Climate change has caused some planting zones to move to the north as the amount of heat, which plays a pivotal role during the maturation process of farm crops, has increased over the past few decades and affected goods like apples, the China Meteorological Administration said.

In Shaanxi province, increased water and heat resources have shifted the apple planting areas northward and westward, according to the latest research results of the agroclimatic zoning research team with the Shaanxi Agricultural Remote Sensing and Economic Crops Meteorological Service Center.

The research showed that from 1991 to 2020, the annual average temperature increased by 0.28 C every 10 years and the annual precipitation rose by 38.9 millimeters on average every 10 years in the province's apple planting areas.

Under these conditions, the boundary of areas with an annual average temperature around 8.5 C and an annual average precipitation at about 400 millimeters－the minimum meteorological requirements that are suitable for apples to grow－has moved to the north and west from 1991 to 2020 compared with the 1981-2010 period, the research paper said.

"Due to the warmer and wetter climate, the planting zone for apples in Shaanxi has shifted to the northern and western areas of the province, where temperatures used to be too low for their growth," said Li Meirong, a senior engineer at the center.

"We have discussed with the provincial fruit industry bureau concentrating on developing apple planting in its optimized zone which has shifted north and reduced apple orchards in some southern parts where heat injuries to the fruit may occur more frequently," she said.

In 2008, the Shaanxi government started to shift its apple orchards northward about 200 kilometers to some counties in the cities of Yan'an and Yulin, the Shaanxi Fruit Industry Center said.

Since 2015, Wuqi county in Yan'an has expanded its apple orchards from 2,000 hectares to 7,800 hectares so far, said the county's fruit industry center.

Liang Yi, a senior engineer of the meteorological service center, has been researching zoning for Shaanxi apple planting. She said she witnessed the evolution of the hilly and gully regions into terraced apple orchards in Wuqi county in northern Shaanxi.

"Before, the place used to be unsuitable for apple growing due to the cold climate in high altitudes compared with the central Shaanxi plain. Now red apples can be seen all over the mountains there, and, because of its greater temperature difference during the day and at night, the apples taste better," she said.

Yin Hong, a senior engineer of the administration's National Climate Center, said from 1961 to 2020, the annual average temperature across China showed a consistent upward trend.

"Climate change has increased thermal resources, which made the cultivable area of thermophilic crops expand. And the northern boundary of the multiple crop zone in China expanded to high latitudes and altitudes," Yin said.

Min Qingwen, a researcher from the Institute of Geographic Sciences and Natural Resources Research with the Chinese Academy of Sciences, told the China Meteorological News in March a reasonable agricultural production structure and regional layout should be made according to the natural conditions of each place.

He was quoted as saying it is necessary to carry out the third national agro-climatic resource survey and zoning work since the country's agricultural climate resources have changed significantly. Since 1949, the country has conducted two such surveys.