特色活动 | Geoinsider在线讲座系列第18期：落叶森林对温度降水干旱的响应与气候变化的复杂影响

活动简介

Geoinsider Webinar

在线讲座系列第18期

题    目：Deciduous forest responses totemperature, precipitation, and drought imply complex climate change impacts, PNAS& RSE paper

报告人：Dr. Yingying Xie, Northwestern University

时   间：

北京时间5月1日（周五）上午10:00

加州时间4月30日（周四）晚上7:00

悉尼时间5月1日（周五）中午12:00

参与方式：采用Zoom平台，点击文末阅读原文进入平台参会。

链接：https://tamu.zoom.us/j/95246134015

 Presentation Abstract 

Changes in spring and autumn phenologyof temperate plants in recent decades have substantial ecological and economicimpacts. How environmental conditions (e.g., frost, heat, wetness, and drought)influence autumn phenological events remain poorly understood. Using remotelysensed phenology data from 2001 to 2012, our study identified and quantifiedsignificant effects of a suite of environmental factors on the timing of falldormancy of deciduous forest communities in New England, United States. Cold, frost,and wet conditions, and high heat-stress tended to induce earlier dormancy ofdeciduous forests, whereas moderate heat- and drought-stress delayed dormancy.Deciduous forests in two eco-regions showed contrasting, nonlinear responses tovariation in these explanatory factors. Based on future climate projection overtwo periods (2041–2050 and 2090–2099), later dormancy dates were predicted innorthern areas. However, in coastal areas earlier dormancy dates werepredicted.

There is a large (and unquantified)uncertainty in estimated Land Surface Phenology (LSP) due to the relativelycoarse temporal resolution of typical data and methodological limitations. Todecrease the temporal uncertainty of estimated phenological processes, wedeveloped a new LSP estimation method using linear change point models todetermine four phenological transitions of deciduous forests in the central andeastern US using twice-daily MODIS EVI from 2000 to 2015. We found that the LSPgenerated from change point estimation with twice daily EVI time series had thehighest accuracy for both spring and fall phenology. Our methodology alsoenables calculation of additional metrics including rates of greenup,green-down, and senescence, EVI values at each phenological transition, and theestimation uncertainties for each transition date. Our LSP estimations willimprove more comprehensive investigations of landscape phenology of deciduousforest and the associated ecosystem processes at regional to global scales.

Linkage：

PNAS论文：https://www.pnas.org/content/112/44/13585.short

RSE论文：https://www.sciencedirect.com/science/article/abs/pii/S0034425720300675

Geoinsider简介 

Geoinsider是一个最初由湾区的Geoscience同行自发形成的公益性交流平台，定位在顶级的产学研交叉，包括PNS级讲座、产业应用转化、留学Intern教职申请等交流，迄今已邀请发表过Science、Nature等高水平文章，以及来自Harvard、Berkeley等顶级机构的Webinar报告交流。

往期报告

致    谢

本活动由Geoinsider主办，得到全国地理学研究生联合会、北京师范大学地理科学学部GEO云讲堂、信达雅科教、环宇易研科技等单位的大力支持。

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• 期间欢迎大家使用Zoom的“Q&A”功能对主讲人留言提问

• 讲座结束后预留了交流时间，欢迎各位同行交流讨论

往期链接：特色活动 | Geoinsider在线讲座系列第17期：利用太阳诱导叶绿素荧光遥感提高对秋季碳循环的认识

欢迎大家积极参加！

 活动简介

Geoinsider Webinar

在线讲座系列第17期

文稿来源：Yelu Zeng

图文排版：魏雪馨

责任编辑：鲁嘉颐

审编：王波涛 

终审： 顾伟男   田巍   梁龙武

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