BIOMSS is a synthetic agro-climatic indicator that takes into account rainfall and temperature to estimate the potential biomass accumulation. Recent departures from average for the 65 global MRUs are shown in figure 1.4.

During this monitoring period, the notable change in rainfall compared with the average has affected the biomass production potential across the world. Over the reporting period, biomass variations are brought about more by RAINanomalies than by TEMP anomalies (the R-squared between BIOMSS and RAIN and between BIOMSS and TEMP are 0.83 and 0.07 respectively).

Due to favorable rainfall in Eurasia, Africa and America, the BIOMSS in28 MRUs show an upward trend compared with the average of the last five years.The greatest positive BIOMSS departures are found in the Northern Great Plains(MRU-12, 45% on RAIN and 30% on BIOMSS), the southwest United States and north Mexican highlands (MRU-18, 33% on RAIN and 36% on BIOMSS), NorthAfrica-Mediterranean (MRU-07, 46% on RAIN and 36% on BIOMSS), central eastern Brazil (MRU-23, 53% on RAIN and 38% on BIOMSS), Ural to Altai mountains (MRU-62,50% on RAIN and 39% on BIOMSS), Gansu-Xinjiang (China) (MRU-32, 173% on RAINand 90% on BIOMASS), and southern Mongolia (MRU-47, 309% on RAIN and 125% on BIOMSS).

Declines in BIOMSS (compared to average values for the same period) are similarly affected by significantly decreased rainfall: In the following MRUs,the BIOMSS departures are well below the average of the last five years:Northern Australia (MRU-53, -71% on RAIN and -71% on BIOMSS), New Zealand (MRU-56,-73% on RAIN and -60% on BIOMSS), maritime Southeast Asia (MRU-49, -52% on RAINand -47% on BIOMSS), Queensland to Victoria (MRU-54, -43% on RAIN and -43% on BIOMSS), Punjab to Gujarat (MRU-48, -41% on RAIN and -43% on BIOMSS) and East Asia (MRU-43, -48% on RAIN and -30% on BIOMSS).

Figure 1.4. Globalmap of biomass accumulation (BIOMSS) by MRU, departure from 5YA, July-October(percentage)