Impacts of an Extreme Early-Season Freeze Event in the Interior Pacific Northwest (30 October–3 November 2002) on Western Juniper Woodlands

Abstract In mid-autumn 2002, an exceptional 5-day cold spell affected much of the interior Pacific Northwest, with minimum temperatures averaging 13°C below long-term means (1953–2002). On 31 October, minimum temperature records occurred at 98 of the 106 recording stations, with records lowered in some locations by 9°C. Calculation of recurrence intervals of minimum temperatures shows that 50% of the stations experienced a >500-yr event. The synoptic conditions responsible were the development of a pronounced high pressure ridge over western Canada and an intense low pressure area centered in the Intermountain West that promoted strong northeasterly winds. The cold spell occurred near the end of the growing season for an ecologically critical and dominant tree species of the interior Pacific Northwest—western juniper—and followed an extended period of severe drought. In spring 2003, it became apparent that the cold had caused high rates of tree mortality and canopy dieback in a species that is remarkable for its longevity and resistance to climatic stress. The cold event altered western juniper dominance in some areas, and this alteration may have long-term impacts on water budgets, fire intensities and frequencies, animal species interrelationships, and interspecific competition among plant species.

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Climatic Regionalization and the Spatio-Temporal Occurrence of Extreme Single-Year Drought Events (1500–1998) in the Interior Pacific Northwest, USA

Quaternary Research ◽

10.1006/qres.2002.2376 ◽

2002 ◽

Vol 58 (3) ◽

pp. 226-233 ◽

Cited By ~ 29

Author(s):

Paul A. Knapp ◽

Henri D. Grissino-Mayer ◽

Peter T. Soulé

Keyword(s):

Pacific Northwest ◽

Radial Growth ◽

Extended Period ◽

Growth Indices ◽

Spring Precipitation ◽

Enso Events ◽

Western Juniper ◽

Northern Nevada ◽

The Pacific ◽

Spatio Temporal

AbstractTree-ring records from western juniper (Juniperus occidentalis var. occidentalis Hook.) growing throughout the interior Pacific Northwest identify extreme climatic pointer years (CPYs) (i.e., severe single-year droughts) from 1500–1998. Widespread and extreme CPYs were concentrated in the 16th and early part of the 17th centuries and did not occur again until the early 20th century. The 217-yr absence of extreme CPYs may have occurred during an extended period of low variance in the Pacific Decadal Oscillation. We mapped climatic boundaries for the interior Pacific Northwest based on the location of sites with similar precipitation variability indices. Three regions, the Northwest (based on chronologies from nine sites), the Southwest (four sites), and the East (five sites) were identified. Our results suggest that western juniper radial growth indices have substantial interannual variability within the northwestern range of the species (central Oregon), particularly when compared with western juniper growing in its eastern range (eastern Oregon, southeastern Idaho, and northern Nevada) and southwestern range (southern Oregon and northeast California). We suspect that the substantial differences in the variability of western juniper radial growth indices are linked to the influence of ENSO events on winter/spring precipitation amounts.

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Recruitment patterns following a severe drought: long-term compositional shifts in Patagonian forests

Canadian Journal of Forest Research ◽

10.1139/x08-149 ◽

2008 ◽

Vol 38 (12) ◽

pp. 3002-3010 ◽

Cited By ~ 80

Author(s):

María L. Suarez ◽

Thomas Kitzberger

Keyword(s):

Vegetation Change ◽

Forest Canopy ◽

Tree Mortality ◽

Forest Composition ◽

Future Climate Change ◽

Severe Drought ◽

Climate Change Scenarios ◽

Recruitment Pattern ◽

Recruitment Patterns

Severe droughts have the potential of inducing transient shifts in forest canopy composition by altering species-specific adult tree mortality patterns. However, permanent vegetation change will occur only if tree recruitment patterns are also affected. Here, we analyze how a massive mortality event triggered by the 1998–1999 drought affected adult and sapling mortality and recruitment in a mixed Nothofagus dombeyi (Mirb.) Blume – Austrocedrus chilensis (D. Don) Flor. et Boult. forests of northern Patagonia. Comparing drought-induced and tree-fall gaps, we assessed changes in forest composition, microenvironments, and seedling density and survival of both species. Drought-kill disturbance shifted species composition of both canopy and sapling cohorts in favour of A. chilensis. Drought gaps were characterized by a shadier and more xeric environment, affecting the recruitment pattern of N. dombeyi seedlings. The seedling cohort was composed mostly of A. chilensis, and its survival was always higher than that of N. dombeyi. Additionally, A. chilensis seedlings showed higher plasticity than N. dombeyi seedlings, increasing its root to shoot ratios in drought gaps. The results suggest that extreme drought itself is a strong driving force in forest dynamics, with important imprints on forest landscapes. Future climate-change scenarios, projecting an increased in frequency and severity of droughts, alert us about expected long-term compositional shifts in many forest ecosystems.

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Differential tree mortality in response to severe drought: evidence for long-term vegetation shifts

Journal of Ecology ◽

10.1111/j.1365-2745.2005.01042.x ◽

2005 ◽

Vol 93 (6) ◽

pp. 1085-1093 ◽

Cited By ~ 332

Author(s):

REBECCA C. MUELLER ◽

CRESCENT M. SCUDDER ◽

MARIANNE E. PORTER ◽

R. TALBOT TROTTER ◽

CATHERINE A. GEHRING ◽

...

Keyword(s):

Tree Mortality ◽

Severe Drought ◽

Vegetation Shifts

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Differential impact of severe drought on infant mortality in two sympatric neotropical primates

Royal Society Open Science ◽

10.1098/rsos.200302 ◽

2020 ◽

Vol 7 (4) ◽

pp. 200302 ◽

Cited By ~ 2

Author(s):

Fernando A. Campos ◽

Urs Kalbitzer ◽

Amanda D. Melin ◽

Jeremy D. Hogan ◽

Saul E. Cheves ◽

...

Keyword(s):

Infant Mortality ◽

Tree Mortality ◽

Natural Populations ◽

Dry Forest ◽

Primate Species ◽

Spider Monkeys ◽

Severe Drought ◽

Climate Conditions ◽

Fruit Abundance

Extreme climate events can have important consequences for the dynamics of natural populations, and severe droughts are predicted to become more common and intense due to climate change. We analysed infant mortality in relation to drought in two primate species (white-faced capuchins, Cebus capucinus imitator, and Geoffroy's spider monkeys, Ateles geoffroyi ) in a tropical dry forest in northwestern Costa Rica. Our survival analyses combine several rare and valuable long-term datasets, including long-term primate life-history, landscape-scale fruit abundance, food-tree mortality, and climate conditions. Infant capuchins showed a threshold mortality response to drought, with exceptionally high mortality during a period of intense drought, but not during periods of moderate water shortage. By contrast, spider monkey females stopped reproducing during severe drought, and the mortality of infant spider monkeys peaked later during a period of low fruit abundance and high food-tree mortality linked to the drought. These divergent patterns implicate differing physiology, behaviour or associated factors in shaping species-specific drought responses. Our findings link predictions about the Earth's changing climate to environmental influences on primate mortality risk and thereby improve our understanding of how the increasing severity and frequency of droughts will affect the dynamics and conservation of wild primates.

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Quantifying whole tree non-structural carbon dynamics under long-term experimental drought using radiocarbon

10.5194/egusphere-egu21-3330 ◽

2021 ◽

Author(s):

Drew Peltier ◽

Mariah Carbone ◽

Christopher Ebert ◽

Xiaomei Xu ◽

Henry Adams ◽

...

Keyword(s):

Stress Responses ◽

Tree Mortality ◽

Carbon Dynamics ◽

Severe Drought ◽

Mature Trees ◽

Coarse Roots ◽

Additional Information ◽

Structural Carbon ◽

Whole Tree

<div> <div> <div> <p>Under increasingly frequent, persistent, and severe drought events, predicting future forest carbon dynamics necessitates quantitative understanding of the physiological processes leading to tree mortality and physiological impairment. The responses of non-structural carbon (NSC; primarily sugars and starch) pools in mature trees is particularly important, as dynamics in NSC interact with hydraulic damage to perturb future tree growth. However, NSC concentration measurements alone are not suUcient to understand the stress responses of tree NSC pools formed over years to decades. Thus, we are using radiocarbon (14C) to quantify the age of NSC stored within, and used by, pi&#241;on pine trees exposed to either severe or long-term drought stress at the Sevilleta LTER, in New Mexico, USA. Measuring the age of NSC allows inference on the storage history of a tree, and how different NSC pools may be altered by drought. Experimental plots are subjected to either 0% (control) or 90% reduction in precipitation. A 45% precipitation reduction plot has also been in place since 2009, offering a chance to study the impacts of a decade of drought. We are measuring &#916;14C of NSC in twigs, bole sapwood, and coarse roots, as well as in CO2 respired from the bole and branches. Our goal is to quantify the role of different-aged NSC pools across tree organs in driving whole-tree physiological responses to drought. Preliminary results show that the long-term droughted trees store and respire on average younger NSC than control trees. Ongoing drought treatments and sampling will provide additional information on how NSC dynamics in these trees are influenced by drought.</p> </div> </div> </div>

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Long-Term Cryopreservation Does Not Affect Quality of Peripheral Blood Stem Cell Grafts: A Comparative Study of Native, Short-Term and Long-Term Cryopreserved Haematopoietic Stem Cells

Cell Transplantation ◽

10.1177/09636897211036004 ◽

2021 ◽

Vol 30 ◽

pp. 096368972110360

Author(s):

Daniel Lysak ◽

Michaela Brychtová ◽

Martin Leba ◽

Miroslava Čedíková ◽

Daniel Georgiev ◽

...

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Statistical Significance ◽

Extended Period ◽

High Dose ◽

Atp Production ◽

Cd34 Cells ◽

Negative Effect

Cryopreserved haematopoietic progenitor cells are used to restore autologous haematopoiesis after high dose chemotherapy. Although the cells are routinely stored for a long period, concerns remain about the maximum storage time and the possible negative effect of storage on their potency. We evaluated the effect of cryopreservation on the quality of peripheral stem cell grafts stored for a short (3 months) and a long (10 years) period and we compared it to native products.The viability of CD34+ cells remained unaffected during storage, the apoptotic cells were represented up to 10% and did not differ between groups. The clonogenic activity measured by ATP production has decreased with the length of storage (ATP/cell 1.28 nM in native vs. 0.63 in long term stored products, P < 0.05). Only borderline changes without statistical significance were detected when examining mitochondrial and aldehyde dehydrogenase metabolic activity and intracellular pH, showing their good preservation during cell storage. Our experience demonstrates that cryostorage has no major negative effect on stem cell quality and potency, and therefore autologous stem cells can be stored safely for an extended period of at least 10 years. On the other hand, long term storage for 10 years and longer may lead to mild reduction of clonogenic capacity. When a sufficient dose of stem cells is infused, these changes will not have a clinical impact. However, in products stored beyond 10 years, especially when a low number of CD34+ cells is available, the quality of stem cell graft should be verified before infusion using the appropriate potency assays.

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Development and Verification of the Available Number of Water Intake Days in Ungauged Local Water Source Using the SWAT Model and Flow Recession Curves

Water ◽

10.3390/w13111511 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1511

Author(s):

Jung-Ryel Choi ◽

Il-Moon Chung ◽

Se-Jin Jeung ◽

Kyung-Su Choo ◽

Cheong-Hyeon Oh ◽

...

Keyword(s):

Water Supply ◽

Water Intake ◽

Water Resource Management ◽

Assessment Tool ◽

Swat Model ◽

High Water ◽

Coefficient Of Determination ◽

Severe Drought ◽

Regional Government

Climate change significantly affects water supply availability due to changes in the magnitude and seasonality of runoff and severe drought events. In the case of Korea, despite high water supply ratio, more populations have continued to suffer from restricted regional water supplies. Though Korea enacted the Long-Term Comprehensive Water Resources Plan, a field survey revealed that the regional government organizations limitedly utilized their drought-related data. These limitations present a need for a system that provides a more intuitive drought review, enabling a more prompt response. Thus, this study presents a rating curve for the available number of water intake days per flow, and reviews and calibrates the Soil and Water Assessment Tool (SWAT) model mediators, and found that the coefficient of determination, Nash–Sutcliffe efficiency (NSE), and percent bias (PBIAS) from 2007 to 2011 were at 0.92, 0.84, and 7.2%, respectively, which were “very good” levels. The flow recession curve was proposed after calculating the daily long-term flow and extracted the flow recession trends during days without precipitation. In addition, the SWAT model’s flow data enables the quantitative evaluations of the number of available water intake days without precipitation because of the high hit rate when comparing the available number of water intake days with the limited water supply period near the study watershed. Thus, this study can improve drought response and water resource management plans.

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How Do Trade-Offs and Synergies between Ecosystem Services Change in the Long Period? The Case Study of Uxin, Inner Mongolia, China

Sustainability ◽

10.3390/su11216041 ◽

2019 ◽

Vol 11 (21) ◽

pp. 6041 ◽

Cited By ~ 2

Author(s):

Zhang ◽

Li ◽

Buyantuev ◽

Bao ◽

Zhang

Keyword(s):

Ecosystem Services ◽

Inner Mongolia ◽

Stepwise Regression ◽

Driving Forces ◽

Extended Period ◽

Trade Offs ◽

Development And Utilization ◽

Long Term Trends

Ecosystem services management should often expect to deal with non-linearities due to trade-offs and synergies between ecosystem services (ES). Therefore, it is important to analyze long-term trends in ES development and utilization to understand their responses to climate change and intensification of human activities. In this paper, the region of Uxin in Inner Mongolia, China, was chosen as a case study area to describe the spatial distribution and trends of 5 ES indicators. Changes in relationships between ES and driving forces of dynamics of ES relationships were analyzed for the period 1979–2016 using a stepwise regression. We found that: the magnitude and directions in ES relationships changed during this extended period; those changes are influenced by climate factors, land use change, technological progress, and population growth.

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