• Journal of Korean Society of Forest Science
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• v.94 no.5 s.162
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• pp.313-320
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• 2005

This study was performed in a 38-year-old Mongolian pine (Pinus sylvestris L. var. mongolica Litvin) plantation in northeast China. Data were collected from 5 sample trees with different canopy position ranging in DBH from 14.6 cm to 23.8 cm. Sawn speciments that included the biggest knot were taken from the stem below the living crown. Number and distribution of knots per whorl below the living crown were studied by relative height below living crown (RHBC). A linear model expressed as function of whorl age (AGE), whorl height ($H_k$) and the stem diameter at which the whorl was located ($D_k$) was developed to predict the knot diameter and angle. The number of annual rings in four periods and the width of respective zone alone stem were used as dependant variables to analyze the knot develop phases. In average, the number of years from branch birth to ceased forming rings was 7.8, the branches remained alive for 4.2 years without forming annual rings, and branches were occluded 14.4 years after their death. These results can provide abundance branch and knot information so as to describe current and past tree growth dynamic of Mongolian pine plantation.

• Journal of Korean Society of Forest Science
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• v.97 no.5
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• pp.485-491
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• 2008

This study was performed in 14 unthinned Mongolian pine (Pinus sylvestris L. var. mongolica Litvin) plantations in northeast China. Data were collected on 70 sample trees of different canopy position with diameter at breast height (DBH) ranging from 6.9 cm to 34.5 cm. Diameter and length of knots per whorl below the living crown were studied by different vertical levels divided by relative knot height (RHK) in this paper. Models taking DBH and height to the crown base (HCB) as independent variables were developed to predict knot diameter (KD) in a sample whorl. According to the vertical distribution tendency and range of sound knot length (KLsound), KLsound was modeled as multiple linear function of DBH, KD and relative knot height (RHK). The loose knot length (KLloose) was described as a function of DBH, KD and height above the ground for knots (HK) in a mixed log-linear model. Results from this study can provide abundant knot information so as to describe the knot size and vertical distribution tendency of Mongolian pine plantation.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.3
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• pp.170-179
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• 2021

Hulunbuir steppe, one of the four largest steppes in China, has experienced rapidly progressing desertification partly due to overgrazing by livestock. The objective of this study was to investigate the effectiveness of various vegetation recovery methods, including the selection of unpalatable plants less affected by grazing livestock. To determine livestock grazing preferences at Hulunbuir restoration sites, we used DNA barcoding methods to analyze fecal materials of horses and cattle grazing on four restored plants: two trees (Pinus sylvestris L. var. mongolica and Populus canadensis) and two shrubs (Caragana microphylla and Corethrodendron fruticosum). Neither of the two tree species were detected in livestock feces, whereas both shrub species were detected at lo w frequencies. There were no significant differences in compositions of species consumed by horses and cattle except that Asteraceae species were more often consumed by cattle. Our results showed that the four plants used for restoration may be classified as unpalatable or less palatable species in the Hulunbuir restoration area. Our results may help inform restoration strategies implemented in restoration areas, especially regarding negative effects of livestock grazing during the initial stage of restoration in Hulunbuir.