Seedbank responses to spring and fall prescribed fire in mountain big sagebrush ecosystems of differing ecological condition at Lava Beds National Monument, California
Seedbank responses to spring and fall prescribed fire in mountain big sagebrush ecosystems of differing ecological condition at Lava Beds National Monument, California
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DOI：
10.1016/j.jaridenv.2013.04.001
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发表时间：
2013-09-01
影响因子：
2.7
通讯作者：
Kauffman, J. Boone
中科院分区：
文献类型：
--
作者：
Ellsworth, Lisa M.;Kauffman, J. Boone
美国西部土地利用的变化改变了以山艾树为主导的生态系统，促进了外来草的入侵，增加了木本物种，改变了火灾制度，以及本土物种的损失。恢复火灾制度可能是恢复山艾树生态系统不可或缺的一部分。然而，鲜为人知的是如何时间规定火不同影响土壤种子库。此外，不同生态条件下的立地对火灾的响应也不尽相同。为了解决这些不确定性，我们在加利福尼亚州熔岩床国家纪念碑的三个山艾树群落中，量化了春季和秋季规定燃烧后入侵的草和植物功能群（本地菊科植物、外来菊科植物、本地束草和本地灌木）的萌发。春火发生后，在绿草和土生草为主的地点，绿草幼苗数量（分别为91%和86%）比未燃烧的对照少，但这种减少在一年后不会持续。秋季烧伤不显著影响草或外来双科植物的发芽。在原生植物占主导地位的地点，原生植物在春季（1620%）和秋季（67%）燃烧后增加了一年，表明对自然火灾制度的适应。研究表明，生态系统的火灾前条件对火灾后萌发响应有很大影响，适应火灾的生态系统可以从自然干扰中受益。Elsevier Ltd.出版。
Land use change in the American West has altered sagebrush dominated ecosystems, facilitating exotic grass invasion, increased woody species, altered fire regimes, and native species losses. Restoring fire regimes may be integral to the restoration of sagebrush ecosystems. However, little is known about how the timing of prescribed fire differentially impacts the soil seedbank. Further, sites of different ecological condition may variably respond to fire. To address these uncertainties, we quantified germination of invasive cheatgrass and plant functional groups (native dicots, exotic dicots, native bunchgrasses, and native shrubs) following spring and fall prescribed burns in three mountain big sagebrush communities at Lava Beds National Monument, California. At cheatgrass and native-dominated sites, there were fewer cheatgrass seedlings (91% and 86%, respectively) immediately following spring fire than in unburned controls, but this reduction did not persist one year later. Fall burns did not significantly impact cheatgrass or exotic dicot germination. At a native dominated site, native dicots increased one year following spring (1620%) and fall burns (67%), suggesting adaptation to a natural fire regime. This research shows that the prefire condition of an ecosystem greatly influences the postfire germination response, and that fire-adapted ecosystems can benefit from the natural disturbance regime. Published by Elsevier Ltd.