Settlement‐era forest structure and composition in the Klamath Mountains: reconstructing a historical baseline
Settlement‐era forest structure and composition in the Klamath Mountains: reconstructing a historical baseline
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克拉马斯山脉定居时代的森林结构和组成：重建历史基线
DOI：
10.1002/ecs2.3250
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发表时间：
2020
期刊：
影响因子：
2.7
通讯作者：
J. Battles
中科院分区：
文献类型：
--
作者：
Clarke A. Knight;C. Cogbill;M. Potts;J. Wanket;J. Battles
森林状况的历史基线为评估森林随时间变化的情况提供了参考。在加利福尼亚州，公共土地调查系统(PLSS)以93.2公里(36英里)的分辨率提供1872年至1884年间的树木清单数据。尽管这些数据提供了定居点时代森林状况的空间广泛记录，但使用PLSS数据重建在西部景观中一直是有限的和有争议的。最近在无图密度估计器(PDE)应用方面的改进使得重建更加准确和稳健。这项研究的目的是使用偏微分方程重建六河国家森林-加州西北部克拉马斯山脉的一种植物多样性的温带森林-定居时代的森林条件，以量化与现代条件的差异。火灾和收获记录与PLSS数据结合使用，以了解上个世纪森林管理的影响。与定居时代相比，六江流域当代森林中的树木数量增加了三倍，树木面积也有了相应的增加。聚落时代的森林组成以道格拉斯冷杉(34.4%)、松树(24.2%)和栎树(21.9%)为主。当代森林支持更多的道格拉斯冷杉(45.2%)和类似数量的松树(26.1%)，而橡树减少了一半以上(9.3%)。尽管在世纪中叶，六条河进行了大量的木材采伐，但树木数量的增加还是出现了。尽管2000年至2019年间，六条河流发生了大火，但在20世纪发生的火灾要少得多。我们的结果表明，有效的灭火有助于六江流域当代森林的致密。
Historical baselines of forest conditions provide reference states to assess how forests have changed through time. In California, the Public Land Survey System (PLSS) provides tree inventory data between 1872 and 1884 at 93.2-km (36 mi) resolution. Although these data provide a spatially extensive record of settlement-era forest conditions, reconstructions using PLSS data have been limited and controversial in western landscapes. Recent improvements in the application of plotless density estimators (PDE) have made reconstructions more accurate and robust. The purpose of this study was to use PDE to reconstruct the settlement-era forest conditions in Six Rivers National Forest—a floristically diverse temperate forest in the Klamath Mountains of northwestern California—to quantify differences with modern conditions. Records of fires and harvests were used in conjunction with the PLSS data to understand the influence of forest management during the previous century. The contemporary forest in Six Rivers contains three times more trees than in the settlement era with a comparable increase in tree basal area. Forest composition during the settlement era was predominantly Douglas-fir (34.4%), pine (24.2%), and oak (21.9%) by basal area. Contemporary forests support more Douglas-fir (45.2%) and a similar amount of pine (26.1%), while oaks have decreased by more than half (9.3%). These increases in tree abundance occurred despite extensive, mid-century timber harvesting in Six Rivers. Although large fires have burned in Six Rivers between 2000 and 2019, far fewer fires occurred during the twentieth century. Our results suggest that effective fire suppression contributed to the densification of the contemporary forests in Six Rivers.