Increasing vulnerability of an endemic Mediterranean-climate conifer to changing climate and fire regime

Frontiers in Forests and Global Change, Год журнала: 2025, Номер 8

Опубликована: Янв. 30, 2025

Conifer species of Mediterranean-type ecosystems (MTEs) are especially sensitive to coupled changes in climate and fire regime. Recently California’s MTE conifers have experienced elevated mortality, range shifts, decreased abundance relative broadleaf trees. Restricted-range may be vulnerable environmental change a high priority for assessment adaptation management. We used distribution modeling wildfire probability models assess the potential vulnerability Pseudotsuga macrocarpa (Bigcone Douglas fir, hereafter BDF), restricted-range conifer southern California mountains that is concern because its ecological importance recent mortality due drought wildfire. also modeled Quercus chrysolepis (CLO), widespread oak can co-dominant with BDF limit spread reduce crown risk compared from surrounding chaparral vegetation. Ensembles MAXENT General Boosted Models were produced 2.1 million ha model domain encompassing BDF’s 672,000 period 1981–2010, projected 2040–2069 2070–2099 using three (warmer-wetter, warmer, hotter-drier) under emission scenario (IPCC 5th Assessment, RCP 8.5). Wildfire projections analyzed only mid-century based on warmer-wetter hotter-drier scenarios. Our analysis contributes several important new insights: (1) topoclimatic habitat could shrink by 19–57% mid-century, southernmost populations; (2) increase 2–4 fold habitat, potentially diminishing value mid-to-high elevation sites as refugia; (3) CLO play role providing refuge severe wildfires soon but end-of-century; (4) extensive areas stable late-century confined national forests San Gabriel Mountains Transverse Ranges. The reduced management actions such mechanical fuel treatments post-fire restoration, these highly constrained topography, access, wildlife species. case study illustrates rapidly increasing endemic forests.

Язык: Английский

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Exploring Water System Vulnerabilities in California's Central Valley Under the Late Renaissance Megadrought and Climate Change

Earth s Future, Год журнала: 2025, Номер 13(4)

Опубликована: Апрель 1, 2025

Abstract California faces cycles of drought and flooding that are projected to intensify, but these extremes may impact water users across the state differently due region's natural hydroclimate variability complex institutional framework governing deliveries. To assess risks, this study introduces a novel exploratory modeling informed by paleo climate‐change based scenarios better understand how impacts propagate through Central Valley's system. A stochastic weather generator, conditioned on tree‐ring data, produces large ensemble daily sequences flood conditions under Late Renaissance Megadrought period (1550–1580 CE). Regional climate changes applied data drive hydrologic projections for Sacramento, San Joaquin, Tulare Basins. The resulting streamflow ensembles used in an stress test using Food‐Energy‐Water System model, highly resolved, model storage conveyance throughout California's Valley. Results show megadrought lead unprecedented reductions inflows at major reservoirs. Both junior senior rights holders experience multi‐year periods curtailed deliveries complete drawdowns groundwater assets. When dynamics combined with change, risks depletion reservoir sustained curtailment multiple years increase. Asymmetries risk emerge depending source, rights, access banks.

Язык: Английский

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Escalating Hydrological Extremes and Whiplashes in the Western U.S.: Challenges for Water Management and Frontline Communities

Earth s Future, Год журнала: 2025, Номер 13(5)

Опубликована: Май 1, 2025

Abstract The Western U.S. is experiencing significant changes in its hydrological dynamics, marked by increased variability and rapid “whiplash” shifts between extreme drought flood conditions. This study quantified these using a customized water year index, which correlated better with surface storage the basins than other drought/wetness indicators. Application of index revealed heightened extremes whiplash events post‐2015 all basins, nearly 72% stations facing critically dry conditions 2021 over 54% wet 2023. Future projections indicate decline 8.5%–13.2% non‐extreme types across major accompanied increases both types. Our findings suggest that similar levels multi‐year duration deficits will likely occur regardless future warming scenarios. trend significantly impacts agriculture, environment, urban use sectors. Notably, vulnerable frontline communities higher risks lower resilience experience disproportionate from droughts compared to communities.

Язык: Английский

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Assessment of Future Precipitation Changes in Mediterranean Climate Regions from CMIP6 ensemble

Опубликована: Янв. 5, 2024

Abstract. Previous studies have indicated a large model disagreement in the future projections of precipitation changes over regions featuring Mediterranean climate. Many these highly populated been experiencing major droughts recent decades, raising concerns about and their impacts. Here we investigate across five climate CMIP6 ensemble, study respective agreements on sign changes. We focus period 2050–2079 relative to 1970–1999, consider two change scenarios (ssp2-4.5 ssp5-8.5) Basin (MED), California (CAL), central coast Chile (SAA), Cape Province area South Africa (SAF) southwest Australia (AUS). The ensemble mean suggests that annual cumulative will decrease all studied with exception northern California. In most cases, this decline is primarily attributed reduction winter precipitation, except Basin, where significant occurs autumn. agreement generally high seasons indicates future, low showing increase or no change. Specifically, southern during seasons, autumn, austral summer means also indicate consecutive dry days (CDD) regions, but again California, Mediterranean, parts Australia. Similarly, wet (CWD) weak CAL, northeast AUS part MED region. maximum one-day increases Mediterranean. conclude despite substantial improvements new generation models, intermodel differences continue be Impact need account for uncertainties whole range projected

Язык: Английский

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Comment on egusphere-2023-3057

Опубликована: Янв. 31, 2024

Abstract. Previous studies have indicated a large model disagreement in the future projections of precipitation changes over regions featuring Mediterranean climate. Many these highly populated been experiencing major droughts recent decades, raising concerns about and their impacts. Here we investigate across five climate CMIP6 ensemble, study respective agreements on sign changes. We focus period 2050–2079 relative to 1970–1999, consider two change scenarios (ssp2-4.5 ssp5-8.5) Basin (MED), California (CAL), central coast Chile (SAA), Cape Province area South Africa (SAF) southwest Australia (AUS). The ensemble mean suggests that annual cumulative will decrease all studied with exception northern California. In most cases, this decline is primarily attributed reduction winter precipitation, except Basin, where significant occurs autumn. agreement generally high seasons indicates future, low showing increase or no change. Specifically, southern during seasons, autumn, austral summer means also indicate consecutive dry days (CDD) regions, but again California, Mediterranean, parts Australia. Similarly, wet (CWD) weak CAL, northeast AUS part MED region. maximum one-day increases Mediterranean. conclude despite substantial improvements new generation models, intermodel differences continue be Impact need account for uncertainties whole range projected

Язык: Английский

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Reply on CC1

Опубликована: Фев. 2, 2024

Abstract. Previous studies have indicated a large model disagreement in the future projections of precipitation changes over regions featuring Mediterranean climate. Many these highly populated been experiencing major droughts recent decades, raising concerns about and their impacts. Here we investigate across five climate CMIP6 ensemble, study respective agreements on sign changes. We focus period 2050–2079 relative to 1970–1999, consider two change scenarios (ssp2-4.5 ssp5-8.5) Basin (MED), California (CAL), central coast Chile (SAA), Cape Province area South Africa (SAF) southwest Australia (AUS). The ensemble mean suggests that annual cumulative will decrease all studied with exception northern California. In most cases, this decline is primarily attributed reduction winter precipitation, except Basin, where significant occurs autumn. agreement generally high seasons indicates future, low showing increase or no change. Specifically, southern during seasons, autumn, austral summer means also indicate consecutive dry days (CDD) regions, but again California, Mediterranean, parts Australia. Similarly, wet (CWD) weak CAL, northeast AUS part MED region. maximum one-day increases Mediterranean. conclude despite substantial improvements new generation models, intermodel differences continue be Impact need account for uncertainties whole range projected

Язык: Английский

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Comment on egusphere-2023-3057

Опубликована: Фев. 2, 2024

Abstract. Previous studies have indicated a large model disagreement in the future projections of precipitation changes over regions featuring Mediterranean climate. Many these highly populated been experiencing major droughts recent decades, raising concerns about and their impacts. Here we investigate across five climate CMIP6 ensemble, study respective agreements on sign changes. We focus period 2050–2079 relative to 1970–1999, consider two change scenarios (ssp2-4.5 ssp5-8.5) Basin (MED), California (CAL), central coast Chile (SAA), Cape Province area South Africa (SAF) southwest Australia (AUS). The ensemble mean suggests that annual cumulative will decrease all studied with exception northern California. In most cases, this decline is primarily attributed reduction winter precipitation, except Basin, where significant occurs autumn. agreement generally high seasons indicates future, low showing increase or no change. Specifically, southern during seasons, autumn, austral summer means also indicate consecutive dry days (CDD) regions, but again California, Mediterranean, parts Australia. Similarly, wet (CWD) weak CAL, northeast AUS part MED region. maximum one-day increases Mediterranean. conclude despite substantial improvements new generation models, intermodel differences continue be Impact need account for uncertainties whole range projected

Язык: Английский

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Reply on CC3

Опубликована: Фев. 2, 2024

Abstract. Previous studies have indicated a large model disagreement in the future projections of precipitation changes over regions featuring Mediterranean climate. Many these highly populated been experiencing major droughts recent decades, raising concerns about and their impacts. Here we investigate across five climate CMIP6 ensemble, study respective agreements on sign changes. We focus period 2050–2079 relative to 1970–1999, consider two change scenarios (ssp2-4.5 ssp5-8.5) Basin (MED), California (CAL), central coast Chile (SAA), Cape Province area South Africa (SAF) southwest Australia (AUS). The ensemble mean suggests that annual cumulative will decrease all studied with exception northern California. In most cases, this decline is primarily attributed reduction winter precipitation, except Basin, where significant occurs autumn. agreement generally high seasons indicates future, low showing increase or no change. Specifically, southern during seasons, autumn, austral summer means also indicate consecutive dry days (CDD) regions, but again California, Mediterranean, parts Australia. Similarly, wet (CWD) weak CAL, northeast AUS part MED region. maximum one-day increases Mediterranean. conclude despite substantial improvements new generation models, intermodel differences continue be Impact need account for uncertainties whole range projected

Язык: Английский

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Reply on CC2

Опубликована: Фев. 2, 2024

Abstract. Previous studies have indicated a large model disagreement in the future projections of precipitation changes over regions featuring Mediterranean climate. Many these highly populated been experiencing major droughts recent decades, raising concerns about and their impacts. Here we investigate across five climate CMIP6 ensemble, study respective agreements on sign changes. We focus period 2050–2079 relative to 1970–1999, consider two change scenarios (ssp2-4.5 ssp5-8.5) Basin (MED), California (CAL), central coast Chile (SAA), Cape Province area South Africa (SAF) southwest Australia (AUS). The ensemble mean suggests that annual cumulative will decrease all studied with exception northern California. In most cases, this decline is primarily attributed reduction winter precipitation, except Basin, where significant occurs autumn. agreement generally high seasons indicates future, low showing increase or no change. Specifically, southern during seasons, autumn, austral summer means also indicate consecutive dry days (CDD) regions, but again California, Mediterranean, parts Australia. Similarly, wet (CWD) weak CAL, northeast AUS part MED region. maximum one-day increases Mediterranean. conclude despite substantial improvements new generation models, intermodel differences continue be Impact need account for uncertainties whole range projected

Язык: Английский

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Comment on egusphere-2023-3057

Опубликована: Янв. 29, 2024

Abstract. Previous studies have indicated a large model disagreement in the future projections of precipitation changes over regions featuring Mediterranean climate. Many these highly populated been experiencing major droughts recent decades, raising concerns about and their impacts. Here we investigate across five climate CMIP6 ensemble, study respective agreements on sign changes. We focus period 2050–2079 relative to 1970–1999, consider two change scenarios (ssp2-4.5 ssp5-8.5) Basin (MED), California (CAL), central coast Chile (SAA), Cape Province area South Africa (SAF) southwest Australia (AUS). The ensemble mean suggests that annual cumulative will decrease all studied with exception northern California. In most cases, this decline is primarily attributed reduction winter precipitation, except Basin, where significant occurs autumn. agreement generally high seasons indicates future, low showing increase or no change. Specifically, southern during seasons, autumn, austral summer means also indicate consecutive dry days (CDD) regions, but again California, Mediterranean, parts Australia. Similarly, wet (CWD) weak CAL, northeast AUS part MED region. maximum one-day increases Mediterranean. conclude despite substantial improvements new generation models, intermodel differences continue be Impact need account for uncertainties whole range projected

Язык: Английский

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