LTREB: Exotic Pests, Nitrogen Saturation, and Nutrient Cycling in a Northeastern Forest

LTREB：东北森林的外来害虫、氮饱和度和养分循环

• 批准号: 0129138
• 负责人: Gary Lovett
• 金额: $ 30万
• 依托单位: Cary Institute of Ecosystem Studies, Inc.
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-01-01 至 2006-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0129138&HistoricalAwards=false
• 关键词: LTREB; Exotic; Pests; Nitrogen; Saturation

Lovett0129138This LTREB project will support sustained research on the direct and indirect effects of two exotic pests that threaten the forests of the eastern US, the gypsy moth and the hemlock wooly adelgid. The gypsy moth is the most important defoliator of eastern forests. It preferentially attacks oak-dominated forests and causes widespread defoliation during periodic outbreaks. The hemlock woolly adelgid is a more recently introduced pest that is devastating hemlock trees in the mid-Atlantic states and New England. It is an aphid-like insect that feeds exclusively on hemlocks, and generally results in 100% mortality of trees within several years after infestation. The research questions here involve the effect of these pests on the nitrogen cycle of forests. Both of these pests are occurring against the backdrop of elevated levels of nitrogen deposition due to nitrogen oxide emissions from fossil fuel combustion and ammonia emission from agricultural activities. These is a strong probability of a complex interaction between nitrogen deposition and the effects of these pests on the nitrogen cycles of the forest ecosystems under study. This LTREB project will continue measurements of forest productivity and nutrient cycling in long-term study plots in Millbrook, NY. The plots include both oak plots in the zone likely to be affected by the gypsy moth, and hemlock plots in an area soon to be infested with hemlock woolly adelgid. In addition, a long-term N-addition experiment in an oak forest will be maintained, as well. This work has direct relevance to management of eastern forests, in that gypsy moth and hemlock woolly adelgid are two of the most devastating pests in the region. The phenomenon of nitrogen saturation and its effects on forest health and the quality of surface waters, is an emerging management and policy issue in the eastern US. Thus, the study of the interaction of these two stresses is of both scientific and practical importance.

Lovett0129138这个LTREB项目将支持对两种威胁美国东部森林的外来有害生物--吉普赛飞蛾和铁杉绵毛飞蛾--的直接和间接影响的持续研究。吉普赛蛾是东部森林最重要的落叶者。它优先攻击以橡树为主的森林，并在周期性暴发期间造成大范围的落叶。铁杉是最近引进的一种害虫，在大西洋中部各州和新英格兰地区对铁杉造成毁灭性的破坏。它是一种类似蚜虫的昆虫，只以铁杉为食，通常在感染后几年内导致树木100%死亡。这里的研究问题涉及到这些害虫对森林氮循环的影响。这两种害虫都是在化石燃料燃烧排放的氮氧化物和农业活动排放的氨导致氮沉积水平上升的背景下发生的。这是氮沉积与这些害虫对正在研究的森林生态系统的氮循环的影响之间存在复杂相互作用的很大可能性。该LTREB项目将在纽约州米尔布鲁克的长期研究地块中继续测量森林生产力和养分循环。这些地块既包括可能受到吉普赛飞蛾影响的地区的橡树地块，也包括即将受到铁杉绵毛虫侵扰的地区的铁杉地块。此外，还将在橡树林中进行长期的氮素添加试验。这项工作与东部森林的管理直接相关，因为吉普赛飞蛾和铁杉绵毛虫是该地区最具破坏性的两种害虫。氮饱和现象及其对森林健康和地表水质量的影响，是美国东部正在出现的一个管理和政策问题。因此，研究这两种应力的相互作用具有重要的科学意义和现实意义。