Although Eucalyptus is widely planted outside its native range for timber and pulp production, the effects of these exotic plantations on biodiversity relative to native semi-natural forests or plantations of native tree species remain incompletely understood. Here, we compare the diversity of saproxylic beetles (Coleoptera) and true bugs (Hemiptera) between non-native Eucalyptus benthamii Maiden and Cambage (Camden white gum) and native Pinus taeda L. (loblolly pine) stands on the upper Coastal Plain of South Carolina, U.S.A. We sampled insects emerging from logs of both species placed in both stand types after 1, 2, 6, and 12 months in the field. Beetle and true bug richness and diversity were both significantly lower from eucalypt than from pine wood. Moreover, the two communities were compositionally distinct. Whereas pine supported many species of host-specific phloeoxylophagous beetles, most species collected from eucalypts were mycophagous or predatory taxa capable of utilizing a wide range of hosts. Species richness did not differ between logs placed in eucalypt vs. pine stands but Shannon’s diversity was significantly higher in the eucalypt stands, possibly due to greater sun exposure in the latter. Contrary to a previous study, we found no support for the idea that eucalypt litter reduces the diversity of saproxylic insects. Our findings add to the growing body of evidence that non-native plantations are less favorable to biodiversity than those consisting of native tree species.

尽管桉树在其原生范围之外广泛种植，用于木材和纸浆生产，但相对于本地半天然森林或本地树种种植园，这些外来种植园对生物多样性的影响仍不完全清楚。在这里，我们比较了南部沿海平原上部的非本地本氏桉树和甘白树（卡姆登白胶）与本地火炬松林之间的腐木甲虫（鞘翅目）和真虫（半翅目）的多样性。美国卡罗来纳州 我们对在田间放置 1、2、6 和 12 个月后放置在两种林分类型中的两种原木中出现的昆虫进行了采样。桉树中的甲虫和真正的昆虫丰富度和多样性均显着低于松木。此外，这两个社区在组成上也截然不同。虽然松树支持许多寄主特异性的草食性甲虫物种，但从桉树中收集的大多数物种都是食菌性或掠食性类群，能够利用多种寄主。放置在桉树林和松林中的原木之间的物种丰富度没有差异，但桉树林中的香农多样性明显更高，这可能是由于后者暴露在阳光下的时间更长。与之前的研究相反，我们没有发现桉树凋落物会降低腐木昆虫多样性的观点。我们的研究结果进一步证明，非本土种植园对生物多样性的影响不如本土树种种植园。