Hillslope Hydrology in Global Change Research and Earth System Modeling

Water Resources Research, Journal Year: 2019, Volume and Issue: 55(2), P. 1737 - 1772

Published: Feb. 1, 2019

Abstract Earth System Models (ESMs) are essential tools for understanding and predicting global change, but they cannot explicitly resolve hillslope‐scale terrain structures that fundamentally organize water, energy, biogeochemical stores fluxes at subgrid scales. Here we bring together hydrologists, Critical Zone scientists, ESM developers, to explore how hillslope may modulate grid‐level fluxes. In contrast the one‐dimensional (1‐D), 2‐ 3‐m deep, free‐draining soil hydrology in most land models, hypothesize 3‐D, lateral ridge‐to‐valley flow through shallow deep paths insolation contrasts between sunny shady slopes top two globally quantifiable organizers of water energy (and vegetation) within an grid cell. We these processes likely impact predictions where when) and/or limiting. further that, if implemented will increase simulated continental storage residence time, buffering terrestrial ecosystems against seasonal interannual droughts. efficient ways capture mechanisms ESMs identify critical knowledge gaps preventing us from scaling up processes. One such gap is our extremely limited subsurface, stored (supporting released stream baseflow aquatic ecosystems). conclude with a set organizing hypotheses call syntheses activities model experiments assess on change predictions.

Language: Английский

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Microclimatic buffering in forests of the future: the role of local water balance

Ecography, Journal Year: 2018, Volume and Issue: 42(1), P. 1 - 11

Published: June 21, 2018

Forest canopies buffer climate extremes and promote microclimates that may function as refugia for understory species under changing climate. However, the biophysical conditions maintain microclimatic buffering its stability through time are largely unresolved. We posited forest is sensitive to local water balance canopy cover, we measured this effect during growing season across a gradient in forests of northwestern United States (US). found maximum temperature vapor pressure deficit (VPD), with biologically meaningful sizes. For example, season, VPD at least 50% were 5.3°C 1.1 kPa lower on average, respectively, compared areas without cover. Canopy was greater higher levels varied balance, implying effects subject changes hydrology. project mid‐21st century predict how such impact ability western US extremes. Our results suggest some will lose their capacity sites become increasingly limited. Changes combined accelerating losses due increases frequency severity disturbance create potentially non‐linear microclimate forests.

Language: Английский

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California forest die-off linked to multi-year deep soil drying in 2012–2015 drought

Nature Geoscience, Journal Year: 2019, Volume and Issue: 12(8), P. 632 - 637

Published: July 1, 2019

Language: Английский

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A low-to-no snow future and its impacts on water resources in the western United States

Nature Reviews Earth & Environment, Journal Year: 2021, Volume and Issue: 2(11), P. 800 - 819

Published: Oct. 26, 2021

Language: Английский

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Why is Tree Drought Mortality so Hard to Predict?

Trends in Ecology & Evolution, Journal Year: 2021, Volume and Issue: 36(6), P. 520 - 532

Published: March 2, 2021

Language: Английский

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Which trees die during drought? The key role of insect host‐tree selection

Journal of Ecology, Journal Year: 2019, Volume and Issue: 107(5), P. 2383 - 2401

Published: April 4, 2019

Abstract During drought, the tree subpopulations (such as size or vigour classes) that suffer disproportionate mortality can be conceptually arrayed along a continuum defined by actions of biotic agents, particularly insects. At one extreme, stress dominates: insects are absent simply kill most physiologically stressed trees. opposite host selection outbreaking trees independently their stress, instead selecting based on other traits. Intermediate responses also possible. Yet for mixed‐species forests, we lack broad understanding relative importance in determining exactly which during and whether these differ among co‐occurring species. an extreme documented roles native bark beetles five species California’s Sierra Nevada. We analysed patterns agents 12 permanent plots 89 temporary plots. Most was associated with beetles. However, growth rates (an indicator chronic stress) sizes suffered greatest beetle‐related differed sharply taxa, variously conforming domination ( Abies concolor ), Pinus lambertiana P. ponderosa ) mix two Calocedrus decurrens ). Quercus kelloggii remained relatively low. Thus, even drought substantial proportions survived because they were mostly avoided fatal insect attack. Conversely, comparatively unstressed died selectively killed Synthesis . Native primarily responsible drought. idiosyncratic host‐tree different beetle taxa meant suffering strikingly taxa—for example, high small species, but large another. If proves to generally common phenomenon, it could help explain weak broadscale correlations between traits

Language: Английский

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Plant sizes and shapes above and belowground and their interactions with climate

New Phytologist, Journal Year: 2022, Volume and Issue: 235(3), P. 1032 - 1056

Published: Feb. 12, 2022

Although the above and belowground sizes shapes of plants strongly influence plant competition, community structure, plant-environment interactions, remain poorly characterized across climate regimes. We investigated relationships among shoot root system size climate. assembled analyzed, to our knowledge, largest global database describing maximum rooting depth, lateral spread, terrestrial - more than doubling Root Systems Individual Plants 5647 observations. Water availability growth form greatly size, depth is primarily influenced by temperature seasonality. Shoot strongest predictor with diameter being two times wider width on average for woody plants. covaries size; however, geometries differ considerably climates, in arid climates having shorter shoots, but deeper, narrower systems. Additionally, estimates spread systems are likely underestimated at scale.

Language: Английский

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Lithologically Controlled Subsurface Critical Zone Thickness and Water Storage Capacity Determine Regional Plant Community Composition

Water Resources Research, Journal Year: 2019, Volume and Issue: 55(4), P. 3028 - 3055

Published: March 13, 2019

Abstract Explanations for distinct adjacent ecosystems that extend across hilly landscapes typically point to differences in climate or land use. Here we document—within a similar climate—how contrasting regional plant communities correlate with underlying lithology and reveal how water storage capacity the critical zone (CZ) explain this relationship. We present observations of subsurface CZ structure groundwater dynamics from deep boreholes quantify catchment‐wide dynamic two Franciscan rock types Northern California Coast Ranges. Our field sites have Mediterranean climate, where rains are out phase solar energy, amplifying importance periods peak ecosystem productivity dry season. In deeply weathered (~30 m at ridge) Coastal Belt argillite sandstone, ample, seasonally replenished moisture supports an evergreen forest drainage sustains baseflow throughout summer. Central argillite‐matrix mélange, thin (~3 limits total (100–200 mm) rapidly sheds winter rainfall via shallow storm saturation overland flow, resulting low plant‐available (inferred predawn tree potential) negligible can drain streams This limitation mechanism explains presence oak savanna‐woodland bounded by ephemeral streams, despite >1,800 mm average precipitation. Through hydrologic monitoring characterization, which type result regionally extensive under climate.

Language: Английский

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Digging deeper: what the critical zone perspective adds to the study of plant ecophysiology

New Phytologist, Journal Year: 2020, Volume and Issue: 226(3), P. 666 - 671

Published: Jan. 8, 2020

Summary The emergence of critical zone (CZ) science has provided an integrative platform for investigating plant ecophysiology in the context landscape evolution, weathering and hydrology. CZ lies between top vegetation canopy fresh, chemically unaltered bedrock plays a pivotal role sustaining life. We consider what perspective recently brought to study ecophysiology. specifically highlight novel research demonstrating importance deeper subsurface water nutrient relations. also point knowledge gaps opportunities, emphasising, particular, greater focus on roles deep, nonsoil resources how those influence coevolve with plants as frontier ecophysiological research.

Language: Английский

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Low Subsurface Water Storage Capacity Relative to Annual Rainfall Decouples Mediterranean Plant Productivity and Water Use From Rainfall Variability

Geophysical Research Letters, Journal Year: 2019, Volume and Issue: 46(12), P. 6544 - 6553

Published: May 28, 2019

Abstract Plant water stress in response to rainfall variability is mediated by subsurface storage, yet the controls on stored plant‐available remain poorly understood. Here we develop a probabilistic balance model for Mediterranean climates that relates amount of over wet season annual statistics and storage capacity soil weathered bedrock. This predicts low capacity—relative winter rainfall—results similar year‐to‐year summer availability, as both relatively dry winters replenish storage. Observed balances seven catchments Northern California Coast Ranges exhibited this dynamic. We hypothesized plants would be decoupled from precipitation at these storage‐capacity‐limited sites observed productivity use (inferred enhanced vegetation index) were independent totals. These areas emerged largely unscathed recent extreme drought, despite widespread plant mortality elsewhere.

Language: Английский

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