• 제목/요약/키워드: ecological responses

검색결과 268건 처리시간 0.03초

실외 온난화 처리에 따른 낙엽송 묘목의 생리 및 생장 반응 (Effect of Experimental Warming on Physiological and Growth Responses of Larix kaempferi Seedlings)

  • 안지애;장한나;박민지;한승현;황재홍;조민석;손요환
    • 한국기후변화학회지
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    • 제7권1호
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    • pp.77-84
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    • 2016
  • Seedling stage is particularly important for tree survival and is easily influenced by warming. Therefore, air temperature being increased due to climate change may affect physiological traits and growth of seedlings. This study was conducted to investigate the physiological and growth responses of Larix kaempferi seedlings to open-field experimental warming. 1-year-old and 2-year-old L. kaempferi seedlings were warmed with infrared lamps since April 2015 and April 2014, respectively. The seedlings in the warmed plots were warmed to maintain the air temperature to be $3^{\circ}C$ higher than that of the control plots. Physiological responses (stomatal conductance, transpiration rate, net photosynthetic rate and total chlorophyll content) and growth responses (root collar diameter (RCD), height and biomass) to experimental warming were measured. Physiological and growth responses varied with the seedling ages. For 2-year-old L. kaempferi seedlings, stomatal conductance, transpiration rate and net photosynthetic rate decreased following the warming treatment, whereas there were no changes for 1-year-old L. kaempferi seedlings. Meanwhile, total chlorophyll content was higher in warmed plots regardless of the seedling ages. Net photosynthetic rate linked with stomatal conductance also decreased due to the drought stress and decrease of photosynthetic efficiency. In response to warming, RCD, height and biomass did not show significant differences between the treatments. It seems that the growth responses were not affected as much as physiological responses were, since the physiological responses were not consistent, nor the warming treatment period was enough to have significant results. In addition, multifactorial experiments considering the impact of decreased soil moisture resulting from elevated temperatures is needed to explicate the impacts of a wide range of possible climate change scenarios.

기후변화 조건에서 수분구배 및 영양소 구배에 따른 굴참나무와 상수리나무 잎 형태적 특성의 생태지위 변화 (Variations in Ecological Niche of Quercus variabilis and Quercus acutissima Leaf Morphological Characters in Response to Moisture and Nutrient Gradient Treatments under Climate Change Conditions)

  • 박여빈;김의주;박재훈;김윤서;박지원;이정민;유영한
    • 한국환경복원기술학회지
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    • 제27권2호
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    • pp.43-53
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    • 2024
  • This study attempted to elucidate the ecological niches and influencing environmental factors of Quercus variabilis and Quercus acutissima, which are representative deciduous broad-leaved trees in Korean forests, taxonomically close and genetically similar, under climate change conditions. Under climate change conditions induced by increased CO2 and temperature, soil moisture and nutrient environments were manipulated in four gradients. At the end of the growing, plants were harvested to measure growth responses, calculate ecological niches, and compare them with those of the control. Eperimental plants were grown for 180 days in a glass greenhouse designed with four gradients each for soil moisture and nutrient environments under climate change conditions induced by increased CO2 and temperature. After harvesting, growth responses of leaf traits were measured, ecological niches were calculated, and these were compared with those of the control groups. Furthermore, the responses of the two species' populations were interpreted using principal component analysis(PCA) based on leaf trait measurements. As a result, under climate change conditions, the ecological niche breadth for moisture environment was broader for Quercus variabilis than Quercus acutissima, whereas for the nutrient environment, Quercus acutissima exhibited a broader niche breadth than Quercus variabilis. And the rate of change in ecological niche breadth due to climate change decreased for Quercus variabilis in both moisture and nutrient environments, while for Quercus acutissima, it increased in the moisture environment but decreased in the nutrient environment. Additionally, in terms of group responses, both Quercus variabilis and Quercus acutissima expanded their ecological niches under climate change conditions in both soil moisture and nutrient conditions, with Quercus acutissima exhibiting a broader niche than Quercus variabilis under nutrient conditions. These results indicate that the changes in leaf morphological characteristics and the responses of individuals reflecting them vary not only under climate change conditions but also depending on environmental factors.

Ecological responses of natural and planted forests to thinning in southeastern Korea: a chronosequence study

  • Cho, Yong-Chan;Pee, Jung-Hun;Kim, Gyeong-Soon;Koo, Bon-Yoel;Cho, Hyun-Je;Lee, Chang-Seok
    • Journal of Ecology and Environment
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    • 제34권4호
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    • pp.347-355
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    • 2011
  • Effects of forest thinning on community level properties have not been understood yet in Korea. We investigated regeneration patterns and trajectories after a disturbance by applying a chronosequence approach. Light availability, litter and woody debris cover, and species composition were determined for twenty 50 m line-transect samples representing a disturbance duration gradient (within 11 years). Environmental factors such as light availability and coverage of woody debris and litter changed abruptly after thinning and then returned to the pre-disturbance state. Although species richness was gained at shrub and ground layer in a limited way in both forests, cover of various functional types revealed diversity in their responses. Notably, Alnus firma stands exhibited a larger increment of cover in woody plants. Ordination analysis revealed different regeneration trajectories between natural and planted stands. Based on ordination analysis, rehabilitated stands showed movement to alternative states compared with natural ones, reflecting lower resilience to perturbation (i.e., lower stability). Our results suggest that community resilience to artificial thinning depends on properties of the dominant species. But to get more explanatory ecological information, longer-term static observations are required.

Sensitivity Analysis of High and Low Flow Metrics to Climate Variations

  • Kim, Jong-Suk;Jang, Ho-won;Hong, Hyun-Pyo;Lee, Joo-Heon
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2018년도 학술발표회
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    • pp.355-355
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    • 2018
  • Natural hydrology systems, including high flow and low flow events, are important for aquatic ecosystem health and are essential for controlling the structure and function of ecological processes in river ecosystems. Ecosystem responses to flow changes have been studied in a variety of ways, but little attention has been given to how episodic typhoons and atmospheric circulation patterns can change these hydrologic regime-ecological response relationships. In this diagnostic study, we use an empirical approach to investigate the salient features of interactions between atmospheric circulation, climate, and runoff in the five major Korean river basins.

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기후변화에 대한 식물의 생태적 반응: 연구동향과 한국에서의 적용가능성 (Ecological Responses of Plants to Climate Change: Research Trends and Its Applicability in Korea)

  • 강혜순
    • 생태와환경
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    • 제46권3호
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    • pp.319-331
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    • 2013
  • Recent climate change, which is mostly ascribed to anthropogenic activities, is believed to be a major factor leading to biodiversity decreases and ecosystem service deteriorations. I have reviewed recent studies on climate change effects for many ecological processes involved with plants, in order to improve our understanding of the nature of ecological complexity. Plants in general have better growth and productivity under high levels of $CO_2$, although the long term effects of such $CO_2$ fertilizers are still controversial. Over the last 30 years, the Earth has been greening, particularly at higher latitudes of the Northern Hemisphere, perhaps due to a relaxation of climatic constraints. Human appropriation of net primary productivity (NPP), which corresponds up to 1/3 of global NPP, is ultimately responsible for climate change and biodiversity decreases. Climate change causes phenological variations in plants, especially in regards to spring flowering and fall leaf coloring. Many plants migrate polewards and towards higher altitudes to seek more appropriate climates. On the other hand, tree mortality and population declines have recently been reported in many continents. Landscape disturbance not only hinders the plant migration, but also makes it difficult to predict the plants' potential habitats. Plant and animal population declines, as well as local extinctions, are largely due to the disruption of species interactions through temporal mismatching. Temperature and $CO_2$ increase rates in Korea are higher than global means. The degree of landscape disturbances is also relatively high. Furthermore, long-term data on individual species responses and species interactions are lacking or quite limited in Korea. This review emphasizes the complex nature of species responses to climate change at both global and local scales. In order to keep pace with the direction and speed of climate change, it is urgently necessary to observe and analyze the patterns of phenology, migration, and trophic interactions of plants and animals in Korea's landscape.

산림 대상 석회 시용의 연구 경향과 산림생태계에 미치는 영향 (Research Trends of Forest Liming and the Effects of Liming on Forest Ecosystems)

  • 김주섭;장한나;노유진;한승현;손요환
    • 환경생물
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    • 제36권1호
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    • pp.50-61
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    • 2018
  • 본 연구는 산림생태계에서의 석회 시용 연구를 연대별, 국가별 그리고 주제별로 경향을 파악하고 석회 시용이 산림생태계의 각 요소 (토양, 식생, 수계 등)에 미치는 영향을 종합 분석하고자 하였다. 산림 대상 석회 시용은 연대별 산성강하물 유입량의 변화에 따라 시용 목적이 달라졌으며, 관련 연구는 산성화로 인한 대규모 산림 피해가 발생한 유럽과 북미 지역에서 주로 수행되었다. 대부분의 석회 시용 연구는 토양 반응을 중심으로 수행되었고, 토양 이외에 식생, 수계 등을 포함한 연구의 수는 비교적 적었다. 한편 산림 대상 석회 시용의 효과는 토양, 식생 및 수계 사이의 유기적인 상호작용을 통해 산림생태계 전체에 미치며 특히 화학적 성질변화가 중요한 것으로 나타났다. 석회 시용 후 토양의 pH, BS, CEC 변화는 토양 층위와 경과 시간에 따라 다르게 나타났다. 그리고 식생의 반응은 지상부 및 지하부 생장과 식물체 내 양분 농도의 변화로 이어졌으며, 수종과 토양 조건에 따라 반응은 다르게 나타났다. 수계는 석회 시용 후 토양에서와 유사한 화학적 성질 변화를 보였으며, 이는 플랑크톤과 어류 등의 생물상 변화로 이어졌다. 본 연구 결과는 향후 석회 시용 관련 연구를 계획하는 단계에서 중요한 기초자료로 활용될 수 있을 것으로 기대된다.

거제수나무, 물푸레나무, 굴참나무 묘목의 실외 인위적 온난화에 대한 수종 특이적 생장 반응 (Species-specific Growth Responses of Betula costata, Fraxinus rhynchophylla, and Quercus variabilis Seedlings to Open-field Artificial Warming)

  • 한새롬;안지애;윤태경;윤순진;황재홍;조민석;손요환
    • 한국농림기상학회지
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    • 제16권3호
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    • pp.219-226
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    • 2014
  • 기후변화 대응 산림 관리 방법을 개발하기 위해서는 온난화에 따른 수목의 반응을 예측하는 것이 중요하다. 본 연구는 우리나라 주요 활엽수종인 거제수나무(Betula costata), 물푸레나무(Fraxinus rhynchophylla), 굴참나무(Quercus variabilis) 묘목의 실외 인위적 온난화에 대한 생장 반응을 알아보기 위하여 수행되었다. 이를 위해 적외선등을 이용하여 지속적으로 기온을 $3^{\circ}C$ 증가시킬 수 있는 실외 인위적 온난화 시스템을 구축하고, 활엽수 3개 수종을 파종한 후, 온도 증가에 대한 발아 당년 묘목의 생장, 생물량 분배 및 순광합성률의 반응을 분석하였다. 연구 결과, 거제수나무, 물푸레나무, 굴참나무 묘목의 생장은 실외 인위적 온난화 처리에 대하여 수종과 시기에 따라 서로 다른 반응을 나타냈다. 즉 거제수나무는 온난화 처리에 따라 근원경 대비 묘고 비율, 총 생물량, 지상부 대비 뿌리 중량 비율, 순광합성률 등이 감소한 반면, 굴참나무는 근원경, 묘고, 총 생물량, 순광합성률 등이 증가하였으며, 물푸레나무는 다른 수종에 비하여 생장 반응이 뚜렷하지 않았다. 시기별 반응으로는, 7월에는 모든 수종에 대하여 온난화 처리에 따른 변화가 나타나지 않았으나 11월에는 굴참나무의 근원경, 묘고, H/D율이 증가한 반면 거제수나무의 H/D율이 감소하였다. 온난화에 대한 수종별 생장 반응의 차이는 순광합성률 및 생물량 분배의 수종별 반응과 유사하게 나타나, 온도 증가에 의한 순광합성률과 생물량 분배의 수종별 차이가 생장에 영향을 미친 것으로 생각된다. 한편, 여름에 비하여 가을에 더 두드러지게 나타난 생장 반응은 온난화에 의한 식물 계절 특성의 변화에 의한 것으로 보인다. 활엽수 3개 수종에 대하여 온난화에 의한 수종 특이적 생장 반응을 밝힌 본 연구 결과는 기후변화에 대응한 산림 관리 정책 개발에 활용될 수 있을 것으로 사료된다.

The Effect of Cognitive Dieting Behavior on Consumers' Food Perceptions, Emotional Responses, and Value Conflict in Restaurants

  • Kim, Min Jung;Kim, Dong-Jin
    • 한국조리학회지
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    • 제23권6호
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    • pp.153-160
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    • 2017
  • This study was intended to examine the influence of health consciousness on health/taste inferences, affect-based inferences, and perceived conflict between taste and health in food decision making. Seven hundred and fifty-four participants completed the survey. Structural equation modeling with a maximum likelihood method was used to test the relationships among constructs, following the two-step approach. The results of this study showed that more health-conscious consumers have a higher perceived healthfulness of food items but lower anticipated taste. In addition, this study also found consumers' cognitive responses influenced affective responses. Results suggested that when restaurants promote menu items as both healthy and tasty, consumers' positive hedonic emotions (such as pleasure) increased and negative self-conscious emotions (such as guilt) decreased, and consumers' efforts to balance health and taste were supported. At last, the implications both for academia and marketing were also established and discussed.