scholarly journals Fast acclimation of freezing resistance suggests no influence of winter minimum temperature on the range limit of European beech

2016 ◽  
Vol 36 (4) ◽  
pp. 490-501 ◽  
Author(s):  
Armando Lenz ◽  
Günter Hoch ◽  
Yann Vitasse
Keyword(s):  
Minimum Temperature ◽  
European Beech ◽  
Range Limit ◽  
Freezing Resistance ◽  
Winter Minimum Temperature

scholarly journals Climatic Variation of Supercooling Point in the Linden Bug Pyrrhocoris apterus (Heteroptera: Pyrrhocoridae)

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 144 ◽  
Author(s):  
Tomáš Ditrich ◽  
Václav Janda ◽  
Hana Vaněčková ◽  
David Doležel
Keyword(s):  
Cold Tolerance ◽  
Minimum Temperature ◽  
Climatic Conditions ◽  
Climatic Variation ◽  
Strongly Correlated ◽  
Supercooling Point ◽  
Pyrrhocoris Apterus ◽  
Winter Minimum Temperature ◽  
Different Populations ◽  
Insect Fitness

Cold tolerance is often one of the key components of insect fitness, but the association between climatic conditions and supercooling capacity is poorly understood. We tested 16 lines originating from geographically different populations of the linden bug Pyrrhocoris apterus for their cold tolerance, determined as the supercooling point (SCP). The supercooling point was generally well explained by the climatic conditions of the population’s origin, as the best predictor—winter minimum temperature—explained 85% of the average SCP variation between populations. The supercooling capacity of P. apterus is strongly correlated with climatic conditions, which support the usage of SCP as an appropriate metric of cold tolerance in this species.

Explaining the exceptional 4270 m high elevation limit of an evergreen oak in the south-eastern Himalayas

2020 ◽  
Vol 40 (10) ◽  
pp. 1327-1342 ◽  
Author(s):  
Yang Yang ◽  
Hang Sun ◽  
Christian Körner
Keyword(s):  
Safety Margin ◽  
High Elevation ◽  
Carbon Limitation ◽  
Range Limit ◽  
The South ◽  
Freezing Resistance ◽  
Eastern Himalayas ◽  
Alpine Treeline ◽  
South Eastern ◽  
Stressful Environment

Abstract Unlike the well-understood alpine treeline, the upper range limits of tree taxa that do not reach the alpine treeline are largely unexplained. In this study, we explored the causes of the exceptionally high elevation (4270 m) occurrence of broad-leaved evergreen oaks (Quercus pannosa) in the south-eastern Himalayas. We assessed the course of freezing resistance of buds and leaves from winter to summer at the upper elevational limit of this oak species. Linked to leaf phenology, we analyzed freezing resistance and assessed minimum crown temperature for the past 65 years. We also examined potential carbon limitation at the range limit of this species. Last season buds and leaves operated at a safety margin of 5.5 and 11 K in mid-winter. Once fully dehardened early in July, last season foliage is damaged at −5.9 and new foliage at −4.6 °C. Bud break is timed for late June to early July when low temperature extremes historically were never below −3.0 °C. The monsoon regime ensures a long remaining season (149 days), thus compensating for the late onset of shoot growth. Compared with a site at 3450 m, specific leaf area is reduced, foliar non-structural carbohydrate concentrations are similar and the δ13C signal is higher, jointly suggesting that carbon limitation is unlikely at the range limit of this species. We also show that these oaks enter the growing season with fully intact (not embolized) xylem. We conclude that the interaction between phenology and freezing tolerance results in safe flushing, while still facilitating shoot maturation before winter. These factors jointly determine the upper range limit of this oak species. Our study illuminates an exceptional case of broad-leaved evergreen tree performance near the treeline, and by exploring a suite of traits, we can underpin the central role of flushing phenology in such a stressful environment.

scholarly journals Estimating Return Intervals for Extreme Climate Conditions Related to Winter Disasters and Livestock Mortality in Mongolia

2021 ◽  
Author(s):  
Masahiko Haraguchi ◽  
Nicole Davi ◽  
Mukund Rao ◽  
Caroline Leland ◽  
Masataka Watanabe ◽  
...  
Keyword(s):  
Minimum Temperature ◽  
Drought Severity ◽  
Summer Drought ◽  
Early 19Th Century ◽  
Climate Conditions ◽  
Winter Conditions ◽  
Return Levels ◽  
Drought Conditions ◽  
Winter Minimum Temperature ◽  
Winter Severity

Abstract. Mass livestock mortality events during severe winters, a phenomenon that Mongolians call dzud, cause the country significant socioeconomic problems. Dzud is an example of a compound event, meaning that multiple climatic and social drivers contribute to the risk of occurrence. Existing studies argue that the frequency and intensity of dzud are rising due to the combined effects of climate change and variability, most notably summer drought and severe winter conditions, on top of socioeconomic dynamics such as overgrazing. Summer droughts are a precondition for dzud because scarce grasses cause malnutrition, which in turn makes livestock more vulnerable to harsh winter conditions. However, these studies typically look at a short time frame (i.e., after 1940); few have investigated either the risk or the recurrence of dzud over a century-scale climate record. This study aims to fill the gaps in technical knowledge about the recurrence probability of dzud by estimating the return levels of relevant climatic variables: summer drought conditions and winter minimum temperature. We divide the country into three regions (Northwest, Southwest, and East Mongolia) based on the mortality index at the soum (county) level. For droughts, our study uses as a proxy the tree-ring reconstructed Palmer Drought Severity Index (PDSI) for three regions between 1700–2013. For winter severity, our study uses observational data of winter minimum temperature after 1901 while inferring winter minimum temperature in Mongolia from instrumental data in Siberia that extends to the early 19th century. The Generalized Extreme Value (i.e., the statistical method to infer the probability of very rare or extreme events) shows that the return levels of drought conditions are changing over time, with variability increasing for all the regions. Winter severity, however, is constant. The median 100-year return levels of the winter minimum temperature in Mongolia have been, over the past 300 years, −26.08 °C for the Southwest, −27.99 °C for the Northwest, and −25.31 °C for the East. This study thus suggests that continued summer drought would lead to increased vulnerability and malnutrition. Here, we link meteorological characteristics to socioeconomic impacts related to livestock populations and draws attention to the need for livestock index insurance.

scholarly journals The influence of debris cover and glacial lakes on the recession of glaciers in Sikkim Himalaya, India

2013 ◽  
Vol 59 (218) ◽  
pp. 1035-1046 ◽  
Author(s):  
Smriti Basnett ◽  
Anil V. Kulkarni ◽  
Tobias Bolch
Keyword(s):  
Minimum Temperature ◽  
Meteorological Station ◽  
Climatic Data ◽  
Landsat Thematic Mapper ◽  
Sikkim Himalaya ◽  
Indian Himalaya ◽  
Supraglacial Lakes ◽  
Debris Cover ◽  
Winter Minimum Temperature ◽  
Summer Minimum

AbstractWe investigated area changes in glaciers covering an area of ∼200 km2 in the Tista basin, Sikkim, Eastern Indian Himalaya, between ∼1990 and 2010 using Landsat Thematic Mapper (TM) and Indian Remote-sensing Satellite (IRS) images and related the changes to debris cover, supraglacial lakes and moraine-dam lakes. The glaciers lost an area of 3.3 ± 0.8% between 1989/90 and 2010. More detailed analysis revealed an area loss of 2.00 ± 0.82, 2.56 ± 0.61 and 2.28 ± 2.01 km2 for the periods 1989–97, 1997–2004/05 and 2004–2009/10, respectively. This indicates an accelerated retreat of glaciers after 1997. On further analysis, we observed (1) the formation and expansion of supraglacial lakes on many debris-covered glaciers and (2) the merging of these lakes over time, leading to the development of large moraine-dam lakes. We also observed that debris-covered glaciers with lakes lose a greater area than debris-covered glaciers without lakes and debris-free glaciers. The climatic data for 24 years (1987–2011), measured at the Gangtok meteorological station (1812 m a.s.l.), showed that the region experienced a 1.0°C rise in the summer minimum temperature and a 2.0°C rise in the winter minimum temperature, indicating hotter summers and warmer winters. There was no significant trend in the total annual precipitation. We find that glacier retreat is caused mainly by a temperature increase and that debris-covered glaciers can retreat at a faster rate than debris-free glaciers, if associated with lakes.

scholarly journals Prediction of winter minimum temperature of Kolkata using statistical model

MAUSAM ◽  
2021 ◽  
Vol 57 (3) ◽  
pp. 451-458
Author(s):  
TAPAN KANTI CHAKRABORTY
Keyword(s):  
Linear Regression ◽  
Minimum Temperature ◽  
Cloud Cover ◽  
Multiple Linear Regression Model ◽  
Skill Score ◽  
Temperature Data ◽  
Wind Flow ◽  
Surface Data ◽  
Winter Minimum Temperature ◽  
Stationarity Test

Lkkj & dksydkrk ¼vfyiqj½ ds U;wure rkieku dk okLrfod iwokZuqeku 12 ?kaVs iwoZ tkjh djus ds mn~ns’; ls ik¡p izkpyksa ij vk/kkfjr cgq jSf[kd lekJ;.k ekWMy fodflr fd;k x;k gS A blds iwoZ lwpdksa dk p;u vfyiqj os/k’kkyk ls izkIr lrg vk¡dM+ksa rFkk ekSle dk;kZy; dksydkrk ds fuEu Lrj ds iou vk¡dM+ksa ds vk/kkj ij fd;k x;k gS A ;g ekWMy 237 fnuksa ds ¼o"kZ 1997&2000 dh vof/k ds tuojh ,oa Qjojh ekg ds½ vk¡dM+ksa ds uewuksa rFkk dkQh yach vof/k ¼o"kZ 1988&2004½ ds U;wure rkieku ds vk¡dM+ksa es fLFkjrk dh tk¡p ds vk/kkj ij fodflr fd;k x;k gS A bl ekWMy dh tk¡p 178 fnuksa ds vk¡dM+ksa ds Lora= uewus ds vk/kkj ij dh xbZ gS A bl ekWMy dh {kerk dh tk¡p lkaf[;dh; vk¡dM+ksa ds vk/kkj ij dh xbZ gS vkSj bls ldkjkRed ik;k x;k gSA bl ekWMy dk mi;ksx ekSle iwokZuqekudRrkZ }kjk U;wure rkieku ds iwokZuqeku dk vkdyu djus ds fy, fd;k tk ldrk gS vkSj ;fn ckny rFkk iou dh xfr ds :[k esa ckn esa ifjorZu laHkkfor gks rks mlesa lq/kkj fd;k tk ldrk gS A  Five parameter multiple linear regression model for objective forecasting of minimum temperature of Kolkata (Alipore) with 12 hours lead period has been developed. The predictors are chosen from the available surface data of Alipore observatory and low level wind data of M. O. Kolkata. Model has been developed from data sample comprising of 237 days (in January and February, period: 1997 – 2000) after stationarity test of minimum temperature data of much longer period (1988–2004). The model is tested with independent sample of 178 days. Efficiencies of the model have been tested with statistical skill score and found to be positive. The model can be used by the forecaster for assessing prediction minimum temperature and modify if cloud cover and wind flow pattern are expected to change subsequently.  

scholarly journals Detection of urbanization signals in extreme winter minimum temperature changes over Northern China

2013 ◽  
Vol 122 (4) ◽  
pp. 595-608 ◽  
Author(s):  
Qingxiang Li ◽  
Jiayou Huang ◽  
Zhihong Jiang ◽  
Liming Zhou ◽  
Peng Chu ◽  
...  
Keyword(s):  
Minimum Temperature ◽  
Northern China ◽  
Temperature Changes ◽  
Winter Minimum Temperature
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