• Title/Summary/Keyword: Nutrient cyclings

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Distribution and Cyclings of Nutrients in Phragmites communis Communities of a Coastal Salt Marsh (해안염습지 갈대 군락의 무기영양소 순환과 분배)

  • 민병미
    • Journal of Plant Biology
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    • v.26 no.1
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    • pp.17-32
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    • 1983
  • The aboveground production, nutrient distribution and nutrient cyclings were compared between two Phragmites communis communities growing in the different salt contents of soil in a coastal salt marsh. Inorganic nutrient contents of soil for plant growth were greater at the low salt stand than at the high salt stand except for sodium(Na). Maximum aboveground biomass of the plant at the low and the high salt stands were 2,533 and 1,719 g dw/$m^2$, respectively, in August. Seasonal changes of nutrient content of biomass in dry weight decreased with growth except for Na. Nutrient contents in biomass per unit land area increased continuously as biomass increases, although the amount of potassium(K) reached the maximum content in July and thereafter decreased. Vertical distributions of total nitrogen(T-N) and phosphorus(P) increased with plant height, but Na showed the reverse trend. That of K was similar to the patterns for T-N and P in the leaves, and to the pattern of Na in the stems. The Na was greatly accumulated in underground biomass but transported scarcely to aboveground. At the low and the high salt stands, the ratios of the inorganic nutrients contained in the plant were 100 : 66 for T-N, 100 : 61 for P, 100 : 62 for K and 100 : 97 for Na. the ratios of the amounts of nutrients retrieved to soil were 100 : 242 for T-N, 100 : 408 for P, 100 : 127 for K and 100 : 269 for Na, respectively. Turnover times of the T-N, P, K and Na in the communities were 56, 1, 15 and 174 years at the low salt stand, and 75, 2, 24 and 323 years at the high salt stand, respectively. In nutrient cyclings, all of the nutrients retrieving to soil were less than uptake by plant. Among the nutrient, especially P is expected to be exhausted from soil, sooner or later, because of the harvest by men.

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Mass Loss Rates and Nutrient Dynamics of Oak and Mixed-Hardwood Leaf Litters in a Gyebangsan (Mt,) Forest Ecosystem

  • Kim, Choonsig
    • The Korean Journal of Ecology
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    • v.26 no.6
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    • pp.335-340
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    • 2003
  • Patterns of mass loss and nutrient release from decomposing oak (Quercus mongolica) and mixed litters (Q. mongolica, Betula schmidtii, Acer pseudo-sieboldianum, Kalopanx pictus and Tilia amurensis) in a natural hardwood forest in Gyebangsan (Mt.) were examined using litterbags placed on the forest floor for 869 days. Mass loss rates from decomposing litter were consistently higher in mixed litter (59%) than in oak litter types (52%) during the study period. Nutrient concentrations such as nitrogen (N), phosphorus (P), potassium (K), and magnesium (Mg) from decomposing litter were also higher in mixed litter than in oak litter types. Nutrient concentrations (N, P, Ca, and Mg) increased compared with initial concentration of litter, while K concentrations dropped rapidly at the first 5 months and then stabilized. The results suggest that mas loss and nutrient release obtained from decomposing litter of single species in mixed hardwood forest ecosystem should be applied with caution because of the potential differences of mass loss and nutrient release between single litter and mixed litter types.

Nutrienr cyclings in mongolian oak(quercus mongolica) forest (신갈나무 숲의 營養監類 循環)

  • Kwak, Young-Se;Kim, Joon-Ho
    • The Korean Journal of Ecology
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    • v.15 no.1
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    • pp.35-46
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    • 1992
  • To elucidate nutrient cyclings such as nitrogen, phosphorus and potassium in mongolian oak(quercus mongolica) forest, nutrient elements of precipitation, throughfall, outflow, soil, various plant organ and litter were determined at mt.nambyeongsan, pyeongchang-gun, gangwon province in central part of korean peninsula. Annual precipitation input, throughfall and outflow of nutrientswere 10.3, 8.6 and 4.2 kg/ha for the N, 0.11, 0.24 and 0.02 kg/ha for the Pand 1.3, 10.9 and 1.2 kg/ha for the K, respectively. Inseasonal changes of nutrient concentrations, N, P and Kconcentrations which were rich in young leaves decreased steadily until autumn and decreased abruptly during autumnal yellowing. The standing N, P and K concent were 565, 37 and 257 kg/ha for standing phytomass of overstory, 33, 3 and 18 kg/ha for understory, 132, 3.6 and 14 kg/ha for litter on ground including deadwood and 20, 752, 14 and 420 kg/ha for the soil, respectively. The amounts of annual uptake, reture and retain were 174.2, 57.2, 117.2 kg/ha for the N, 9.9, 3.5, 6.4 kg/ha for the P and 73.2, 30.3, 42.9 kg/ha for the K, respectively. Reabsorption efficiency, ratio of the nutrient amount reabsorbed into woody organs to that in the mature leaves before shedding, was 71%(or 99.8 kg/ha in the amount), 69%(or 5.1 kg/ha) and 57%(or 33.1% kg/ha) and recycling coeffciently made with which the large amount of nutrients is absorbed through roots during growing season(UPTAKE) and reasorbed from the leaves before shedding(RETAIN) but the small amount of nutrients is returned through litterfall(RETURN).

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