[Effect of arid climate on underground growth of Bothrichloa ischaemum community].
The underground growth of Bothrichloa ischaemum community in extremely arid year were compared with that of the community in 1991 with normal precipitation, and hence, could reflect the effect of drought on underground growth of Bothrichloa ischaemum community. The results indicated that the peak value of underground biomass reached 1249 g.m-2 in extremely arid year, higher than that in normal year (586 g.m-2). Most roots distributed downwards in extremely arid year or arid seasons, and distributed upwards in normal year or rain seasons. The turnover rate of underground biomass in extremely arid year was 52.64%, significantly higher than that in normal year (18.36%). In extremely arid year, underground part and aboveground part competed with each other at the middle and later stage of growth, however, in normal year, they increased simultaneously presenting beeline correlativity on the whole. The biomass ratio of underground to aboveground in extremely arid year was 11.19 and significantly higher than that in normal year (2.03). Net underground primary production in extremely arid year was 390.7 g.m-2.yr.-1 and 2.63 times higher than that in normal year.
Zhang
Na
N
Department of Geoscience, Graduate School of Chinese Academy of Sciences, Beijing 100039. zn@earth.gscas.ac.cn
Liang
Yimi
Y
D002980:Climate; D005618:Fresh Water / Q000032:analysis; D006109:Poaceae / Q000254:growth & development*; D012987:Soil / Q000032:analysis
D012987:Soil