Reproduction of Chaparral Shrubs After Fire: A Comparison of Sprouting and Seeding Strategies
Reproduction of Chaparral Shrubs After Fire: A Comparison of Sprouting and Seeding Strategies
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火灾后丛林灌木的繁殖：发芽和播种策略的比较
DOI：
10.2307/2424939
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发表时间：
1978
影响因子：
0.6
通讯作者：
P. Zedler
中科院分区：
文献类型：
--
作者：
J. Keeley;P. Zedler
本文通过对灌木林中同一种对种群的调查，研究了发芽灌木和未发芽灌木从火灾中恢复的相对能力。选择的物种对，首先命名不发芽的物种，是Arctostaphylos glauca ？A. glandullosa和Ceanothus greg- glll - C. leucodermls。还获得了某些伴生物种的数据，特别是网状腺瘤。测量了各样点组成物种的数量、大小和状况。苗种和非苗种均表现出较强的火灾恢复能力。燃烧后的林分似乎最终会达到与未燃烧林分相当的发展状态，而不会在组成上有任何显著的变化。对于没有发芽的灌木，火灾造成的死亡是完全的，但在发芽种类上有所不同。其中一些基本上没有死亡率，而另一些，尤其是腺瘤，死亡率相当高。灌木种属的成苗率差异显著，且似乎与火灾致死的程度相关。在两种不发芽灌木的生活史上观察到深刻的差异。然而，在火灾后，海鳗产生了非常高的幼苗数量，而灰熊葡萄产生的数量则少得多。对活茎和死茎密度大小分布的比较表明，灰毛杨在退伐初期死亡率较高，而青花毛杨在没有火灾的情况下，即使经过90年的退伐，其个体损失也很少。根据这些结果，我们提出了一个模型，我们相信它解释了在南加州灌木林中义务播种策略的适应意义。
The relative ability of sprouting and nonsprouting chaparral shrubs to recover from fire was studied by examining popula- tion of congeneric pairs of species in burned and adjacent unburned areas. The pairs of species selected, with the nonsprouting species named first, were Arctostaphylos glauca ? A. glandulosa and Ceanothus greg- gll - C. leucodermls. Data were also obtained on certain associated species, particularly Adenostoma fasclculatum. The numbers, sizes and condition of the component species at each of the sites were measured. Both sprouting and nonsprouting species showed vigorous recovery from fire. It seemed likely that the burned stands would eventually reach a state of development comparable to that shown in the preburn stand without any significant shifts in composition Mortality of shrubs resulting from the fire was complete for nonsprouters but varied in sprouting species. In some there was essentially no mortality, while in others, especially Adenostoma, it was rather high. Seedling establish- ment in the shrub species varied markedly and seemed to be correlated with the degree of fire-caused mortality. A profound difference was observed in the life histories of the two nonsprouting shrubs. Whereas Ceanothus greggll produced a very high number of seedlings after fire, Arctostaphylos glauca produced substan- tially fewer. A comparison of the density-size distribution of live and dead stems indicated that C. greggll suffers high mortality early in suc- cession, but A. glauca loses very few individuals even after 90 years without fire. In light of these results a model is proposed which we be- lieve explains the adaptive significance of the obligate-seeding strategy in the southern California chaparral.