The contribution of the Coweeta Hydrologic Laboratory to developing an understanding of long-term (1934-2008) changes in managed and unmanaged forests
The contribution of the Coweeta Hydrologic Laboratory to developing an understanding of long-term (1934-2008) changes in managed and unmanaged forests
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DOI：
10.1016/j.foreco.2010.03.010
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发表时间：
2011-03-01
影响因子：
3.7
通讯作者：
Vose, James M.
中科院分区：
文献类型：
--
作者：
Elliott, Katherine J.;Vose, James M.
美国农业部林业局实验林场(EF&R)的长期记录是极其宝贵的科学资源，也是自然资源管理研究的共同基础。Coweeta水文实验室位于北卡罗来纳州西部的阿巴拉契亚山脉南部，是遍布美国和波多黎各的82个EF&R之一。自1934年成立以来，考维塔水文实验室研究所获得的丰富和广度的科学知识为公共和私人土地管理者提供了关于林地管理的信息，并增加了自然资源科学的知识库。我们描述了考维塔早期的流域研究，并使用长期测量和清单(从1934年到2008年)来：(1)探索大范围干扰和植被响应对生态系统过程的影响；(2)评估外来入侵物种对阿巴拉契亚南部落叶森林的长期和短期影响。我们侧重于受自然和管理干扰影响的植被模式的变化，然后描述了长期植被测量与水量和质量反应之间的联系。对于自然干扰，我们使用了在参考流域和未管理地区建立的900多个永久植被样地的网络；第一次测量是在1934年，子集重新测量是在1969-1972、1988-1993和2003-2008年。在管理干扰、砍伐和物种转换实验中，在处理前后对处理流域内的永久地块进行了植被测量。到1934年调查时，在板栗疫病(栗疫病菌)导致几乎所有剩余的板栗树死亡之前，森林只有10年的时间从采伐中恢复。随着锯齿猴优势种的丧失，红枫和蒙大拿成为优势种，鹅掌材和加拿大铁杉在海湾和河岸走廊增加。加拿大铁杉目前受到另一种入侵物种铁杉的威胁，2003年至2008年间，加拿大铁杉有33%的树木死亡。较小规模的干扰，如干旱和风灾，造成了树冠空隙，干扰因素、林隙大小和特定物种的人口统计(扩散、存活、生长和死亡)影响了殖民和补充。一般而言，更新到树冠空隙中的物种的组成反映了干扰时已经存在的植被，因为更新主要通过树苗或萌芽进行。在林隙大得多(9-59公顷)的管理林中，早期演替物种更新并形成，长期植被模式与未管理森林不同。植被数据描述了森林结构和组成随时间和空间的变化，并已被用来开发基于过程的模型，以扩大到集水区一级。长期的气候、水文、生物地球化学和植被数据库与基于过程的生态水文学和生态生理学模型相结合，对于理解更广泛和更复杂的环境问题至关重要，例如气候变化、碳循环、大气沉积以及水的供应和质量。爱思唯尔出版公司(Elsevier B.V.)
Long-term records from USDA Forest Service Experimental Forests and Ranges (EF&Rs) are exceptionally valuable scientific resources and common ground for research in natural resource management. Coweeta Hydrologic Laboratory, Southern Appalachian Mountains in western North Carolina, is one of 82 EF&Rs located throughout the United States and Puerto Rico. Since its establishment in 1934, the wealth and breadth of scientific knowledge gained from Coweeta Hydrologic Laboratory research has provided both public and private land managers information on forest land management and has added to the knowledge base of natural resource science.We described the early watershed research at Coweeta and used long-term measurements and inventories (from 1934 to 2008) to: (1) explore the influences of large-scale disturbances and vegetation responses on ecosystem processes and (2) assess the long-term and short-term impacts of an exotic, invasive species on a southern Appalachian deciduous forest. We focused on changes in vegetation patterns influenced by natural and managed disturbances and then described the linkages between long-term vegetation measurements and water yield and quality responses. For natural disturbances, we used a network of over 900 permanent vegetation plots established in reference watersheds and unmanaged areas; first measured in 1934 and a subset re-measured in 1969-1972, 1988-1993, and 2003-2008. For the managed disturbances, clearcuts and species conversion experiments, vegetation was measured in permanent plots within treated watersheds before and after treatment.By the time of the 1934 survey, the forest had only 10 years to recover from logging before chestnut blight (Cryphonectria parasitica) induced mortality of virtually all remaining Castanea dentata trees. With the loss of C dentata as the dominant species, Acer rubrum and Quercus montana became the dominant species and Liriodendron tulipifera and Tsuga canadensis increased in coves and along riparian corridors. T. canadensis is currently threatened by another invasive species, hemlock woolly adelgid (HWA, Adelges tsugae), with 33% tree mortality between 2003 and 2008. Smaller-scale disturbances, such as drought and windthrow, have created canopy gaps and the disturbance agent, gap size, and species-specific demography (dispersal, survival, growth, and mortality) affected colonization and recruitment. In general, the composition of species recruiting into canopy gaps was a reflection of the vegetation already in place at the time of disturbance, because regeneration occurred primarily through saplings or sprouts. In managed forests, where gaps were much larger (9-59 ha), early successional species recruit and become established and the long-term vegetation patterns are different than in unmanaged forests. The vegetation data provide a description of changes in forest structure and composition through time and space, and they have been used to develop process-based models to scale-up to the catchment level. Long-term climatic, hydrologic, biogeochemical, and vegetation databases coupled with process-based ecohydrology and ecophysiology models are essential to understanding broader- and more complex environmental issues such as climate change, carbon cycling, atmospheric deposition, and water supply and quality. Published by Elsevier B.V.