D'Antonio Carla M, Odion Dennis C, Tyler Claudia M
Department of Biological Sciences, University of California, 93106, Santa Barbara, CA, USA.
Department of Geography, University of California, 93106, Santa Barbara, CA, USA.
Oecologia. 1993 Mar;95(1):14-21. doi: 10.1007/BF00649501.
Invasion by the alien succulent,Carpobrotus edulis, has become a common occurrence after fire in maritime chaparral in coastal California, USA. We studied post-burnCarpobrotus establishment in chaparral that lackedCarpobrotus plants before the fire and compared seedbank and field populations in adjacent burned and unburned stands.Carpobrotus seeds were abundant in deer scat and in the soil before burning. Burning did not enhance germination: many seeds were apparently killed by fire and seed bank cores taken after fire revealed no germinable seeds. Laboratory tests showed that temperatures over 105°C for five minutes killedCarpobrotus seeds. In a field experiment involving use of herbivore exclosures, we found that herbivory was an important source of mortality for seedlings in both burned and unburned chaparral. All seedlings, however, died outside of the burn regardless of the presence of cages. Establishment there is apparently limited by factors affecting plant physiology. In the burned area, seedlings that escaped herbivory grew very rapidly. Overall, it appears that herbivory limited seedling establishment in both burned and unburned sites but that the post-burn soil environment supportedCarpobrotus growth in excess of herbivore use, thus promoting establishment.
外来肉质植物可食日中花（Carpobrotus edulis）的入侵，在美国加利福尼亚州沿海的海岸丛林火灾后已屡见不鲜。我们研究了火灾后可食日中花在火灾前没有可食日中花植物的丛林中的定殖情况，并比较了相邻火烧地和未火烧地的种子库及田间种群。火灾前，可食日中花的种子在鹿粪和土壤中大量存在。火烧并没有促进种子萌发：许多种子显然被火烧死了，火灾后采集的种子库样本中未发现可萌发的种子。实验室测试表明，105°C以上的温度持续五分钟会杀死可食日中花的种子。在一项涉及使用食草动物围栏的田间试验中，我们发现食草作用是火烧地和未火烧地幼苗死亡的一个重要原因。然而，无论是否有笼子，所有幼苗在火烧地以外的地方都会死亡。那里的定殖显然受到影响植物生理的因素限制。在火烧区域，逃脱了食草作用的幼苗生长非常迅速。总体而言，食草作用似乎限制了火烧地和未火烧地的幼苗定殖，但火烧后的土壤环境支持可食日中花的生长超过了食草动物的啃食，从而促进了定殖。
