Stohlgren T J, Parsons D J, Rundel P W
Sequoia and Kings Canyon National Parks, National Park Service, 93271, Three Rivers, CA, USA.
Laboratory of Biomedical and Environmental Sciences, University of California, 90024, Los Angeles, CA, USA.
Oecologia. 1984 Sep;64(1):87-91. doi: 10.1007/BF00377549.
In the low elevation chaparral areas of Sequoia National Park, California, pure stands of chamise (Adenostoma fasciculatum) are periodically rejuvenated by fire. Mature stands showed considerable variability in density and total biomass even though a positive correlation exists between the two. Mature stands showed a preponderance of individuals in the smaller size classes (inverse-J shape distribution). Dead shrubs found in mature stands also tended to be in the smaller size classes. This relatively high mortality of small individuals is important to post-fire stand development. In addition, resprout and seedling biomass one year after fire both showed inverse-J shaped size-class structures. A positive correlation existed between the preburn basal area of a shrub and its first year resprout biomass. Shrub biomass and distance to nearest neighbor were poorly correlated. A significant correlation existed between stand density and a stand's variance-to-mean ratio, indicating a trend toward more regular spacing as density increases. Pre-burn and fire-induced mortality tended to move the stand towards a more clumped distribution. Seedlings replaced dead individuals after a fire and thus restored regular spacing.
在加利福尼亚州红杉国家公园的低海拔灌丛地区，纯群落的滨藜叶栎（Adenostoma fasciculatum）会定期因火灾而更新。成熟群落的密度和总生物量存在相当大的变异性，尽管两者之间存在正相关关系。成熟群落中较小尺寸等级的个体占优势（反J形分布）。在成熟群落中发现的死亡灌木也往往处于较小尺寸等级。小个体相对较高的死亡率对火灾后群落的发展很重要。此外，火灾一年后的萌条和幼苗生物量均呈现反J形的尺寸等级结构。灌木燃烧前的基部面积与其第一年的萌条生物量之间存在正相关关系。灌木生物量与到最近邻体的距离相关性较差。群落密度与群落的方差均值比之间存在显著相关性，表明随着密度增加，有向更规则间距发展的趋势。燃烧前和火灾引起的死亡率倾向于使群落向更聚集的分布发展。火灾后幼苗取代了死亡个体，从而恢复了规则间距。
