Holmquist Anna J, Adams Seira A, Gillespie Rosemary G
Department of Environmental Science, Policy and Management University of California: Berkeley Berkeley California USA.
Ecol Evol. 2023 Feb 22;13(2):e9820. doi: 10.1002/ece3.9820. eCollection 2023 Feb.
Earth systems are nearing a global tipping point, beyond which the dynamics of biological communities will become unstable. One major driver of instability is species invasion, especially by organisms that act as "ecosystem engineers" through their modification of abiotic and biotic factors. To understand how native organisms respond to modified habitat, it is essential to examine biological communities within invaded and non-invaded habitat, identifying compositional shifts in native and non-native taxa as well as measuring how modification by ecosystem engineers has affected interactions among community members. Using dietary metabarcoding, our study examines the response of a native Hawaiian generalist predator (Araneae: spp.) to habitat modification by comparing biotic interactions across metapopulations of spiders collected in native forest and sites invaded by kāhili ginger. Our study shows that, although there are shared components of the dietary community, spiders in invaded habitat are eating a less consistent and more diverse diet consisting of more non-native arthropods which are rarely or entirely undetected in spiders collected from native forest. Additionally, the frequency of novel interactions with parasites was significantly higher in invaded sites, reflected by the frequency and diversity of non-native Hymenoptera parasites and entomopathogenic fungi. The study highlights the role of habitat modification driven by an invasive plant in altering community structure and biotic interactions, threatening the stability of the ecosystem through significant changes to the biotic community.
地球系统正接近一个全球临界点，超过这个临界点，生物群落的动态将变得不稳定。不稳定的一个主要驱动因素是物种入侵，尤其是那些通过改变非生物和生物因素而充当“生态系统工程师”的生物。为了了解本地生物如何应对栖息地的改变，有必要研究被入侵和未被入侵栖息地中的生物群落，识别本地和非本地分类群的组成变化，并衡量生态系统工程师的改变如何影响群落成员之间的相互作用。通过饮食代谢条形码技术，我们的研究通过比较在原生森林和被卡希利姜入侵的地点收集的蜘蛛种群中的生物相互作用，研究了夏威夷本地的广食性捕食者（蜘蛛目：多种）对栖息地改变的反应。我们的研究表明，尽管饮食群落有共同的组成部分，但入侵栖息地中的蜘蛛饮食不太一致且更多样化，由更多非本地节肢动物组成，而这些节肢动物在从原生森林收集的蜘蛛中很少或完全未被发现。此外，在入侵地点与寄生虫的新相互作用频率显著更高，这体现在非本地膜翅目寄生虫和昆虫病原真菌的频率和多样性上。该研究强调了入侵植物驱动的栖息地改变在改变群落结构和生物相互作用方面的作用，通过生物群落的重大变化威胁生态系统的稳定性。
