School of Biological Sciences, University of Queensland, St Lucia, Qld, 4072, Australia.
Queensland Herbarium, Department of Science, Information Technology and Innovation, Brisbane Botanic Gardens, Mt Coot-tha Road, Toowong, Qld, 4066, Australia.
Glob Chang Biol. 2015 Oct;21(10):3777-85. doi: 10.1111/gcb.12981. Epub 2015 Jul 4.
Predicting the consequences of climate change on forest systems is difficult because trees may display species-specific responses to exaggerated droughts that may not be reflected by the climatic envelope of their geographic range. Furthermore, few studies have examined the postdrought recovery potential of drought-susceptible tree species. This study develops a robust ranking of the drought susceptibility of 21 tree species based on their mortality after two droughts (1990s and 2000s) in the savanna of north-eastern Australia. Drought-induced mortality was positively related to species dominance, negatively related to the ratio of postdrought seedlings to adults and had no relationship to the magnitude of extreme drought within the species current geographic ranges. These results suggest that predicting the consequences of exaggerated drought on species' geographic ranges is difficult, but that dominant species like Eucalyptus with relatively slow rates of population recovery and dispersal are the most susceptible. The implications for savanna ecosystems are lower tree densities and basal area.
预测气候变化对森林系统的影响具有挑战性，因为树木可能会表现出对过度干旱的特定物种反应，而这些反应可能无法反映其地理范围的气候范围。此外，很少有研究考察过耐旱树种的旱后恢复潜力。本研究根据澳大利亚东北部稀树草原 21 种树木在两次干旱（20 世纪 90 年代和 21 世纪初）后的死亡率，对它们的耐旱性进行了稳健的排序。干旱引起的死亡率与物种优势呈正相关，与旱后幼苗与成体的比例呈负相关，与物种当前地理范围内极端干旱的程度无关。这些结果表明，预测极端干旱对物种地理范围的影响具有挑战性，但像桉树这样优势物种，其种群恢复和扩散速度相对较慢，最容易受到影响。对稀树草原生态系统的影响是树木密度和基部面积降低。
