon sequestration and water use despite exhibiting greater sensitivity to water stress and higher drought coupling. The long‐term eddy covariance measurements analysed in this study have helped to enhance our understanding of water exchange processes in the temperate conifer forest ecosystems in Eastern North America. Specifically, this work contributes to a better understanding of how different‐aged forests respond to extreme weather events, aiding in the development of new strategies for managing water resources and ensuring water security in the region under a changing climate. 
    more » « less
  3. ; (, Soil Science Society of America Journal)
    Abstract Expanding biofuel production is expected to accelerate the conversion of unmanaged marginal lands to meet biomass feedstock needs. Greenhouse gas production during conversion jeopardizes the ensuing climate benefits, but most research to date has focused only on conversion to annual crops and only following tillage. Here we report the global warming impact of converting USDA Conservation Reserve Program (CRP) grasslands to three types of bioenergy crops using no‐till (NT) vs. conventional tillage (CT). We established replicated NT and CT plots in three CRP fields planted to continuous corn, switchgrass, or restored prairie. For the 2 yr following an initial soybean year in all fields, we found that, on average, NT conversion reduced nitrous oxide (N2O) emissions by 50% and CO2emissions by 20% compared with CT conversion. Differences were higher in Year 1 than in Year 2 in the continuous corn field, and in the two perennial systems the differences disappeared after Year 1. In all fields net CO2emissions (as measured by eddy covariance) were positive for the first 2 yr following CT establishment, but following NT establishment net CO2emissions were close to zero or negative, indicating net C sequestration. Overall, NT improved the global warming impact of biofuel crop establishment following CRP conversion by over 20‐fold compared with CT (−6.01 Mg CO2e ha−1 yr−1for NT vs. −0.25 Mg CO2e ha−1 yr−1for CT, on average). We also found that Intergovernmental Panel on Climate Change estimates of N2O emissions (as measured by static chambers) greatly underestimated actual emissions for converted fields regardless of tillage. Policies should encourage adoption of NT for converting marginal grasslands to perennial bioenergy crops to reduce C debt and maximize climate benefits. 
    more » « less
  4. ; ; ; (, Geophysical Research Letters)
    Abstract Quantifying relative contributions of plant transpiration (T) and soil evaporation to evapotranspiration (ET) is crucial to better understand how vegetation influences and controlsET, the largest efflux of the terrestrial water balance. Here, we derive estimates of transpiration fraction (T/ET) using consistent isotope‐basedETpartitioning methods for 13 sites spanning five ecosystem types of the continental US, capturing 56 snapshots ofT/ETduring the growing season. We found transpiration dominated theETflux across all sites with a meanT/ETof 0.81 ± 0.08 (±standard error). Sites and dates with higher vegetation indices exhibited higherT/ETand transpiration rates, with the latter increasing 0.30 mm/day per unit Leaf Area Index and 2.9 mm/day per unit Normalized Difference Vegetation Index. Counter to expectations, antecedent precipitation had no effect onT/ET. Despite the breadth of ecosystems and conditions represented, evaporation exceeded transpiration only once, suggesting that evaporation rarely dominatesETin the growing season. 
    more » « less
  5. ; ; (, GCB Bioenergy)
    Abstract Changes in land surface albedo can alter ecosystem energy balance and potentially influence climate. We examined the albedo of six bioenergy cropping systems in southwest Michigan USA: monocultures of energy sorghum (Sorghum bicolor), switchgrass (Panicum virgatumL.), and giant miscanthus (Miscanthus×giganteus), and polycultures of native grasses, early successional vegetation, and restored prairie. Direct field measurements of surface albedo (αs) from May 2018 through December 2020 at half‐hourly intervals in each system quantified the magnitudes and seasonal differences in albedo (∆α) and albedo‐induced radiative forcing (RF∆α). We used a nearby forest as a historical native cover type to estimate reference albedo and RF∆αchange upon original land use conversion, and a continuous no‐till maize (Zea mays L.) system as a contemporary reference to estimate change upon conversion from annual row crops. Annually,αsdiffered significantly (p < 0.05) among crops in the order: early successional (0.288 ± 0.012SE) >> miscanthus (0.271 ± 0.009) ≈ energy sorghum (0.270 ± 0.010) ≥ switchgrass (0.265 ± 0.009) ≈ restored prairie (0.264 ± 0.012) > native grasses (0.259 ± 0.010) > maize (0.247 ± 0.010). Reference forest had the lowest annualαs(0.134 ± 0.003). Albedo differences among crops during the growing season were also statistically significant, with growing seasonαsin perennial crops and energy sorghum on average ~20% higher (0.206 ± 0.003) than in no‐till maize (0.184 ± 0.002). Average non‐growing season (NGS)αs(0.370 ± 0.020) was much higher than growing seasonαs(0.203 ± 0.003) but these NGS differences were not significant. Overall, the original conversion of reference forest and maize landscapes to perennials provided a cooling effect on the local climate (RFαMAIZE: −3.83 ± 1.00 W m−2; RFαFOREST: −16.75 ± 3.01 W m−2). Significant differences among cropping systems suggest an additional management intervention for maximizing the positive climate benefit of bioenergy crops, with cellulosic crops on average ~9.1% more reflective than no‐till maize, which itself was about twice as reflective as the reference forest. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email