气候变暖对陆地生态系统的影响

人类活动引起的温室效应导致全球气候变暖,气候变暖对全球生态环境的影响越来越受到人们的关注.作为人类赖以生存的环境主体,陆地生态系统对气候变暖将做出何种响应,更是人们关注的重点.植物物候的变化可以直观地反映某些气候变化,尤其是气候变暖.气候变暖影响植物的生长节律,进而引起植物与环境关系的改变及生态系统物质循环(如水和碳的循环)的改变.不同种类植物对气候变化的差异响应,会使植物间和动植物间的竞争与依赖关系发生深刻的变化,如北半球中高纬度地区植被生长季延长、植物提早开花、昆虫提早出现、鸟类提早产蛋以及冰川退缩、永冻土带融化、江河湖泊结冰推迟而融化提早等.本文主要从陆地生态系统的分布和演替两方面着眼,以植物和动物作为考察对象,系统论述了森林、草原、荒漠、湿地及农田等陆地生态系统在气候变暖背景下产生的变化,并从微观和宏观尺度上提出陆地生态系统变化的生态学机制,最后在技术和政策层面给出若干对策.     

The impact of climate change on cherry trees and other species in Japan

Studies from throughout the world have provided evidence that climate change is already affecting the ecology and persistence of species. Japan contributes valuable insights into understanding these changes through long-term records of the timing of cherry blossoms and other phenomena of ecological and cultural interest. The wide latitudinal spread of Japan also provides an opportunity to examine species over a broad range of environmental conditions. In this review, we examine phenological studies that have taken place in Japan and summarize their significance to climate change and conservation research. In Kyoto, records of the timing of celebrations of cherry blossom festivals going back to the 9th century reconstruct the past climate and demonstrate the local increase in temperature associated with global warming and urbanization. This record is probably the longest annual record of phenology from anyplace in the world and shows that cherries are currently flowering earlier than they have at any time during the previous 1200 years. Detailed mapping of cherry tree flowering times in and around Osaka and other cities in Japan show that urbanization causes plants to flower earlier within the city environs than in nearby parks and outlying suburban areas. Flowering records from a large cherry arboretum at Mt. Takao, on the outskirts of Tokyo, show that both among and within species, early flowering is associated with greater responsiveness to temperature variation. Lastly, records of phenology for a wide range of plants and animals recorded at over 100 weather stations throughout Japan show that species vary greatly in their phenological responses to climate change, and highlight ecological relationships that need to be investigated in the field. Together, these studies provide important insights into how species are responding to climate change in Japan. Further research, particularly targeted field observations and experiments, is needed to build on these findings and to improve our understanding of how climate change is altering biological communities and how it will continue to affect them in the future.     

中国夏玉米和冬小麦近年生育期变化及其与气候的关系

作物物候期受气候条件和人为耕作的共同影响,而水热气候条件又直接影响着人为耕作时间。全球变暖背景下温度增加的趋势在近年来出现了停滞现象,针对这一新的气候变化特征,本研究选取作物物候观测和气象观测的站点数据,利用经典的统计学方法分析2000—2013年中国夏玉米和冬小麦主要物候期的变化趋势和空间分布,及作物生育期与对应水热条件的相关关系。研究发现:夏玉米和冬小麦各主要物候期均呈现一定程度的延后,其中64%的站点显示夏玉米成熟期延后,冬小麦成熟期延后的站点数比例达78%。研究期间,夏玉米和冬小麦的生育期历时对温度和降水变化均比较敏感,88%和64%的站点分别显示出夏玉米和冬小麦的生育期历时与平均温度之间呈负相关关系,而71%和77%的站点显示夏玉米和冬小麦生育期历时与年均降水量呈正相关关系。本研究时段内的气温变化也不同于一般性认为的单调升温,夏玉米生育期对应的平均温度呈增加和降低趋势的站点数基本相同,但显示降水量增加的站点较多,达到总站点数的68%;而冬小麦整个生育期显示冷干化趋势的站点居多,显示温度降低和降水量下降的站点数均占总站点数的60%以上。此外,本研究还用轮作站点探讨说明了可以利用年值气候数据替代生育期气候数据分析夏玉米和冬小麦轮作的物候和生育期特征。本研究通过站点数据证实了作物生长发育过程对气候变化的敏感性,新的气候条件下我国夏玉米和冬小麦的物候也对应产生了新的特征。     

气候变暖对山西南部典型植物物候的影响

选取山西省运城市、临汾市、晋城市和长治县农业气象试验站典型木本和草本植物1982-2004年物候观测资料及各地1970-2004年气温资料,运用距平、线性趋势等方法分析各地气温和植物物候期的变化特征,以及气温对植物物候期的影响。结果表明,(1)春季物候期普遍呈提前趋势,生长季呈延长趋势;木本植物秋季物候期呈推迟趋势,大部分地区草本植物黄枯始期表现为略提前趋势,黄枯末期表现为推迟趋势。(2)随着年平均气温的不断升高,植物春季物候期呈提前趋势;木本植物秋季物候期呈推迟趋势,草本植物黄枯末期大多呈提前趋势。气温每升高1℃,植物展叶始期提前1～18d。     

草本植物物候及其物候模拟模型的研究进展

草地生态系统在全球变化过程中具有不容忽视的作用。为深入了解草本植物物候与气候因素间的相互作用机制,建立精确的草地植被物候动态模型,更好地模拟和预测天然草地生态系统对气候变化的响应,本文对国内外草本植物物候及有关草本植物物候模型研究进行了回顾。已有的研究表明物候变化能在一定程度上反映出气候变化的趋势,且温度、光照和水分等环境因素作为物候的主要驱动力在不同的时期发挥着重要的作用。植物物候模型从简单统计模型,逐渐向可描述生长与环境相互作用过程的动态机理模型发展。但可用于天然草地植被物候模拟的模型较少,仍存在物种单一、适用范围小、缺少机理性研究等问题。针对目前的研究现状,只有加强对天然草地植被物候与非生物因子关系的分析,特别是水分对物候的影响研究,努力探索各个物候期的生理特征,不断验证完善已有物候模型,才能建立起精确的草地植被物候模型服务于全球气候变化的研究。     

2001-2020年南盘江流域植被物候时空变化及其对气候的响应

植被物候对气候敏感易观测,是观测生态变化与全球气候变化的重要指标,研究植被物候变化及其对气候的响应对于了解全球气候变化与植被之间的复杂关系具有重要意义。为揭示近20年来南盘江流域植被物候时空变化及其对气候的响应特征,基于2001—2020年增强型植被指数(MOD13Q1-EVI),运用S-G滤波、动态阈值法、Sen斜率分析法、相关性分析法等方法,获取了南盘江流域植被物候参数,分析其时空分布特征,利用偏相关系数分析了气候变化对SOS,EOS的影响。结果表明:(1)2001—2020年,南盘江流域物候特征变化较大,SOS(Start of the growing season)呈提前趋势,EOS(End of the growing season)和LOS(Length of the growing season)呈推迟延长趋势,物候变化具有空间异质性,不同子流域植被物候存在较大差异。(2)植被物候变化受到地形的影响,EOS随海拔升高,结束时间提前; SOS随海拔变化的规律与LOS的规律相反,都存在1 000 m,2 000 m和2 600 m分界线。(3)南盘江流域SOS变化与气温、降水呈正相关关系,EOS与气温呈正相关关系、与降水呈负相关关系。该研究可为南盘江流域的生态环境保护与植被资源可持续发展提供科学依据。     

2001-2020年青藏高原草地物候变化遥感监测

[目的]探究青藏高原草地物候时空变化规律,对于理解高寒生态系统与区域气候之间的相互作用和生态安全屏障保护与建设具有重要的科学意义。[方法]基于2001—2020年MODIS归一化植被指数(NDVI)时序产品,采用非对称高斯函数拟合法和动态阈值法,提取了青藏高原草地NDVI峰值、NDVI峰值期、返青期(SOS)、枯黄期(EOS)和生长季长度(LOS)参数。[结果](1)研究区草地物候的空间分布规律明显,自西向东,草地NDVI峰值增加、峰值期提前、SOS提前、EOS推迟、LOS延长。(2) 20年间,青藏高原草地物候年际变化主要表现为SOS呈提前趋势(12.11%的区域显著提前),EOS呈推迟趋势(18.49%的区域显著推迟),LOS呈延长趋势(18.87%的区域显著延长)。(3)青藏高原气温、降水对SOS有1～2个月的滞后效应;气温对EOS有1～2个月的滞后效应,而降水对EOS的滞后效应不明显。考虑滞后效应的条件下,气温是影响草地SOS,EOS年际变化的主导因子。[结论]青藏高原草地物候具有空间异质性,且气温是影响草地物候时空变化的主要因素。     

北京植被净初级生产力对物候变化的响应

植被净初级生产力（Net Primary Productivity,NPP）对物候的响应是全球气候变化背景下的重要研究内容,气候变化对植物物候与NPP的影响仍需明了,物候的时空变异规律更需深入探讨。该研究基于2001-2020年MODIS归一化植被指数（Normalized Difference Vegetation Index,NDVI）数据提取北京植被物候信息,利用CASA（Carnegie-Ames-Stanford-Approach）模型模拟NPP,通过线性回归、趋势分析和结构方程模型等方法,阐明NPP与物候时空变化特征,探究气象因素和物候变化对NPP的影响。结果显示：1）2001-2020年超过70 %的区域出现生长季开始（Start of Growing Season,SOS）逐渐提前,平均每年提前0.53 d。超过90%的区域生长结束期（End of Growing Season,EOS）逐渐推迟,平均每年推迟0.51 d。2）SOS提前和生长季（Length of Growing Season,LOS）延长均对NPP增长产生显著影响（P<0.05）。SOS每提前1 d,NPP增长3.74 g/m2;LOS每延长1 d,NPP增长2.56 g/m2 。秋季EOS推迟对NPP变化影响不显著。3）春季和秋季,气候通过改变物候（SOS、EOS）对NPP的间接影响大于直接影响,而夏季温度和降雨对NPP的直接影响更大。该研究表明春季物候变化是NPP年际变异的重要驱动因子,春季物候提前导致NPP年总量增加。研究结果是都市区植被生产力如何响应气候变化认识的重要补充。     

Reprint of “Soil extracellular enzyme dynamics in a changing climate”

Assays for extracellular enzyme activity (EEA) have become a common tool for studying soil microbial responses in climate change experiments. Nevertheless, measures of potential EEA, which are conducted under controlled conditions, often do not account for the direct effects of climate change on EEA that occur as a result of the temperature and moisture dependence of enzyme activity in situ. Likewise, the indirect effects of climate on EEA in the field, that occur via effects on microbial enzyme producers, must be assessed in the context of potential changes in plant and soil faunal communities. Here, EEA responses to warming and altered precipitation in field studies are reviewed, with the goal of evaluating the role of EEA in enhancing our understanding of soil and ecosystem responses to climate change. Seasonal and interannual variation in EEA responses to climate change treatments are examined, and potential interactions with elevated atmospheric CO₂, increased atmospheric N deposition and changes in disturbance regimes are also explored. It is demonstrated that in general, soil moisture manipulations in field studies have had a much greater influence on potential EEA than warming treatments. However, these results may simply reflect the low magnitude of soil warming achieved in many field experiments. In addition, changes in plant species composition over the longer term in response to warming could strongly affect EEA. Future challenges involve extending studies of potential EEA to address EEA responses to climate change in situ, and gaining further insights into the mechanisms, such as enzyme production, stabilization and turnover, that underlie EEA responses.     

Soil extracellular enzyme dynamics in a changing climate

Assays for extracellular enzyme activity (EEA) have become a common tool for studying soil microbial responses in climate change experiments. Nevertheless, measures of potential EEA, which are conducted under controlled conditions, often do not account for the direct effects of climate change on EEA that occur as a result of the temperature and moisture dependence of enzyme activity in situ. Likewise, the indirect effects of climate on EEA in the field, that occur via effects on microbial enzyme producers, must be assessed in the context of potential changes in plant and soil faunal communities. Here, EEA responses to warming and altered precipitation in field studies are reviewed, with the goal of evaluating the role of EEA in enhancing our understanding of soil and ecosystem responses to climate change. Seasonal and interannual variation in EEA responses to climate change treatments are examined, and potential interactions with elevated atmospheric CO₂, increased atmospheric N deposition and changes in disturbance regimes are also explored. It is demonstrated that in general, soil moisture manipulations in field studies have had a much greater influence on potential EEA than warming treatments. However, these results may simply reflect the low magnitude of soil warming achieved in many field experiments. In addition, changes in plant species composition over the longer term in response to warming could strongly affect EEA. Future challenges involve extending studies of potential EEA to address EEA responses to climate change in situ, and gaining further insights into the mechanisms, such as enzyme production, stabilization and turnover, that underlie EEA responses.     

黄土高原半干旱区物候变化特征及其对气候变暖的响应

利用黄土高原半干旱区1994-2014年典型植物物候和气温资料,通过相关分析等方法分析典型植物展叶始期、展叶盛期、开花始期、开花盛期等春季物候期和叶初变期、叶全变期、落叶始期、落叶末期等秋季物候期的变化特征,以揭示黄土高原典型植物物候期对气候变暖的响应规律。结果表明:(1)在展叶期,草本植物历史最早和最晚出现日期相差20~36d,木本植物为20~38d;(2)草本植物春季物候期表现为明显的提前趋势,木本植物物候期的变化趋势差异较大,牡丹、旱柳展叶始期提前趋势明显;草本植物叶变色始期、黄枯始期以及木本植物落叶始期等秋季物候期的推迟趋势明显;(3)研究期内牡丹生长季的变化趋势不明显,其余典型植物生长季均一致表现为显著延长趋势(P0.05);(4)典型植物开花始期对前1月、前第3月(车前草为当月)以及春季(3-5月)气温的响应明显,春季气温每升高1℃,植物开花始期提前5~8d。研究结果表明黄土高原草本植物对气候变暖的响应比木本植物更明显,因此,在黄土高原生态脆弱区,选用对气候变化反应较为迟钝的杏树、榆树等乔木进行地区生态恢复重建较适宜。     

西安植物园木本植物近十余年物候变化的特征分析

通过对1988-2002年西安市植物园20种木本植物物侯资料的分析。结果表明：近十余年西安市植物园20种木本植物物侯变化趋势明显表现为所有植物春季物侯逐年提前、大多数植物秋季物侯逐年推迟的趋势；春季物侯对气侯变化的响应程度显著大于秋季物侯。大多植物生殖生长期的物侯变化幅度大于营养生长期。因此，春季物侯和生殖生长期物侯更加适宜作为气侯变化的物侯指标。该研究对于评价物侯及物侯不同指标对气侯变化的响应有一定的参考价值。     

Flowering phenology and the interrelations between phenological stages in apple trees (Malus domestica Borkh.) as influenced by the Nordic climate

In order to assess to what degree the ongoing global warming has affected flowering time of apple trees in the Nordic climate, we studied flowering phenology of trees in an orchard in Southern Norway. Correlation analysis of a 70-year (1946–2016) data series for flowering time of the cultivar ‘Gravenstein’ revealed a close relationship of the flowering phenophase with April–May heat accumulation (r?=??0.98). Over the last 50-year period, flowering was advanced by 16 days in response to the temperature rises. Similarly, on average for 12 cultivars of varying earliness, flowering was advanced by 9 days over the latest 30-year period (1986–2016). Furthermore, the interrelationship between various phenological stages and floral morphogenesis of the same cultivars in the years 2013 and 2014 was studied, and related to flower-bud formation. The different stages of floral morphogenesis were identified, presented and used as a basis for assessment of flower-bud development in serial dissections. Floral initiation in spurs of actively growing trees took place in late July, approx. 8 weeks after full bloom, whereas in extension shoots, initiation took place after growth cessation in August, approximately 2 weeks later. Decreasing temperatures in mid-August coincided with the cessation of growth and floral initiation in extension shoots, suggesting that the processes may be causally related. The results show that, in the Nordic climate, the period between blooming and initiation of new floral primordia is considerably shorter than in warmer climates, suggesting that the period is only marginally long for completion of shoot growth, and hence, timely floral initiation. This may be an important reason for the irregular flowering and frequent incidences of alternate bearing in apple trees in the cool Nordic climate. The presented information can be useful for determination of the correct timing of flower and fruit thinning to counterbalance biennial bearing.     

基于遥感的黄土高原植被物候监测及其对气候变化的响应

为了分析黄土高原地区植被物候特征,该文基于AVHRR传感器获取的陆地长期数据记录(land long term data record,LTDR)V4 NDVI数据,对黄土高原1982-2011年间植被物候的时空变化进行分析,并借助偏相关分析方法对物候与气温和降雨的关系进行量化分析。结果表明:黄土高原近30 a间春季物候提前显著(0.54 d/a,P0.001),主要集中在北部草地和灌木植被;秋季物候推迟显著(0.74 d/a,P0.001),主要分布在甘肃、陕北、内蒙古和山西北部等地。不同植被的春秋物候稍有差异,稀疏灌木林春季物候提前趋势最多(1.31 d/a),常绿针叶林最小(0.19 d/a);秋季物候推迟最多的为乔木园地(1.18 d/a),最少的是水田(0.17 d/a)。黄土高原植被物候主要受气温影响,降雨的变化也会对物候产生一定影响。冬季和前年秋季气温上升是春季物候提前的主要驱动因子;夏季和秋季降雨则对秋季物候休眠期延迟起着重要作用。该研究可为黄土高原生态环境评价及气候变化预测模型提供一定依据。     

Correlation between temperature and phenology prediction error in rice (Oryza sativa L.)

For rice (Oryza sativa L.), simulation models like ORYZA2000 and CERES-Rice have been used to explore adaptation options to climate change and weather-related stresses (drought, heat). Output of these models is very sensitive to accurate modelling of crop development, i.e. phenology. What has to date received little attention in phenology calibration is the temperature range within which phenological models are accurate. Particularly the possible correlation between temperature and phenology prediction error has received little attention, although there are indications that such correlation exists, in particular in the study by Zhang et al. (2008). The implication of such correlation is that a phenology model that is accurate within the calibration temperature range can be less accurate at higher temperatures where it can systematically overestimate or underestimate the duration of the phase from emergence to flowering. We have developed a new rice phenology calibration program that is consistent with ORYZA2000 concepts and coding. The existing calibration program DRATES of ORYZA2000 requires an assumption of default cardinal temperatures (8, 30 and 42 °C) and then calculates cultivar specific temperature sums and development rates. Our new program estimates all phenological parameters simultaneously, including the cardinal temperatures. Applied to nine large datasets from around the world we show that the use of default cardinal temperatures can lead to correlation between temperature and phenology prediction error and temperature and RMSE values in the order of 4-18 days for the period from emergence to flowering. Our new program avoids such correlation and reduces phenology prediction errors to 3-7 days (RMSE). Our results show that the often made assumption of a rapid decrease in development rate above the optimal temperature can lead to poorer predictions and systematic errors. We therefore caution against using default phenological parameters for studies where temperatures may fall outside the range for which the phenological models have been calibrated. In particular, this applies to climate change studies, were this could lead to highly erroneous conclusions. More phenological research with average growing season temperatures above the optimum, in the range of 32-40 °C, is needed to establish which phenological model best describes phenology in this temperature range.     

气候变化对中国北方玉米种植及物候的影响

通过分析北方地区玉米生产典型区1992—2012年40个有长时间序列记录站点的物候信息与年均温度及≥10℃有效积温之间的关系发现:随着年际之间气温波动,玉米自身进行着生育期的调整,年均温每升高1℃,玉米生育期大致缩短3～5 d;年均温11℃可能是春夏玉米的分界阈值,也可能是一年一作和一年两作两种种植方式的温度划分基线;东北和西北地区作物在1992—2012年间对气候变化响应程度强于华北地区,潜在适应性更强。通过本研究发现玉米物候对气候变化的响应规律,对于阐明玉米品种空间分布与气候变化的关系以及未来气候条件下玉米物候、品种及种植结构变化趋势具有重要意义。     

2000-2012年山西省不同植被类型物候变化及其对气候变化的响应

利用非对称高斯函数重建山西省2000—2012年MODIS-NDVI时间序列影像,通过动态阈值法提取植被生长季始期（SOG）、生长季末期（EOG）、生长季长度（LOG）信息,研究不同植被类型物候的时空变化及其与气候因子（气温、降水、日照时数）的相关关系。结果表明:（1）13 a来,山西省不同植被类型物候的年际变化均表现出SOG提前、EOG推迟、LOG延长的趋势。（2）山西植被物候存在明显的空间差异。植被平均物候由南向北表现为SOG逐渐推迟,EOG逐渐提前,LOG逐渐缩短。从变化趋势看,研究区大部分地区表现出植被SOG提前、EOG推迟、LOG延长的趋势。其中,SOG提前、EOG推迟、LOG延长的地区主要分布在昕水河以北的黄河干流、汾河上游、桑干河、滹沱河等地区;而SOG推迟、EOG提前、LOG缩短的地区主要分布在管涔山、恒山、五台山、吕梁山、太岳山南部等地区。（3）降水和日照时数可能是影响该区植被物候的主要因素,不同植被类型物候对气候变化的响应不同。春季降水增多和3月平均日照时间变短可能是植被（针叶林除外）SOG提前的主要原因,9月降水量增多和平均日照时间变短可能是植被（针叶林和草甸除外）EOG推迟的主要原因。     

“一带一路”区域极端气候事件变化及其对典型农业区生长季的影响

以“一带一路”区域为研究区，基于1990−2018年的逐月历史气候数据和1981−2016年的逐年植被物候数据，采用趋势分析和统计分析等方法研究极端气候事件和植被物候的时空变化规律，并选取欧洲东南部耕地、中国北部内蒙古草原、印度中部耕地和泰国北部耕地为典型农业区，分析典型极端气候事件对生长季的影响规律。结果表明：（1）“一带一路”区域的极端气候事件主要以极端热事件和极端冷事件为主，且总体上呈现增加的趋势。极端高温事件的增加趋势明显，而极端低温事件则表现出减少的趋势；（2）生长季始期（SOS）、生长季末期（EOS）和生长季长度（LOS）总体上随纬度位置层状变化，海拔和降水也显著影响生长季。在全球变暖的影响下，“一带一路”区域大部分地区的SOS呈提前的趋势，而EOS呈延后的趋势，这导致了LOS的普遍延长；（3）当极端高温事件发生时，SOS普遍提前，而EOS普遍延后。极端低温事件则会导致SOS的延迟和EOS的提前。此外，极端气候事件越剧烈，对植被物候的影响越大。     

模拟降水变化下黄土丘陵区草地群落特征及其物候期响应

在全球气候变化背景下,黄土高原降水格局呈现出季节波动增强和极端降水事件增加趋势,降水格局变化势必会引起草地群落特征和物候期发生重要改变。为研究黄土丘陵区草地生态系统对降水改变的响应,选取黄土丘陵区退耕草地为研究对象,连续定位观测自然恢复小区不同降雨梯度下(0,±20%,±40%,±60%)物候动态变化,探究了物候期和群落结构对降水变化的响应状况。结果表明:(1)不同降水条件下群落物种组成及丰度存在明显差异,与对照组相比,增雨与减雨均提高了物种的种类。增雨60%群落种类最多,为18种。(2)降水梯度递增处理下,群落盖度呈先增加后降低趋势,地上生物量随呈单峰趋势。增雨20%处理和减雨20%处理均能够显著提高群落植被盖度和地上生物量,地上生物量在增雨处理下明显高于减雨处理。(3)丰富度和Shannon-Wiener指数总体上都呈增加趋势,减雨20%,40%,60%均使Pielou均匀度指数降低。(4)不同降水条件对物种物候期的影响显著(p<0.05),群落返青期、繁殖期和和枯黄期在减雨处理下显著提前,而增雨处理则使其繁殖期和枯黄期发生推迟。综上,群落物种组成、植被盖度和地上生物量在不同降水处理下表现出显著差异,而物种多样性对降水变化响应不敏感。     

Assessing the effects of climate change on the phenology of European temperate trees

Modelling phenology is crucial to assess the impact of climate change on the length of the canopy duration and the productivity of terrestrial ecosystems. Focusing on six dominant European tree species, the aims of this study were (i) to examine the accuracy of different leaf phenology models to simulate the onset and ending of the leafy season, with particular emphasis on the putative role of chilling to release winter bud dormancy and (ii) to predict seasonal shifts for the 21st century in response to climate warming.Models testing and validation were done for each species considering 2 or 3 years of phenological observations acquired over a large elevational gradient (1500 m range, 57 populations). Flushing models were either based solely on forcing temperatures (1-phase models) or both on chilling and forcing temperatures (2-phases models). Leaf senescence models were based on both temperature and photoperiod.We show that most flushing models are able to predict accurately the observed flushing dates. The 1-phase models are as efficient as 2-phases models for most species suggesting that chilling temperatures are currently sufficient to fully release bud dormancy. However, our predictions for the 21st century highlight that chilling temperature could be insufficient for some species at low elevation. Overall, flushing is expected to advance in the next decades but this trend substantially differed between species (from 0 to 2.4 days per decade). The prediction of leaf senescence appears more challenging, as the proposed models work properly for only two out of four deciduous species, for which senescence is expected to be delayed in the future (from 1.4 to 2.3 days per decade). These trends to earlier spring leafing and later autumn senescence are likely to affect the competitive balance between species. For instance, simulations over the 21st century predict a stronger lengthening of the canopy duration for Quercus petraea than for Fagus sylvatica, suggesting that shifts in the elevational distributions of these species might occur.