• 한국산림과학회지
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• 제113권2호
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• pp.143-152
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• 2024

본 연구는 울산광역시에 위치한 봉대산 산불피해지의 식생복원을 위해 2009년에 조림된 4 수종(백합나무, 왕벚나무, 상수리나무, 곰솔)을 대상으로 시비처리 후 임목생장 및 토양특성 변화를 조사하였다. 조림 4년 후인 2013년 4월과 2014년 3월 복합비료(N₆P₄K₁)를 시비하고 2016년 10월까지 매년 임목의 생장과 토양 및 잎의 양분 동태를 조사하였다. 조림목의 흉고직경 생장 증가에 대한 시비구와 대조구 사이의 회귀계수(slope)는 4 수종 모두 유의적인 차이가 있어 시비는 조림목의 흉고직경 생장에 효과가 있었으나, 수고 생장의 회귀계수는 곰솔을 제외하고 유의성이 없었다. 시비 처리에 따른 토양 호흡과 토양 EC 값은 대조구에 비해 유의적으로 높았으나 토양수분 함량, 토양 유기탄소 및 전질소 농도는 대조구에 비해 낮았다. 그러나 토양 유효 인, 교환성 칼슘과 마그네슘은 시비구가 대조구에 비해 높은 값을 보였다. 조림목의 잎 내 질소 및 인 농도는 시비구가 대조구에 비해 증가하였으나, 칼륨, 칼슘, 마그네슘 농도는 시비의 영향이 뚜렷하지 않았다. 조사한 4 수종 중 왕벚나무와 백합나무는 잎 내 양분 농도가 상수리나무나 곰솔에 비해 높아 토양 양분요구량이 큰 것으로 나타났다. 본 연구 결과에 따르면 도시 숲의 산불피해 복원지에 시비 처리는 조림된 수목의 생장과 토양 양분의 유효도 향상에 효과적이었다.

• Animal cells and systems
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• 제7권4호
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• pp.289-294
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• 2003

To quantify nutrient loading from emergent macrophytes through leaching in the littoral zones of Paldang Reservoir, we conducted incubation experiments using leaf litter of the emergent macrophyte, Zizaniz latifolia. To separate the leaching process from microbial decay, we used $HgCl_2$ to suppress microbial activity during the experiment. We measured electric conductivity, absorbance at 280nm, total nitrogen and dissolved inorganic nitrogen, total phosphorus and soluble reactive phosphorus, Na, K, Mg and Ca amounts in leaf litter and in water. In addition, we examined the effects of water temperature and ion concentrations of ambient water on the leaching process. A total of 6% of the initial ash-free dry mass of leaf litter was lost due to leaching during incubation (four days). Electric conductivity and A280 continued to increase and saturate during the incubation. To compare reaching rates of different nutrients, we fitted leaching dynamics with a hyperbolic saturation function [Y=AㆍX/(B+X)]. From these fittings, we found that ratios of leaching amounts to nutrient concentration in the litter were in the order of K > Na > Mg > P > Ca > N. Leaching from leaf litter of Z. latifolia was dependent on water temperature while it was not related with ion concentrations in the ambient water. Our results suggest that the leaching process of nutrients, especially phosphorus, from aquatic macrophytes provides considerable contribution to the eutrophication of the Paldang Reservoir ecosystem.

• The Korean Journal of Ecology
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• 제7권3호
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• pp.109-118
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• 1983

Near future dynamics of water qualities (nutrient concentration) of the Han River was predicted, based on a mathematical model representing the relationship between the nutrient concentration in th river wagter and environmental factors (population density, land-use types, rock compositions and nutrient accumulation) in the basin. The population density and land-use types were forecasted to change distinctly in the downstream area, especially in Seoul City area in 1985~1990 whereas any environmental factor was not expected to change its level significantly in both upstream and middle reaches areas. It was indicated by the model that the nutrients concentration in the up- and mid-streams would keep its level in future as it was, but it would increase drastially in the downstream area. For the preservation of the water qualities in the downstream at least to keep its level as it was in 1980, practical countermeasures were proposed, based on the assessment of the contribution of each environmental factor to the water qualities.

• 한국해양학회지:바다
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• 제22권1호
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• pp.1-17
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• 2017

본 연구는 소하천 하구의 영양염 분포를 조절하는 요인에 대해 알아보기 위하여 수행되었다. 남해안 당항포에 위치한 세 하천(닫힌 하구: 고성천, 열린 하구: 구만천, 마암천)에서 2010-12년까지 계절별로 영양염(질산염, 암모늄, 인산염) 농도를 측정하였다. 고성천의 댐은 담수의 희석을 막고 체류시간을 증가시켜 높은 영양염 농도의 원인이 되어 인위적인 요인이 소하천 하구의 영양염 분포에 중요함을 나타내었다. 그 외에 물리, 기후, 생지화학적 요인이 세 하천 영양염 분포에 영향을 주었다. 세 하천 모두에서 질산염은 상류에서 높고 하류로 갈수록 감소하였다. 이것은 상류 집수역에서 공급이 많고, 하류로 갈수록 희석 및 하구 내 생지화학적 과정에 의한 제거가 활발하기 때문으로 여겨진다. 특히 탈질소화 등 대표적인 생지화학적 질소영양염 제거과정은 상류에서 하류로 갈수록 감소하는 경향이 뚜렷하였다. 그러나 암모늄과 인산염은 하천에서 유입되는 농도가 높은 경우에만 상류에서 하류로 갈수록 농도가 낮아지는 경향이 뚜렷하게 나타났다. 영양염 농도의 계절 분포는 여름철에 낮고, 겨울철에 높은 경향을 보였다. 여름철 유량으로 인해 체류시간이 감소하였고, 희석 증가로 하천 내 영양염 농도를 감소시켰으며, 높은 수온으로 인한 생물 생산에 의한 영양염 제거 역시 낮은 영양염 농도에 영향을 주었다. 소하천 하구는 높은 질소제거율(-k) 을 가지는 등 대형하구와는 구별되는 영양염 거동을 보이며 향후 소하천 하구 관리를 위해서는 이러한 특성을 파악하는 것이 필수적이다.

• Journal of Ecology and Environment
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• 제39권1호
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• pp.51-60
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• 2016

This study was conducted to examine litter fall, litter decomposition, and a short-term nutrient (C, N, P, K, Ca, and Mg) status for one year at various levels of basal area (21.4, 27.0, 30.8, 37.0, 42.1, and 46.7 m² ha^-1) in approximately 40-yearold red pine (Pinus densiflora S. et Z.) stands in the Hwangmaesan mountain forest in Korea. Monthly fluxes of litter fall components such as needles, broad leaves, branches, bark and total litter fall followed a similar pattern at various levels of basal area. Mean annual needle, bark and total litter fall fluxes were positively correlated with increased basal area (p<0.05), but the woody litter such as branches and cones was not correlated with basal area. Carbon and K concentrations of needle litter were negatively correlated with increased basal area, while nutrient (C, N, P, K, Ca, and Mg) fluxes were positively correlated with the basal area treatments. Remaining mass, N and P concentration and remaining N and P stocks in decomposing needle litter were not affected by the basal area. However, the concentration and stocks remaining of K, Ca, and Mg from decomposing litter were positively correlated with increased basal area during the initial three months of decomposition. The results indicate that basal area has an impact on nutrient cycles through change in litter fall and litter decomposition processes; thus, the dynamics of nutrient cycles based on a stand scale could differ considerably with different levels of basal area in red pine stands.

• ALGAE
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• 제23권3호
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• pp.241-250
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• 2008

Since seagrasses in the coastal and estuarine ecosystems achieve high levels of production, they require high inorganic carbon and nutrient incorporation. Thus, seagrasses may play a significant role in carbon and nutrient cycling in the coastal and estuarine ecosystems. To examine growth dynamics of Zostera marina L. environmental factors such as underwater irradiance, water temperature, and salinity, and biological parameters such as shoot density, biomass, shoot morphology, and leaf productivity were measured in two bay systems (Jindong Bay and Gamak Bay) on the southern coast of Korea. While underwater irradiance did not show distinct seasonal trend, water temperature at both sites exhibited clear seasonal trend throughout the experimental period. Shoot density increased dramatically during winter due to the increased seedlings through germination of seeds in Jindong Bay and due to the increased lateral shoots in Gamak Bay. Eelgrass biomass increased during winter and decreased during summer. Maximum biomass in Jindong Bay and Gamak Bay was 250.2 and 232.3 g dry weight m–a2, respectively. Carbon incorporation into the eelgrass leaf tissues was estimated from productivity and leaf tissues carbon content. The calculated annual carbon incorporations at the Jindong Bay and Gamak Bay sites were 163 and 295 g C m–`2 y–`1, respectively. This high carbon incorporation into seagrass tissues suggests that seagrass habitats play an important role as a carbon absorber in the coastal and estuarine ecosystems.

• Journal of Ecology and Environment
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• 제29권3호
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• pp.205-212
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• 2006

본 연구는 경기도 양평지역 내 서로 인접하여 있고 동일한 입지 환경 위에 생육하고 있는 41년생 리기다소나무와 낙엽송 조림지를 대상으로 질소와 인 시비처리가 리기다소나무와 낙 엽송의 낙엽 생산량 및 양분 동태에 미치는 영향을 구명하기 위하여 수행되었다. 낙엽 생산량은 시료채취 시기와 수종간에 통계적으로 유의성이 인정된 반면, 시비 처리간에는 유의적인 차이가 없었던 것으로 나타났다. 연간 낙엽 생산량은 리기다소나무가 6,377 kg/ha 그리고 낙엽송이 4,778 kg/ha이었다. 낙엽 내 양분농도는 낙엽송이 리기다소나무에 비해 높았으며, 두 수종 모두 처리구간에 유의적인 차이가 있는 것으로 나타났다. 또한 낙엽 내 양분 농도는 낙엽송에서의 Ca 함량을 제외하고 두 수종 모두 연중 낙엽 생산량이 가장 많았던 늦가을에서 가장 낮았으며, 연중 낙엽 생산량이 가장 적었던 여름에 가장 높았던 것으로 나타났다. 또한 리기다소나무와 낙엽송 임분 임상의 총 유기물 함량은 24,296 kg/ha, 그리고 10,763 kg/ha였으며, 임상 내질소와 인의 함량은 리기다소나무가 126, 10 kg/ha, 그리고 102, 8 kg/ha로 각각 나타났다.

• ALGAE
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• 제32권2호
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• pp.139-153
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• 2017

The ability of a red tide species to take up nutrients is a critical factor affecting its red tide dynamics and species competition. Nutrient uptake by red tide species has been conventionally measured by incubating nutrient-depleted cells for a short period at 1 or 2 light intensities. This method may be applicable to certain conditions under which cells remain in oligotrophic water for a long time and high nutrients are suddenly introduced. Thus, a new method should be developed that can be applicable to the conditions under which cells are maintained in eutrophicated waters in healthy conditions and experience light and dark cycles and different light intensities during vertical migration. In this study, a new repletion method reflecting these conditions was developed. The nitrate uptake rates of the red tide dinoflagellate Prorocentrum micans originally maintained in nitrate repletion and depletion conditions as a function of nitrate concentration were measured. With increasing light intensity from 10 to $100{\mu}E\;m^{-2}s^{-1}$, the maximum nitrate uptake rate ($V_{max}$) of P. micans increased from 3.6 to $10.8 pM\;cell^{-1}d^{-1}$ and the half saturation constant ($K_{s-NO3}$) increased from 4.1 to $6.9{\mu}M$. At $20{\mu}E\;m^{-2}s^{-1}$, the $V_{max}$ and $K_{s-NO3}$ of P. micans originally maintained in a nitrate repletion condition were similar to those maintained in a nitrate depletion condition. Thus, differences in cells under nutrient repletion and depletion conditions may not affect $K_{s-NO3}$ and $V_{max}$. Moreover, different light intensities may cause differences in the nitrate uptake of migratory phototrophic dinoflagellates.

• 한국토양비료학회지
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• 제49권4호
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• pp.310-317
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• 2016

This study aimed to evaluate the nutrient load balance from rice paddy fields with different topographies, alluvial plain and local valley. Continuous monitoring from May to September, 2013 was conducted for water quantification and qualification from alluvial plain in Yeoju region (32 ha) and local valley in Jincheon region (24 ha). The discharge rates of T-N from the alluvial plain were 57.2, 5.84, 22.7, and $5.20kg\;ha^{-1}$ for irrigation, precipitation, drainage, and percolation, respectively. In case of local valley, T-N loads were 34.6, 4.73, 21.1, and $4.15kg\;ha^{-1}$ for irrigation, precipitation, drainage, and percolation, respectively. In contrary, the T-P loads from the alluvial plain were 2.23, 2.22, 2.54, and $0.41kg\;ha^{-1}$ for irrigation, precipitation, drainage, and percolation, respectively. In case of local valley, T-P loads were 1.44, 1.57, 1.82, and $0.34kg\;ha^{-1}$ for irrigation, precipitation, drainage, and percolation, respectively. The nutrient contents in drainage water were influenced by the amount of waters, rainfall, and surface drainage water. The Pearson correlation analysis showed that rainfall was significantly correlated with nutrient loads from July to August due to the amount of runoff in local valley paddy field, and irrigation was related with nutrient loads of drainage from July to August. This study showed that paddy rice farming in alluvial plain and local valley might be beneficial to water quality protection.

• 한국생태학회:학술대회논문집
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• 한국생태학회 2002년도 VIII 세계생태학대회
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• pp.127-131
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• 2002

In order to elucidate the characteristics of standing crop biomass, production and nutrient content of dead bole in mature ecosystem, we surveyed the dynamics of decaying bole of old-aged deciduous forest in 1993 and 2002 in Kwangnung Experimental Forest Station. In addition, we and estimated annual bole production, water content, wood density and nutrient content and compared the results with that of temperate ecosystem. Total dead wood biomass was estimated to be 5.6ton/ha in 1993 and 17.6ton/ha in 2002. Standing dead tree accounted for a total of 1.1ton/ha in 1993 and 4.8ton/ha in 2002, which was 20% and 27% of the sum of dead bole mass in 1993 and 2002, respectively. Annual production of bole biomass was 1.3 ton/ha/yr. These values fall into the low range of dead wood biomass for the mature temperate ecosystems. Tree species composing standing bole was mainly Quercus and Carpinus trees. This bole species composition resembles alive species composition of this forest. Water content of bole increased as positive logarithmically, but wood density of bole decreased as negative exponentially along with the progress of decay. N, P, Ca and Mg concentrations in decaying boles generally increased with decay, except for K. Annual nutrient input via dead bole is 1.6kg/ha/yr for N, 0.04 kg/ha/yr for P. 1.0 kg/ha/yr for K, 1.7kg/ha/yr for Ca and 0.3 kg/ha/yr for Mg, respectively.