scholarly journals Increased climate pressure on the agricultural frontier in the Eastern Amazonia–Cerrado transition zone

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
José A. Marengo ◽  
Juan C. Jimenez ◽  
Jhan-Carlo Espinoza ◽  
Ana Paula Cunha ◽  
Luiz E. O. Aragão
Keyword(s):  
Transition Zone ◽  
Large Scale ◽  
Vapor Pressure Deficit ◽  
Environmental Changes ◽  
Severe Drought ◽  
Wet Season ◽  
Agricultural Frontier ◽  
Global Food Security ◽  
Drought Conditions ◽  
Global Food

AbstractSeveral large-scale drivers of both anthropogenic and natural environmental changes are interacting nonlinearly in the transition zone between eastern Amazonia and the adjacent Cerrado, considered to be another Brazilian agricultural frontier. Land-use change for agrobusiness expansion together with climate change in the transition zone between eastern Amazonia and the adjacent Cerrado may have induced a worsening of severe drought conditions over the last decade. Here we show that the largest warming and drying trends over tropical South America during the last four decades are observed to be precisely in the eastern Amazonia–Cerrado transition region, where they induce delayed wet-season and worsen severe drought conditions over the last decade. Our results evidence an increase in temperature, vapor pressure deficit, subsidence, dry-day frequency, and a decrease in precipitation, humidity, and evaporation, plus a delay in the onset of the wet season, inducing a higher risk of fire during the dry-to-wet transition season. These findings provide observational evidence of the increasing climatic pressure in this area, which is sensitive for global food security, and the need to reconcile agricultural expansion and protection of natural tropical biomes.

scholarly journals Increased Climate Pressure on the New Agricultural Frontier in the Eastern Amazonia-Cerrado Transition Zone

2021 ◽  
Author(s):  
José A. Marengo ◽  
Juan C. Jimenez ◽  
Jhan-Carlo Espinoza ◽  
Ana Paula Cunha ◽  
Luiz E. O. Aragão
Keyword(s):  
South America ◽  
Transition Region ◽  
Transition Zone ◽  
Large Scale ◽  
Environmental Changes ◽  
Severe Drought ◽  
Wet Season ◽  
Agricultural Frontier ◽  
Drought Conditions ◽  
Tropical South America

Abstract Several large-scale drivers of both anthropogenic and natural environmental changes are interacting nonlinearly in the transition zone between eastern Amazonia and the adjacent Cerrado, considered to be the new Brazilian agricultural frontier. Land-use change for agrobusiness expansion together with climate change in the transition zone between eastern Amazonia and the adjacent Cerrado may have induced a worsening of severe drought conditions over the last decade. The largest warming and drying trends observed over tropical South America during the last four decades are found to be precisely in this eastern Amazonia-Cerrado transition region, where they induce delayed wet-season onset. Here we show that the largest warming and drying trends over tropical South America during the last four decades are observed to be precisely in the eastern Amazonia-Cerrado transition region, with a worsening of severe drought conditions over the last decade. Our results evidence an increase in temperature, vapor pressure deficit, subsidence, dry-day frequency, and a decrease in precipitation, humidity, and evaporation, plus a delay in the onset of the wet season, inducing a higher risk of fire during the dry-to-wet transition season. These findings provide observational evidence of the increasing climatic pressure in this area, which is sensitive for global food security, and the need to reconcile agricultural expansion and protection of natural tropical biomes.

scholarly journals Towards understanding hydroclimatic change in Victoria, Australia – why was the last decade so dry?

2009 ◽  
Vol 6 (5) ◽  
pp. 6181-6206 ◽  
Author(s):  
A. S. Kiem ◽  
D. C. Verdon-Kidd
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Large Scale ◽  
Regional Scale ◽  
Seasonal Rainfall ◽  
Severe Drought ◽  
Physical Mechanisms ◽  
Drought Conditions ◽  
Hydroclimatic Change ◽  
Impacts Of Climate Change

Abstract. Since the mid-1990s Victoria, located in southeast Australia, has experienced severe drought conditions characterized by streamflow that is the lowest on record in many areas. While severe decreases in annual and seasonal rainfall totals have also been observed, this alone does not seem to explain the observed reduction in flow. In this study, we investigate the large-scale climate drivers for Victoria and demonstrate how these modulate the regional scale synoptic patterns, which in turn alter the way seasonal rainfall totals are compiled and the amount of runoff per unit rainfall that is produced. The hydrological implications are significant and illustrate the need for robust hydrological modelling, which takes into account insights into physical mechanisms that drive regional hydroclimatology, in order to properly understand and quantify the impacts of climate change (natural and/or anthropogenic) on water resources.

scholarly journals Trends and Extremes of Drought Episodes in Vietnam Sub-Regions during 1980–2017 at Different Timescales

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 813 ◽  
Author(s):  
Milica Stojanovic ◽  
Margarida L.R. Liberato ◽  
Rogert Sorí ◽  
Marta Vázquez ◽  
Tan Phan-Van ◽  
...  
Keyword(s):  
Large Scale ◽  
Root Zone ◽  
Southern Oscillation ◽  
Standardized Precipitation Index ◽  
Lower Troposphere ◽  
Severe Drought ◽  
Positive Trend ◽  
Drought Conditions ◽  
Northern Regions ◽  
Dry Conditions

This study investigated the temporal occurrence of dry conditions in the seven climatic sub-regions of Vietnam during the 1980–2017 period. This assessment was performed using the Standardized Precipitation Evapotranspiration Index (SPEI) and the Standardized Precipitation Index (SPI) at 1 to 24 months timescales. Results show that the main periods of extreme drought occurred simultaneously throughout the country in 1992–1993 and 2003–2004, except for 2015–2016, when it was not identified in the southern region. In addition, a slight temporal lag was identified latitudinally (north–south) at the beginning of dry conditions, revealing the largest difference between the northern and southern regions. A positive trend in the time series of both indices (SPEI and SPI) prevailed in all sub-regions, with the SPEI minus SPI difference always being negative, suggesting the importance of temperature and evapotranspiration for this trend. Further detailed analyses were then performed using SPEI at 1-month and 12-months timescales for all climate sub-regions, as well as the main indicators to characterize duration and severity. Results show that the number of drought episodes did not vary much between regions, but they did vary in duration and severity at the annual scale. Moreover, changes in the soil root zone are largely associated with dry and wet conditions not only from season to season, but also in longer accumulation periods and more strongly in the northern regions of Vietnam. Indeed, a study of the most severe drought episodes also revealed the occurrence of negative anomalies of the root-soil moisture in the subsequent four or more months. Dynamic atmospheric conditions associated with the peak of most severe drought episodes show the crucial role of subsidence of dry air in the middle and high atmosphere, which prevents convection in the lower troposphere. Finally, the linkages between drought conditions in Vietnam and large-scale atmospheric and oceanic teleconnection patterns were revealed to be quite different among northern and southern sub-regions. During the positive phase of El Niño–Southern Oscillation (ENSO), drought episodes at different timescales were identified in the southern climate sub-regions, while the negative phase was associated with drought conditions in the northern regions.

scholarly journals Global food insecurity. Treatment of major food crops with elevated carbon dioxide or ozone under large-scale fully open-air conditions suggests recent models may have overestimated future yields

2005 ◽  
Vol 360 (1463) ◽  
pp. 2011-2020 ◽  
Author(s):  
Stephen P Long ◽  
Elizabeth A Ainsworth ◽  
Andrew D.B Leakey ◽  
Patrick B Morgan
Keyword(s):  
Carbon Dioxide ◽  
Food Security ◽  
Large Scale ◽  
Extensive Study ◽  
Interactive Effects ◽  
Yield Losses ◽  
Air Concentration ◽  
Global Food Security ◽  
Large Yield ◽  
Global Food

Predictions of yield for the globe's major grain and legume arable crops suggest that, with a moderate temperature increase, production may increase in the temperate zone, but decline in the tropics. In total, global food supply may show little change. This security comes from inclusion of the direct effect of rising carbon dioxide (CO 2 ) concentration, [CO 2 ], which significantly stimulates yield by decreasing photorespiration in C 3 crops and transpiration in all crops. Evidence for a large response to [CO 2 ] is largely based on studies made within chambers at small scales, which would be considered unacceptable for standard agronomic trials of new cultivars or agrochemicals. Yet, predictions of the globe's future food security are based on such inadequate information. Free-Air Concentration Enrichment (FACE) technology now allows investigation of the effects of rising [CO 2 ] and ozone on field crops under fully open-air conditions at an agronomic scale. Experiments with rice, wheat, maize and soybean show smaller increases in yield than anticipated from studies in chambers. Experiments with increased ozone show large yield losses (20%), which are not accounted for in projections of global food security. These findings suggest that current projections of global food security are overoptimistic. The fertilization effect of CO 2 is less than that used in many models, while rising ozone will cause large yield losses in the Northern Hemisphere. Unfortunately, FACE studies have been limited in geographical extent and interactive effects of CO 2 , ozone and temperature have yet to be studied. Without more extensive study of the effects of these changes at an agronomic scale in the open air, our ever-more sophisticated models will continue to have feet of clay.

A consistent link between drought and forest diebacks across Europe

2020 ◽  
Author(s):  
Cornelius Senf ◽  
Allan Buras ◽  
Christian Zang ◽  
Anja Rammig ◽  
Rupert Seidl
Keyword(s):  
Vapor Pressure ◽  
Large Scale ◽  
Tree Mortality ◽  
Vapor Pressure Deficit ◽  
Tree Canopy ◽  
Drought Indices ◽  
Spatially Explicit ◽  
Quantitative Evidence ◽  
Drought Conditions ◽  
Landsat Satellite

<p>Drought has been suggested as major driver of large-scale forest diebacks, but quantitative evidence covering large spatial and long temporal scales is rare for Europe. Combining spatially explicit maps of canopy mortality (i.e., partial or full loss of the dominant tree canopy) generated from Landsat satellite data for the period 1986-2016 and gridded drought indices (0.5° resolution; including vapor pressure deficit, climatic water balance, and precipitation deficit), we report a consistent link between pulses of above-average tree mortality and drought conditions as measured in all three drought indices. As such, we deliver first quantitative evidence that drought conditions can trigger large-scale forest diebacks across Europe’s forests. A future increase in the severity and intensity of droughts as predicted for Europe might thus have unforeseen consequences for Europe’s forests, with large-scale forest diebacks likely becoming more common in the future.</p>

scholarly journals Mitigating Drought Conditions under Climate and Land Use Changes by Applying Hedging Rules for the Multi-Reservoir System

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3095
Author(s):  
Zejun Li ◽  
Bensheng Huang ◽  
Zhifeng Yang ◽  
Jing Qiu ◽  
Bikui Zhao ◽  
...  
Keyword(s):  
Land Use ◽  
Environmental Changes ◽  
Land Use Changes ◽  
Hydrologic Model ◽  
Future Climate ◽  
Severe Drought ◽  
Reservoir System ◽  
Operating Rules ◽  
Drought Conditions ◽  
Hedging Rules

Climate and land use changes have substantially affected hydrologic cycles and increased the risk of drought. Reservoirs are one of the important means to provide resilience against hydrologic variability and achieve sustainable water management. Therefore, adaptive reservoir operating rules are needed to mitigate their adverse effects. In this study, the Hanjiang River Basin in southeast China was selected as the study area. Future climate and land use projections were produced by the Delta method and CA-Markov model, respectively. Future climate forcings and land use patterns were then incorporated into a distributed hydrologic model to evaluate river flow regime shifts. Results revealed that climate and land use changes may lead to severe drought conditions in the future. Lower flows are shown to be more sensitive to environmental changes and a decline of monthly flows could reach up to nearly 30% in the dry season. To address the threat of increasing drought uncertainties in the water supply system, the aggregation-decomposition method incorporated with hedging rules was applied to guide the multi-reservoir operation. Parameters of optimal hedging rules were obtained by a multi-objective optimization algorithm. The performance of hedging rules was evaluated by comparison to standard operating policies and conventional operating rules with respect to reliability, resiliency, vulnerability, and sustainability indices. Results showed that the multi-reservoir system guided by hedging rules can be more adaptive to the environmental changes.

Toward large-scale crop production forecasts for global food security

2016 ◽  
Vol 60 (5/6) ◽  
pp. 5:1-5:11 ◽  
Author(s):  
G. Badr ◽  
L. J. Klein ◽  
M. Freitag ◽  
C. M. Albrecht ◽  
F. J. Marianno ◽  
...  
Keyword(s):  
Food Security ◽  
Crop Production ◽  
Large Scale ◽  
Global Food Security ◽  
Global Food

scholarly journals Towards understanding hydroclimatic change in Victoria, Australia – preliminary insights into the "Big Dry"

2010 ◽  
Vol 14 (3) ◽  
pp. 433-445 ◽  
Author(s):  
A. S. Kiem ◽  
D. C. Verdon-Kidd
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Large Scale ◽  
Regional Scale ◽  
Seasonal Rainfall ◽  
Severe Drought ◽  
Physical Mechanisms ◽  
Drought Conditions ◽  
Hydroclimatic Change ◽  
Impacts Of Climate Change

Abstract. Since the mid-1990s the majority of Victoria, Australia, has experienced severe drought conditions (i.e. the "Big Dry") characterized by streamflow that is the lowest in approximately 80 years of record. While decreases in annual and seasonal rainfall totals have also been observed, this alone does not seem to explain the observed reduction in flow. In this study, we investigate the large-scale climate drivers for Victoria and demonstrate how these modulate the regional scale synoptic patterns, which in turn alter the way seasonal rainfall totals are compiled and the amount of runoff per unit rainfall that is produced. The hydrological implications are significant and illustrate the need for robust hydrological modelling, that takes into account insights into physical mechanisms that drive regional hydroclimatology, in order to properly understand and quantify the impacts of climate change (natural and/or anthropogenic) on water resources.

scholarly journals Features and applications of haplotypes in crop breeding

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Javaid Akhter Bhat ◽  
Deyue Yu ◽  
Abhishek Bohra ◽  
Showkat Ahmad Ganie ◽  
Rajeev K. Varshney
Keyword(s):  
Agricultural Production ◽  
Large Scale ◽  
Production Systems ◽  
Complex Trait ◽  
Disease Dynamics ◽  
Crop Breeding ◽  
Global Food Security ◽  
Breeding Efficiency ◽  
Global Food ◽  
Agricultural Production Systems

AbstractClimate change with altered pest-disease dynamics and rising abiotic stresses threatens resource-constrained agricultural production systems worldwide. Genomics-assisted breeding (GAB) approaches have greatly contributed to enhancing crop breeding efficiency and delivering better varieties. Fast-growing capacity and affordability of DNA sequencing has motivated large-scale germplasm sequencing projects, thus opening exciting avenues for mining haplotypes for breeding applications. This review article highlights ways to mine haplotypes and apply them for complex trait dissection and in GAB approaches including haplotype-GWAS, haplotype-based breeding, haplotype-assisted genomic selection. Improvement strategies that efficiently deploy superior haplotypes to hasten breeding progress will be key to safeguarding global food security.

Sign in / Sign up

Export Citation Format

Share Document