Table 1. Climate of the three Chinese localities.

			Mean annual temperature, °C		Mean annual relative humidity, %		Total annual precipitation, mm·yr-1		Annual potential evaporation, mm·yr-1
Locality	Latitude	Longitude	Long-term	1999	Long-term	1999	Long-term	1999	Long-term	1999
Lanzhou	36°01′N	103°59′E	9.5 (21)	11.1	58	49	338 (21)	319	655 (?)	1,586
Beijing	39°57′N	116°19′E	11.8 (36)	13.1	57	53	619 (112)	380	799 (95)	1,785
Nanjing	32°04′N	118°47′E	15.7 (16)	15.7	73	76	979 (25)	1,231	864 (32)	1,395

Long-term climatic data from ref. 30 values in parentheses indicate the length of the record in years where known. Climatic data for 1999 were obtained from refs. 31 and 32