Responses of Growth, Photosynthesis and VOC Emissions of Pinus tabulaeformis Carr. Exposure to Elevated CO2 and/or Elevated O3 in an Urban Area

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.

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Drought Alleviated the Negative Effects of Elevated O3 on Lonicera maackii in Urban Area

Bulletin of Environmental Contamination and Toxicology ◽

10.1007/s00128-017-2179-2 ◽

2017 ◽

Vol 99 (5) ◽

pp. 648-653 ◽

Cited By ~ 7

Author(s):

Sheng Xu ◽

Wei Fu ◽

Xingyuan He ◽

Wei Chen ◽

Weiwei Zhang ◽

...

Keyword(s):

Urban Area ◽

Lonicera Maackii ◽

Negative Effects ◽

Elevated O3

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Impacts of urban land-surface forcing on ozone air quality in the Seoul metropolitan area

Atmospheric Chemistry and Physics ◽

10.5194/acp-13-2177-2013 ◽

2013 ◽

Vol 13 (4) ◽

pp. 2177-2194 ◽

Cited By ~ 50

Author(s):

Y.-H. Ryu ◽

J.-J. Baik ◽

K.-H. Kwak ◽

S. Kim ◽

N. Moon

Keyword(s):

Boundary Layer ◽

Air Quality ◽

Urban Area ◽

Metropolitan Area ◽

Land Surface ◽

Urban Boundary Layer ◽

Breeze Circulation ◽

Air Masses ◽

Elevated O3 ◽

Seoul Metropolitan Area

Abstract. Modified local meteorology owing to heterogeneities in the urban–rural surface can affect urban air quality. In this study, the impacts of urban land-surface forcing on ozone air quality during a high ozone (O3) episode in the Seoul metropolitan area, South Korea, are investigated using a high-resolution chemical transport model (CMAQ). Under fair weather conditions, the temperature excess (urban heat island) significantly modifies boundary layer characteristics/structures and local circulations. The modified boundary layer and local circulations result in an increase in O3 levels in the urban area of 16 ppb in the nighttime and 13 ppb in the daytime. Enhanced turbulence in the deep urban boundary layer dilutes pollutants such as NOx, and this contributes to the elevated O3 levels through the reduced O3 destruction by NO in the NOx-rich environment. The advection of O3 precursors over the mountains near Seoul by the prevailing valley-breeze circulation in the mid- to late morning results in the build-up of O3 over the mountains in conjunction with biogenic volatile organic compound (BVOC) emissions there. As the prevailing local circulation in the afternoon changes to urban-breeze circulation, the O3-rich air masses over the mountains are advected over the urban area. The urban-breeze circulation exerts significant influences on not only the advection of O3 but also the chemical production of O3 under the circumstances in which both anthropogenic and biogenic (natural) emissions play important roles in O3 formation. As the air masses that are characterized by low NOx and high BVOC levels and long OH chain length are advected over the urban area from the surroundings, the ozone production efficiency increases in the urban area. The relatively strong vertical mixing in the urban boundary layer embedded in the sea-breeze inflow layer reduces NOx levels, thus contributing to the elevated O3 levels in the urban area.

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Long-term effects of elevated CO2, nighttime warming and drought on plant secondary metabolites in a temperate heath ecosystem

Annals of Botany ◽

10.1093/aob/mcaa037 ◽

2020 ◽

Vol 125 (7) ◽

pp. 1065-1075

Author(s):

Tao Li ◽

Päivi Tiiva ◽

Åsmund Rinnan ◽

Riitta Julkunen-Tiitto ◽

Anders Michelsen ◽

...

Keyword(s):

Climate Change ◽

Secondary Metabolites ◽

Elevated Co2 ◽

Chemical Constituents ◽

Plant Secondary Metabolites ◽

Plant Secondary Metabolite ◽

Summer Drought ◽

Voc Emissions ◽

Nighttime Warming ◽

Change Components

Abstract Background and Aims Plant secondary metabolites play critical roles in plant stress tolerance and adaptation, and are known to be influenced by the environment and climate changes, yet the impacts and interactions of multiple climate change components are poorly understood, particularly under natural conditions. Methods Accumulation of phenolics and emissions of volatile organic compounds (VOCs) were assessed on heather, Calluna vulgaris, an abundant evergreen dwarf shrub in European heathlands, after 6 years of exposure to elevated CO2, summer drought and nighttime warming. Key Results Drought alone had the strongest effects on phenolic concentrations and compositions, with moderate effects of elevated CO2 and temperature. Elevated CO2 exerted the greatest impact on VOC emissions, mainly by increasing monoterpene emissions. The response magnitudes varied among plant tissue types and chemical constituents, and across time. With respect to interactive effects of the studied climate change components, the interaction between drought and elevated CO2 was most apparent. Drought mainly reduced phenolic accumulation and VOC emissions, while elevated CO2 mitigated such effects. Conclusions In natural ecosystems, co-occurring climate factors can exert complex impacts on plant secondary metabolite profiles, which may in turn alter ecosystem processes.

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The effects of elevated CO2, elevated O3, elevated temperature, and drought on plant leaf gas exchanges: a global meta-analysis of experimental studies

Environmental Science and Pollution Research ◽

10.1007/s11356-020-11728-6 ◽

2020 ◽

Author(s):

Jinmeng Zhang ◽

Lei Deng ◽

Hong Jiang ◽

Changhui Peng ◽

Chunbo Huang ◽

...

Keyword(s):

Elevated Temperature ◽

Elevated Co2 ◽

Meta Analysis ◽

Experimental Studies ◽

Gas Exchanges ◽

Plant Leaf ◽

Elevated O3 ◽

Leaf Gas Exchanges

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The Dark Septate Endophytes and Ectomycorrhizal Fungi Effect on Pinus tabulaeformis Carr. Seedling Growth and their Potential Effects to Pine Wilt Disease Resistance

Forests ◽

10.3390/f10020140 ◽

2019 ◽

Vol 10 (2) ◽

pp. 140 ◽

Cited By ~ 5

Author(s):

Honglong Chu ◽

Chuyan Wang ◽

Zhumei Li ◽

Haihua Wang ◽

Yuguo Xiao ◽

...

Keyword(s):

Ectomycorrhizal Fungi ◽

Growth Traits ◽

Pine Wilt Disease ◽

Wilt Disease ◽

Pinus Tabulaeformis ◽

Conifer Forest ◽

Cumulative Mortality ◽

Pine Wilt ◽

Pinus Tabulaeformis Carr ◽

The Relationship

Pine wilt disease (PWD), a worldwide threat to pine forests, has caused tremendous damage to conifer forest in the world. However, little research has been conducted on the relationship between symbiosis functions of root associated fungi and pine wilt disease. In this study, we assessed the influence of seven ectomycorrhizal fungi (ECMF) and five dark septate endophytic fungi (DSE) on the growth traits and root morphology as well as the correlation of these parameters to the cumulative mortality and the morbidity rates in Pinus tabulaeformis Carr.showed the lowest cumulative mortality rates. We propose that the ECMF/DSE symbiosis enhanced the resistance of pine wilt disease via mitigation the dysfunction of water caused by PWN infection. Our research provided evidence that inoculation of ECMF/DSE could be a potential way for pine wilt disease prevention. To find highly efficient fungi for pine wilt disease management, more ECMF and DSE species should be tested.

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