Forest Management Under Megadrought: Urgent Needs at Finer Scale and Higher Intensity
Forest Management Under Megadrought: Urgent Needs at Finer Scale and Higher Intensity
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DOI：
10.3389/ffgc.2020.502669
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发表时间：
2020-12-23
影响因子：
3.2
通讯作者：
Allen, Craig D.
中科院分区：
文献类型：
--
作者：
Field, Jason P.;Breshears, David D.;Allen, Craig D.
干旱和气候变暖日益导致大范围的树木死亡和极端的野火。森林管理者正在努力改善预期的森林管理实践，因为“热干旱”（比历史条件更温暖的干旱）引发了更频繁，更广泛和更严重的野火和树木死亡事件。更令人担忧的是，多年干旱或“特大干旱”的可能性越来越大--持续干旱持续数年至数十年，而且在气候仍在变暖的情况下，其温度也将超过历史标准。气温升高下的特大干旱令人不安，因为它们有可能引发更严重的森林死亡、火灾周期、病原体和昆虫爆发。在这个角度来看，我们确定了潜在的预期和/或并发选项下megadrew，这是必要的非木材森林管理行动更集中在更精细的空间尺度，如使用更高强度的管理林分水平。这些管理行动以注重生长和产量（而不是收获）的造林做法为基础。目前可以在更小范围内集中注意的管理办法包括关键的造林做法：有选择地间伐;使用精心挑选的前瞻性混合种子;场地轮廓;植被和虫害管理;土壤侵蚀控制;火灾管理。对于特大干旱带来的极端挑战，管理层必须更加注重在优先地点采取更小规模、更高强度的行动，如培育林分庇护所;通过土壤改良剂协助林分恢复;加强根系发育;深层土壤保水;以及浅水蓄水。干旱引起的森林死亡，从巨大的树木可能会导致根本性的变化，结构，功能和森林的组成及其提供的生态系统服务。
Drought and warming increasingly are causing widespread tree die-offs and extreme wildfires. Forest managers are struggling to improve anticipatory forest management practices given more frequent, extensive, and severe wildfire and tree die-off events triggered by "hotter drought"-drought under warmer than historical conditions. Of even greater concern is the increasing probability of multi-year droughts, or "megadroughts"-persistent droughts that span years to decades, and that under a still-warming climate, will also be hotter than historical norms. Megadroughts under warmer temperatures are disconcerting because of their potential to trigger more severe forest die-off, fire cycles, pathogens, and insect outbreaks. In this Perspective, we identify potential anticipatory and/or concurrent options for non-timber forest management actions under megadrought, which by necessity are focused more at finer spatial scales such as the stand level using higher-intensity management. These management actions build on silvicultural practices focused on growth and yield (but not harvest). Current management options that can be focused at finer scales include key silvicultural practices: selective thinning; use of carefully selected forward-thinking seed mixes; site contouring; vegetation and pest management; soil erosion control; and fire management. For the extreme challenges posed by megadroughts, management will necessarily focus even more on finer-scale, higher-intensity actions for priority locations such as fostering stand refugia; assisted stand recovery via soil amendments; enhanced root development; deep soil water retention; and shallow water impoundments. Drought-induced forest die-off from megadrought likely will lead to fundamental changes in the structure, function, and composition of forest stands and the ecosystem services they provide.