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Yang H.,CAS Shenyang Institute of Applied Ecology | Yang H.,University of Chinese Academy of Sciences | Yang H.,Liaoning Institute of Forest Management | Wang S.,CAS Shenyang Institute of Applied Ecology | And 3 more authors.
Journal of Food, Agriculture and Environment

We measured the dynamics of both biomass and nutrient pools on 7-, 17-, 31- and 51-year-old Pinus massoniana plantations in southern China. Using a chronosequence approach, we found that biomass of each component increased with aging while its proportion decreased except stem-wood. Nutrient pools varied with biomass pools except for foliage. For all harvest intensities (stem only, stem and branches, and aboveground), increasing the rotation length from 31 yrs to 51 yrs increased the biomass collection by ≥7.1% and reduced the nutrient export for K, Ca and Mg by ≤6.3% during 155 years, while N and P pools varied with harvesting intensities. A decreasing rotation length from 51 yrs to 17 yrs would increase the biomass collection by ≥12.4%, but remove significantly more nutrients. Although more biomass would be collected if harvesting intensity increased, the nutrient removal would have disproportionally increased. Therefore, increasing the rotation length and decreasing harvest intensity are recommended to sustain the site productivity for future Masson pine plantation. Source

Yang H.-X.,CAS Shenyang Institute of Applied Ecology | Yang H.-X.,Huitong National Research Station of Forest Ecoecosystem | Yang H.-X.,University of Chinese Academy of Sciences | Yang H.-X.,Liaoning Institute of Forest Management | And 8 more authors.
Chinese Journal of Applied Ecology

By using a chronosequence approach, this paper studied the nutrients accumulation, allocation, and cycling in 7-, 17-, 31-, and 51-year-old Masson pine plantations, aimed to analyze the dynamics of nutrients in Masson pine plantation at its different developmental stages. The results showed that 1 ) nutrient accumulation was not synchronized with biomass accumulation, with the accumulation rate of biomass being 3. 3, 5. 4, 3. 3, 3. 7, and 9. 8 times of that of N, P, K, Ca, and Mg from age 17 to 51, respectively, 2) nutrient allocation to a specific component was related to the growth rate of the nutrient pool in the component, and the nutrient allocation to stem as well as the ratio of nutrient allocation to root/shoot increased with plantation age, and 3) the biomass production per unit nutrient, i. e., nutrient use efficiency, and the nutrient cycling coefficient also increased with plantation age, being higher for 51 -year-old plantation than for younger plantations, suggesting that shortening the rotation length could reduce the possibility to raise the nutrient use efficiency. It was suggested that both extending the cuixent rotation length to as long as 50 years and reducing the harvest intensity could be helpful to conserve the nutrients and to maintain long-term productivity. Source

Pan P.-K.,Beijing Forestry University | Pan P.-K.,Liaoning Institute of Forest Management | Yu H.-L.,Beijing Forestry University | Tang Y.,Beijing Forestry University | And 2 more authors.
Chemistry and Industry of Forest Products

The pretreatments of steam explosion, sodium hydroxide, alkaline peroxide and the coupling were used to remove the hemicellulose and lignin in acorn hull and increase the glucose yield. The hemicellucose in acorn hull decreased from 26.81% to 5.79% with a removal of 87.28% with 2.25 MPa steam explosion pretreatment. However, the glucose yield increased from 10.32% to 38.36% after enzymatic hydrolysis for 120 h. The lignin removal was 54.29% after pretreating acorn hull by 2.25 MPa steam explosion coupled with sodium hydroxide. The glucose yield was 76.65% obtained from acorn hull pretreated with 2.25MPa steam explosion and alkaline peroxide. It was 7.4 times of that from raw acorn hull untreated. ©, 2015, Edited & Published by Editorial Board of «Chemistry and Industry of Forest Products». All right reserved. Source

Xu H.-W.,Northeast Forestry University | Liu Y.,Northeast Forestry University | Li Z.-X.,Northeast Forestry University | Peng R.-S.,Liaoning Provincial Institute of Poplar | And 4 more authors.
Beijing Linye Daxue Xuebao/Journal of Beijing Forestry University

Multi-site forestation testing is a key step in the evaluation of stability and growth traits of tree family or clone. Tree height (H) and diameter at breast height (DBH) of ten families of five-year-old birch planted in Huinan County, Linghai and Dandong cities were measured and jointly analyzed. The results showed that differences in tree height among sites and families, and interaction between sites and families, were significant (P<0.05). The differences in DBH were only significant among sites at the level P<0.05. Families 201, 203, 204, 316 and 318 had excellent traits in Huinan, as did families 201, 202, 314, 316, 318 and 319 in Linghai and 202, 315, 318 and 319 in Dandong. We used AMMI model to evaluate the stability of tree height of tested families. Results indicated that families 203, 204, 318, 319 and 316 are high-yield and stable types, 201 and 202 high-yield but instable types, 320 and 315 low-yield yet stable types, and 314 low-yield and instable types. These results provide a theoretical basis for selection and a reference for the spread of birch crossbreeds. © 2015, Beijing Forestry University. All right reserved. Source

Yang H.-X.,CAS Shenyang Institute of Applied Ecology | Yang H.-X.,University of Chinese Academy of Sciences | Yang H.-X.,Liaoning Institute of Forest Management | Wang S.-L.,CAS Shenyang Institute of Applied Ecology | And 3 more authors.
Chinese Journal of Ecology

By using chronosequence method, an investigation was conducted on the annual litter mass and nutrient return of Masson pine plantations at different ages. The litter mass of the plantations varied obviously with season, and affected by species characteristics and climate. There was a lag effect of climate on litter mass. The nutrient concentrations in each litter component had an obvious seasonal variation, with the difference reached more than one-fold. With increasing stand age, the K return through litterfall decreased, while the other nutrients return showed 'V' shape. The stand at age 51 had higher nutrient use efficiency. Litterfall played an important role in maintaining stand fertility. Litter output, especially for fallen needles, would cut the key link of biogeochemical cycle, aggravate the nutrient deficiency of soil, and lead to the decrease of stand productivity. Therefore, in the management of Masson pine plantation, litter output should be reduced as possible to maintain the long-term productivity of the site. Source

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