EFFECT OF STORAGE CONDITIONS ON GERMINATION OF SEEDS OF 489 SPECIES FROM HIGH ELEVATION GRASSLANDS OF THE EASTERN TIBET PLATEAU AND SOME IMPLICATIONS FOR CLIMATE CHANGE

Premise of the study : Little is known about the effect of environmental conditions on seed dormancy break at the community level or how it could be affected by climate change. This study tested the effects of storage conditions on germination of 489 species from high-elevation natural grasslands on the Tibet Plateau. Methods : We stored seeds in dry cold, dry warm, and wet cold environments to test the effect of these conditions on germination. Germination responses were classified with the use of cluster analysis. The effect of phylogeny on germination response to storage conditions was determined. Key results : Compared with results of wet cold conditions, storing seeds at dry warm or dry cold conditions decreased the mean community germination percentage by 17.93% and 16.07%, respectively. Storing seeds at dry warm vs. dry cold conditions decreased the community mean germination percentage by 4.61%. The germination response to moisture conditions during storage showed significant phylogenetic patterns, whereas the germination response to storage temperature did not. On the basis of the germinability of seeds of the same species stored under different conditions, germination may increase, decrease, or stay the same. Conclusions : Within the high-elevation Tibetan grassland community, the different responses in dormancy breaking and germination behavior to the same storage conditions may have implications for understanding how this community might respond to climate change. In particular, some species may increase in the community, whereas others may decrease or remain the same. However, the potential for such change can be detected only by studying the responses of many species.