• Journal of Forest and Environmental Science
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• v.29 no.2
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• pp.147-156
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• 2013

Multiple use forestry is capable of generating income for forest based communities through Non-Timber forest products (NTFPs) which provide food, medicine, materials for domestic use and cash income for communities adjoining forest areas in developing countries. This study evaluates the economics of producing ginger rhizomes under teak canopy in a multiple land use system during 2007 and 2008 in even aged teak plantations in Ibadan and Ife, Nigeria. Twelve $6m^2$ sample plots were randomly selected in Completely Randomized Block Design within and outside the plantation. Average ginger rhizome of (50-60 g) were planted on the slightly tilled soil. NPK 15:15:15 was applied at 180 kg/ha on a split unit dose. ANOVA, Profitability, Benefit-Cost (B/C) ratio were used to analyze data. Results showed no significant differences between sites in ginger rhizome yield, (0.089 and 0.718, ${\rho}{\leq}0.05$) in 2007 and 2008 respectively. Average yield were higher outside teak canopy in both sites and treatments, (Ibadan -40.05 g>32.9 g, Ife -67.6 g>25.2 g and Ibadan -41.3 g>31.5 g, Ife -66.8 g>25.0 g) with and without NPK respectively. NPK had no effect on yields within teak plantation, (Ibadan -31.5<32.9 g, Ife -25 g<25.2 g). Ginger rhizome production was viable financially without inorganic fertilizer during second cropping season within and outside plantation (B/C=1.02, 1.09) respectively. Ginger could be raised profitably under teak canopy, however, studies on insolation requirement of ginger under teak canopy and other tree plantations are recommended.

• Journal of Ecology and Environment
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• v.32 no.3
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• pp.159-165
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• 2009

The purpose of this study was to investigate the effects of thinning on fine root biomass and vertical distribution. and litterfall amount in a 50 year old Pinus koraiensis plantation in Chuncheon, Kangwon Province. Fine root (< 2 mm in diameter) biomass ($367\;g/m^2$) in the site 'OC_75', thinning once in 1975, was 68% of those in the site 'CON', no thinning after planting, and in the site 'TC_00', thinning twice in 1975 and 2000. There were no significant differences of dead roots among treatments. Diameter $0{\sim}1\;mm$ roots were vertically decreased only in the TC_00 site. The litterfall was very similar between OC_75 ($5.2\;Mg\;ha^{-1}\;yr^{-1}$) and TC_00 ($4.7\;Mg\;ha^{-1}\;yr^{-1}$), but the composition of litterfall was different: The proportion of leaves and branches was 80% and 13% in OC_75 and 56% and 36% in TC_00, respectively. Reduction of P. koraiensis density by thinning decreased leaf litter as well as fine roots of P. koraiensis, but increased fine roots production by neighboring understory plants offset the reduction of fine roots of P. koraiensis. We suggest that belowground as well as aboveground responses, including both over- and understory vegetation, should be considered to measure the responses of trees in thinned forest ecosystems.

• The Korean Journal of Ecology
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• v.25 no.6
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• pp.399-403
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• 2002

Cellulose mass loss by cellulose filter papers was measured for 3 time (35 days, 70 days, 105 days) incubation during the growing season (from May to September 2002) with different tree density and after fertilization in a Japanese larch (Larix leptolepis) plantation. Cellulose mass loss rates were significantly different between tree density types and fertilization treatments during the study periods. After 105 day incubation of cellulose filter paper, cellulose mass loss rates were significantly higher in the low tree density (70.1 $\%$) than in the high tree density (49.9$\%$). Cellulose mass loss rates averaged 62.8$\%$ in the fertilization and 58.9% in the unfertilization treatments during the same periods. However, cellulose mass loss was not significantly different between the forest floor and the mineral soil layer except for 35 day incubation. The results indicate that cellulose decomposition rates are a useful index to express differences in organic matter decomposition activity in different tree density and after fertilizer treatments.

• Journal of Forest and Environmental Science
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• v.34 no.6
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• pp.451-456
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• 2018

The use of single component distribution to describe the irregular stand structure of degraded forest often lead to bias. Such biasness can be overcome by the application of finite mixture distribution. Therefore, in this study, finite mixture distribution was used to characterise the irregular stand structure of the Gmelina arborea plantation in Omo forest reserve. Thirty plots, ten each from the three stands established in 1984, 1990 and 2005 were used. The data were pooled per stand and fitted. Four finite mixture distributions including normal mixture, lognormal mixture, gamma mixture and Weibull mixture were considered. The method of maximum likelihood was used to fit the finite mixture distributions to the data. Model assessment was based on negative loglikelihood value ($-{\Lambda}{\Lambda}$), Akaike information criterion (AIC), Bayesian information criterion (BIC) and root mean square error (RMSE). The results showed that the mixture distributions provide accurate and precise characterisation of the irregular diameter distribution of the degraded Gmelina arborea stands. The $-{\Lambda}{\Lambda}$, AIC, BIC and RMSE values ranged from -715.233 to -348.375, 703.926 to 1433.588, 718.598 to 1451.334 and 3.003 to 7.492, respectively. Their performances were relatively the same. This approach can be used to describe other irregular forest stand structures, especially the multi-species forest.

• Journal of Korean Society of Forest Science
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• v.35 no.1
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• pp.9-14
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• 1977

The productive structure and the productivity of ${\times}$Populus albaglandulosa plantations, where are middle parts of the Korean peninsula, were studied by means of stratifying clip technique and of allometry. The densities of stands in the sample areas were 693 trees/ha in 6 year-old plantation and 527 or 625 trees/ha in 9 year-old one. The photosynthetic part of the productive structure was not shown normal conical form but layering. So this was efficient to transmit solar radiation into the stand floor. The standing crop of the terrestrial parts of 6 year-old plantation was 18.11 ton/ha and that of 9 year-old one 38.8 to 47.3 ton/ha. The wood volume to trunk to 6 year-old was $31.3m^3/ha$ and that of 9 year-old was 68.8 to $83.9m^3/ha$. The annual net production of 6 year-old plantation was 4.8 ton/ha/year and that of 9 year-old one was 10.0 to 11.7 ton/ha/year and its wood volume of trunks was 17.9 to $21.1m^3/ha/year$. In the 9 year-old plantation the standing crop or the annual net production was different between two sample areas. This seemed that the cause was not due to chemical character but to physical character of soil.

• Korean Journal of Environmental Biology
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• v.19 no.4
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• pp.278-281
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• 2001

Ecological measurement and biological environment of the Moak Provicial Park surveyed based on the habitat; deciduous broad leaved forest (Quercus mongolica variabilis-Pinus densiflora, Capinus tschonoskii, Quercus Mongolica, Quercus acutissima-Pinus densiflora, and Quercus variabilis), coniferous forest (Pinus densiflora), plantation forest (Pinus rigida), and the other place (pond, lake, rice field, stream, and river). Totally, 1 orders, 4 families, 8 species of amphibians were found at Mt. Moak provincial park. Biodiversity indices of studied region were as follow; richness was 1.270, diversity was 1.775, and evenness was 0.853 in amphibians. 42.1% of amphibians were found in deciduous broad leaved forest, 11.3% in coniferous forest, 1.6% in plantation forest, and 45.0% in the other region.

• Journal of Ecology and Environment
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• v.29 no.5
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• pp.445-452
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• 2006

The number of species and forest area has decreased as urbanization is progressed. The landscape degradation was examined by analyzing vegetation map, satellite image and characteristics of actual vegetation. The study was conducted in Mt. Baekja and its surroundings located on Gyeongsan city, southeastern Korea. As the result of landscape analysis, agricultural field was a characteristic attribute of the study area. Lowlands of this study area were occupied by agricultural field and various plantations. For 15 years from 1987 to 2002, forest area decreased from 2,072.9 ha to 1,853.2 ha, and shape index and fractal dimension of vegetation patches increased from 1.32 to 1.65 and from 1.05 to 1.09, respectively. Pinus densiflora Siebold & Zucco. community showed the highest species diversity, whereas Larix kaempferi (Lamb.) Carriere community showed the lowest species abundance. As forest management implications, monitoring of endangered plant species (Jeffersonia dubia (Maxim.) Benth. & Hook.f. ex Baker & S.Moore), and restoration of lowland forest from plantation to natural forest were discussed. Further, establishment of greenways utilizing existing streams, roadside, and public facilities were recommended.

• Journal of Korean Society of Forest Science
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• v.96 no.2
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• pp.138-144
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• 2007

This study was undertaken to compare the biomass of Abies koreana growing at two sites. A $10{\times}10m$ plot was established in each site of a natural stand in Mt. Jiri and a plantation in Gyeongsan nursery. Five trees of A. koreana were randomly selected in each site. The following traits were investigated from each tree : height, basal diameter, age, weight of stem, branches, and needles as above-ground traits and weight of total roots, horizontal roots, and vertical roots as below-ground traits. In Gyeongsan nursery, age of sample trees was negatively correlated with both height and weight of total stem, while height was highly correlated with weight of horizontal roots. There was high correlation between the basal diameter and weight of total stem, and between the basal diameter and weight of roots. In Mt. Jiri stand, most of the above-ground traits except age were significantly correlated with the below-ground traits. The linear regression equation between the cross section area of base (X) and the weight of total stem (Y) in Gyeongsan nursery was Y=12.66X-12.92, and correlation was significant ($R^2=0.89$). The linear regression equation between the cross section area of base(X) and the weight of total branches (Y) in Mt. Jiri stand was Y=25.51X+6.00, and correlation was highly significant ($R^2=1.0$).

• Journal of Korean Society of Forest Science
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• v.96 no.2
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• pp.151-159
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• 2007

This study was conducted to investigate the effects of thinning on changes in stand characteristics and understory vegetation in a silvopasture practiced Japanese larch plantation in the Research Forest of Kangwon National University, Korea. Three different thinning intensities (64%, 35%, and control) were applied. Before and after thinning, the understory plant species increased its number from 48 (7 tree species, 7 shrubs species, 28 herbaceous species, and 6 woody climbers) to 100 (11 tree species, 15 shrub species, 67 herbaceous species, and 7 woody climbers). Thinning made plants invade easily on the forest floor, and plot A (325 stems/ha) had much higher number of undersory species than those Of plot B (575 stems/ha) and control plot (1,150 stems/ha). In three years after thinning, understory aboveground biomass (kg/ha) of herbs were 523 for control, 1,230 for plot B, and 1,288 for plot A. The canopy coverage had remarkable influence on the understory biomass production, resulting in relatively small amount of herbage production on control plot. The differences were statistically significant between thinned plots and unthinned plot, but there were no significant differences among the thinned plots (p<0.05).

• Journal of Ecology and Environment
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• v.42 no.3
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• pp.128-138
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• 2018

Background: This study investigated the variation of soil organic carbon in four land cover types: natural and mixed forest, cultivated land, Eucalyptus plantation and open bush land. The study was conducted in the Birr watershed of the upper Blue Nile ('Abbay') river basin. Methods: The data was subjected to a two-way of ANOVA analysis using the general linear model (GLM) procedures of SAS. Pairwise comparison method was also used to assess the mean difference of the land uses and depth levels depending on soil properties. Total of 148 soil samples were collected from two depth layers: 0-10 and 10-20 cm. Results: The results showed that overall mean soil organic carbon stock was higher under natural and mixed forest land use compared with other land use types and at all depths ($29.62{\pm}1.95Mg\;C\;ha^{-1}$), which was 36.14, 28.36, and 27.63% more than in cultivated land, open bush land, and Eucalyptus plantation, respectively. This could be due to greater inputs of vegetation and reduced decomposition of organic matter. On the other hand, the lowest soil organic carbon stock under cultivated land could be due to reduced inputs of organic matter and frequent tillage which encouraged oxidation of organic matter. Conclusions: Hence, carbon concentrations and stocks under natural and mixed forest and Eucalyptus plantation were higher than other land use types suggesting that two management strategies for improving soil conditions in the watershed: to maintain and preserve the forest in order to maintain carbon storage in the future and to recover abandoned crop land and degraded lands by establishing tree plantations to avoid overharvesting in natural forests.