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He J.N.,Central South University of forestry and Technology | Kang W.X.,Central South University of forestry and Technology | Kang W.X.,National Engineering Laboratory for Applied Technology of Forestry and Ecology in South China | Wang D.,Central South University of forestry and Technology | Yao L.H.,Central South University of forestry and Technology
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2015

Based on the small watershed technique and the located observation method, the hydrology data collected of the precipitation, penetrate the canopy water, surface and underground runoff, and determine its nutrient content, which were used for analyzing the nutrient dynamic in hydrologic process on the successive rotations of Chinese fir plantations at near mature forest. The replanting its purpose to reveal functional differences in the two generations of Chinese fir in biogeochemical cycling of nutrients, and study the problem of declining productivity even planted fir plantations provide ideas and evidence. The results showed that the nutrient concentrations in precipitation of the second generation forest was 20.30%-39.64% higher than that in first-generation forest, which accounted in total for 38.52% more input of nutrients in second generation than that in the first generation forest. The nutrient concentrations in the through fall in the forest of the first and the second generation was relatively 4.149-4.895 g/kg and 4.271-5.605 g/kg higher than that in the corresponding atmospheric precipitation, respectively. Rain canopy leaching of nutrients,which the nutrient content was 2.94% to 21.37% higher in the second generation forest than that in the first generation forest after leaching through the canopy. There was not significantly different between the nutrient concentrations in surface runoff of the first and that in the second generation forest. The nutrient concentrations subsurface runoff of second generation forest, however, was 48.06% -78.87% higher than that in the first generation forest, which induced the runoff output in the runoff, the second generation forest was 1.58 to 2.61 times more than that in the first generation forest. The nutrient geochemical rate was 26.75% to 29.95% in the first generation forest, while in the second generation forest the nutrient geochemical cycle was 37.24% to 47.43%, and The nutrient geochemical cycle was 3.3 to 3.7 years in the first generation forest, while was 2.1 to 2.7 years in the second generation forest. The nutrient loss rate of the second generation forest was from 1.30 to 1.72 times higher than that in the first generation forest, and the nutrient accumulation rate in the second generation forest was from 73.57% to 87.14% of that in the first generation forest. As to the retention and utilization in the input of nutrients from the outside, the nutrient retention and utilization efficiency of the second generation forest was lower than that of the first generation forest. © 2015, Ecological Society of China. All rights reserved. Source


He J.N.,Central South University of forestry and Technology | Kang W.X.,Central South University of forestry and Technology | Kang W.X.,National Engineering Laboratory for Applied Technology of Forestry and Ecology in South China | Wang D.,Central South University of forestry and Technology
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2015

As a principal timber species, Chinese fir (Cunninghamia lanceolata (Lamb.) Hook) is widely planted throughout southern China and it covers approximately 9.21 million hectares, almost one third of total plantation in China and it contributes greatly to meeting the expanding timber demand. The heat value of the tree represents, to some degree, the capacity of the physiological function and productivity of the plant. In this study, the calorific values of plants in Chinese fir (Cunninghamia lanceolata) plantation at different ages were studied, based on located observations from a national key field scientific experimental station in Huitong, Hunan Province, China. The biomass, carbon concentration of different component of the tree, understory vegetation and dead litter layer were investigated at 11-year, 14-year, 18-year, 20-year old Chinese fir plantation. By using the six standard tree method, the allometric equations for biomass were established for the Chinese fir plantations at different stand ages, including the trunk, leaves, barks, twigs and roots. The dry matters were ground and the calorific value of different component of the plant and ecosystem were measured with automatic calorimeter (WZR-1TCII). We analyzed the data with one-way ANOVA, two-way ANOVA and Duncan by using SPSS 13.0 and the results showed that at the same age, the different organs of Chinese fir had different calorific values, they shared a similar pattern and in a small range, between 17.3 to 20.6 J/ g and ranked as needle>bark > twig > trunk > root. As to the different organs of Chinese fir, the calorific values increased with the age. At the same age,The calorific values of shrubs was in the order needle > twig > root. For The calorific values in aboveground organs of herb was higher than that of root. Over time, calorific values in shrubs and herb decreased with the age. At the same age,the calorific values of litter was in the order needle > litter twig > detritus >dead roots. The calorific values of the litter components increased with the age. As to Chinese fir plantation ecosystem, the calorific values of the components was in the order of tree layer > shrub layer > herb layer > litter layer. There was no robust relationship between ash content and calorific values in the different organs of Cunninghamia lanceolata,but that of the Shrubs and herb organs has a significantly negative correlation with its ash content (P<0.05). The Calorific value of organs of Cunninghamia lanceolata changed with the age, which might affect the organs of Chinese fir with stand age, the increased lignifications for instance. Furthermore, the environmental factors could also contribute to the calorific values over time, such as the rainfall, solar radiation, temperature, and so on, in that the calorific values of plants in Chinese fir plantations, the components beneath the system will be affected by the receiving resources for solar energy for different plants located in the different layer, which could also be true even in the different layers of leaves for Chinese fir itself. © 2015, Science Press. All rights reserved. Source


Yao L.H.,Central South University of forestry and Technology | Kang W.X.,Central South University of forestry and Technology | Kang W.X.,National Engineering Laboratory for Applied Technology of Forestry and Ecology in South China | Zhao Z.H.,Central South University of forestry and Technology | He J.N.,Central South University of forestry and Technology
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2015

Based on located observations biomass and carbon content carbon of plants from a national key field scientific experimental station in Huitong, carbon storage, carbon allocation characteristics of each component in Chinese fir (Cunninghamia lanceolata) plantations, the ability to stand fixed carbon dynamics in Cinese fir plantation at different ages were studied. The results showed that the carbon content of the Stand components increased with the age, which in the ranked as follow: needle> bark > root > trunk > twig at the same age. Forest carbon storage ranged from 22.93 to 86.98 t/ hm2,the carbon storage is greater in tree layer than the understory vegetation layer, and the understory vegetation layer is greater than the layer of dead matter. Tree layer of carbon on the relative distribution of organs ranked as trunk> root> leaf> bark> branch. Trunk carbon allocation to increase with age, branches, leaves decrease with age, although the roots and bark fluctuated, the change is relatively stable. The needle, twig,trunk, bark, roots carbon accumulation, the average annual change showed a single peak-shaped curve, but the crest of a different time. The fixed carbon dynamic characteristics can be divided into five stages of the fir forest, i.e. the establishment of the function of the fixed carbon, carbon fixation ability to rapidly increase, the ability to achieve maximum fixed carbon, the ability of the fixed carbon is relatively stable, decreased ability of the fixed carbon. The Carbon sequestration in Chinese fir plantations is affected not only by the constraints of the biological characteristics of the different growth stages of growth and development rhythm, but also by the stand canopy structure and soil fertility conditions. © 2015, Ecological Society of China. All rights reserved. Source


Kang W.,Central South University of forestry and Technology | Kang W.,National Engineering Laboratory for Applied Technology of Forestry and Ecology in South China | Yao L.,Central South University of forestry and Technology | He J.,Central South University of forestry and Technology | And 2 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2012

In order to provide the scientific basis for saving energy, reducing CO2emissions and promoting the rapid development of economy of Liaoning Province, the Gross Domestic Product (GDP) and CO2emissions were surveyed and the relationship between economic growth and energy utilization efficiency, energy consumption intensity was analyzed in this study. The results showed that total energy consumption in second industry was extremely high, which was 5.67-8.41 times higher than that of the third industry, and 7.2-9.0 times higher than that of the first industry. The energy consumption per unit capita of GDP was 52%-70% higher than the national average level, mainly due to concentrated high energy demanding industries, such as coat mining, dressing, electricity and supply, etc. Besides, the energy utilization efficiency of second industry was quite low, equivalent to 11.89% of the first the industry, 12.60% of the third industry. Although annual GDP growth rate was faster than the growth rate of energy consumption, which might indicate the increased energy input promoted the improvement of gross domestic product, economic growth is not completely dependent on energy consumption growth. Instead, the adjustment of industrial structure and technical innovation played a critical role on the development of economy in Liaoning. CO2 emissions and annual change of per capita GDP presented turning point in 2001 and 2005, with the increase of per capita GDP, emissions of CO2 appeared to fluctuate repeatedly, suggesting the relationship between environment and the economy in Liaoning is still not in the balanced and collaborative developing stage. To solve these issues, structure adjustments, technology innovation and reform were needed to improve energy utilization efficiency and improve economy. Source


Kang W.,Central South University of forestry and Technology | Kang W.,National Engineering Laboratory for Applied Technology of Forestry and Ecology in South China | Xiong Z.,Central South University of forestry and Technology | He J.,Central South University of forestry and Technology | Li J.,Central South University of forestry and Technology
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2012

The energy storage and distribution were studied in the 11-year-old Chinese fir plantations in Huitong, the central production area and Zhuting, the expanded cultivation area based on the biomass and thermal value of try matter. The result showed that the the amount of existing energy in Chinese fir plantation of Huitong area (12406×108-14733×108J/hm2) was significantly higher than that in Zhuting (9294×108-10894×108J/hm2), suggesting the stand condition and climate play a critical role on the energy accumulation in Chinese fir plantations. Besides, the amount of existing energy in both Chinese fir plantation areas decreased with increasing density in a certain range of stand density, mainly due to the reduced existing energy of the trunk capacity, whereas the amount of existing energy of branches and leaves maintains at a stable state. The allocation of the energy to the different componentsof the tree was different, ranked with decreasing order: stem, roots, leaves, and branches. The energy distribution ratio in Huitong is different from that in Zhuting, e.g. the for both planations, for energy allocated into stem was 56.8%-61.2% in Huitong plantation, which was higher than that of 47.0%-53.5% in Zhuting, while in leaves, the allocation ratio is much lower in Huitong (22.2%-25.9%) than that in Zhuting (28.3%-34.2%). For the spatial distribution of the amount of existing energy at the stand level, most of existing energy was distributed at the soil surface and 2/3 height of the canopy above the ground, where was regarded the most important places for the exchange of substances and energy including water, light, gas and heat in the surrounding environment in forest. Results indicated that: (1) where there is the most urgency in supply of water and nutrients, there is the largest gathering of energy flows at the ecosystem level, and (2) for the 11a stand, there were some factors not suited to the growth of Chinese fir plantation in Zhuting area, in terms of micrometeorologic factors and stand conditions compared with Huitong area, the central area of China fir plantation. Source

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