Evaluating the role of cutting treatments, fire and soil seed banks in an experimental framework in ponderosa pine forests of the Black Hills, South Dakota
Evaluating the role of cutting treatments, fire and soil seed banks in an experimental framework in ponderosa pine forests of the Black Hills, South Dakota
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评估南达科他州布莱克山黄松林实验框架中砍伐处理、火和土壤种子库的作用
DOI：
10.1016/j.foreco.2004.02.004
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发表时间：
2004
影响因子：
3.7
通讯作者：
G. McPherson
中科院分区：
文献类型：
--
作者：
Cody L. Wienk;C. Sieg;G. McPherson
黄松法。（黄松）森林在过去的一个世纪里发生了很大的变化，部分原因是一个世纪或更长时间以来没有发生过周期性火灾。一些研究已经探讨了采伐木材或焚烧对黄松林下林生产的影响，但需要在实验框架内设计包括砍伐和规定焚烧的研究，以确定造成所观察到的变化的机制。本研究首次对黑山北部黄松林分的扰动历史和土壤种子库进行了表征。然后，我们通过实验研究了规定燃烧和减少林下植被对林下植被的影响。在盎格鲁人定居该地区之前，平均火灾间隔为14年，1879年之后没有火灾记录。火灾的停止，黄松的大量再生，以及随后在1903年的砍伐，导致了一个非常密集，年龄均匀的黄松林，很少有林下植被，土壤种子库中很少有可存活的种子。在1080个土壤样本中，只有57个单株，或186个种子/m2。施用后第一个生长季林下植被响应稀疏，处理效果不显著。然而，在第二个生长季，处理效果显著。林下生物量从未处理地块的5.8kg/公顷到砍伐后未燃烧地块的1724kg/公顷不等。草本菊科植物占林下生物量的90%以上。林下物种丰富度和均匀度对处理均有响应，但林下木本植物密度对两种处理均无响应。土壤种子库中有效种子的缺乏似乎并没有限制南达科他州浓密黄松林林下植被的补充。
Pinus ponderosa Laws. (ponderosa pine) forests have changed considerably during the past century, partly because recurrent fires have been absent for a century or more. A number of studies have explored the influence of timber harvest or burning on understory production in ponderosa pine forests, but study designs incorporating cutting and prescribed burning in an experimental framework are needed to identify mechanisms responsible for the observed changes. In this study, we first characterized the disturbance history and the soil seed bank of a ponderosa pine stand in the northern Black Hills. We then experimentally addressed the effects of prescribed burning and overstory reduction on understory vegetation. Before Anglo settlement of the area, the mean fire interval was 14 years and no fires were recorded after 1879. Cessation of fires, prolific regeneration of ponderosa pine, and subsequent logging in 1903 has led to a very dense, even-aged ponderosa pine stand with very little understory vegetation and very few viable seeds in the soil seed bank. Only 57 individual plants, or 186seeds/m2, emerged from 1080 soil samples. Response of understory vegetation during the first growing season after application of treatments was sparse, with no significant treatment effect. There were, however, significant treatment effects during the second growing season. Total understory biomass ranged from 5.8kg/ha on untreated plots to 1724kg/ha on clearcut, unburned plots. Herbaceous dicots comprised over 90% of total understory biomass. Both understory species richness and evenness responded to treatments, but understory woody plant density did not respond to either treatment. Paucity of viable seeds in the soil seed bank does not appear to constrain recruitment of understory vegetation in dense ponderosa pine forests of South Dakota.