Cargando…

Seasonal Shift in Climatic Limiting Factors on Tree Transpiration: Evidence from Sap Flow Observations at Alpine Treelines in Southeast Tibet

Alpine and northern treelines are primarily controlled by low temperatures. However, little is known about the impact of low soil temperature on tree transpiration at treelines. We aim to test the hypothesis that in cold-limited forests, the main limiting factors for tree transpiration switch from l...

Descripción completa

Detalles Bibliográficos
Autores principales: Liu, Xinsheng, Nie, Yuqin, Luo, Tianxiang, Yu, Jiehui, Shen, Wei, Zhang, Lin
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4942459/
https://www.ncbi.nlm.nih.gov/pubmed/27468289
http://dx.doi.org/10.3389/fpls.2016.01018
_version_ 1782442411148967936
author Liu, Xinsheng
Nie, Yuqin
Luo, Tianxiang
Yu, Jiehui
Shen, Wei
Zhang, Lin
author_facet Liu, Xinsheng
Nie, Yuqin
Luo, Tianxiang
Yu, Jiehui
Shen, Wei
Zhang, Lin
author_sort Liu, Xinsheng
collection PubMed
description Alpine and northern treelines are primarily controlled by low temperatures. However, little is known about the impact of low soil temperature on tree transpiration at treelines. We aim to test the hypothesis that in cold-limited forests, the main limiting factors for tree transpiration switch from low soil temperature before summer solstice to atmospheric evaporative demand after summer solstice, which generally results in low transpiration in the early growing season. Sap flow, meteorological factors and predawn needle water potential were continuously monitored throughout one growing season across Smith fir (Abies georgei var. smithii) and juniper (Juniperus saltuaria) treelines in southeast Tibet. Sap flow started in early May and corresponded to a threshold mean air-temperature of 0°C. Across tree species, transpiration was mainly limited by low soil temperature prior to the summer solstice but by vapor pressure deficit and solar radiation post-summer solstice, which was further confirmed on a daily scale. As a result, tree transpiration for both tree species was significantly reduced in the pre-summer solstice period as compared to post-summer solstice, resulting in a lower predawn needle water potential for Smith fir trees in the early growing season. Our data supported the hypothesis, suggesting that tree transpiration mainly responds to soil temperature variations in the early growing season. The results are important for understanding the hydrological response of cold-limited forest ecosystems to climate change.
format Online
Article
Text
id pubmed-4942459
institution National Center for Biotechnology Information
language English
publishDate 2016
publisher Frontiers Media S.A.
record_format MEDLINE/PubMed
spelling pubmed-49424592016-07-27 Seasonal Shift in Climatic Limiting Factors on Tree Transpiration: Evidence from Sap Flow Observations at Alpine Treelines in Southeast Tibet Liu, Xinsheng Nie, Yuqin Luo, Tianxiang Yu, Jiehui Shen, Wei Zhang, Lin Front Plant Sci Plant Science Alpine and northern treelines are primarily controlled by low temperatures. However, little is known about the impact of low soil temperature on tree transpiration at treelines. We aim to test the hypothesis that in cold-limited forests, the main limiting factors for tree transpiration switch from low soil temperature before summer solstice to atmospheric evaporative demand after summer solstice, which generally results in low transpiration in the early growing season. Sap flow, meteorological factors and predawn needle water potential were continuously monitored throughout one growing season across Smith fir (Abies georgei var. smithii) and juniper (Juniperus saltuaria) treelines in southeast Tibet. Sap flow started in early May and corresponded to a threshold mean air-temperature of 0°C. Across tree species, transpiration was mainly limited by low soil temperature prior to the summer solstice but by vapor pressure deficit and solar radiation post-summer solstice, which was further confirmed on a daily scale. As a result, tree transpiration for both tree species was significantly reduced in the pre-summer solstice period as compared to post-summer solstice, resulting in a lower predawn needle water potential for Smith fir trees in the early growing season. Our data supported the hypothesis, suggesting that tree transpiration mainly responds to soil temperature variations in the early growing season. The results are important for understanding the hydrological response of cold-limited forest ecosystems to climate change. Frontiers Media S.A. 2016-07-13 /pmc/articles/PMC4942459/ /pubmed/27468289 http://dx.doi.org/10.3389/fpls.2016.01018 Text en Copyright © 2016 Liu, Nie, Luo, Yu, Shen and Zhang. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Plant Science
Liu, Xinsheng
Nie, Yuqin
Luo, Tianxiang
Yu, Jiehui
Shen, Wei
Zhang, Lin
Seasonal Shift in Climatic Limiting Factors on Tree Transpiration: Evidence from Sap Flow Observations at Alpine Treelines in Southeast Tibet
title Seasonal Shift in Climatic Limiting Factors on Tree Transpiration: Evidence from Sap Flow Observations at Alpine Treelines in Southeast Tibet
title_full Seasonal Shift in Climatic Limiting Factors on Tree Transpiration: Evidence from Sap Flow Observations at Alpine Treelines in Southeast Tibet
title_fullStr Seasonal Shift in Climatic Limiting Factors on Tree Transpiration: Evidence from Sap Flow Observations at Alpine Treelines in Southeast Tibet
title_full_unstemmed Seasonal Shift in Climatic Limiting Factors on Tree Transpiration: Evidence from Sap Flow Observations at Alpine Treelines in Southeast Tibet
title_short Seasonal Shift in Climatic Limiting Factors on Tree Transpiration: Evidence from Sap Flow Observations at Alpine Treelines in Southeast Tibet
title_sort seasonal shift in climatic limiting factors on tree transpiration: evidence from sap flow observations at alpine treelines in southeast tibet
topic Plant Science
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4942459/
https://www.ncbi.nlm.nih.gov/pubmed/27468289
http://dx.doi.org/10.3389/fpls.2016.01018
work_keys_str_mv AT liuxinsheng seasonalshiftinclimaticlimitingfactorsontreetranspirationevidencefromsapflowobservationsatalpinetreelinesinsoutheasttibet
AT nieyuqin seasonalshiftinclimaticlimitingfactorsontreetranspirationevidencefromsapflowobservationsatalpinetreelinesinsoutheasttibet
AT luotianxiang seasonalshiftinclimaticlimitingfactorsontreetranspirationevidencefromsapflowobservationsatalpinetreelinesinsoutheasttibet
AT yujiehui seasonalshiftinclimaticlimitingfactorsontreetranspirationevidencefromsapflowobservationsatalpinetreelinesinsoutheasttibet
AT shenwei seasonalshiftinclimaticlimitingfactorsontreetranspirationevidencefromsapflowobservationsatalpinetreelinesinsoutheasttibet
AT zhanglin seasonalshiftinclimaticlimitingfactorsontreetranspirationevidencefromsapflowobservationsatalpinetreelinesinsoutheasttibet