Subjects: Geosciences >> Atmospheric Sciences submitted time 2023-03-28 Cooperative journals: 《干旱区研究》
Abstract： With the established standard chronology of the tree- ring width of Larix principis-rupprechtii in the Guancen Mountain in the northern section of Lvliang Mountain as basis, Pearson correlation analysis concluded that the average maximum temperature from March to April was the main controlling climate factor for the radial growth of trees in the study area (R = 0.509, P < 0.05). First-order linear regression equation was used to simulate and construct the change process of the average maximum temperature in the Guancen Mountains from March to April in the past nearly a century. The reconstructed equation was then cross-checked by the elimination method of leave-one-out test to verify its stability and reliability. Analysis of the temperature changes of the reconstructed temperature series showed that two warm periods and three cold periods in the past nearly a century in the Guancen Mountain area; the warm periods were 1932-1945 and 1957-1970, and the cold periods were 1946- 1956, 1971-1983, and 1993-2010. Periodic analysis of the reconstructed temperature series based on Morlet wavelet analysis revealed periodic distribution characteristics of 3~5 a, 10~13 a, 22~33 a, and 40~45 a. El Niño- Southern Oscillation and sunspot activity were the drivers of this periodic variation. Large- scale spatial correlation analysis indicated that the reconstructed temperature series had a good spatial representation of temperature changes in large- scale regions such as central and eastern Russia, northern Japan, and central and eastern China. These results have important reference value for forest management and agriculture and animal husbandry development in Guancen Mountain area.
Subjects: Geosciences >> Atmospheric Sciences submitted time 2022-12-20 Cooperative journals: 《干旱区研究》
Abstract：
Based on the annual ring cores of Larix principis- rupprechtii collected from three altitudes of Luya Mountain, the residual chronology of earlywood and latewood tree rings was established. Using the method of tree ring climatology and taking 1984/1985 as the boundary, heterogeneity characteristics of radial growth of earlywood and latewood of L. principis-rupprechtii at different altitudes in response to climate factors in 1957- 1984 and 1985-2020 were discussed. The results showed that the following: (1) the radial growth changes of earlywood and latewood were difficult to fit the climate warming trend in the study area from 1957 to 2020, and the response to temperature is separated. (2) From 1957 to 1984, no significant correlation existed between low altitude and climate factors in the growth of earlywood. Precipitation during the growing season, which had a significant positive correlation with precipitation in March and negative correlation in June, had an obvious restrictive effect on the growth of earlywood at medium and high altitudes. The precipitation factors in the growing season from 1985 to 2020 had a significant positive correlation with precipitation in April and had an influence on the growth of earlywood at a low altitude, thereby enhancing it. The growth of earlywood at medium and high altitudes was mainly affected by precipitation in January, and the restrictive effect on the growth and development of earlywood at medium and high altitudes was weakened. (3) Nutrient accumulation before growth is very important for latewood growth of L. principis- rupprechtii: from 1957 to 1984. The chronology of latewood width at three altitudes showed a significant positive correlation with precipitation in May. From 1985 to 2020, the radial growth of tree latewood was limited by the comprehensive factors of temperature and precipitation before growth in November of the previous year and January, March, and May of the current year. (4) In two different time periods, the change of the pattern of earlywood growth at a low altitude may have been caused by drought stress, which was caused by increased temperatures. The difference in the growth patterns of earlywood at medium and high altitudes was most likely due to the fact that the increased temperature alleviated the inhibitory effect of low temperature on the growth of earlywood at medium and high altitudes. With global warming, there are different response characteristics and response modes of earlywood and latewood of L. principis-rupprechtii of three altitudes of Luya Mountain to climate factors in two time periods. There is a certain “response divergence”phenomenon with the response of climate factors that should be considered concerning future climate reconstruction in this area
Hits
Hits
Downloads
Comment