• The Korean Journal of Ecology
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• v.27 no.2
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• pp.67-71
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• 2004

This study was carried out to evaluate soil carbon and nutrient storage of three adjacent coniferous plantations (Larix leptolepis, Pinus densiflora and Pinus rigitaeda) growing on a similar site with a same planting age (42-year old) in the Sambong Exhibition Forests, Hamyang-gun, Gyungsangnam-do. The soil carbon concentration among three plantations was not significantly different in 0∼10cm soil depth, but other two depths (10∼20cm and 20∼30cm) showed higher carbon concentration in P. densiflora plantation than the other two plantations. The exchangeable cation concentrations (Ca and Mg) in 0∼10cm depth were significantly lower in L. leptolepis plantation than in the other two plantations, while nitrogen and phosphorus concentrations were not significantly different among three plantations except for nitrogen at 10∼20cm depth in P. rigitaeda plantation. Soil carbon storage in 0∼20cm depth of three plantations was unaffected by the stand types. Soil nutrient storage was not significantly different at each depth except for nitrogen storage at 10∼20cm depth in P. rigitaeda plantation because of the variation of bulk density and coarse fragment. This result demonstrates that soil carbon and nutrient concentrations among the plantations on a similar soil condition can be altered significantly by tree species effects over 40 years after plantation establishment.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.447-452
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• 2005

The characters of Chamaecyparis obtusa community extended around the Mt. Gyeryoung in Geoje-cik were investigated for several ecological parameters and the results can be summarized as fellows. Chamaecyparis obtusa is prevailing in the plantation area, whereas Pinus densiflora and Quercus mongolica are prevailing in its outskirts. Plant biomass and net production which estimated from degree of green naturality and Miami's model were much higher in the plantation than those of the natural forest. However, the mean species diversity of plantation was lower than that of natural populations. In stratification of investigated areas, overstory tree layer was dominant in the zone of plantation and dominant layers in the natural forest were understory tree layer, shrub, and herb.

• The Korean Journal of Ecology
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• v.12 no.4
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• pp.245-256
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• 1989

Nitrogen cycling was in vestigated in Piuns koraiensis plantations with different ages, 1, 2, 3, 6, 9 and 11 years, which were reforested after clear-cutting. Annual N input by bulk precipitation was 10kg., and output by runoff decreased as the plantation aged, especially in-N. The standing N content of the whole vegetation increased approximately 5 times through 11 years. Understory surpassed P. koraiensis plants in the distribution of standing N content for the initial 9 years, but reversed thereafter. Annual N uptake of P. koraiensis plants increased greatly through 11 years, but that of understory increased somewhat until 9 years and decreased thereafter. The maximum N uptake of the whole vegetation was made in the 9-yr-old plantation. In the 1-yr-old one, 59% of the maximum was already absorbed by understory which mainly consisted to herbs. The recycling coefficient, ratio of annual return to rptake, of the whole vegetation decreased as the plantation aged and the value of understory was greater than that of P koraiensis plants. On the contrary, the N use efficiency, ratio of the net primary production to N uptake, of the whole vegetation increased as the plantation aged and the value of understory was less than that of P. koraiensis plants. Consequently, it is emphasized that understory played an important role in such plantation reforesred after clear-cutting for the initial 9 years.

• Journal of Forest and Environmental Science
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• v.38 no.4
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• pp.275-283
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• 2022

A study was designed to investigate the pattern of sexual dimorphism in a plantation of Garcinia kola. Twenty trees were randomly selected for the study and have been observed to flower regularly. A total of 100 inflorescence were randomly collected from the crown of each tree and 500 flowers randomly assessed within the period of four (4) flowering seasons. Floral sex assessment was done visually and with a hand magnifying lens; floral morphometric measurements (i.e. pedicel and perianth length and breadth), inflorescence length, and breadth) was taken using a veneer caliper; number of flowers per inflorescence and inflorescence per twig was counted; while, data analysis was conducted on excel using analysis of variance and pairwise t-test comparison. Four floral sexes were identified in the G. kola plantation studied which were unisexual male flowers, unisexual female flowers, cosexual unisexual male flowers, and cosexual hermaphrodite flowers. Three tree sexes were identified viz: inconstant male, invariant female, and cosexual trees. The plantation was significantly sexually dimorphic in floral sex and phenotypic traits (i.e. pedicel and perianth size), and as well as sexually dimorphic in tree sex and reproductive phenotypic traits (i.e. inflorescence size, number of inflorescences per twig, and number of flower bud per inflorescence). The sexual system of the plantation was therefore trioecious with features suggestive of evolving dioecy through the gynodioecious pathway.

• Journal of Environmental Science International
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• v.17 no.1
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• pp.1-6
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• 2008

The characters of Castanea crenata community which is associated with human activities recently extended around the field of Saengbiryang-myeon at Sanseong-gun in Gyeongsangnam-do. The C. crenata community and its outskirts were investigated for several ecological parameters and the results can be summarized as fellows. C. crenata is prevailing in the plantation area, whereas Pinus densiflora and Quercus mongolica are prevailing in its outskirts. The mean species diversity of plantation was lower than that of natural forests. In stratification of investigated areas, overstory tree layer was dominant in the zone of plantation and dominant layers in the natural forest were understory tree layer, shrub, and herb. Plant biomass and net production which estimated from degree of green naturality were much higher in natural forests than those of the plantation community. Least significant differences (LSD) post hoc analysis revealed that P. densiflora and Q. mongolica community had significantly greater than densities than C. crenata community.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.727-733
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• 1993

An attempt was made to mechanize the infield transportation system in a cocoa plantation. A small trailer was designed and fabricated and used with a commercial 2-wheeled walking tractor modified into a 4-wheeled tractor-trailer unit to suit the plantation conditions. The transporter had a capacity of 800 kg and could be loaded with about 1000 cocoa pods at a time and was well within the towing capability of a 10 hp tractor. Time and motion studies were conducted on a 30 acre, 6 year old cocoa plantation intercropped with coconut to compare manual and the tractor-trailer combination in relation to infield transportation. The total time taken to harvest 80 trees manually was computed to be 24 manuhours per hectare whilst the tractor-trailer combination required 18manhours.

• Journal of Forest and Environmental Science
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• v.31 no.4
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• pp.280-287
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• 2015

Soil samples were collected from three depths (0-10 cm, 10-40 cm and 40-80 cm) of two forest sites including one plantation dominated by teak with some other minor species and another degraded natural forest in Cox's Bazar, Bangladesh to compare their soil properties. Some vegetation parameters were also studied. For this study $10{\times}10\;m$ and $2{\times}2\;m$ quadrats were used for the tree and undergrowth parameters, respectively. Soil samples were also collected from these quadrats. Between the two forest types, the highest levels of organic carbon, total nitrogen, available phosphorus, exchangeable bases and cation exchange capacity (CEC) were found in soils of the plantation. The soils were acidic in nature and exchangeable Al concentrations were low. Teak dominated forest plantation had higher soil fertility index (SFI) than the degraded natural forest site. Steps for reforestation and appropriate protection are needed to improve the situation.

• Journal of Forest and Environmental Science
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• v.33 no.1
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• pp.22-32
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• 2017

An experiment was set to assess the effect of mixed plantings on initial growth and biomass yield of two common plantation tree species of Bangladesh namely Acacia auriculiformis (A) and Gmelina arborea (G). Study was carried out in the nursery bed of the Seed Research Laboratory and Nursery of Institute of Forestry and Environmental Sciences, Chittagong University (IFESCU), Bangladesh during February to November, 2015. The treatments consisted of two pure planting plots (100% A and 100% G) and five mixed planting plots (50%A: 50%G, 35%A: 65%G, 25%A: 75%G, 65%A: 35%G and 75%A: 25%G) of these two species. In nursery, seedlings were raised in a randomized blocks with four replicates of seven treatment plots. Periodic increments on height (cm), collar diameter (cm) and leaf/phyllode number of the seedlings was taken in every month and continued up to 10 months. The growth and biomass yield of seedlings were measured 10 months after the first seed was emerged. The effects of mixed plantation on growth and biomass were compared to that of seedlings grown in pure plantation. At the age of 10 months it was found that G. arborea seedlings were significantly tallest (240.13 cm) when planted with A. auriculiformis in a proportion of 25%A: 75%G, whereas A. auriculiformis were tallest in the pure 100% A plot, with an average mean height of 135.36 cm. Maximum collar diameter (1.38 cm) was recorded for G. arborea in the mixed plots 75%A: 25%G. Fresh and dry weight of shoots and roots of the seedlings were found significantly (p<0.05) highest in 50%A: 50%G plot for G. arborea. G. arborea also showed highest quality index when mixed with A. auriculiformis in a proportion of 50:50, with an average value of 8.96. The results revealed a positive correlation between seedling growth and various planting patterns.

• The Korean Journal of Ecology
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• v.23 no.5
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• pp.377-382
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• 2000

Picea abies plantation in Mt. Eifel, Germany was studied phytosociologically, with special reference to species composition, structure, ecology and dormancy form, comparing to those of Fagus sylvastica population that once dominated the P. abies plantation. Thirteen plant species appeared on average. According to their ecological distribution, they were classified into three groups, F sylvastica forests, natural coniferous forests and bare-land after clear-cutting. In Luzulo-Fagetum population, Luzula luzuloides was the dominated species while in P. abies plantation was dominated by Avenella flesuosa. In assessment of herbaceous plants by indicator species of Ellenberg, increasing number of shade-intolerant species and acid-tolerant species occurred. In analysis of plant dormancy form, species of Chamaephytes, Phanerophytes and Hemikryptophytes increased, while that of Geophytes decreased. As a result, we found P. abies plantation unstable in ecological aspects.

• Journal of Ecology and Environment
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• v.46 no.3
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• pp.204-217
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• 2022

Background: Increasing land demands for food production have led to biodiversity loss and land degradation in the Madhupur Sal forest. Reforestation activities such as agroforestry and woodlot plantation support the conservation of diversity, restoration of forest and prevention of soil erosion in degraded natural Sal forest. Knowing about these reforestation activities, this study is needed to compare the species composition, richness, and soil nutrients of these two plantation activities to the natural Sal forest in the degraded Madhupur Sal forest in Bangladesh. Results: The analysis showed that in between the reforestation activities, the highest Shannon-Wiener index (1.79), evenness (0.60) and Simpson's index (0.79) were found in the agroforestry site compared to the woodlot plantation site. On the contrary, the highest species richness (n = 14), tree basal area (19.56 m² ha^-1), Margalef's index (1.96) were recorded in woodlot plantation than in the agroforestry site. We observed that at 0-15 cm depth, soil organic matter (2.39%), total nitrogen (0.14%), available phosphorous (62.67 ㎍ g^-1) and exchangeable potassium (0.36 meq/100 g) in agroforestry plots were significantly higher compared to other forest sites. At topsoil (15-30 cm depth), soil organic matter (1.67%) and available phosphorous (21.09 ㎍ g^-1) were found to be higher in agroforestry site. Conclusions: Both reforestation approaches improved soil function, although woodlot plantation had the higher species richness. Therefore, plantation activities by the sustainable implementation of these two practices are the best alternative to restore the biodiversity, richness and conserve soil fertility in the Madhupur Sal forest of Bangladesh.