Time-lagged lichen extinction in retained buffer strips 16.5 years after clear-cutting
Time-lagged lichen extinction in retained buffer strips 16.5 years after clear-cutting
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DOI：
10.1016/j.biocon.2018.06.016
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发表时间：
2018-09-01
影响因子：
5.9
通讯作者：
Hylander, Kristoffer
中科院分区：
文献类型：
--
作者：
Johansson, Victor;Wikstrom, Carl-Johan;Hylander, Kristoffer
砍伐树木保留是林业中一项相对较新的措施，旨在在幼年时期为森林物种提供救生艇。然而，保留树木对于维持生物多样性多年的有效性仍然知之甚少。我们调查了周围森林砍伐后沿小溪保留的缓冲带中地衣的持久性，并与砍伐和未砍伐的参考进行比较。具体来说，我们比较了皆伐前、皆伐后2.5年和16.5年的红色名录/信号物种、杯状生物和下垂物种的丰富度和频率，并分析了它们随时间的定植-灭绝动态。结果表明，缓冲带中红色名录/信号物种和杯状生物的丰富度在16.5年后显着下降，但在2.5年后没有明显下降，而频率在2.5年后已表现出显着差异。随着时间的推移，下垂地衣的丰富度保持相对稳定，但频率在16.5年后显着下降。在空地中，所有组的下降幅度都比缓冲带中的下降幅度更大（-2-3.5 倍），并且主要下降已经发生在 2.5 年后。随着时间的推移，参考文献保持稳定。殖民-灭绝动态反映了丰富度的下降，在砍伐区早期灭绝率较高，在缓冲带中灭绝率较低但较晚，以及（再）殖民化程度较低。我们得出的结论是，由于灭绝时间滞后，保留的缓冲带不能随着时间的推移保持地衣的丰富度，但它们显然比砍伐更有效。更宽的缓冲带可能会降低树木死亡率并减少地衣灭绝。大量直立的枯木使缓冲带成为未来潜在的殖民目标。
Tree retention on clear-cuts is a relatively new measure in forestry aimed at lifeboating' forest species during young seral periods. However, the effectiveness of tree retention for maintaining biodiversity for more than a few years is still poorly known. We investigated lichen persistence in retained buffer strips along small streams after clear-cutting of the surrounding forest, and compared with clear-cuts and un-cut references. Specifically, we compared richness and frequency of red-listed/signal species, calicioids and pendulous species before clear cutting with 2.5 years and 16.5 years after clear-cutting, and also analysed their colonization-extinction dynamics over time. The results show that the richness of red-listed/signal species and calicioids in buffer strips had declined significantly after 16.5 years, but not after 2.5 years, while frequency displayed a significant difference already after 2.5 years. The richness of pendulous lichens remained relatively stable over time, but the frequency had declined significantly after 16.5 years. In clear-cuts all groups declined more than in buffer-strips (-2-3.5 times more) and the main decline had occurred already after 2.5 years. References remained stable over time. The colonization-extinctions dynamics reflected the richness declines, with high early extinction in clear cuts and lower but late extinction in buffer-strips, and low (re)colonization. We conclude that retained buffer strips cannot maintain lichen richness over time due to time-lagged extinction, but they are clearly more effective than clear-cuts. Wider buffer strips could potentially reduce tree mortality and decrease lichen extinction. The large amounts of standing dead wood makes buffer strips potential future colonization targets.