Grassland green-up period slightly earlier than usual across China this year

Industry News Jan 1, 1970By Sophie Bennett 0 views

The Grassland Supervision Center of the Ministry of Agriculture monitored and analyzed grassland forage green-up conditions nationwide using ground observation, satellite remote sensing, and analysis combined with meteorological data. The results show that from March to May, temperatures in most grassland areas nationwide were normal to slightly high with abundant precipitation, and the overall water and heat conditions were favorable for forage green-up and growth; during this period, northern grassland areas experienced several strong cold air processes, which had a certain negative impact on forage green-up and growth. As of May 20, 87% of grasslands nationwide had greened up, and compared with normal years, the grassland green-up time nationwide was slightly earlier.

I. Meteorological conditions

Since the beginning of spring, temperatures in most grassland areas of China have been normal to slightly high, and the overall heat conditions have been favorable for grassland forage green-up; however, temperatures in northern grassland areas fluctuated sharply, causing a relatively large negative impact on forage green-up in some high-latitude and high-altitude grassland areas. After entering March, temperatures in most grassland areas nationwide rose relatively quickly and were slightly higher than normal, and the favorable heat conditions were conducive to snowmelt, soil thawing, and forage germination. However, since April, northern grassland areas experienced several strong-wind and low-temperature weather processes; during this period, the Ili River Valley and Altay region of Xinjiang experienced strong winds, cold waves, and snowfall, while Inner Mongolia, Northeast China, and northern North China experienced prolonged low-temperature weather, with snowfall in some areas and low-temperature frost weather with daily minimum temperatures below 2°C for 3 to 5 days in some localities.

Since March, except for southwestern Xinjiang, northwestern Qinghai, and central Gansu, most grassland areas nationwide have had abundant precipitation; among them, southwestern and eastern Tibet, southern Qinghai, southeastern Gansu, most of Ningxia, most of Inner Mongolia, and the central and northern parts of Northeast China received more than 30% above normal precipitation, providing good moisture conditions for forage green-up and growth.

II. Forage green-up and vegetation conditions

According to satellite remote sensing monitoring and observations at more than 900 ground sample points in 100 counties, as of May 20, 87% of grasslands nationwide had greened up, and compared with normal years, the grassland green-up time was slightly earlier. Areas with earlier green-up were mainly located in most of the Northwest and most of the Southwest, while areas with delayed green-up were mainly located in northern North China and parts of Northeast China. At present, the growth conditions of grassland vegetation that has already greened up are generally normal; among them, areas with relatively favorable growth conditions are mainly distributed in western Inner Mongolia, most of Gansu, central and northern Xinjiang, and most of the Qinghai-Tibet Plateau, while areas with relatively poor growth conditions are mainly distributed in southwestern Xinjiang, central and eastern Inner Mongolia, and other places. Grasslands that have not yet greened up are mainly located in the high-altitude areas of western Tibet, and grasslands in these areas are expected to green up successively in early June.

From the perspective of major pastoral areas: Xinjiang grasslands began to green up successively from the end of March; except for places such as Changji Prefecture where green-up was delayed by about 10 days, most grasslands across the region greened up 5 to 10 days earlier than normal. Sichuan grasslands began large-scale green-up in mid-to-late April, and the forage green-up time was basically consistent with normal years. Forage green-up in Gansu grasslands was slightly earlier than normal, and as of mid-May, 90% of the province's grasslands had greened up. Inner Mongolia grasslands showed a pattern of earlier green-up in the central and western regions and delayed green-up in the central and eastern regions; areas west of Ulanqab greened up more than 10 days earlier than normal, Xilin Gol grasslands greened up about 10 days later than normal, and Hulunbuir grasslands were slightly delayed in the south and basically on par with normal years in the north. Qinghai grasslands began to green up from the low-altitude river valleys in the east toward high-altitude areas in the west such as the Sanjiangyuan region starting in mid-April, with green-up in most areas about 5 days earlier than normal. Tibet grasslands began to green up gradually from southeast to northwest starting in mid-to-late April; forage green-up in the southern Shigatse region was earlier than normal, while parts of the central and western regions were slightly delayed, and green-up in other grasslands was roughly comparable to normal years.

III. Analysis of the later situation and recommendations

According to forecasts by the National Meteorological Center, for some time to come, temperatures in most grassland areas nationwide will be normal to slightly high, precipitation in northern areas will generally be below normal, and drought may occur in places such as southwestern Xinjiang. All localities should reasonably arrange grassland production and livestock management activities according to the current grassland forage green-up situation and meteorological conditions. In grassland areas where drought occurs, supervision of grass-livestock balance should be strengthened, and herders should be guided to extend the time of barn feeding and confined raising. At the same time, all grassland areas should do a good job in monitoring, early warning, and control of rodent and insect pests, and effectively strengthen grassland fire prevention work.

Figure 1 Temperature anomaly from March to mid-May 2015 (°C)