Impacts of rodent eradication on seed predation and plant community biomass

Island ecosystems have experienced massive biodiversity loss, and invasive species, in particular rodents, are responsible for much of this loss (~15%). Rodent eradications have led to the recovery of over 100 island vertebrates and their ecological roles. While the focus of most eradication efforts has been vertebrate recovery, rodents are generalists that predominantly eat seeds and fruit. However, there has been limited work on the effects of rodent eradication on plant communities and plant-mediated ecological processes. In this study, we conducted repeated surveys of seed, juvenile, and adult tree abundance and survival in permanent vegetation plots across an islet network (Palmyra Atoll) in the Central Tropical Pacific, before and after the eradication of black rats (Rattus rattus). Our aim was to examine the role of seed predation on tree communities and biomass. We observed an 84% decrease in seed predation of an introduced foundational species (the coconut palm, Cocos nucifera), and a 14-fold increase in juvenile tree biomass in all species following eradication. Juvenile C. nucifera abundance increased 2-5 times more than other tree species, leading to a 10% increase in population growth rate and a 4-fold increase in adult tree biomass accumulation over the next tree generation. We conclude that rodents can have nuanced impacts on island ecosystems, including facilitation of other invasive species and alteration of ecosystem functions such as carbon and nutrient cycling and storage. Future eradication efforts need to incorporate plant responses, since plants can shape post-eradication recovery trajectories.

These data include census data from permanent vegetation plots on Palmyra Atoll, data used to determine community biomass from these plots, maps of Palmyra Atoll and the vegetation plot locations, and statistical tests used to determine changes in stages and vital rates for tree species in the permanent vegetation plots.

岛屿生态系统曾遭受大规模生物多样性丧失，其中入侵物种尤其是啮齿类动物，是约15%此类丧失的主要诱因。啮齿类动物的根除行动已促使超过100种岛屿脊椎动物及其生态功能得以恢复。尽管多数根除行动的核心目标为脊椎动物恢复，但啮齿类属于广食性物种，主要以种子和果实为食。然而，目前针对啮齿类根除对植物群落及植物介导的生态过程所产生影响的研究仍较为匮乏。本研究于热带中太平洋的巴尔米拉环礁（Palmyra Atoll）岛群的永久植被样地中，在黑鼠（Rattus rattus）根除前后，针对种子、幼树和成树的丰度与存活情况开展了重复调查。本研究旨在探究种子捕食作用对树木群落及生物量的影响。研究结果显示，根除黑鼠后，外来基础物种椰子树（Cocos nucifera）的种子捕食率下降了84%，所有树种的幼树生物量均提升了14倍。椰子树幼树的丰度增幅较其他树种高出2至5倍，这使得种群增长率提升了10%，且在后续一个树木世代中，成树生物量积累量增长了4倍。综上，啮齿类动物对岛屿生态系统可产生具有细微差异的复杂影响，包括促进其他入侵物种的扩散，以及改变碳循环、养分循环与储存等生态系统功能。未来的根除行动需纳入植物响应相关的考量，因为植物可决定根除后的生态恢复轨迹。

本数据集包含巴尔米拉环礁永久植被样地的普查数据、用于计算这些样地群落生物量的相关数据、巴尔米拉环礁及植被样地位置分布图，以及用于分析永久植被样地内树木物种各发育阶段及生命率变化的统计检验结果。