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
  • A moving target: trade‐offs between maximizing carbon and minimizing hydraulic stress for plants in a changing climate
Title: A moving target: trade‐offs between maximizing carbon and minimizing hydraulic stress for plants in a changing climate
Summary Observational evidence indicates that tree leaf area may acclimate in response to changes in water availability to alleviate hydraulic stress. However, the underlying mechanisms driving leaf area changes and consequences of different leaf area allocation strategies remain unknown.Here, we use a trait‐based hydraulically enabled tree model with two endmember leaf area allocation strategies, aimed at either maximizing carbon gain or moderating hydraulic stress. We examined the impacts of these strategies on future plant stress and productivity.Allocating leaf area to maximize carbon gain increased productivity with high CO2, but systematically increased hydraulic stress. Following an allocation strategy to avoid increased future hydraulic stress missed out on 26% of the potential future net primary productivity in some geographies. Both endmember leaf area allocation strategies resulted in leaf area decreases under future climate scenarios, contrary to Earth system model (ESM) predictions.Leaf area acclimation to avoid increased hydraulic stress (and potentially the risk of accelerated mortality) was possible, but led to reduced carbon gain. Accounting for plant hydraulic effects on canopy acclimation in ESMs could limit or reverse current projections of future increases in leaf area, with consequences for the carbon and water cycles, and surface energy budgets.  more » « less
Award ID(s):
2003205
PAR ID:
10548385
Author(s) / Creator(s):
; ; ;
Publisher / Repository:
Wiley
Date Published:
Journal Name:
New Phytologist
ISSN:
0028-646X
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; (, Functional Ecology)
    Structural overshoots, where biomass is overallocated to tree leaf area compared to sapwood area, could result in lethal stress during droughts. Climate change may alter climatic cues that drive leaf area production, such as temperature and precipitation, as well as seasonal dynamics that underlie summer rainfall due to the North American Monsoon (NAM). Combined, this could lead to temporal mismatches between leaf area‐driven water demand and availability, and increased drought‐induced mortality events.We used leaf area to sapwood area ratios to investigate the prevalence of overshoots and whether overshoots increase drought‐induced mortality. We measured populations of aspen spanning the northern transition zone of the NAM during and following severe droughts.We observed increased overshoots and drought‐induced mortality in southern latitude populations that rely more on summer monsoon rainfall. Changes in convective activity from low snowpack the preceding winter may be a climatic driver of heightened summer monsoon rainfall in the region and therefore may also trigger increased production of leaf area during wetter summers.Our results suggest that an overshoot of leaf area to sapwood area (AL:AS) ratios is associated with drought‐induced tree mortality and highlight that climate‐change driven alterations to the NAM could have major consequences for tree species' acclimation to environmental change. Read the freePlain Language Summaryfor this article on the Journal blog. 
    more » « less
  2. ; ; ; ; (, Journal of Ecology)
    Abstract Tree diversity may play a role in buffering forest ecosystems against climate extremes. We asked how diverse tree communities could (1) influence local atmospheric water demand, and (2) how changes in microclimate could be linked to the productivity of trees within forest communities.To assess forest canopy characteristics and calculate above‐ground productivity, we measured plant fractional cover using UAV‐LiDAR and conducted growth inventories in 148 forest plots of a young temperate tree diversity experiment. We monitored the microclimate and tracked soil moisture in a subset of forest plots to understand the relative influence of above‐ground and below‐ground water status on tree growth. Gas exchange, spectral reflectance and leaf mass per area were measured on four tree species distributed throughout the experiment to assess the influence of microclimate on tree physiology.We found that fast‐growing, early successional tree species increased forest cover, which was linked to buffered daily amplitudes of vapour pressure deficits (VPD) within forest plots and increases in the annual wood production of slower‐growing, shade‐tolerant tree species. In assemblages with more buffered microclimates, several slower‐growing tree species showed increased leaf water content and reduced physiological stress. Plots with reduced amplitude in VPD exhibited greater complementarity and productivity relative to those with higher variability.Synthesis. Our findings show that tree diversity and the proportion of fast‐growing, early successional tree species can increase canopy cover and buffer the microclimates of young forests, benefiting the physiology and productivity of slower‐growing, shade tolerant tree species. We reason that a self‐reinforcing dynamic of tree growth and microclimate buffering is likely at play. In the context of a rapidly changing climate, our findings suggest that diverse forest communities can shape local microenvironments to support sustainable ecosystem functioning. 
    more » « less
  3. ; ; ; ; ; ; ; ; ; ; et al (, New Phytologist)
    Summary Allocation of leaf phosphorus (P) among different functional fractions represents a crucial adaptive strategy for optimizing P use. However, it remains challenging to monitor the variability in leaf P fractions and, ultimately, to understand P‐use strategies across diverse plant communities.We explored relationships between five leaf P fractions (orthophosphate P, Pi; lipid P, PL; nucleic acid P, PN; metabolite P, PM; and residual P, PR) and 11 leaf economic traits of 58 woody species from three biomes in China, including temperate, subtropical and tropical forests. Then, we developed trait‐based models and spectral models for leaf P fractions and compared their predictive abilities.We found that plants exhibiting conservative strategies increased the proportions of PNand PM, but decreased the proportions of Piand PL, thus enhancing photosynthetic P‐use efficiency, especially under P limitation. Spectral models outperformed trait‐based models in predicting cross‐site leaf P fractions, regardless of concentrations (R2 = 0.50–0.88 vs 0.34–0.74) or proportions (R2 = 0.43–0.70 vs 0.06–0.45).These findings enhance our understanding of leaf P‐allocation strategies and highlight reflectance spectroscopy as a promising alternative for characterizing large‐scale leaf P fractions and plant P‐use strategies, which could ultimately improve the physiological representation of the plant P cycle in land surface models. 
    more » « less
  4. ; (, Functional Ecology)
    Abstract Despite the importance of flowers to plant fitness, it remains unclear whether flowers display ecophysiological strategies and how floral traits are associated with leaf economic traits.Using a comparative analysis of flowers and leaves, we evaluated associations between seven homologous traits related to carbon and water economics in 245 plant species sampled at four locations spanning more than 100 degrees of latitude: Arctic tundra, tropicalcampos rupestres, Patagonian steppe and a botanical garden in the Mediterranean‐type climate of California. We used correlation analysis, standard major axes, principal component analysis and trait networks to evaluate the associations among flower and leaf traits.We found flower trait combinations ranging from large‐sized flowers with thick petals and lengthy water turnover times (τ) to small‐sized flowers with thin petaloid structures and high residual conductance (gres). There was positive scaling among flower and leaf traits such asgres,τ, petal and leaf thickness, and area. Network analysis showed no modular structure of flower and leaf traits when all species were evaluated together.Our results showcase that flower phenotypes are distributed along a continuum of trait variation and are functionally linked to leaves through water‐ and size‐related traits. This cross‐organ correlation indicates that habitat filtering based on the ecophysiological strategies of one organ would influence the phenotypes of the other organ. Read the freePlain Language Summaryfor this article on the Journal blog. 
    more » « less
  5. ; ; ; ; ; (, New Phytologist)
    Summary The onset of stomatal closure reduces transpiration during drought. In seed plants, drought causes declines in plant water status which increases leaf endogenous abscisic acid (ABA) levels required for stomatal closure. There are multiple possible points of increased belowground resistance in the soil–plant atmospheric continuum that could decrease leaf water potential enough to trigger ABA production and the subsequent decreases in transpiration.We investigate the dynamic patterns of leaf ABA levels, plant hydraulic conductance and the point of failure in the soil–plant conductance in the highly embolism‐resistant speciesCallitris tuberculatausing continuous dendrometer measurements of leaf water potential during drought.We show that decreases in transpiration and ABA biosynthesis begin before any permanent decreases in predawn water potential, collapse in soil–plant hydraulic pathway and xylem embolism spread.We find that a dynamic but recoverable increases in hydraulic resistance in the soil in close proximity to the roots is the most likely driver of declines in midday leaf water potential needed for ABA biosynthesis and the onset of decreases in transpiration. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Text Encoded Conversion
  • XML
  • Save / Share this Record
  • Send to Email