Climate change ‘likely’ to cut tropics crop diseases

一项研究说，气候变化可能会杀死全球南部热带国家的某些作物疾病，而疾病的风险则在欧洲和中国等北部地区增加。

However, this is expected to be accompanied by a shift in yields, with crop productivity stalling in tropical regions and rising in more northerly latitudes, according to the studypublished this week(5 August) inNature Climate Change。

Plant pest and disease outbreaks have caused massive food shortages and famines over the years,killing millions。

“Plant pathogens already threaten agricultural production globally and we need to prepare for how these threats will change in the future,” says Thomas Chaloner, an author of the study from the University of Exeter, who now works as a data analyst at CABI, theparent organisationof SciDev.Net.

来自英国和荷兰的研究人员研究了80种影响农作物的真菌样疾病。

Using crop and climate models, they analysed current (2011-2030) yields and future (2061-80) yield projections for 12 important crops, including wheat, maize, sugar cane, millet and soybean.

The study suggests that, in tropical countries,climate change尽管导致农作物疾病下降，但仍会降低几种农作物的产量。

“This is because temperatures will become too high for both the crops and their pathogens,” explained Dan Bebber, an author of the study and associate professor of ecology at the University of Exeter, UK.

The researchers predicted that, over the 21st century at lower latitudes, reductions may be seen in the yields of millet, maize and sugar cane but these crops will face a decreased risk from a number of infections.

In tropical areas, there will be little gain in yields of wheat, sunflower and soybean, but again the risk from various temperature-dependent pathogens will be less.

Bebber补充说：“对于热带地区的农民来说，高温耐受性的农作物的繁殖非常重要，并且管理层可以帮助农作物处理高温（例如灌溉）。”

Taking into account a situation where no irrigation is provided, maize yields were projected to decrease in Latin America —with the exception of Argentina — and in Africa and northern Australia, the study said.

There was also a projected decrease in the productivity of sugar cane in Brazil and other Latin American countries and in Southeast Asia.

Researchers forecast an increase in the risk of temperature-dependent infections in Europe and China, but a decrease in India, Brazil, Sub-Saharan African and Southeast Asian countries.

However, Bebber struck a note of caution about the crop disease projections. “First, we did not investigate all known pathogens due to a lack of relevantdata, particularly for tropical pathogens. Second … pathogens might evolve to cope with higher temperatures,” he said.

CABI气候变化经理乔纳森·凯西（Jonathan Casey）说，这项研究表明，气候变化会影响作物的各个方面，并将大大改变农民面临的害虫和疾病威胁。

“These findings can help inform early warning and early action for farmers in affected regions — particularly in more northern regions — to take timely action to adapt to the increased pressures brought about by climate change,” said Casey.

“尽管气候变化是一种全球现象，但其影响在全球范围内并没有平等地感受到”

Koteswararao Kundeti, climate researcher, Azim Premji University, India

印度班加罗尔Azim Premji大学气候变化与可持续性中心的气候研究人员Koteswararao Kundeti表示：“尽管气候变化是全球现象，但其影响并非同样受到全球的影响。

“Most of the developing countries that lie in between the tropics are especiallyvulnerableto climate change. Global climate models’ projections indicate that we need to prepare for extreme weather conditions, with more droughts, heavy rainfall, and storms in regions of highagricultural生产。”

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