This year, the national grassland will return to green slightly ahead of schedule

The grassland Supervision Center of the Ministry of Agriculture adopted the methods of ground observation, satellite remote sensing and meteorological data analysis to monitor and analyze the situation of grassland grass turning green in the whole country. The results show that from March to May, the temperature in most steppe areas in China is slightly higher, the precipitation is abundant, and the hydrothermal conditions are generally conducive to the green growth of forage grasses, during which the northern grasslands have experienced several strong cold air processes. the green growth of the original forage grass was negatively affected. As of May 20, 87% of the country's grasslands had turned green, slightly earlier than all the year round.

I. Meteorological conditions

Since the beginning of spring, the temperature in most grasslands in China is normal and slightly higher, and the overall heat conditions are beneficial to the greening of grassland grasses, but the temperature in northern grasslands fluctuates violently, which has a great negative impact on the greening of grasslands in some high-latitude and high-altitude areas. After entering March, the temperature in most grassland areas of the country rebounded quickly, and the temperature was slightly higher than normal years. Good heat conditions were conducive to snow thawing, soil thawing and forage germination. However, since April, there have been many strong wind and low temperature weather processes in the northern grassland region, during which strong wind, cold wave and snowfall occurred in the Yili River Valley and Altay region of Xinjiang, and long-term low temperature weather occurred in Inner Mongolia, Northeast China and the northern part of North China, with snow in some areas and low temperature frost weather with a daily minimum temperature of less than 2 ℃ in 3-5 days in some areas.

Since March, precipitation has been abundant in most grassland areas of the country, except in southwest Xinjiang, northwest Qinghai and central Gansu. Among them, the precipitation in the southwest and east of Xizang, the south of Qinghai, the southeast of Gansu, most of Ningxia, most of Inner Mongolia and the middle and north of Northeast China is more than 30% more than that of normal years, which provides good water conditions for forage grass to turn green and grow.

II. Greening of forage grass and vegetation status

According to satellite remote sensing monitoring and observation of more than 900 ground sample sites in 100 counties, as of May 20, 87% of the country's grasslands had turned green, slightly earlier than usual. The areas in advance of turning green are mainly located in most of the northwest and southwest, and the delayed areas are mainly in the north of North China and parts of Northeast China. At present, the growth status of grassland vegetation that has turned green is generally normal, in which the preferred areas are mainly distributed in western Inner Mongolia, most of Gansu, north-central Xinjiang and most of the Qinghai-Tibet Plateau. The areas with deviated growth conditions are mainly distributed in the southwest of Xinjiang and the central and eastern part of Inner Mongolia. At present, the grasslands that have not yet returned to green are mainly located in the high-altitude areas in the west of Xizang, and the grasslands in these areas are expected to turn green one after another in early June.

From the perspective of the main pastoral areas, Xinjiang grasslands began to turn green one after another at the end of March. With the exception of Changji Prefecture and other places, the rejuvenation of most grasslands in Xinjiang was 5-10 days earlier than usual. Sichuan grassland began to turn green in mid-late April, and the time of grass turning green is basically the same as that of the whole year. The grasslands in Gansu have returned to green a little earlier than usual, and 90% of the grasslands in the province have turned green by the middle of May. The Inner Mongolia grassland shows a pattern of returning green ahead of time in the central and western regions and delayed in the central and eastern part of the country. the time of returning green to the west of Wulanchabu is more than 10 days earlier than usual, and that of Xilingol grassland is about 10 days later than usual. Hulunbuir grassland in the south is slightly delayed, and the north is basically the same as all the year round. Since the middle of April, the Qinghai grassland has gradually turned green from the eastern low-altitude river valleys to the western high-altitude areas such as Sanjiangyuan, and the time of turning green in most areas is about 5 days earlier than usual. Xizang grassland began to turn green gradually from southeast to northwest from mid to late April, the time of grass turning green in the southern Xigaze region was earlier than usual, some parts of the central and western regions were slightly delayed, and the green time of other grasslands was about the same as that of the whole year.

III. Analysis and suggestions of the late situation

According to the forecast of the National Meteorological Center, in the coming period of time, the temperature in most grassland areas of the country will be slightly higher, the precipitation in the northern region will be less, and drought may occur in southwestern Xinjiang and other places. All localities should reasonably arrange grassland production and animal husbandry management activities in the light of the current situation of grassland grass turning green and meteorological conditions. In grassland areas where drought occurs, it is necessary to strengthen the supervision of the balance of grass and livestock and guide herdsmen to extend the time of house feeding and captivity. At the same time, all grassland areas should do a good job in monitoring, early warning, prevention and control of rodent and insect pests, and earnestly strengthen the work of grassland fire prevention.

Fig. 1 temperature anomaly from March to mid-May 2015 (℃)

Fig. 2 percentage of precipitation anomaly from March to mid-May 2015 (%)

Fig. 3 the time when the grasslands across the country turned green in mid-May 2015

Area ratio (compared to the same period of many years)

(contributed by the Monitoring Office of the grassland Supervision Center)