Drought-induced tree death in savanna.

摘要: Increasing densities of woody plants in savannas has been attributed to both elevated atmospheric CO2 and reduced burning with grazing management, such that the biome could represent a substantial carbon sink. However, we show extreme droughts (less than two-thirds expected rainfall over 3 years) occur drier half savanna can cause tree death. An Australian case study reveals net increase cover five decades above-average was offset by sudden death during drought. The relationship between change is moderated competition growth being facilitated low drought-induced more likely as component increases. results are not supportive sustained xeric resulting from fertilization or land management. Extensive regions will become stark consequence climate if predictions increasing severity frequency drought realized.