LTREB renewal: Climatic change and community organization across three trophic levels: long-term research at a sentinel site in semiarid north-central Chile

LTREB 更新：三个营养级的气候变化和社区组织：智利中北部半干旱哨点的长期研究

• 批准号: 1456729
• 负责人: Douglas Kelt
• 金额: $ 47.01万
• 依托单位: University of California-Davis
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2021-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1456729&HistoricalAwards=false
• 关键词: LTREB; renewal; Climatic; change; community

Increases in semi-arid and arid lands may affect economic stability and societies globally. This long-term project examines the shifting forces that influence a semi-arid community and thus serves as an important sentinel for societal ramifications of increased aridity with climate change. Since 1989, unexpected changes in rainfall patterns and species invasions have replaced native species interactions as key drivers of a semi-arid thorn scrub community in northern Chile. Long-term ecological data from this site contribute directly to decisions on wise management of these changing environments. It also will provide information to help the general public understand the decision-making process by improving their knowledge of its wildlife and natural areas. The project will provide important comparisons with ongoing research in semi-arid sites in North America, where important drivers of long-term change differ. The project represents a long-term collaboration between US and Chilean researchers and managers, and will provide valuable opportunities for US students to participate in international research. This long-term field project utilizes 20 experimental grids in which small mammals and ephemeral plants are sampled monthly, cover by shrubs is measured every three months, soil samples are taken every 4 months to estimate seed density, and fox owl diets are assessed. Previous results document the effects of predators on small mammals and plants that were overwhelmed by El Niño‐associated rainfall. Based on predictions of more frequent and intense El Niño events as a consequence of ongoing global climate change, the project will emphasize the dual and interactive roles of climate change and invasive species (lagomorphs, numerous ephemeral plants) on community-level dynamics in this habitat. Data collected over the next five years will be analyzed to answer three important questions: 1) will a major El Niño event in the next 5 years reverse the trends that have been apparent since 2002, or has a critical transition occurred that will be stable for the foreseeable future? 2) what further changes may ensue from the apparent decline in perennial shrub cover and an increase in invasive vegetation since 2003? and 3) what will be the consequences of these changes for the north-central Chilean semiarid zone more generally? These goals are facilitated by extensive collaboration with multiple investigators in Chile, Spain, and the United States. This research integrates population, community, and geographical ecology in the context of global climate change and predicted vegetative responses, spans 3 trophic levels, and provides important insight into the relative importance of biotic vs. abiotic factors, and top-down versus bottom-up control in semi-arid systems.

半干旱和干旱土地的增加可能影响全球的经济稳定和社会。这一长期项目审查了影响半干旱社区的变化力量，从而成为气候变化导致干旱加剧的社会影响的重要哨兵。自1989年以来，降雨模式和物种入侵的意想不到的变化已经取代了本地物种的相互作用的半干旱刺灌丛社区在北方智利的关键驱动程序。从这个网站的长期生态数据直接有助于这些不断变化的环境明智的管理决策。它还将提供信息，帮助公众了解决策过程，提高他们对野生动物和自然区的了解。该项目将提供与北美半干旱地区正在进行的研究的重要比较，那里长期变化的重要驱动因素不同。该项目代表了美国和智利研究人员和管理人员之间的长期合作，并将为美国学生提供参与国际研究的宝贵机会。这一长期实地项目利用20个实验网格，每月对小型哺乳动物和短命植物进行取样，每三个月测量灌木覆盖率，每四个月采集土壤样本以估计种子密度，并评估狐鸮的饮食。先前的结果记录了捕食者对小型哺乳动物和植物的影响，这些哺乳动物和植物被厄尔尼诺现象#8208;相关的降雨淹没。根据对目前全球气候变化造成的更频繁和更强烈的厄尔尼诺现象的预测，该项目将强调气候变化和入侵物种（兔形目动物、许多短命植物）对这一生境社区一级动态的双重和相互作用。将分析未来五年收集的数据，以回答三个重要问题：1）未来五年的重大厄尔尼诺事件是否会扭转自2002年以来明显的趋势，或者是否发生了在可预见的未来保持稳定的关键转变？2)自2003年以来，多年生灌木植被明显减少，入侵植被增加，这可能会带来什么进一步的变化？以及3）这些变化对智利中北部半干旱区的影响是什么？这些目标是通过与智利，西班牙和美国的多名研究人员的广泛合作而实现的。这项研究整合了人口，社区和地理生态学的背景下，全球气候变化和预测的植被反应，跨越3个营养水平，并提供了重要的洞察生物与非生物因素的相对重要性，自上而下与自下而上的控制在半干旱系统。