Biology subjects

Anderegg, L. D. L.

Publications and source records attributed to Anderegg, L. D. L..

4 recordsLinked to original sources

bioRxiv2026

The PSInet Plant Water Potential Database: advancing new perspectives on plant water status, traits, and hydraulic processes

Water potential gradients drive water flow within and between soils and plants, and the internal plant water potential controls a wide range of physiological processes including photosynthesis, growth, and mortality. Notwithstanding this clear relevance for many critical aspects of ecosystem function, water potential data have historically been relatively inaccessible and unnetworked. The absence of a centralized repository for plant water potential time series limits our ability to integrate a wealth of ecophysiological information from other networks and from remote sensing. Closing this gap is necessary to address unresolved questions about plant responses to drought and heat stress, and to make confident predictions about plant and ecosystem function in a warming world. Here, we introduce the PSInet database -- a global collection of plant water potential time series from 285 datasets representing 523 species. We present the workflow that guided database development and evaluate its key features. Through a series of preliminary analyses, we then highlight the potential of the PSInet database for applications including: a) advancing plant water use strategy frameworks; b) disentangling the impacts of soil versus atmospheric drought stress; c) assessing the long-held assumption of pre-dawn equilibration of ecosystem water potential; d) understanding the risk of drought-driven mortality; and e) benchmarking remote-sensing data products and land-surface models.

plant biology↗

bioRxiv2025

Maximum water stress is decoupled from climate, traits and growth in a xeric oak

O_LIWidespread drought-induced forest mortality highlights the ecological consequences of climate change, yet our ability to explain, let alone predict, the spatial patterns of forest mortality remains limited. C_LIO_LIWe conducted a range-wide survey of drought stress, growth, and allocation traits in a widespread oak species (Quercus douglasii, blue oak) to test the predictability of stress across populations and explore how water availability and allocation mediate spatial variation in tree growth. C_LIO_LIAcross 15 sites, we found little relationship between end-of-season water availability (predawn leaf water potentials) or maximum water stress (midday water potentials) and climate or soils. Instead, water availability (within and among sites) was predicted by access to deep water resources inferred from stem water stable isotopes. C_LIO_LIWe also found a remarkable three-way decoupling of water stress, growth, and allocation to leaf tissue, which challenged a data-parameterized mechanistic plant model. C_LIO_LIOur results reveal that deeply rooted trees can be hydrologically decouple from above-ground climate, and that the seasonality of growth, trait development and hydraulic risk are phenologically disconnected. The complicated relationship between carbon gain and hydraulic risk in seasonal environments and limited data on critical zone hydrology are key challenges to predicting drought vulnerability. C_LI Plain Language SummaryBelow-ground structure complicates our understanding of plant water stress. We show that below-ground complexity and highly seasonal environments can both disconnect trees from their above-ground climate and disconnect drought mortality risk from growth and trait development.

ecology↗

bioRxiv2023

Plasticity drives geographic variation and trait coordination in blue oak drought physiology

Our ability to predict drought stress across the landscape remains limited. This uncertainty stems in part from an incomplete understanding of within-species variation in hydraulic physiology, particularly coordinated variation across multiple traits. This variation reflects genetic differentiation among populations (ecotypic variation) and phenotypic plasticity. We examined among-population differentiation in morphological and hydraulic traits in California blue oak (Quercus douglasii) using a 30 year-old common garden. We compared trait differentiation and trait-trait coordination in the garden to wild phenotypes from the original source populations. We found remarkably limited among-population differentiation in all traits in the common garden but considerable site-to-site variation in the field that could rarely be explained with site climate variables. Trait-trait relationships were also stronger in the field than in the garden, particularly links between leaf morphology, leaf hydraulic efficiency and stem hydraulic efficiency. Only four trait-trait relationship were present in both the wild and garden, but 12 of 45 relationships showed significant wild phenotypic correlations, with strong coordination among leaf and stem hydraulic efficiency apparently mediated by leaf size. Ultimately, we found limited evidence for ecotypic variation but considerable geographic in phenotypic integration in the wild, suggesting considerable acclimation potential in the face of climate change.

ecology↗

bioRxiv2020

Aridity drives coordinated trait shifts but not decreased trait variance across the geographic range of eight Australian trees

ContextLarge intraspecific functional trait variation strongly impacts many aspects of natural communities and ecosystems, yet is inconsistent across traits and species. ApproachWe measured within-species variation in leaf mass per area (LMA), leaf dry matter content (LDMC), branch wood density (WD), and allocation to stem area vs. leaf area in branches (branch Huber value, HV) across the aridity range of seven Australian eucalypts and an Acacia species to explore how traits and their variances change with aridity. Results and ConclusionsWithin-species, we found consistent increases in LMA, LDMC and WD, and HV with increasing aridity, resulting in consistent trait coordination across tissues. However, this coordination only emerged across sites with large climate differences. Unlike trait means, patterns of trait variance with aridity were mixed across populations and species and showed limited support for constrained trait variation in dryer populations or more xeric species. SynthesisOur results highlight that climate can drive consistent within-species trait patterns, but that these patterns might often be obscured by the complex nature of morphological traits and sampling incomplete species ranges or sampling confounded stress gradients.

ecology↗