Long-term Growth Variation and Selection of Geographical Provenances of Cunninghamialanceolata (Lamb.) Hook

Wu Wu,Zhang Zhang,Duan Duan

doi:10.3390/f10100876

Abstract

In order to understand the long-term growth variation of Chinese fir’s geographical provenances and promote long-term genetic improvement, the experimental provenance forest of Chinese fir planted in 1981 was taken as a research object.The provenances originated from southeastern China. The study measured each diameter at breast height (DBH) and tree height at 5, 6, 8, 12, and 33 years of age and analyzed the genetic variation of major growth traits of trees withdifferent provenances at different forest ages. Additionally, the study analyzed the geographical variation of Chinese fir by using the trend surface and principal component analysis (PCA) and evaluated the long-term selection effect of provenance by using juvenile–mature correlation and cluster analysis. The heritability of the DBH, treeheight, and volume of Chinese fir with different provenances reached 0.35–0.76, and with increasing forest age, the heritability of each trait showed a rising and gradually stabilizing trend. There were obvious differences in geographical variation patterns among the tested provenances, and both the DBH and the tree height growth patterns are two-way gradients. This variation pattern is associated with climatic conditions in different regions, and the factors limiting the growth difference of Chinese fir may be the mean temperature in winter and the precipitation in autumn and winter.An early selection age has a significant effect on shortening the timber production cycle of Chinese fir. The selection of trees aged between 6 and 12 years is more conducive to improving the efficiency of the genetic improvement of Chinese fir.The 42 excellent provenances selected from the 33-year-old mature Chinese fir forests have a larger increase in growth than trees with local provenances, which are concentrated in the Wuyi and Xuefeng mountains and are suitable for plantation in the Guangxi Zhuang Autonomous Region and surrounding areas.

Highlights

The effect of the genetic improvement of forest trees is related to the source of the seeds [1].Successful afforestation programs depend, to a large extent, on the use of seeds with excellent geographic sources
There were obvious differences in geographical variation patterns among the tested provenances, and both the diameter at breast height (DBH) and the tree height growth patterns are two-way gradients. This variation pattern is associated with climatic conditions in different regions, and the factors limiting the growth difference of Chinese fir may be the mean temperature in winter and the precipitation in autumn and winter
33-year-old mature Chinese fir forests have a larger increase in growth than trees with local provenances, which are concentrated in the Wuyi and Xuefeng mountains and are suitable for plantation in the Guangxi Zhuang Autonomous Region and surrounding areas

Summary

Introduction

The effect of the genetic improvement of forest trees is related to the source of the seeds [1]. Successful afforestation programs depend, to a large extent, on the use of seeds with excellent geographic sources. The provenance test is an important means to identifythe geographical variation ofa tree species. The adaptability and productivity of trees with different provenances in a certain area (habitat) are determined, and high-yield, high-quality, and stable provenances are selected for forestry production. Provenance selection is one of the basic methods of forest genetic improvement [2].

Methods

Results

Conclusion