Nutrient availability alters the correlation between spring leaf-out and autumn leaf senescence dates
Fu, Yongshuo H.. (Beijing Normal University. College of Water Sciences)
Piao, Shilong (Sino-French Institute for Earth System Science)
Delpierre, Nicolas (Université Paris-Sud. Laboratoire de Ecologie Systématique Evolution)
Hao, Fanghua (Beijing Normal University. College of Water Sciences)
Hänninen, Heikki (Zhejiang Agriculture and Forestry University. State Key Laboratory of Subtropical Silviculture)
Geng, Xiaojun (Beijing Normal University. College of Water Sciences)
Peñuelas, Josep (Centre de Recerca Ecològica i d'Aplicacions Forestals)
Zhang, Xaun (Beijing Normal University. College of Water Sciences)
Janssens, Ivan (Universiteit Antwerpen. Departement Biologie)
Campioli, Matteo (Universiteit Antwerpen. Departement Biologie)

Date:	2019
Abstract:	Leaf senescence (LS) affects tree fitness, species distribution and ecosystem structure and functioning. The drivers of LS and the processes underlying it have been studied, but the studies have mainly focused on environmental cues and have mainly been based on statistical analyses using in situ data sets. Experimental investigation and field verification of the processes and drivers are thus urgently needed. We conducted a nutrient-addition experiment after a spring-warming experiment in which an ~40-day range of leaf-out (LO) dates was induced in horse chestnut (Aesculus hippocastanum) and beech (Fagus sylvatica) saplings. We found that both increased nutrient supply and advanced LO date significantly affected the timing of LS, but their effects were opposite, as the former delayed and the latter advanced the senescence. The effects of nutrient supply and LO interacted species specifically. In chestnut, the delay of senescence caused by fertilization increased with the delay of LO and was thus stronger for individuals that flushed late in the spring. On the contrary, in beech the delay of senescence caused by fertilization decreased with the delay of LO and was insignificant for individuals with the latest LO. The experimental findings for beech were confirmed with mature trees at a regional scale. The interactive effect between nutrients and LO on senescence may be associated with variable sensitivity to photoperiod, growth sink limitation and/or direct effect of foliar nutrition on the timing of senescence. Our novel results show that the interactive effects of LO and nutrient supply on the timing of LS should be further addressed experimentally in forthcoming studies. It would also be interesting to consider our results in the further development of phenological models used in assessing the effects of climatic change. The differences found in the present study between horse chestnut and beech suggest that the results found for one species cannot necessarily be generalized to other species, so studies with different temperate tree species are called for.
Grants:	European Commission 610028
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió acceptada per publicar
Subject:	Climate change ; Fertilization ; Leaf senescence ; Legacy effect ; Spring leaf out
Published in:	Tree physiology, Vol. 39, issue 8 (Aug. 2019) , p. 1277-1284, ISSN 0829-318X

PMID: 30989235

Postprint 28 p, 1.2 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > CREAF (Centre de Recerca Ecològica i d'Aplicacions Forestals) > Imbalance-P
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