Possible planting boundaries of winter wheat in China under different
emissions scenarios
Abstract
Suitable planting areas for winter wheat in north China are expected to
shift northwardly due to climate change, however, the increasing extreme
events and the deficiency of water supply are threatening the security
of planting system. Thus, based on predicted climate data for 2021–2050
under the SSP1-2.6, SSP3-7.0, and SSP5-8.5 emission scenarios, as well
as historical data from 1961–1990, we use four critical parameters of
percentage of extreme minimum temperature occurrence, first day of the
overwintering period (FD), sowing date (SD), and precipitation before
winter (PBW) to determine the planting boundary of winter wheat. The
results show that, the frequency of extreme minimum temperature
occurrence is expected to decrease in the North winter wheat area, which
will result in a northward movement of the western part of northern
boundary by 73, 94, and 114 km on average, as well as FD delays ranging
from 6.0 to 10.5 days. Moreover, the agrometeorological conditions in
the Huang-Huai winter wheat area are expected to exhibit more pronounced
changes than the rest of the studied areas, especially near the southern
boundary, which is expected to retreat by approximately 213, 215, and
233 km northwardly. The north boundary is expected to move 90–140 km
northward. Therefore, the change in southern and northern boundaries
will lead the potential planting areas of the entire North winter wheat
area to increase by 10,700 and 28,000 km2 on average in the SSP3-7.0 and
SSP5-8.5 scenarios but decrease 38,100 km2 in the SSP1-2.6 scenario.