Publications by authors named "Iain Colin Prentice"
Forest primary production is a crucial process for both ecosystem functioning and global carbon cycling. Primary production responds to both temperature and vapour pressure deficit (VPD) through separate mechanisms. Vegetation models need to quantify both responses.
View Article and Find Full Text PDFAccurately representing the relationships between nitrogen supply and photosynthesis is crucial for reliably predicting carbon-nitrogen cycle coupling in Earth System Models (ESMs). Most ESMs assume positive correlations amongst soil nitrogen supply, leaf nitrogen content, and photosynthetic capacity. However, leaf photosynthetic nitrogen demand may influence the leaf nitrogen response to soil nitrogen supply; thus, responses to nitrogen supply are expected to be the largest in environments where demand is the greatest.
View Article and Find Full Text PDFEvidence for widespread thermal acclimation of canopy photosynthesis.
Jiangong Liu
,
Youngryel Ryu
,
Xiangzhong Luo
,
Benjamin Dechant
,
Benjamin D Stocker
,
Iain Colin Prentice
Nat Plants
December 2024
Plants acclimate to temperature by adjusting their photosynthetic capacity over weeks to months. However, most evidence for photosynthetic acclimation derives from leaf-scale experiments. Here we address the scarcity of evidence for canopy-scale photosynthetic acclimation by examining the correlation between maximum photosynthetic rates (A) and growth temperature ( ) across a range of concurrent temperatures and canopy foliage quantity, using data from >200 eddy covariance sites.
View Article and Find Full Text PDFGlobal patterns of plant functional traits and their relationships to climate.
Commun Biol
September 2024
Article Synopsis
- * An extensive dataset for 16 different FTs is analyzed using advanced statistical methods to explore trait relationships among non-woody, woody deciduous, and woody evergreen plants.
- * Key findings reveal that plant size traits generally increase in warmer climates, while leaf characteristics are influenced by moisture levels, providing a foundation for global trait-based ecosystem modeling.
Article Synopsis
- During dry periods, decreasing soil moisture leads to plant water stress, highlighting the need for better quantification of a critical soil moisture threshold (θ) to improve climate and resource projections.* -
- By combining satellite data and ground observations, researchers created a global map of θ, finding it averages at 0.19 m/m, with variations based on ecosystem types.* -
- The study identified key factors influencing θ, such as aridity, leaf area, and soil texture, and noted an increase in the number of stressful days for plants over the last 40 years, which has implications for understanding water stress in ecosystems.*
Article Synopsis
- - Tropical forests in equatorial Africa are crucial for the global carbon cycle, but there has been insufficient biometric data on their productivity levels (GPP and NPP).
- - A study conducted on 14 one-hectare plots in West Africa revealed that these forests generally exhibit higher productivity and lower carbon use efficiency compared to a similar aridity gradient in the Amazon.
- - The research highlighted that the highest reported NPP and GPP for intact forests occur at a medium-aridity site in Ghana, with findings indicating that existing data models underestimate forest productivity in both regions.
Incorporating photosynthetic acclimation improves stomatal optimisation models.
Plant Cell Environ
September 2024
Article Synopsis
- Stomatal opening in leaves helps regulate carbon and water exchange, crucial for understanding plant responses to climate change.
- New optimality-based models analyze stomatal behavior but often overlook how plants adjust biochemically to drought stress.
- A study on 37 plant species shows that including photosynthetic acclimation in these models significantly improves predictions of carbon assimilation during drought conditions.
Article Synopsis
- Leaf dry mass per unit area (LMA), carboxylation capacity, and leaf nitrogen are crucial traits for understanding plant ecology and ecosystem models, but there’s no clear agreement on how to regulate or model them.* -
- This study confirmed that leaf nitrogen can be accurately predicted from LMA and carboxylation capacity at 25°C, with global variations in these traits linked to climate factors, as proposed by leaf-level optimality theory.* -
- The research found that LMA is the strongest predictor of leaf nitrogen, explaining significant portions of global variation, while soil type affected predictions, suggesting that leaf nitrogen should be viewed as a result of environmental optimization rather than a cause.*
Towards a unified theory of plant photosynthesis and hydraulics.
Jaideep Joshi
,
Benjamin D Stocker
,
Florian Hofhansl
,
Shuangxi Zhou
,
Ulf Dieckmann
,
Iain Colin Prentice
Nat Plants
November 2022
Article Synopsis
- The global carbon and water cycles are influenced by gas exchanges through plant leaves, which are regulated by plants’ adaptations to optimize carbon gain while managing water risks.
- A new trait-based optimality theory has been developed that connects plant responses and biochemical adjustments to rapidly changing environmental conditions.
- This model, tested on 18 plant species, accurately predicts declines in carbon absorption and stomatal conductance during drought, while aligning with empirical data on how gas exchange is affected by factors like atmospheric pressure and temperature.
Coordination of photosynthetic traits across soil and climate gradients.
Glob Chang Biol
February 2023
"Least-cost theory" posits that C plants should balance rates of photosynthetic water loss and carboxylation in relation to the relative acquisition and maintenance costs of resources required for these activities. Here we investigated the dependency of photosynthetic traits on climate and soil properties using a new Australia-wide trait dataset spanning 528 species from 67 sites. We tested the hypotheses that plants on relatively cold or dry sites, or on relatively more fertile sites, would typically operate at greater CO drawdown (lower ratio of leaf internal to ambient CO , C :C ) during light-saturated photosynthesis, and at higher leaf N per area (N ) and higher carboxylation capacity (V ) for a given rate of stomatal conductance to water vapour, g .
View Article and Find Full Text PDFOptimality principles explaining divergent responses of alpine vegetation to environmental change.
Glob Chang Biol
January 2023
Article Synopsis
- - Recent observations show mixed vegetation responses on the Tibetan Plateau, with drier areas experiencing greening and wetter regions facing browning, despite similar climatic trends from 1982 to 2016.
- - A new model based on eco-evolutionary optimality (EEO) effectively explains these divergent trends by examining the limitations of water and energy, achieving a strong correlation with satellite data.
- - The study suggests that while increased CO2 promotes plant growth, its effects on photosynthesis are diminishing, indicating a shift in vegetation sensitivity from water to energy limitations due to climate change.
Article Synopsis
- Leaf morphology shows distinct patterns related to climate, with key traits differing between wetter and drier environments, as well as between seasonal and non-seasonal climates.
- A study analyzed 22 leaf traits from 662 woody species across China, uncovering significant trait variation driven by moisture, temperature, and plant family.
- The research identified specific trait syndromes linked to climate types, highlighting contrasts such as microphyll leaves in moist regions versus smaller, glaucous leaves in arid areas.
Article Synopsis
- Nitrogen (N) limitation may restrict carbon uptake in plants, particularly with rising CO2 and climate change, highlighting concerns over declining carboxylation capacity and leaf N content.
- Researchers predicted changes in leaf-level photosynthetic nitrogen (N) using satellite data from 1982-2016, finding that leaf N content declined at a similar rate to observed data, despite increasing leaf area index (LAI).
- The study suggests that rising CO2 and temperature may actually reduce the overall N demand of canopies more than LAI increases it, offering a different perspective on declining leaf N that isn't solely based on increased N limitation.
Past rapid warmings as a constraint on greenhouse-gas climate feedbacks.
Commun Earth Environ
August 2022
There are large uncertainties in the estimation of greenhouse-gas climate feedback. Recent observations do not provide strong constraints because they are short and complicated by human interventions, while model-based estimates differ considerably. Rapid climate changes during the last glacial period (Dansgaard-Oeschger events), observed near-globally, were comparable in both rate and magnitude to current and projected 21st century climate warming and therefore provide a relevant constraint on feedback strength.
View Article and Find Full Text PDFArticle Synopsis
- - Understanding carbon isotope discrimination (Δ C) in woody plants is essential for studying photosynthesis, but its variation over decades and relationships with gross primary production (GPP) are not fully understood.
- - A new modeling capability in the land-surface model JULES was implemented to analyze Δ C, revealing that most models overestimate average Δ C and underestimate variability due to neglecting the impact of soil water stress.
- - The study found that Δ C trends vary significantly by region from 1979 to 2016 but remain constant globally, and correlations between Δ C and GPP differ across environments, with negative correlations in wet-humid regions due to temperature effects.
AusTraits, a curated plant trait database for the Australian flora.
Daniel Falster
,
Rachael Gallagher
,
Elizabeth H Wenk
,
Ian J Wright
,
Dony Indiarto
,
Iain Colin Prentice
Sci Data
September 2021
Article Synopsis
- - AusTraits is a comprehensive database that compiles data on 448 traits from 28,640 taxa in Australian flora, integrating information from various sources like field studies and published literature.
- - The database includes a wide range of traits, from physiological performance measures (like photosynthesis) to morphological features (such as leaf size and plant height), linking these traits to ecological variations.
- - The latest version, 3.0.2, presents 997,808 trait-by-taxon combinations and aims to facilitate collaboration in archiving and sharing plant trait data, serving as a model for similar initiatives worldwide.
Article Synopsis
- Accurate monitoring of vegetation stress is essential for improving the modeling and forecasting of primary production, especially as climate change leads to more heatwaves and droughts.
- Variabilities in formaldehyde (HCHO) concentrations in the atmosphere are primarily influenced by local emissions of biogenic and pyrogenic volatile organic compounds from plants under stress.
- New analytical techniques now allow for better detection of extreme events in satellite data, revealing that HCHO is a reliable indicator of vegetation response to significant climate stress, particularly in forests.
Article Synopsis
- Global vegetation and land-surface models play a crucial role in understanding how plants and ecosystems react to environmental changes and their relationships with climate.
- Current models struggle with systematic errors and significant differences in predicting carbon and water cycles, indicating room for improvement in the underlying processes.
- Implementing unifying eco-evolutionary optimality (EEO) principles can lead to simpler, more accurate representations of plant functions, enhancing global models and allowing for better assessments of plant responses to environmental changes.
An improved statistical approach for reconstructing past climates from biotic assemblages.
Proc Math Phys Eng Sci
November 2020
Article Synopsis
- - The study focuses on improving a statistical method called WA-PLS, which is used to reconstruct past climates from fossil data but has a tendency to compress results toward the center of the climate range, potentially leading to biases.
- - The researchers propose a new approach that considers the theoretical abundance patterns of species in relation to climate and adjusts taxon abundances based on their climate tolerances to provide more accurate reconstructions.
- - By implementing these changes, specifically a method that corrects for compression bias and incorporates frequency data from climate variables, the improved model demonstrates better performance in climate reconstructions using a large modern pollen dataset.
Article Synopsis
- - The study examines how atmospheric aridity and drought affect plant leaf physiology, particularly the ratio of internal to external CO2 pressure (χ), which relates to stomatal conductance and photosynthesis, and finds that existing models often overlook soil water's influence on this ratio.
- - Using stable carbon isotope data from various woody plant species, researchers discovered that the costs associated with water transport increase as soil dries, leading to a linear decrease in the ratio of cost factors for carbon uptake and transpiration (β) with reduced soil water.
- - The findings indicate that both angiosperms and gymnosperms respond similarly to soil water stress, and incorporating soil water conditions into models improves predictions of χ by approximately 6.3
Article Synopsis
- The study examined how leaf traits such as leaf area (LA), mass per area (LMA), nitrogen per unit area (N), and leaf-internal to ambient CO ratio (χ) vary among species and in response to environmental changes across a north-south transect in Australia.
- Measurements from 705 species at 116 sites showed that while traits like LA and χ increased with higher temperatures, LMA and N decreased, indicating predictable responses based on environmental conditions.
- Results highlighted that within-species variability was minor for LA but significant for χ, suggesting that both individual acclimation and species selection play a role in shaping these relationships, although their contributions vary by trait.
Article Synopsis
- Several studies explored changes in leaf traits and carbon cycling across a gradient from the Amazon to the Andes, focusing on varying elevation and temperature conditions.
- Photosynthesis generally increases at higher elevations due to temperature drops but faces limits from reduced light availability, leading to a decline in overall plant productivity.
- The research aimed to predict relationships between leaf traits and primary production, finding that while certain photosynthetic capacities improved with elevation, overall production decreased, demonstrating a link between optimal plant adaptation and environmental conditions.
Article Synopsis
- Plant traits, which include various characteristics like morphology and physiology, play a crucial role in how plants interact with their environment and impact ecosystems, making them essential for research in areas like ecology, biodiversity, and environmental management.
- The TRY database, established in 2007, has become a vital resource for global plant trait data, promoting open access and enabling researchers to identify and fill data gaps for better ecological modeling.
- Although the TRY database provides extensive data, there are significant areas lacking consistent measurements, particularly for continuous traits that vary among individuals in their environments, presenting a major challenge that requires collaboration and coordinated efforts to address.
Plant respiration: Controlled by photosynthesis or biomass?
Alessio Collalti
,
Mark G Tjoelker
,
Günter Hoch
,
Annikki Mäkelä
,
Gabriele Guidolotti
,
Iain Colin Prentice
Glob Chang Biol
March 2020
Article Synopsis
- Two main hypotheses suggest that whole-plant respiration is linked either to photosynthesis or to biomass.
- A carbon balance model applied at a forest site indicates that respiration is influenced by the rate of biomass turnover; fast turnover relies on photosynthesis, while slow turnover relies on biomass.
- Both hypotheses were found to be incorrect, with respiration being more closely related to recent photosynthesis and available reserves rather than simply to total biomass.
Article Synopsis
- Water-use efficiency (WUE) is how well plants use water to grow while taking in carbon dioxide.
- Rising CO2 levels can help plants take in more carbon, which might increase their WUE at the leaf level, but how this works for entire ecosystems isn't fully understood.
- Current models that try to predict WUE are often wrong or inconsistent, so researchers are looking for better ways to measure and understand WUE to make these models more accurate.