EAPSI: Nitrogen Cycle Responses to Increasing Presence of Parasitic Mistletoes in Australian Eucalypt Forests

EAPSI：氮循环对澳大利亚桉树林中寄生槲寄生数量增加的反应

• 批准号: 1714056
• 负责人: Holly Andrews
• 金额: $ 0.54万
• 依托单位: Andrews Holly M
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-06-01 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1714056&HistoricalAwards=false
• 关键词: EAPSI; Nitrogen; Cycle; Responses; Increasing

Australian eucalypt forests are increasingly inundated with mistletoes, in large response to changes in land management. Mistletoes are parasitic plants that reduce the growth of their host eucalyptus trees but also promote increased bird diversity in forests, resulting in conflicting opinions about how mistletoes affect forest function and productivity. Assessing how biologically-important nutrients, such as nitrogen, cycle through forests in response to mistletoe parasitism may give insight into forest health and function. Changes in nitrogen processes resulting from increasing abundance of mistletoe will likely have ramifications for forest health and global climate, and may inform future land management decisions in Australian woodlands and elsewhere. This project, conducted in collaboration with Dr. Elise Pendall at the Hawkesbury Institute for the Environment at Western Sydney University in Australia, will explore the role of mistletoe for nitrogen cycling in eucalyptus woodlands. Dr. Pendall is a renowned ecosystem ecologist known for her work in biogeochemical cycling in response to ecological disturbances.Relatively little is known about the impacts of Amyema miquelii mistletoe litter on decomposition, nitrification, and denitrification processes in woodlands dominated by Eucalyptus moluccana and E. fibrosa found in Cumberland Plain, Australia. Presumably, nitrogen-rich mistletoe litter could increase decomposition rates and serve as a substrate for increased emissions of nitrous oxide (N2O), a potent greenhouse gas. This study will explore how rates of various components of nitrogen cycling respond to increasing proportions of A. miquelii litter in Eucalyptus forests. By analyzing the quality and quantity of litterfall from plants, the soil microbial activity responsible for processing plant litter and its nitrogenous components, and the emissions of N2O from forest soils, the researcher will determine the increasing contribution of A. miquelii to soil processes and nitrogen cycling in previously nitrogen-poor systems.This award, under the East Asia and Pacific Summer Institutes program, supports summer research by a U.S. graduate student and is jointly funded by NSF and the Australian Academy of Science.

由于土地管理的变化，澳大利亚的桉树林越来越多地被槲寄生淹没。槲寄生是一种寄生植物，它会减少寄主桉树的生长，但也会促进森林中鸟类多样性的增加，导致关于槲寄生如何影响森林功能和生产力的观点相互矛盾。评估生物重要的营养物质（例如氮）如何在森林中循环以应对槲寄生寄生，可以深入了解森林的健康和功能。 槲寄生丰度增加导致的氮过程变化可能会对森林健康和全球气候产生影响，并可能为澳大利亚林地和其他地方未来的土地管理决策提供信息。该项目与澳大利亚西悉尼大学霍克斯伯里环境研究所的 Elise Pendall 博士合作开展，将探索槲寄生在桉树林地氮循环中的作用。 Pendall 博士是一位著名的生态系统生态学家，因其在应对生态干扰的生物地球化学循环方面的工作而闻名。对于 Amyema miquelii 槲寄生凋落物对以毛鹿桉和 E. 为主的林地分解、硝化和反硝化过程的影响知之甚少。纤维组织发现于澳大利亚坎伯兰平原。 据推测，富含氮的槲寄生凋落物可以提高分解速度，并成为增加一氧化二氮（N2O）（一种强效温室气体）排放的基质。这项研究将探讨氮循环的各个组成部分的速率如何响应桉树林中密克林凋落物比例的增加。通过分析植物凋落物的质量和数量、负责处理植物凋落物及其含氮成分的土壤微生物活动以及森林土壤中 N2O 的排放，研究人员将确定 A. miquelii 对土壤过程和氮的日益增加的贡献该奖项属于东亚和太平洋夏季研究所计划，支持美国研究生的夏季研究，并由美国国家科学基金会和澳大利亚科学院联合资助。