• Journal of Ecology and Environment
• /
• v.35 no.3
• /
• pp.227-234
• /
• 2012

Quercus aliena and Q. serrata are both occur as natural vegetation alongside natural freshwater bodies of the southern Korea Peninsula. Q. serrata dominates over Q. aliena as secondary forest vegetation in the present day. In order to explain these natural distributional traits of the oak species, we conducted some experiments with oak seedlings which treated with major important environmental resources, including light, moisture and nutrients, under controlled conditions. We then measured the ecological niche breadths and overlap from 15 eco-morphological characteristics. The ecological niche breadth of Q. aliena and Q. serrata were higher in terms of the nutrient factor applied, but was lower terms of light. The niche breadth of Q. serrata was wider than that of Q. aliena in light and moisture exposure. On the other hand, the niche breadth of Q. aliena was similar with that of Q. serrata in terms of the nutrient factor applied. These results imply that Q. serrata has a broader ecological distribution in over a wider variety of light and moisture environments than that of Q. alien. Ecological niche overlap between two oak species was the widest in terms of the light treatment factor applied, and narrowest in terms of moisture. This response pattern was also verified by cluster and principle component analysis. These results suggest competitive interactions between Q. serrata and Q. aliena seedlings may be higher for light resources than moisture or nutrient resources, and that Q. serrata is more shade tolerant than Q. aliena.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.15 no.3
• /
• pp.153-160
• /
• 2013

This study was conducted to investigate the effect of ecological factors affecting Pinus densiflora forest distribution associated with climate change in the future. Ecological niche is used as a method to quantify the position occupied in biological communities, space, influence and all ecological factors. Ecological niche breadth was analyzed on meteorological and growth factors of P. densiflora. Nine sites (i.e., Gangneung, Jeongseon, Pyeongchang, Hamyang, Bonghwa, Yeongyang, Uljin, Uiseong and Boseong) were selected to set $20m{\times}20m$ quadrat from September to October 2010. The height, DBH, clearlength, crown width and basal area were measured at each quadrat and used as growth factors. In addition, the measured values from the closest weather stations of each survey area of the maximum, mean and minimum temperature, humidity and precipitation were used as meteorological factors. The ecological niche breadth of the five meteorological factors except humidity was low. It is considered that precipitation could effect on the distribution of P. densiflora forest. In particular, maximum temperature showed low ecological niche breadth less than 0.4 in most of the survey areas. However, the ecological niche breadth of the five growth factors was high in all survey areas.

• Korean Journal of Environmental Biology
• /
• v.27 no.2
• /
• pp.191-197
• /
• 2009

In order to characterize the ecological traits of Q. mongolica, we treated the seedlings of this species with three environmental factors, light, moisture and nutrient gradients from March to October 2007, and measured morphological and ecological 17 characters. Lastly calculated ecological niche breadth and niche overlap between Q. mongolica-Q. acutissima and Q. mongolica-Q. variabilis, and analysed them with a special reference to ecological distribution pattern and their competition relationship in Korea. The ecological niche breadth of Q. mongolica showed the lowest in nutrient treatment, but the highest in soil moisture treatment. The ecological niche value under light was intermediate. On comparison of the ecological niche breadth of three oak species, Q. mongolica showed the highest in light environment, which might be a reason for the dominant distribution in the forest plant community, Korea. The ecological niche overlap of Q. mongolica-Q. acutissima and Q. mongolica-Q. varabilis was the widest in moisture treatment, but the narrowest in nutrient treatment and the intermediate in light one. These results means that these three oak species be most competitive in moisture environment than light or nutrient one, and that there are least differentiated among oak species for soil moisture condition. Cluster and PCA ordination showed that Q. mongolica and Q. acutissima were more closely arranged than Q. mongolica and Q. variabilis. From these results, it can be explained that Q. mongolica have more similar ecological niche with Q. acutissima than with Q. variabilis, consequently competition between Q. mongolica and Q. acutissima is intensive than Q. mongolica and Q. variabilis for environment condition, especially in soil moisture.

• Korean Journal of Ecology and Environment
• /
• v.46 no.3
• /
• pp.429-439
• /
• 2013

This study was conducted to determine the changes of the ecological niche breadth and niche overlap of Quercus acutissima and Quercus variabilis under elevated $CO_2$ concentrations and under elevated temperature conditions. We investigated the growth responses by environmental factor, $CO_2$ concentration, air temperature, light, soil moisture and nutrients. Rising $CO_2$ concentration was treated with 1.6 times than control (ambient) and increased temperature with $2.2^{\circ}C$ above the control (ambient) in the glass greenhouse. Ecological niche breadth and niche overlap was calculated the two oak species (Q. acutissima and Q. variabilis), which were cultivated with light, soil moisture and nutrient gradients at four levels. As a result, the ecological niche breadth of Quercus acutissima was determined to be increased under the warming treatment, but decreased under soil moisture and nutrient environments. The ecological niche breadth of Quercus variabilis was increased under light, soil moisture and nutrients of the warming treatment than control. Ecological niche overlap between Quercus acutissima-Quercus variabilis was increased under light of the warming treatment than control, but decreased under soil moisture and nutrient environments. These results means that two oak species are more severe competition in light environments than soil moisture and nutrient environments. According to analyses of the Cluster and PCA, the two oak species were more sensitive react under light environment than to elevated $CO_2$ concentration or elevated temperature.

• Korean Journal of Ecology and Environment
• /
• v.53 no.1
• /
• pp.102-108
• /
• 2020

This study is to analyze the growth response of the Quercus dentata seedlings to four environmental factors and measure the ecological niche breadth. Environmental factors were light, moisture content, soil texture, and organic matter, treated with four gradients. The more quantity light increased, the heavier the leaves biomass, aboveground biomass, belowground biomass and plant biomass was. In treatment of water content and soil texture, growth response was no difference. The more organic matter increased, the heavier aboveground biomass was, but the remaining trait of plant was no difference. The ecological niche breadth was 0.865 in light, 0.995 in moisture content, 0.994 in soil texture and 0.988 in nutrient. Ecological niche breadth was the widest in the moisture content treatment and the narrowest in the light treatment. This means that the growth of Q. dentata seedlings grows well as the amount of light increases, and is sensitive to light, Thus, it is determined a growth and ecological niche breadth by light factors.

• Journal of Korean Society of Forest Science
• /
• v.90 no.3
• /
• pp.380-387
• /
• 2001

The characteristics of ecological niche, breadth and overlap, for seventeen major tree species were evaluated in the natural deciduous forest in Mt. Chumbong area. Employed by the plot sampling method, the environmental gradient for vertical niche was based on the intensity of light within the forest, and that for horizontal niche was based on multi-dimensional resources in distribution pattern. The result showed that Fraxinus rhynchophylla had the highest value of vertical niche breadth and Maackia amurensis had the lowest, and Acer pseudo-sieboldianum had the highest value of horizontal niche breadth and Betula costata had the lowest. There was no significant correlation between both measures of niche breadth. However, the tolerance index for each species was positively correlated to the values of niche breadth. Spearman's rank correlation coefficients were applied to test the correlationship between the species ranks of tolerance index and those of two ecological niche breadths. The coefficient of $r_s=0.432$ ($P{\leq}0.1$) was not enough to support significant correlationship between the tolerance index and vertical niche breadth at the 95% probability. If Carpinus cordata, rarely reach canopy of the forest due to its own growth form, are excluded from the analysis, coefficient was calculated as $r_s=0.650$ ($P{\leq}0.01$), resulting in highly significant correlationship. The Spearman's rank correlation coefficient was $r_s=0.797$ ($P{\leq}0.01$) for tolerance indices and the values of horizontal niche breadth, indicating highly significant. Four distinctive species groups, produced by cluster analysis on the basis of ecological niche overlap for each pair of species, were in considerable accord with the positively associated species constellation pattern created by the inter-species association analysis.

• Korean Journal of Environmental Biology
• /
• v.32 no.2
• /
• pp.95-101
• /
• 2014

In order to investigate effects of elevated $CO_2$ concentration and temperature on the ecological niche of Quercus serrata in Korea. We divided experimental condition in the greenhouse that are control (ambient condition) and treatment with elevated $CO_2$ (approximately 1.6 above than control) and increased air temperature (approximately $2.2^{\circ}C$ above than control). We measured twenty kind characters of seedlings and calculated the ecological niche breadth. As a result, the ecological niche breadth, treatment was widened in the light gradient than the control, was narrowed in the moisture and nutrient gradient. This is may be predicted when the global warming progress, Q. serrata is increases resistance to light environment, and decrease resistance to moisture and nutrient environment. According to the principal component analysis (PCA), control and treatment were arranged based on factor 1 and 2 in each environment gradients. Ecological response is involved variety characters. Among them, indicating that Characters of production is involved in many a parts.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.26 no.5
• /
• pp.47-56
• /
• 2023

The Quercus variabilis and Quercus dentata, which are said to be relatively drought tolerant among the important genus Quercus that represent deciduous broad-leaved forests in Korea. These two species are widely distributed worldwide in Korea, Japan and China (northern, central, western and eastern subtropical regions). This study compared the ecological niche breadth and overlap according to growth response in 4 soil moisture gradients for the two species and tried to reveal degree of competition and ecological niche characteristics. The ecological niche breadth was 0.977±0.020 for Q. variabilis and 0.979±0.014 for Q. dentata, the latter being slightly wider. And they were similar in 5 traits (stem length, leaf lamina length, leaf width length, stem weight, leaf petiole weight), Q. variabilis was more dominant in 4 traits (leaves number, stem diameter, leaf area, leaf petiole length), and Q. dentata was more dominant in 7 traits (root length, shoot length, plant weight, root weight, shoot weight, leaf weight, leaf petiole weight). The ecological niche overlap for soil moisture between the two species overlapped most in plant structure-related traits and least in photosynthetic organ-related traits such as petiole length. As a result of principal component analysis, degree of competition between the two species for soil moisture was more severe when the soil moisture condition was low than high. Among the measured traits that affect the two-dimensional distribution, 8 traits (Leaves number, Shoot length, Stem length, Plant weight, Root weight, Shoot weight, Stem weight, Leaves weight) were correlated with the factor 1, and 2 traits (Leaf width length, Leaf petiole weight) were correlated with the factor 2 (r>0.5). These results show that the ecological response of the two species to soil moisture is not a few traits involved, but several traits are involved simultaneously.

• 한국생태학회:학술대회논문집
• /
• 1999.05a
• /
• pp.107.2-107.2
• /
• 1999

• Journal of Ecology and Environment
• /
• v.44 no.3
• /
• pp.162-177
• /
• 2020

Background: Ecologists have achieved much progress in the study of mechanisms that maintain species coexistence and diversity. In this paper, we reviewed a wide range of past research related to these topics, focusing on five theoretical bodies: (1) coexistence by niche differentiation, (2) coexistence without niche differentiation, (3) coexistence along environmental stress gradients, (4) coexistence under non-equilibrium versus equilibrium conditions, and (5) modern perspectives. Results: From the review, we identified that there are few models that can be generally and confidently applicable to different ecological systems. This problem arises mainly because most theories have not been substantiated by enough empirical research based on field data to test various coexistence hypotheses at different spatial scales. We also found that little is still known about the mechanisms of species coexistence under harsh environmental conditions. This is because most previous models treat disturbance as a key factor shaping community structure, but they do not explicitly deal with stressful systems with non-lethal conditions. We evaluated the mainstream ideas of niche differentiation and stochasticity for the coexistence of plant species across salt marsh creeks in southwestern Denmark. The results showed that diversity indices, such as Shannon-Wiener diversity, richness, and evenness, decreased with increasing surface elevation and increased with increasing niche overlap and niche breadth. The two niche parameters linearly decreased with increasing elevation. These findings imply a substantial influence of an equalizing mechanism that reduces differences in relative fitness among species in the highly stressful environments of the marsh. We propose that species evenness increases under very harsh conditions if the associated stress is not lethal. Finally, we present a conceptual model of patterns related to the level of environmental stress and niche characteristics along a microhabitat gradient (i.e., surface elevation). Conclusions: The ecology of stressful systems with non-lethal conditions will be increasingly important as ongoing global-scale climate change extends the period of chronic stresses that are not necessarily fatal to inhabiting plants. We recommend that more ecologists continue this line of research.