• Journal of Wetlands Research
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• v.12 no.1
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• pp.15-22
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• 2010

We measured net primary productivity, annual accumulation of organic carbon and leaf decomposition of Salix community in the flood plain of the Han River and the Nakdong River. Net primary productivity, annual accumulation of organic carbon of the Salix community were 22.5ton/ha/yr(16.7ton/ha/yr-31.2ton/ha/yr) and 9.7ton C/ha/yr(7.5ton C/ha/yr-14.0ton C/ha/yr) respectively, which showed the highest values among the woody plant communities reported in the Korea. It means that planting Salix in the flood plain of the river is the best way to remove carbon dioxides. The faster leaf decomposition occurred around, under and the herb of Salix community in order. Leaf decomposition rate of Salix was higher than that of mesophytes, but lower than that of hydrophytes.

• The Korean Journal of Ecology
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• v.19 no.1
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• pp.9-19
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• 1996

The model PINUSCO2 hased of physiology was creted to simulate carbon dioxide budget in a population of red pine(pinus densiflora) which is one of the dominant species in Korea. Driving forces of PINUSCO2 are global radiation, maximum and minimum air temperatures. State variables fo the model are standing crops of leaf, branch, trunk and root of the red pine population. PINUSCO2 calculates net photosynthesis of canopy and respiration of each organ with 1 hour time step. PINUSCO2 estimated the annual gross productivity, respiration and net productivity of the red pine population as 43.99, 24.55, and 19.44 ton CO2·ha-1·yr-1, respectively, at the study sity(35°58′00"N, 128°25′35"E). PINUSCO2 showed that the red pine population grew mainly in spring and fall, and that in summer daily net population productivity frequently became negative.

• Journal of Wetlands Research
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• v.1 no.1
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• pp.61-69
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• 1999

The above ground biomass and annual net productivity of Salix nipponica were estimated by the allometric method in the littoral zone of Parksil-nup wetland, Hapcheon-gun, Gyeongsangnam-do Korea. The density of stems and individuals per hectare were 14,950 and 6,140, respectively and the mean number of stems per individual was 2.43. The proportion of the above ground biomass of stem, branch, and leaf were 59.2%, 28.3% and 12.5%, respectively. The standing crops was 109.7 ton/ha and total phytomass was 926.7 ton in the study area. Annual net production was 25.3 ton/ha estimated from the standing crops and the age structure.

• The Korean Journal of Ecology
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• v.7 no.2
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• pp.61-66
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• 1983

Seasonal changes of aquatic environmental factors, phytoplankton biomass and primary productivity were investigated in the Jido pond (a phytoplankton proliferating pond) from August 1982 to October 1983. Secchi disc transparency, pH, alkalinity and inorganic nitrogen concentration ranged 24~105cm, 7.5~10.6, 50~175mgCaCO3/l 0.1~4.0mgN/l, respectively. The minimum values of transparency, alkalinity and inorganic nitrogen concentration and the maximum value of pH were obtained during the phytoplankton proliferating season. The phytoplankton biomass changed in the range of 51~1146mgchl/m3 with considerable fluctuations but maintained fairly constant in winter. Themaximum and minimum rates of monthly carbon inflow (net primary production) of the phytoplankton community attained 1190gc/m2 in August 1982 and 68g/m2 in February 1983, respectively. The annual rates of inflow and outflow from August 1982 to July 1983 were 7.384 and 7.396kgc/m2, respectively. Turnover rate of phytoplankton carbon and efficiency of radiation of the phytoplankton community varied in the ranges of 60~130%/day (annual mean, 90%/day) and 0.9~11.2% (annual mean, 6.3%), respectively.

• Journal of Plant Biology
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• v.18 no.3
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• pp.122-128
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• 1975

With the cultivated mulberry plant which feeds silkworm on its leaves in sericulture, the measuring methods of biomass of terrestrial organs were compared and the annual net productivity was estimated. The measurement of the standing crops by means of allometric method on basis of relation between the parameter D230H, square of the diameter of the branch on 30cm high above ground($D{\frac}{2}{30}$) multiplied by its height(H), and the amount of leaves(WL) or of branch (Ws) was more accurate than other methods on basis of correlation between a character of the branch such as H, D30 or D230 and WL or Ws. The estimate of value of the net productivity of terrestrial parts of mulberry was 9.06-12.54 ton/ha.year, which was similar to that obtained from secondary forests in cool temperate zone.

• The Korean Journal of Ecology
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• v.24 no.6
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• pp.335-339
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• 2001

The dynamic model was developed to simulate the photosynthetic rate of Phragmites communis stands in coastal ecosystem. The model was composed of the compartments of both climatic and biological variables. The former were photosynthetic photon flux density(PPFD), daily maximum- and minimum-temperature. The latter were combinations of the specific physiological responses of plant organs with the biomass of each organs. The PPFD and air temperature were calculated and using those values, gas exchange rate of each plant organ was calculated at every hour. The carbon budget was constructed using the modelled predictions. Analysis of annual productivity and fluxes showed that yearly gross population productivity, yearly population respiration and yearly net population productivity were 33.4, 21.3 and 12.1 $CO_2ton{\cdot}ha^{-2}{\cdot}yr^{-1}$, respectively. The final result was tested over two stands, produced promising predictions with regards to the levels of production attained. The model can be used to determine production potential under given climatic conditions and could even be applied to plant canopies with analogous biological characteristics.

• The Korean Journal of Ecology
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• v.1 no.2
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• pp.57-65
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• 1977

The biomass and net production of alder and oak trees was estimated by allometric method. The productivity of the two stands of alder and oak was obviously different judging from the rate of photosynthesis productive structure and vertical distribution of light. The amounts of net photosynthesis under the saturated light were 2.31, 1.42mg $CO_2/dm^2\cdot$hr. in the sun and shade leaves of alder tree and 1.58, 0.84mg $CO_2/dm^2\cdot$hr in that of the oak, respectively. Total annual respiration loss calculated from the respiration measured at $25^{\circ}C$ and the mean air temperature from every 10 days were 13.56ton/ha.yr in the alder stand and 19.83 ton/ha.yr in the oak. The productive structure and the vertical distribution of light in the stand were assumedly more effective to produce dry matter in the oak stand than in the alder. The biiomasses measured in 1975 and 1976 were 51.51 and 56.82 ton/ha in the alder stand and 73.35, 86.77 ton/ha in the oak one, respectively. Annual net production and gross production were 8.56 and 22.12 ton/ha.yr in the alder stand but those were 17.90 and 37.74 ton/ha.yr in the oak stand. The ratios of respiration to gross procution (R/Pg) were prespectively 0.61 and 0.53 inthe alder and oak stands. Efficiencies of solar energy utilizaztion of net production during the growing season(May-Oct.) were 0.67 and 1.40% and those of gross production were 1.72 and 2.94% in the alder and oak stands respectively.

• The Korean Journal of Ecology
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• v.15 no.1
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• pp.19-33
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• 1992

The density, litterfall, phytomass, and primary productivity for 7 years in quercus mongolian forest locasted at mt. nambyengsan, pyeongchang-gun, gangwon provance in central part of korean peninsula were estimated quantitatively. at the first year in 1984, a stand had 1, 450 trees/ha in tree density, which was 0.67 of skewness and 0.54 of kurtosis in frequency distribution, however, at the 7th year in 1990, the stand had 1, 133 trees/ha in the density with 22%(or 316 tree/ha)in mortality, which was 1.16 of skewness and 1.89 of kurtosis in the frequency. annual mean litterfall was 5 ton DM/ha, which was composed of 68% of leaves, 17% of branches, 3% of bud scales, 9% of arcons and cups, 0.7% of flowers and others. the phytomass of tree layer for 7 years was gradually increased from 149.7 ton DM/ha at the first year to 188.5 ton DM/ha at the 7th year.annual net productivity for the tree layer studied ranged from 8.76 ton DM/ha.yr-1 to 11.62 ton DM/ha. yr-1 with heavy fluctuation year by year. average annual productivity of the stand of trunk, branches, leaves and roots for 7 years were 4.42, 0.67, 3.85 and 1.29 ton DM/ha.yr-1, respectively. turnover rate of the stand was 6.9% at the first year and 5.6% at the 7th year. such fluctuation of the productivity was caused by the chang of density, mortality, mortality and turnover rate.

• The Korean Journal of Ecology
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• v.24 no.6
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• pp.377-380
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• 2001

Herbivory is an important selective forces on plants by reducing the ability of the plant to compete with its neighbors and to produce offspring. Oak nut weevil(Mechoris ursulus Roelofs) females lay eggs in unmatured acorns and cut off the branch of oviposited acorns. To investigate the influences of branch-cutting behavior of oak nut weevils on oak production, we surveyed the horizontal and vertical distribution ranges of damaged oaks and depth of sites of overwintering larvae and quantified the amounts of biomass and acorn removed by the weevils on deciduous oak species. All of the endemic oak species in Korea were damaged by oak nut weevils in all of the study sites including Mt. Halla and Mt. Seorak. The upper limit of vertical distribution of damaged oaks by the weevils raried from 700 m to 900 m. Mostly their larvae were found in soil from 8.1 cm to 10.0 cm depth in winter. Percentage of annual net primary productivity($720g{\cdot}m^{-2}{\cdot}day^{-1}$) of oak species removed by the weevils was about 7%, which is higher than the percentage removed by all the herbivores in typical temperate forest(5%) and equivalent to that by all the herbivores in tropical forest. The predation percentage of annual acorn production by oak nut weevil was 27% in Q. mongolica and 33% in Q. acutissima. This results indicate that the branch-cutting behavior of oak nut weevil may be the most important factor regulating oak population and affecting other predators dependent on acorns.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.1
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• pp.8-12
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• 1985

In the pure Phragmites communis grassland in the lower course of Nakdong river, the seasonal changes of standing crop and productive structure, annual changes of the maximum standing crop, and annual net production were estimated. The maximum standing crop of the pure P. communis grassland is on mid-September, the maximum average daily productivity was $32.7g/m^2/day$ from June to July. The leaf area index of the pure reed grassland increased to July, and then decreased slowly. The logitudinal growth of above-ground parts of the reed grassland was maximum state, 320cm, on mid September. Annual net production was $3,399g/m^2/year$, and it suggests that grassland is stable. Productive structure of the pure reed grassland indicated that the distribution of leaf was concentrated on the upper parts according to the grassland maturation.