Leaf- to field-level compound effects of warm and dry conditions on crops and potential mitigating strategies

Xiangyu Luan

Leaf- to field-level compound effects of warm and dry conditions on crops and potential mitigating strategies

Bidragets översatta titel: Blandade effekter av löv till fältnivå av varma och torra förhållanden på grödor och potentiella mildrande strategier

Xiangyu Luan

Institutionen för växtproduktionsekologi

Publikation: Avhandling › Doktorsavhandling

4 Nedladdningar

Sammanfattning

Den globala livsmedelssäkerheten hotas av de pågående klimatförändringarna. Klimatförändringar förväntas leda till ökande risk för varma och torra förhållanden (här benämnda samverkande effekter) på många platser där jordbruk bedrivs. Samverkande effekter skadar jordbruksgrödor, men det finns få studier av effekten av samverkande effekter på jordbruksgrödor baserade på modelleringsmetodik. I denna avhandling etablerade vi mekanistiska och statistiska modeller för att analysera hur bladtemperaturen, transpirationshastighet och grödans avkastning påverkas av samverkande effekter. Vårt syfte var att utforska hur grödor påverkas av samverkande effekter, samt hjälpa till att identifiera anpassningsstrategier för att minska de negativa effekterna. Våra resultat indikerade att kombinationen av varma och torra förhållanden gav den högsta bladtemperaturen, och därmed den högsta risken för värmestress hos grödan och minskad avkastning. Både bladtemperaturen och avkastningsförlusterna var högre med våta och svala förhållanden än med torra och heta förhållanden. Hur temperatur och nederbörd varierade inom säsongen och deras säsongsmedel spelade lika stor roll för hur de samverkande effekterna påverkade grödan. Mer periodisk nederbörd och längre torrperioder ökade bladtemperaturen och minskade avkastningen även när de genomsnittliga klimatförhållandena förblev oförändrade. Grödor som inte bevattnats hade en specifik mängd nederbörd som var gynnsam, och denna ökade med ökad temperatur. Bevattning av grödan visade sig kunna minska men inte eliminera de negativa effekterna av samverkande effekter. En annan anpassning är en övergång från årliga till fleråriga spannmålsgrödor. Huruvida fleråriga spannmålsgrödor är mindre utsatta för värme och vattenstress beror på vissa viktiga växtegenskaper, såsom bladyteindex, något som framtida växtförädlingsprogram bör rikta in sig på för att anpassa grödor till framtida klimat.

Bidragets översatta titel	Blandade effekter av löv till fältnivå av varma och torra förhållanden på grödor och potentiella mildrande strategier
Originalspråk	Engelska
Kvalifikation	Doktor i filosofi
Förlag	Department of Crop Production Ecology, Swedish University of Agricultural Sciences
Tryckta ISBN	978-91-7760-772-4
Elektroniska ISBN	978-91-7760-773-1
Status	Publicerad - 2021

FN:s SDG:er

Detta resultat bidrar till följande hållbara utvecklingsmål:

SDG 2 – Ingen hunger
SDG 12 – Hållbar konsumtion och produktion
SDG 13 – Bekämpa klimatförändringarna

Nyckelord

Climate change
adaptation
canopy and leaf temperature
compound effect
crop yields
modeling

SLU-serie

Acta Universitatis Agriculturae Sueciae

Åtkomst av dokument

FulltextSlutlig publicerad version, 4,36 MBLicens: Ej specificerad

Andra filer och länkar

Permanent länk till denna sida

Citera det här

@phdthesis{96f3ef4dd5c1451d953dfc2ca8239e8f,

title = "Leaf- to field-level compound effects of warm and dry conditions on crops and potential mitigating strategies",

abstract = "Ongoing climate change has been threatening global food security. Under climate change, increasing risk of hot and dry conditions (termed compound events) is projected in many agricultural regions. Compound events cause detrimental effects on crops, yet their effects have rarely been quantified based on modeling approach. In this thesis, we established mechanistic and statistical models to analyze crop canopy temperature, transpiration rate, and yield responses to compound effects. We aimed to explore the compound effects on crops and help identifying adaptation strategies. Our results suggested that hot and dry conditions interacted in enhancing canopy temperature, i.e. the risk of potential crop heat stress, and crop yield losses. Both canopy temperature and yield losses increased from wet-cool conditions to dryhot conditions. Short-term intra-seasonal conditions and growing season averages were equally important in assessing crop responses to compound events. More intermittent precipitation regimes and longer dry spells negatively affected canopy temperature and yields even when the mean climatic conditions remained unaltered. Rainfed crop yields showed yield maximizing precipitation, which increased with temperature. As one of the adaptation strategies, irrigation could alleviate but not cancel the negative effects of adverse climate. Another adaptation is a shift from annual to perennial grain crops. Whether perennial grain crops are less vulnerable to heat and water stress depends on some key plant traits, such as leaf area index, which should be targeted for future breeding program to adapt to climate change.",

keywords = "Climate change, adaptation, canopy and leaf temperature, compound effect, crop yields, modeling, Climate change, adaptation, canopy and leaf temperature, compound effect, crop yields, modeling",

author = "Xiangyu Luan",

year = "2021",

language = "English",

isbn = "978-91-7760-772-4",

series = "Acta Universitatis Agriculturae Sueciae",

publisher = "Department of Crop Production Ecology, Swedish University of Agricultural Sciences",

number = "2021:47",

}

TY - BOOK

T1 - Leaf- to field-level compound effects of warm and dry conditions on crops and potential mitigating strategies

AU - Luan, Xiangyu

PY - 2021

Y1 - 2021

N2 - Ongoing climate change has been threatening global food security. Under climate change, increasing risk of hot and dry conditions (termed compound events) is projected in many agricultural regions. Compound events cause detrimental effects on crops, yet their effects have rarely been quantified based on modeling approach. In this thesis, we established mechanistic and statistical models to analyze crop canopy temperature, transpiration rate, and yield responses to compound effects. We aimed to explore the compound effects on crops and help identifying adaptation strategies. Our results suggested that hot and dry conditions interacted in enhancing canopy temperature, i.e. the risk of potential crop heat stress, and crop yield losses. Both canopy temperature and yield losses increased from wet-cool conditions to dryhot conditions. Short-term intra-seasonal conditions and growing season averages were equally important in assessing crop responses to compound events. More intermittent precipitation regimes and longer dry spells negatively affected canopy temperature and yields even when the mean climatic conditions remained unaltered. Rainfed crop yields showed yield maximizing precipitation, which increased with temperature. As one of the adaptation strategies, irrigation could alleviate but not cancel the negative effects of adverse climate. Another adaptation is a shift from annual to perennial grain crops. Whether perennial grain crops are less vulnerable to heat and water stress depends on some key plant traits, such as leaf area index, which should be targeted for future breeding program to adapt to climate change.

AB - Ongoing climate change has been threatening global food security. Under climate change, increasing risk of hot and dry conditions (termed compound events) is projected in many agricultural regions. Compound events cause detrimental effects on crops, yet their effects have rarely been quantified based on modeling approach. In this thesis, we established mechanistic and statistical models to analyze crop canopy temperature, transpiration rate, and yield responses to compound effects. We aimed to explore the compound effects on crops and help identifying adaptation strategies. Our results suggested that hot and dry conditions interacted in enhancing canopy temperature, i.e. the risk of potential crop heat stress, and crop yield losses. Both canopy temperature and yield losses increased from wet-cool conditions to dryhot conditions. Short-term intra-seasonal conditions and growing season averages were equally important in assessing crop responses to compound events. More intermittent precipitation regimes and longer dry spells negatively affected canopy temperature and yields even when the mean climatic conditions remained unaltered. Rainfed crop yields showed yield maximizing precipitation, which increased with temperature. As one of the adaptation strategies, irrigation could alleviate but not cancel the negative effects of adverse climate. Another adaptation is a shift from annual to perennial grain crops. Whether perennial grain crops are less vulnerable to heat and water stress depends on some key plant traits, such as leaf area index, which should be targeted for future breeding program to adapt to climate change.

KW - Climate change

KW - adaptation

KW - canopy and leaf temperature

KW - compound effect

KW - crop yields

KW - modeling

KW - Climate change

KW - adaptation

KW - canopy and leaf temperature

KW - compound effect

KW - crop yields

KW - modeling

UR - https://res.slu.se/id/publ/112815

M3 - Doctoral thesis

SN - 978-91-7760-772-4

T3 - Acta Universitatis Agriculturae Sueciae

PB - Department of Crop Production Ecology, Swedish University of Agricultural Sciences

ER -