• Asian-Australasian Journal of Animal Sciences
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• v.12 no.7
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• pp.1015-1018
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• 1999

Single trait mixed models have been dominantly utilized for genetic evaluation of the reproductive traits in swine. However employing multiple trait approach may lead to more accurate genetic evaluations. For 5 litter size and litter weight traits of Danish Landrace, genetic parameters were estimated with a multiple trait mixed model. The heritability estimates were 0.02, 0.03, 0.03, 0.05, and 0.07, respectively for litter size at birth, litter size born alive, litter weight at birth, litter size at weaning, and litter weight at weaning. Negative genetic correlations were all positive. The litter weight at birth showed genetic antagonism with litter size born alive (-0.65) and litter size at weaning (-0.31), but positive with litter size at birth (0.47) and litter weight at weaning (0.31). The estimates of environmental correlations were larger than their corresponding genetic correlation estimates except for those between litter weight at birth and the other four traits. This study recommends simultaneous selection for two or more traits with multivariate mixed models in order to improve overall economic response.

• Journal of Forest and Environmental Science
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• v.29 no.1
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• pp.38-48
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• 2013

Decomposition of plant material is an important component in the study of forest ecosystem because of its critical role in nutrient cycling. Different tree species has different nutrient release patterns, which are related to leaf litter quantitative traits and seasonal environmental factors. The quantitative traits of leaf litter are important predictors of decomposition and decomposition rates increase with greater nutrient availability in the forest ecosystems. At the ecosystem level, litter quantitative traits are most often related to the physical and chemical characteristics of the litter, for example, leaf toughness and leaf mass per unit area, and lignin content tannin and total phenolics. Thus, the analysis of litter quantitative traits and decomposition are highly important for the understanding of nutrient cycling in forest ecosystems. By studying the role of litter quantitative traits on decomposition and nutrient cycling in forest ecosystems will provide a valuable insight to how quantitative traits influence ecosystem nutrient dynamics. Such knowledge will contribute to future forest management and conservation practices.

• Journal of Ecology and Environment
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• v.44 no.2
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• pp.81-89
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• 2020

In the forest ecosystems, litterfall is an important component of the nutrient cycle that regulates the accumulation of soil organic matter (SOM), the input and output of the nutrients, nutrient replenishment, biodiversity conservation, and other ecosystem functions. Therefore, a profound understanding of the major processes (litterfall production and its decomposition rate) in the cycle is vital for sustainable forest management (SFM). Despite these facts, there is still a limited knowledge in tropical forest ecosystems, and further researches are highly needed. This shortfall of research-based knowledge, especially in tropical forest ecosystems, may be a contributing factor to the lack of understanding of the role of plant litter in the forest ecosystem function for sustainable forest management, particularly in the tropical forest landscapes. Therefore, in this paper, I review the role of plant litter in tropical forest ecosystems with the aims of assessing the importance of plant litter in forest ecosystems for the biogeochemical cycle. Then, the major factors that affect the plant litter production and decomposition were identified, which could direct and contribute to future research. The small set of studies reviewed in this paper demonstrated the potential of plant litter to improve the biogeochemical cycle and nutrients in the forest ecosystems. However, further researches are needed particularly on the effect of species, forest structures, seasons, and climate factors on the plant litter production and decomposition in various types of forest ecosystems.

• Journal of Ecology and Environment
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• v.34 no.4
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• pp.401-410
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• 2011

We assayed the effects of simulated acid rain on the mass loss, $CO_2$ evolution, dehydrogenase activity, and microbial biomass-C of decomposing Sorbus alnifolia leaf litter at the microcosm. The dilute sulfuric acid solution composed the simulated acid rain, and the microcosm decomposition experiment was performed at 23$^{\circ}C$ and 40% humidity. During the early decomposition stage, decomposition rate of S. alnifolia leaf litter, and microbial biomass, $CO_2$ evolution and dehydrogenase activity were inhibited at a lower pH; however, during the late decomposition stage, these characteristics were not affected by pH level. The fungal component of the microbial community was conspicuous at lower pH levels and at the late decomposition stage. Conversely, the bacterial community was most evident during the initial decomposition phase and was especially dominant at higher pH levels. These changes in microbial community structure resulting from changes in microcosm acidity suggest that pH is an important aspect in the maintenance of the decomposition process. Litter decomposition exhibited a positive, linear relationship with both microbial respiration and microbial biomass. Fungal biomass exhibited a significant, positive relationship with $CO_2$ evolution from the decaying litter. Acid rain had a significant effect on microbial biomass and microbial community structure according to acid tolerance of each microbial species. Fungal biomass and decomposition activities were not only more important at a low pH than at a high pH but also fungal activity, such as $CO_2$ evolution, was closely related with litter decomposition rate.

• Journal of the Korean Wood Science and Technology
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• v.48 no.5
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• pp.591-607
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• 2020

This study was aimed to investigate the changes of chemical composition of the volatile organic compounds (VOCs) emitted from red pine needles in the process of needle abscission or senescence. The VOCs in intact, senescent, and litter red pine needle samples were analyzed by headspace-solid phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC/MS). And then, multivariate statistical interpretation of the processed data sets was conducted to investigate similarities and dissimilarities of the needle samples. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to investigate the dataset structure and discrimination between samples, respectively. From the data preview, the levels of major components of VOCs from needles were not significantly different between needle samples. By PCA investigation, the data reduction according to classification based on the chlorophyll a / chlorophyll b (Ca/Cb) ratio were found to be ideal for differentiating intact, senescent, and litter needles. The following OPLS-DA taking Ca/Cb ratio as y-variables showed that needle samples were well grouped on score plot and had the significant discriminant compounds, respectively. Several compounds had significantly correlated with Ca/Cb ratio in a bivariate correlation analysis. Notably, the litter needles had a higher content of oxidized compounds than the intact needles. In summary, we found that chemical compositions of VOCs between intact, senescent, and litter needles are different each other and several compounds reflect characteristic of needle.

• Korean Journal of Environment and Ecology
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• v.32 no.1
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• pp.23-29
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• 2018

The litter production, the nutrient concentration of each component of litterfall, and the amounts of nutrient into the forest floor via litterfall were assessed for 5 years from January 2009 through December 2013 in a Pinus densiflora forest in Mt. Worak National Park. The average amounts of leaf litter, branch and bark, reproductive organs(flowers and cones), and miscellaneous categories for 5 years were $1.940{\pm}0.21$, $0.505{\pm}0.15$, $0.259{\pm}0.09$, and $0.737{\pm}0.14t\;ha^{-1}yr^{-1}$, respectively. The average percentage of leaf litter, branch and bark, reproductive organs and miscellaneous categories for 5 years were 56.4, 14.7, 7.5, and 21.4%, respectively. The amounts of total litterfall in 2009, 2010, 2011, 2012, and 2013 were 2.810, 3.796, 3.268, 3.284, and $4.045ton\;ha^{-1}yr^{-1}$, respectively. The average amounts of litterfall for 5 years were $3.441{\pm}0.4ton\;ha^{-1}yr^{-1}$. The average amounts of N, P, K, Ca, and Mg returned to the forest floor via litterfall for 5 years in this Pinus densiflora forest were $22.73{\pm}4.92$, $1.05{\pm}0.42$, $4.26{\pm}1.69$, $8.48{\pm}4.62$, and $2.42{\pm}1.01kg\;ha^{-1}yr^{-1}$, respectively.

• Journal of Ecology and Environment
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• v.30 no.1
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• pp.63-68
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• 2007

Litter production, nutrient contents of each component of litterfall and amount of nutrients returned to forest floor via litterfall were investigated from May 2005 through April 2006 in Quercus mongolica, Quercus variabilis and Pinus densiflora forests at Mt. Worak National Park. Total amount of litterfall during one year in Q. mongolica, Q. variabilis and P. densiflora forests was 542.7, 459.2 and $306.9\;g\;m^{-2}\;yr^{-1}$, respectively. Of the total litterfall, leaf litter, branch and bark, reproductive organ and the others occupied 50.3%, 22.7%, 10.1 % and 16.9% in Q. mongolica forest, 81.9%, 7.2%, 3.1% and 7.9% in Q. variabilis forest, 57.4%, 12.8%, 5.6% and 24.1 % in P. densiflora forest, respectively. Nutrients concentrations in oak litterfall were higher than those in needle litter. N, P, K, Ca and Mg concentration in leaf litterfall were 13.8, 1.1, 7.2, 4.2 and 1.3 mg/g for Q. mongolica forest, 10.5, 0.7, 3.2, 3.7 and 1.6 mg/g for Q. variabilis forest, 5.3, 0.4, 1.2, 2.8 and 0.6mg/g for P. densiflora forest, respectively. The amount of annual input of N, P, K, Ca and Mg to the forest floor via litterfall was 43.36, 2.89, 21.38, 23.31 and $5.62\;kg\;ha^{-1}\;yr^{-1}$ for Q. mongolica forest, 32.28, 2.01, 10.23, 20.29 and $7.78\;kg\;ha^{-1}\;yr^{-1}$ for Q. variabilis forest, 15.80, 1.04, 3.99, 9.70 and $2.10\;kg\;ha^{-1}\;yr^{-1}$ for P. densiflora forest, respectively.

• Korean Journal of Environmental Biology
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• v.27 no.3
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• pp.261-265
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• 2009

Litter production, nutrient concentration of each component of litterfall and amount of nutrients input to forest floor via litterfall were investigated for three years from May 2005 through April 2008 in Pinus densiflora forest at Mt. Worak National Park. Amount of litterfall in 2005, 2006, 2007 were 3.070, 3.066, 3.099 ton $ha^{-1}yr^{-1}$, respectively. Average amount of litterfall for three years was $3.078{\pm}0.018\;ton\;ha^{-1}yr^{-1}$. Average percentage of leaf litter, branch and bark, reproductive organ and the miscellaneous for three years were 61.9, 10.4, 5.2, 22.5%, respectively. Average amount of N, P, K, Ca and Mg returned to forest floor via litterfall for three years in this P. densiflora forest were 18.014, 0.878, 4.240, 7.349 and 2.172 kg $ha^{-1}yr^{-1}$, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.2
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• pp.128-136
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• 1998

Most of total nitrogen in the surface soil exists in organic forms, of which amino acid-N is the major fraction. By-product fertilizers provide soil with humic substances, and humic acid is an essential component of humus. Amino acids(AAs) are easily converted to inorganic-N forms and thus play an important role in N fertility. This experiment was conducted to investigate the contents and distributions of AAs in humic acids which were extracted from the commercial by-product fertilizers of different composting materials. Total contents of AAs in humic acids ranged from 1.2 to 5.6%, of which neutral AAs were the highest with ranges of 0.8~4.5%. AAs contents in fertilizers composted from the plant residues such as leaf litter, sawdust and bark were in an order of neutral>acidic>basic AAs. In contrast, those from animal wastes, such as poultry and pig manures, were in an order of neutral>basic>acidic AAs. Distributions of total, acidic and neutral AAs were in the respective order of leaf litter>sawdust>pig manure>poultry manure>peat, bark>sawdust>leaf litter>peat and leaf litter>sawdust>bark>peat. Distributions of the basic AAs were in the reversed order of the acidic AAs. In bark fertilizer with increasing compost maturity, contents of the acidic AAs were increased in compensation for the decreases in those of neutral and basic AAs. Results demonstrated that distributions of amino acids in humic acid of by-product fertilizers were different from composting raw materials and degrees of humification.

• Korean Journal of Environment and Ecology
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• v.25 no.4
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• pp.573-580
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• 2011

Litter production, nutrient concentration of each component of litterfall and amount of nutrients input to forest floor via litterfall were investigated for four years from May 2005 through April 2009 in Quercus variabilis forest at Mt. Worak National Park. Amount of litterfall in 2005, 2006, 2007, 2008 were 5.181, 5.372, 5.314, 5.361 ton $ha^{-1}yr^{-1}$, respectively. Average amount of litterfall for four years was 5.307${\pm}$0.09 ton $ha^{-1}yr^{-1}$. Average percentage of leaf litter, branch and bark, reproductive organ and the miscellaneous for four years were 67.5${\pm}$1.9, 13.3${\pm}$0.8, 10.1${\pm}$0.5 and 9.1${\pm}$1.2%, respectively. Average amount of N, P, K, Ca and Mg returned to forest floor via litterfall for four years in this Q. variabilis forest were 44.47${\pm}$6.70, 2.50${\pm}$0.25, 12.26${\pm}$0.30, 17.23${\pm}$2.32 and 9.56${\pm}$0.54 kg $ha^{-1}yr^{-1}$, respectively.