期刊
ECOSPHERE
卷 6, 期 5, 页码 -出版社
WILEY
DOI: 10.1890/ES14-00447.1
关键词
Adelges tsugae; ecosystem dynamics; foundation species; Formicidae; Harvard Forest; indirect effects; nitrogen; soil respiration; Tsuga canadensis
类别
资金
- NSF [0400759, 0452254, 0620443, 0930516, 1003938, 1237491]
- Direct For Biological Sciences
- Division Of Environmental Biology [1237491] Funding Source: National Science Foundation
- Direct For Biological Sciences
- Div Of Biological Infrastructure [0930516, 0452254, 0400759] Funding Source: National Science Foundation
The decline of Tsuga canadensis (eastern hemlock)-a foundation tree species-due to infestation by Adelges Tsugae (hemlock woolly adelgid) or its complete removal from a stand by salvage logging dramatically affects associated faunal assemblages. Among these assemblages, species composition (richness and abundance) of ants increases rapidly as Tsuga canadensis is lost from the stands. Because ants live and forage at the litter-soil interface, we hypothesized that environmental changes caused by hemlock loss (e.g., increased light and warmth at the forest floor, increased soil pH) and shifts in ant species composition would interact to alter soil ecosystem variables. In the Harvard Forest Hemlock Removal Experiment (HF-HeRE), established in 2003, Tsuga canadensis in large plots were killed in place or logged and removed to mimic adelgid infestation or salvage harvesting, respectively. In 2006, we built ant exclosure subplots within all of the canopy manipulation plots to examine direct and interactive effects of canopy change and ant assemblage composition on soil and litter variables. Throughout HF-HeRE, Tsuga canadensis was colonized by the adelgid in 2009, and the infested trees are now declining. The experimental removal of Tsuga canadensis from the canopy was associated with an increase in the rate of cellulose decomposition by >50%, and exclosure of ants from subplots directly reduced their soil nitrate availability by 56%. Partial least squares path models revealed sequential interactive effects prior to adelgid infestation: canopy change (as a proxy for associated environmental changes) altered both decomposition and ant assemblage structure; changes in ant assemblage structure and decomposition rates altered nitrogen availability. The results illustrate that biotic changes directly associated with decline of Tsuga canadensis can have cascading effects on ecosystem nutrient availability and cycling.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据