Response Characteristics of Chinese Pine (Pinus tabulaeformis Carr.) Radial Growth to Climate and Drought Variability Reconstruction in Western Liaoning, Northeast China

Abstract

Chinese pine (Pinus tabulaeformis Carr.) plays an important role in maintaining ecosystem health and stability in western Liaoning Province and the southern Horqin sand land, Northeast China, with benefits including sand fixation and soil erosion. In the context of climate change, developing a better understanding of the relationship between climate factors and growth rates of this species will be extremely valuable in guiding management activities and meeting regional conservation objectives. Here, the results based on two groups of tree-ring samples show that the radial growth of Chinese pine is controlled primarily by water conditions. The longer chronology had the highest correlation coefficient with the January-September mean self-calibrating Palmer Drought Severity Index (scPDSI); therefore, drought variability was reconstructed for the period 1859-2014. Statistical analysis showed that our model explained 41.9% of the variance in radial growth during the 1951-2014 calibration period. Extreme dry and wet events, defined as the criteria of one standard deviation less or greater than the mean value, accounted for 19.9% and 18.6% of the 156-year climate record, respectively. During the past century, the regional hydroclimate experienced significant long-term fluctuations. The dry periods occurred from the early-1900s-1930s and 1980s-2000s, and the wet periods occurred from the 1940s-1970s. The drought reconstruction was consistent with the decreasing trend of the East Asian summer monsoon since the late 1970s. The reconstructed temporal patterns in hydroclimate in western Liaoning were closely related to the large-scale climate drivers in the North Pacific and the tropical equatorial Pacific. The teleconnections were confirmed by spatial correlations between the reconstructed sequence and sea surface temperature (SST) in the North Pacific, as well as the correlations with the Pacific Decadal Oscillation (PDO) and El Niño Southern Oscillation (ENSO) indices. Aerosols played an important role in affecting drought variations over the past several decades. Moisture stress caused by global warming and interdecadal changes in the PDO will have long-term effects on the growth of pines in the study area in the future.

Water Use by Chinese Pine Is Less Conservative but More Closely Regulated Than in Mongolian Scots Pine in a Plantation Forest, on Sandy Soil, in a Semi-Arid Climate

“…Measurements at the leaf scale show that MP features a higher photosynthetic rate, lower transpiration rate, and higher water use efficiency than CP under favorable soil moisture conditions ( Bai et al, 2008 ; Ding et al, 2011 ). However, this trend would change under severely dry soil conditions ( Liu et al, 2019 ). Combining these pieces of information, it can be concluded that the drought stress seems to be more harmful to the needles of CP , while it imparts greater damage to the fine roots of MP .…”

“…It has been reported that CP maintains its leaf water potential at a relatively constant level of approximately −1.7 MPa by markedly reducing its leaf stomatal conductance ( Wen et al, 2017 ; Tang et al, 2018 ; Wu et al, 2018 ). Direct measurements at the leaf scale also indicate that both CP and MP may be drought-tolerant tree species with high water potential and delayed dehydration ( Tang et al, 2018 ); their leaves exhibit relatively strong water retention capacity and an ability to maintain turgor ( Ding et al, 2011 ; Liu et al, 2019 ).…”

“…Chinese pine ( Pinus tabuliformis, CP ) is a pine species endemic to China, and Mongolian Scots pine ( Pinus sylvestris var. mongolica , MP ) is one of the geographical varieties of Scots pine; these two Pinus species have together served as the lead actors in the ongoing “Great Green Wall” projects, specifically in Horqin Sandyland regions where the shelterbelt afforestation to combat desertification began in 1955 ( Liu et al, 2019 ; Zhu and Zheng, 2019 ). MP , as a pine species introduced to low latitudes to the Horqin Sandyland, exhibits more favorable afforestation survival, growth, and cold tolerance than does the Chinese endemic CP pine species ( Jiao, 2001 ; Liu et al, 2019 ).…”

“…mongolica , MP ) is one of the geographical varieties of Scots pine; these two Pinus species have together served as the lead actors in the ongoing “Great Green Wall” projects, specifically in Horqin Sandyland regions where the shelterbelt afforestation to combat desertification began in 1955 ( Liu et al, 2019 ; Zhu and Zheng, 2019 ). MP , as a pine species introduced to low latitudes to the Horqin Sandyland, exhibits more favorable afforestation survival, growth, and cold tolerance than does the Chinese endemic CP pine species ( Jiao, 2001 ; Liu et al, 2019 ). However, serious declines in the MP plantations have been found in the Horqin Sandyland in northern China since 1991 ( Jiao, 2001 ; Zhu et al, 2005 ), whereas co-existing CP plantations are growing healthily.…”

Effects of nitrogen addition and root fungal inoculation on the seedling growth and rhizosphere soil microbial community of Pinus tabulaeformis

“…Pinus tabulaeformis Carr., a coniferous evergreen tree of Pinaceae, is characterized by a well-developed root system, rapid growth, strong ecological adaptability and stress resistance and is a pioneer tree for vegetation restoration in a variety of stress environments (Liu et al, 2019;Zeng et al, 2020). Research has found that there are a variety of ectomycorrhizal fungi in the roots of P. tabulaeformis (Hibbett and Matheny, 2009;Wang and Guo, 2010).…”