Journal of Northwest Forestry University, Volume. 40, Issue 4, 1(2025)
Study on Radial Growth of Adjacent Trees of Larix principis-rupprechtii Based on the Logging Space Unit
Taking Larix principis-rupprechtii plantation as the research object based on the cutting space unit composed of cutting tree and its surrounding adjacent tree the effects of cutting space unit size and spatial parameters on the radial growth of adjacent tree before and after cutting were explored It is of great significance for the rational management and protection of Larix principis-rupprechtii and provides reference for further scientific research The sample plot survey was carried out before harvesting After harvesting 105 adjacent trees around the harvested tree were sampled by micro-core method to measure their radial growth The results show that The average spatial structure parameters of adjacent trees in each cutting space unit changed after cutting and the angle scale increased to 0 5 while the size ratio and competition index decreased The radial growth therefore changes From 2018 to 2022 the average annual radial growth of adjacent trees was 476 92 μm 472 57 μm 427 34 μm 605 12 μm and 782 90 μm respectively The average annual radial growth in the two years before tending felling 2018—2019 was 474 74 μm and the average annual radial growth in the two years after tending felling 2021—2022 was 694 01 μm The radial growth before tending felling showed a downward trend and the radial growth after tending felling was significantly higher than that before tending felling There was a significant difference in the radial growth rate of adjacent trees in different logging space units P<0 05 and the average growth rate of adjacent trees was 54 66% The average growth rate of adjacent trees in the smallest logging space unit 0 55 m2 was 75 93% and the average growth rate of adjacent trees in the largest logging space unit 12 00 m2 was 26 03% The average radial growth rate of adjacent trees with logging space unit area< 10 m2 was significantly higher than that of adjacent trees with area>10 m2 There were significant differences in the radial growth rate of adjacent trees before logging P<0 05 After cutting the competition intensity of the adjacent tree itself is divided into three levels Low CI<2 21 Medium 2 21≤CI≤3 35 and High CI>3 35 The corresponding average radial growth increments were 235 58 μm 223 26 μm and 106 19 μm respectively The average growth change rates of adjacent trees were 51 5% 75 9% and 98 25% respectively All adjacent trees had different degrees of growth release mild release moderate release and severe release accounting for 16% 20% and 21% respectively It can be seen that thinning reduces the intensity of competition increases the radial growth rate and results in growth release
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LIANG Chunling, WANG Ling, YANG Hua, HE Danni. Study on Radial Growth of Adjacent Trees of Larix principis-rupprechtii Based on the Logging Space Unit[J]. Journal of Northwest Forestry University, 2025, 40(4): 1
Received: May. 29, 2024
Accepted: Sep. 12, 2025
Published Online: Sep. 12, 2025
The Author Email: YANG Hua (huayang8747@163.com)