Insect outbreaks produce distinctive carbon isotope signatures in defensive resins and fossiliferous ambers
Insect outbreaks produce distinctive carbon isotope signatures in defensive resins and fossiliferous ambers
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DOI：
10.1098/rspb.2011.0276
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发表时间：
2011-11-07
影响因子：
4.7
通讯作者：
Sanchez-Azofeifa, G. Arturo
中科院分区：
文献类型：
--
作者：
McKellar, Ryan C.;Wolfe, Alexander P.;Sanchez-Azofeifa, G. Arturo
尽管几个世纪以来对琥珀及其各种内含物的研究，但对刺激地质相关的植物树脂产量的具体事件所知甚少，最终产生琥珀矿床。虽然许多假说都援引了昆虫的作用，但迄今为止，这些假说已被证明难以验证。在这里，我们使用目前的山松甲虫爆发在加拿大西部作为一个类比的影响，在树脂中的碳的稳定同位素组成的侵扰。我们表明，感染的结果在一个快速（约。1年）（13）C富集的新鲜lodgepole松树脂，在模式直接可比的树脂收集从未受感染的树木进行水分胁迫。此外，树脂同位素值被证明可以跟踪侵染的进展和恢复的情况。这些发现可以扩展到化石树脂，包括多米尼加共和国的中新世琥珀和晚白垩世新泽西琥珀，揭示了视觉上干净的琥珀和那些与钻木昆虫攻击有关的琥珀之间相似的碳同位素模式。植物分泌物三角洲（13）C值构成了现代和古代森林生态系统中的生态压力的敏感监测器，并提供了相当多的见解有关的地质记录中的琥珀的成因。
Despite centuries of research addressing amber and its various inclusions, relatively little is known about the specific events having stimulated the production of geologically relevant volumes of plant resin, ultimately yielding amber deposits. Although numerous hypotheses have invoked the role of insects, to date these have proven difficult to test. Here, we use the current mountain pine beetle outbreak in western Canada as an analogy for the effects of infestation on the stable isotopic composition of carbon in resins. We show that infestation results in a rapid (approx. 1 year) (13)C enrichment of fresh lodgepole pine resins, in a pattern directly comparable with that observed in resins collected from uninfested trees subjected to water stress. Furthermore, resin isotopic values are shown to track both the progression of infestation and instances of recovery. These findings can be extended to fossil resins, including Miocene amber from the Dominican Republic and Late Cretaceous New Jersey amber, revealing similar carbon-isotopic patterns between visually clean ambers and those associated with the attack of wood-boring insects. Plant exudate delta(13)C values constitute a sensitive monitor of ecological stress in both modern and ancient forest ecosystems, and provide considerable insight concerning the genesis of amber in the geological record.