Collaborative Research: LTREB Renewal: RUI: Cyclic vs. anthropogenic causes of long-term variation in the regeneration of tropical forests with contrasting latitude and diversity

合作研究：LTREB 更新：RUI：具有对比纬度和多样性的热带森林再生长期变化的循环与人为原因

• 批准号: 2325528
• 负责人: Jess Zimmerman
• 金额: $ 30万
• 依托单位: University of Puerto Rico-Rio Piedras
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2028-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2325528&HistoricalAwards=false
• 关键词: Collaborative; Research; LTREB; Renewal; RUI

Successful plant reproduction – flowering and fruiting – is sensitive to environmental conditions, as are the early life stages that follow – seed germination and seedling survival and growth. Plants often use variation in their environment as a cue to reproduce, ensuring, for example, there is adequate energy and moisture for fruit development or that their seeds are dispersed when conditions are favorable for the growth and survival of young seedlings. The reproduction and regeneration of tropical forests are therefore vulnerable to a changing climate. This project, renewed for five more years, uses long-term data to understand how the timing and success of reproduction in tropical plants varies year-to-year as the cues and conditions for flowering, fruiting, and seedling survival vary due to within-year seasonality, multi-year climate cycles such as El Niño, and/or the effects of climate change. The research takes place at three tropical forest study sites (Ecuador, Puerto Rico, and Panama) to separate the effects of local site conditions from long-term regional climate patterns. Undergraduates and early career interns participating in this research receive training each year and support for projects that expand on the long-term scope of this work. Tropical forests are globally important because of their high biodiversity and large contributions to carbon storage, and thus a better understanding of the environmental conditions that affect tropical plant reproduction will strengthen our ability to predict the survival of tropical forests and the benefits these forests confer.This research spans forests differing in diversity, seasonality, disturbance, and climate to test hypotheses concerning: (1) environmental cues that induce flowering; (2) effects of multiyear or multidecadal natural climate cycles on reproduction in tropical forests; (3) survival and growth of seedlings from species with different functional traits in response to climatic variation; and (4) how episodic reproduction structures adult populations, effectively closing the demographic gap between studies of early reproduction and the dynamics of sapling and adult tree populations. Standardized methodology used at our three sites includes weekly or biweekly recording of species-specific flower, fruit, and seed rain in permanent traps and annual censuses of all woody seedlings in plots adjacent to the traps. The research take place within large (16-50 ha) mapped forest dynamics plots where all trees 1 cm in diameter are identified and regularly measured. Similar methodology is also employed in multiple temperate and tropical forests, which facilitates cross-site comparisons that broaden the generalizability of our results. This project is jointly funded by the Population and Community Ecology program, and the Established Program to Stimulate Competitive Research (EPSCoR).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

成功的植物繁殖（开花和结果）对环境条件很敏感，随后的生命早期阶段（种子发芽和幼苗存活和生长）也对环境条件敏感，植物经常利用环境的变化作为繁殖的线索，以确保存在。为果实发育提供足够的能量和水分，或者在有利于幼苗生长和存活的条件下种子传播。因此，热带森林的繁殖和再生很容易受到气候变化的影响。该项目再延长五年。 ，使用长期数据了解热带植物繁殖的时间和成功率如何逐年变化，因为开花、结果和幼苗存活的线索和条件因年内季节性、多年气候周期（如厄尔尼诺现象）和/或气候变化的影响 该研究在三个热带森林研究地点（厄瓜多尔、波多黎各和巴拿马）进行，旨在将当地条件与参与的长期区域气候模式的影响分开。这项研究接受培训热带森林具有高度的生物多样性和对碳储存的巨大贡献，因此对扩大这项工作长期范围的项目的支持将加强对影响热带植物繁殖的环境条件的更好了解。我们预测热带森林的生存以及这些森林带来的好处的能力。这项研究涵盖了多样性、季节性、干扰和气候方面不同的森林，以检验以下假设：(1) 诱导开花的环境因素；(2) 多年生影响；或多年代自然气候循环对繁殖的影响在热带森林中；（3）具有不同功能特征的物种的幼苗对气候变化的生存和生长；以及（4）间歇性繁殖如何构建成年种群，从而有效缩小早期繁殖和树苗动态研究之间的人口差距我们三个地点使用的标准化方法包括每周或每两周记录永久陷阱中特定物种的花、果实和种子雨，以及对陷阱附近的所有木本幼苗进行年度普查。在大型（16-50 公顷）森林动态图中，所有直径为 1 厘米的树木都被识别并定期测量，类似的方法也适用于多个温带和热带森林，这有助于跨地点比较，扩大我们结果的普遍性。该项目由人口和社区生态学计划以及刺激竞争性研究既定计划 (EPSCoR) 共同资助。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准。