Forest Ecology and Management 474 (2020) 118357 Contents lists available at ScienceDirect Forest Ecology and Management journal homepage: www.elsevier.com/locate/foreco Radial growth response of Pinus yunnanensis to rising temperature and drought stress on the Yunnan Plateau, southwestern China T Jiayan Shena,b,c, Zongshan Lid, Chengjie Gaoa, Shuaifeng Lia,c, Xiaobo Huanga,c, Xuedong Langa,c, ⁎ Jianrong Sua,c, a Research Institute of Resources Insects, Chinese Academy of Forestry, Kunming 650224, China b Nanjing Forestry University, Nanjing 210037, China c Puèr Forest Ecosystem Research Station, National Forestry and Grassland Administration of China, Puèr 665000, China d State Key Laboratory of Urban and Regional Ecology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China ARTICLE INFO ABSTRACT Keywords: The relative influence of energy and water availability on tree growth at specific sites under warming conditions Tree radial growth remains insufficiently understood on the Yunnan Plateau, which obstructs the rational selection and develop- Warming ment of forest management measures in the context of climate change. In this study, a dendroecological in- Drought stress vestigation was conducted in four sites on the Yunnan Plateau to evaluate growth trends and climate responses P. yunnanensis of Pinus yunnanensis under warming and drought stress across cold-dry (CD), warm-humid (WH), warm (WR), Climate zones and hot-dry (HD) zones. The effects of energy and water availability on the radial growth of P. yunnanensis varied Yunnan Plateau in different sites and showed site-specific characteristics. The radial growth of P. yunnanensis in the CD zone benefited from rising temperatures, especially in the pre-growing season and core growing season. However the radial growth of P. yunnanensis in the WH zone was restricted by excess water in the core growing season. The radial growth of P. yunnanensis in the WR and HD zones became increasingly limited by temperature and drought stress, and the growth switched from responding to energy stress to moisture stress. The sensitivity of P. yun- nanensis to climate factors in the warm-humid zone and humid seasons was relatively stable; in contrast, this species was vulnerable to warming and drought stress under harsh growth conditions and showed considerable instability. Intense warming in the future may cause a significant variation of tree growth response to climate. It would trigger a noticeable redistribution effect of energy and water availability on forest growth, which moti- vates assessments of climate-growth relationships, not only at large spatial scales, but also in specific sites. This research provides a basis for the adoption of effective forest management measures for specific sites according to their response characteristics associated with the distribution of climate drivers. 1. Introduction season can decrease photosynthesis. All these situations may not be conductive to the storage of photosynthetic products for growth (Sidor Forests are essential components of the Earth’s ecosystem, and cli- et al., 2015; Ponocná et al., 2016; Conlisk et al., 2017). However, the mate change has severely influenced the productivity, carbon stocks, synergistic effect of temperature and moisture may affect tree growth in community structure, and species compositions of forest in recent different ways at specific sites and among seasons (Gao et al., 2018). decades (Seidl et al., 2017; Ponocná et al., 2018). Environmental var- For instance, tree growth at high elevations is mostly temperature- iations in tree growth are typically attributed to the comprehensive limited, whereas that at lower elevations is more sensitive to pre- impact of temperature, precipitation, and other environmental factors cipitation variations (Fritts, 1976; Fan et al., 2008a; Salzer et al., 2009; rather than a single driver (Walther, 2004; Piao et al., 2014; Seddon Körner, 2012; Huo et al., 2017). Tree growth in cold environments will et al., 2016; Jung et al., 2017). Temperature and precipitation are two benefit from warming, whereas in moisture-limited regions, growth will distinct climate factors that can balance and interact with each other. be restricted by drought stress caused by warming (Dang et al., 2012; High temperature and low precipitation enhance drought stress, Liu et al., 2013; Conlisk et al., 2017). whereas low temperature and high precipitation during the growing Precipitation in the growing season and even pre-growing season ⁎ Corresponding author. E-mail address: [email protected] (J. Su). https://doi.org/10.1016/j.foreco.2020.118357 Received 8 April 2020; Received in revised form 19 June 2020; Accepted 21 June 2020 Available online 08 July 2020 0378-1127/ © 2020 Elsevier B.V. All rights reserved. J. Shen, et al. Forest Ecology and Management 474 (2020) 118357 has apparent effects on trees: adequate rainfall during the growing The current research provides insight into whether distantly spaced season facilitates the photosynthetic process and promotes growth. For individuals share common climatic constraints and how these climatic example, the impacts of spring precipitation on tree growth are parti- constrains vary with the warming effect. cularly evident in arid and semi-arid regions (Antonova and Stasova, In this study, we aim to examine how the relative importance of 1993; Caritat et al., 2000; Gruber et al., 2010; Ren et al., 2015). Tem- climatic drivers of tree growth vary with climate warming across spe- perature and water availability are projected to change dramatically in cific sites, and to investigate how the variation in temperature and the future, and many studies have revealed noticeable warming and water availability affect the growth trajectory of P. yunnanensis on the drying characteristics in many areas around the world (Truettner et al., Yunnan Plateau. Based on the hypothesis that plant growth in cold 2018; Babst et al., 2019; Schurman et al., 2019). Rising temperature environments is controlled by temperature, whereas in drought en- and drought stress may seriously affect the growth trajectories of forests vironments, plant growth controlled by moisture (Körner, 2015; (Tei et al., 2017). Thus, a better understanding of the interplay between Ponocná et al., 2016; Conlisk et al., 2017), we hypothesize that the temperature and water effects is essential to predict changes in the radial growth of P. yunnanensis in cold environments would benefit growth dynamics of forests and to assess potential ecosystem vulner- from warming, whereas more severe drought stress would be en- ability (Fan et al., 2009a). Recent studies have revealed that the re- countered in moisture-limited regions under warming. We tested the lationship between regional vegetation growth and large-scale climate radial growth trends of P. yunnanensis in response to climate change variability shows a temporally weakening phenomenon (Carrer and across different climate zones based on the tree-ring width index (RWI). Urbinati, 2006; Gao et al., 2018; Fkiri et al., 2019). The relationship Furthermore, we tested the temporal stability of the climate growth between vegetation productivity and temperature changes over time relationships of P. yunnanensis, which not only has fundamental im- following the alterations in other environmental factors; and the plications for reconstructions of natural climate variability on the strength of this relationship decreases with an increase of drought (Shi Yunnan Plateau but could also provide an opportunity to determine et al., 2010; Piao et al., 2014). In response, researchers have focused on whether the year-to-year climate growth response is stationary over the stability of the relationship between climate change and the radial time. The findings of this research will contribute to simulating the growth of trees (Porter and Pisaric, 2011; Li et al., 2010); however, radial growth and distribution dynamics of P. yunnanensis under various further studies are needed to explore the occurrence and possible causes climate change scenarios and aid in predicting the performance of of variation in growth-climate relationships to assess the nature of these forests in the southwestern region of China under global climate change changes in detail (Carrer and Urbinati, 2006). to allow the rational formulation of forest management policies at P. yunnanensis is the most typical dry and warm coniferous species specific sites. in southwestern China. It is ranked within the top ten dominant tree species in China, in terms of area and volume (Forest Resources 2. Materials and methods Management Division, SFA of China, 2010) and is mainly distributed in the western part of southwestern China from 1 500 to 3 000 m above 2.1. Study area and climate sea level. The Yunnan Plateau, located in the west of southwestern China, is the central region for the growth of P. yunnanensis (Deng et al., This study was conducted in the P. yunnanensis natural forest eco- 2013, 2014) and is the core drought region in the area, with seasonal system of the Yunnan Plateau, southwestern China. Previous research drought and multiple recurrence trends (Wang et al., 2010; Xing and on P. yunnanensis divided the distribution region of P. yunnanensis Ree, 2017). The severe drought on the Yunnan Plateau is mainly due to forests into distinct groups for the stereo climate on the Yunnan Plateau much lower precipitation and much warmer temperature than normal (Jin and Peng, 2004). Thus, we divided our research