- KOREAN
- P-ISSN2287-8327
- E-ISSN2288-1220
- SCOPUS, KCI
ISSN : 2287-8327
Vol.34 No.1
Abstract
The Korea National Long-Term Ecological Research (KNLTER) was initiated in 2004 by the Korean Ministry of Environment. This project entered its third and final phase in 2010. Committee members have suggested that the project needs to be assessed in terms of its achievement and advised regarding its refinement. In this review, we recapitulated the last 7 years of KNLTER progress for developing further program improvements. We reviewed cological research before the existing LTER, project initiation, the increase in the number of research sites, and research topics. Then, we briefly examine the status of KNLTER and discuss areas for improvement and avenues for further research. The KNLTER established 20 research sites covering 80 topics related to terrestrial, freshwater, coastal, and animal ecology. To strengthen its role in LTER research, KNLTER participants need to confirm standard protocols and data formats for an efficient interaction with other LTER programs. All participants should enhance communication at both the domestic and international levels to reach out and collaborate on research and multidisciplinary studies. Climate change and environmental pollution issues will be solved with a global research network and long-term research projects focusing on this issue.
Abstract
The Korean National Long-Term Ecological Research (KNLTER) project seeks to predict the effects on Korean ecosystems caused by stress derived from environmental changes from a national perspective. The objective of this article about the KNLTER program, continuously supported by the Ministry of Environment (MOE) since 2004, was to inspect the general plans and to evaluate the project for the KNLTER program objectively, and to make suggestions about the developmental direction of the project. As a result of evaluation on the research site, the numbers of research sites in 2010correspond to 50% of those presented in the basic plan of the KNLTER project. As a result of evaluation on the research contents in the terrestrial ecosystem section of the KNLTER project, monitoring of climatic and atmospheric changes using eco-towers should be conducted over a long-term period. Additionally, the soil respiration part of the study needs to be expanded further in order to better understand soil systems. In the freshwater ecosystem section, we need to establish common standard investigation items, which can be used as indicators of the actual freshwater environment, considering that freshwater ecosystem management is closely related to human life. In the coastal ecosystem section, we should intensively analyze the correlation between the collected data accumulated thus far, as well as environmental changes including climate change, pollution, etc. For very sensible cases such as topographic changes due to rises in sea level, we should generate data applicable to prediction and confrontation for future changes through the continuous addition of variables and applications of a variety of simulation methods. In the animal ecology section, we should evaluate ecosystem changes based on animal phenology by selecting indicator animal species, which can be applied to each relevant ecosystem: namely, terrestrial, freshwater, and coastal ecosystems. As a result of synthetic evaluation conducted under the auspices of KNLTER, the stability of study areas is frequently implicated as the most common problem. If private lands are designated as study sites, it is very difficult to maintain them as study sites for a prolonged period. Therefore, it is necessary to designate national and public lands, such as national or provincial parks, as study sites. Efforts thus far conducted toward the construction of an appropriate database and modeling studies remain insufficient. After investigating the phenology of the specific species growing in all research sites, it is necessary to assess and report the overall changes in Korean ecosystems by applying that knowledge. The collection, analysis, and systematization of recent domestic and foreign research data related to natural ecosystem changes owing to environmental changes such as climate change and environmental pollution have been insufficient. Therefore, studies performed to obtain this information should be continuously pursued in the third stage.
Abstract
Since the initiation of national Long-Term Ecological Research (LTER) Network activities in the US and China from 1980 and 1988, respectively, and that of the International LTER (ILTER) Network activities from 1993, there are currently more than 40 national/territorial LTER networks developed globally. The developmental stage of each national/territorial LTER network can be evaluated as a fully active network, a consolidating network, or an inactive network. In order for the Korea LTER Network to be promoted from a consolidating network to a fully active network, the categories and criteria for evaluating the stage of the Networks were suggested by stage, current status was evaluated, and further directions were suggested for each category. In this review, the developmental histories of the fully active LTER networks of the US and China were reviewed, and best practices were introduced. In order for the Korea LTER Network to be promoted from a consolidating network to a fully active network, the criteria to be further promoted include: establishing bylaws and organizational entities specified in the bylaws; making strategic plans in science, monitoring, and research; and finding the core mechanism to serve societies in education and outreach. The highest priority is to develop a strategic plan to promote the Korea LTER Network.
Abstract
The Han River is the main water resource for the Seoul metropolitan area (Korea) with twenty million people relying on it, and its eutrophication is of great concern for preserving drinking water quality. In this study, long-term trends in biological oxygen demand (BOD), chemical oxygen demand (COD), total phosphorus (TP), total nitrogen (TN), and suspended solids at a downstream site of the river (St. Gui) are presented from 1989 to 2006 using data from the Ministry of the Environment. Longitudinal distributions in TP, TN, and chlorophyll-a concentration were measured in the downstream reaches between the Paldang Dam and Haengju Bridge. The long-term average BOD was 1.82 ± 0.67 mg/L and showed a decreasing trend, whereas COD did not vary consistently with a long-term average of 3.46 ± 0.87 mg/L, and consequently, the BOD/COD ratio decreased. This pattern can be interpreted as an increasing trend in the nonbiodegradable organic matter/biodegradable organic matter ratio, which can be attributed to enhanced sewage treatment. The long-term record for concentration did not show a consistent delate trend, whereas the seasonal variation was remarkably large with high concentrations during the flood season. In contrast, phytoplankton density was higher during low-flow seasons. It seemed that hydraulic residence time was the major factor controlling phytoplankton, as is typical in a lotic environment, which overwhelmed the effects of other factors such as temperature, nutrients, and solar radiation. In conclusion, BOD has decreased in the lower Han River system, but nonbiodegradable organic matter and phosphorus concentrations have not decreased.
Abstract
In 2004, the Korean Ministry of Environment initiated the National Long Term Ecological Research (LTER) program. We have attempted to analyze longitudinal patterns in limnological aspects based on LTER monitoring data collected from June 1994 to May 2008 in the Nakdong River, a regulated river ecosystem. Factor analysis, a multivariate ordination statistical method, was employed. Relationships among measured parameters were evaluated at different sites of the river. Overall, the trophic state of the Nakdong River was hyper-trophic (total nitrogen, 3.5-4.8 mg/L; total phosphorous, 57-95 μg/L; chlorophyll a, 15.2-38.5 μg/L). Among the three study sites, recurrent algal blooms consistently appeared in the lower reaches of the river. Extracted factors revealed different patterns, particularly for chlorophyll a concentration, and a rigid separation of limnological patterns was found at site 3 (Mulgeum) based on the factor analysis. From the results, more sustained observations through LTER will be helpful to manage and conserve ecosystems in the future. Furthermore, recent issues regarding ecosystem dynamics such as water quality with respect to global climate change require long-term datasets. Information collected by the LTER approach is hereby indispensable for ecological characterization.
Abstract
We monitored the zooplankton community dynamics of a regulated river system (the Nakdong River) in South Korea, in an effort to characterize the relationship between basin rainfall quantity and changes in zooplankton community structure. The river studied herein has four multipurpose dams upstream and one estuarine barrage at the river mouth, resulting in intensive flow regulation. We hypothesized that flow regulation would effect zooplankton community structure changes not only within the summer period of concentrated rainfall, but also during the subsequent seasons. Field monitoring was conducted on a weekly basis (1999 to 2009) at the study site (27 km upstream from the estuary dam). The studied years were divided into two groups: rainy years with annual rainfall greater than total average annual rainfall, and dry years (years with lower than average annual rainfall). The zooplankton community data was also divided into two groups according to year and community structural characteristics. The summer density of zooplankton was low during the summer concentrated rainfall period. In the autumn, zooplankton density was statistically related to river flow (r^2 = 0.30, P < 0.05, N = 11), which was affected by the summer concentrated rainfall (r^2 = 0.31, P < 0.05, N = 11). Furthermore, autumn zooplankton density was positively related to that observed in the summer (r^2 = 0.53, P < 0.05, N = 11). Therefore, it can be concluded that summer concentrated rainfall can affect the following seasons’ zooplankton densities caused by dam flow control, and the potential growth rate of zooplankton
Abstract
To evaluate fish community changes and the impact of exotic fish between the Nakdong River (lotic) and Upo Wetlands (lentic) using long-term ecological monitoring results, we conducted seasonal surveys of the fish community from 2005 to 2010. A fixed shore net (mesh 15 × 15 mm), cast net (7 × 7 mm), and scoop-net (5 × 5 mm) were used to collect fish specimens. Changes in the fish community were not significantly different in the Nakdong River and Upo Wetlands, respectively (R_s > 0.322, N = 44, P < 0.05). Changes in the fish community between the Nakdong River and Upo Wetlands were identified as significant according to the results of cluster analysis. The relative abundance of exotic species increased steadily during the study period, and reached 34.2% and 89.7% in the Nakdong River and Upo Wetlands, respectively, in 2010. The bluegill (Lepomis macrochirus) was used to evaluate the level of health according to prevalence around all study sites. The length-weight relationship for bluegill in the Upo Wetlands was shown to have the highest values, via the formula (W = aL^b), with an average of 3.26 for the ‘b’ variable. According to the results of this study, lentic and lotic systems differed significantly; exotic species had an impact on both the lentic and lotic systems, but the impact of exotic species in lentic systems was greater than in the lotic systems. Additionally, the exotic species tested herein (bluegill) adapted well in the lentic system.
Abstract
The wintering population of Bean Goose (Anser fabalis) at the Upo Wetland from 2005 to 2010 has been monitored by the long term ecological research (LTER) project in South Korea. The principal objective of this study was to define the primary factors determining the wintering Bean Goose population distribution in the wetland system, such as: usage pattern of habitat in and around the Upo Wetland, and departure timing related to temperature. We conducted a comprehensive literature review regarding Bean Goose population dominance in the wetland, and there was a clear tendency toward an increase in this species’ dominance until 2002. The LTER monitoring data also exhibited a similar trend, but not as strongly as was seen in previous research. When the Bean Goose population arrived at the Upo Wetland,they utilized the wetland as their resting site, while they moved to other places surrounding the wetlands to forage for food sources. The flight distance of the Bean Goose for feeding ranged between ca 1 to 25 km from the Upo area. The population changes of the Bean Goose at the Upo were related to the lowest temperatures in winter (r = -0.461, P = 0.009). In particular, the lowest temperature in March was important for creating flocks of the Bean Goose before returning to the northern region. The results of this study can provide us with basic information regarding migratory bird population changes in the Upo Wetland in relation to the land use patterns of human beings, as well as meteorological variations.
Abstract
Species composition, frequency distribution of diameter classes, species diversity, and stem vitality of woody plants were analyzed in a Mongolian oak (Quercus mongolica Fisch. ex Ledeb.) forests in permanent quadrates of Mt. Nam and Mt. Jeombong, which were installed for Long Term Ecological Research (LTER). The principal objective of this study was to clarify the ecological characteristics of both sites by comparing the Mongolian oak communities established in Mt. Nam surrounded by urban area and in Mt. Jeombong as a natural area, to accumulate the basic data for long-term monitoring, and furthermore to predict possible changes in vegetation due to climate change. The species composition of the Mongolian oak community on Mt. Nam differed from that of Mt. Jeombong. Such differences were usually due to Sorbus alnifolia, Styrax japonicus, Oplismenus undulatifolius, Ageratina altissima and so on, which appeared in higher coverage in Mt. Nam. Species diversity of the Mongolian oak community in Mt. Nam was lower than that in Mt. Jeombong. This result was attributed to the fact that the Mongolian oak community in Mt. Nam is under continuous management and was dominated excessively by S. alnifolia, and S. japonicus, which were originated from artificial interference and chronic air pollution. As the results of analyses on the frequency distribution of diameter classes of major tree species and the transitional probability model based on Markov chain theory, the Mongolian oak community in Mt. Nam showed a possibility of being replaced by a S. alnifolia. Considering that this replacement species is not only a sub-tree but is also shade-intolerant, such a successional trend could be interpreted as a sort of retrogressive succession. The Mongolian oak community established in Mt. Jeombong differed from the community in Mt. Nam in terms of its probability of being continuously maintained.
Abstract
Various responses of forest ecosystems to climate change underscore the need to improve our understanding of the environmentally-driven changes in forests, most effectively by long-term monitoring protocols. We have explored vegetation dynamics based on changes in community structure, species composition, diversity and demographics in four Korean National Long Term Ecological Research (KNLTER) sites--Mt. Nam, Mt. Jeombong, Mt. Worak, and Mt. Jiri-- between 2004 and 2009. Most of the sites and forests studied exhibited increments in total basal area, but this was not observed in Quercus mongolica forests in Mt. Nam and Mt. Worak. Stem density exhibited various changes. Altitude gradient was the representative factor in differences in species composition. Two patterns of compositional change--convergence and divergence--were detected. The vegetation of Mt. Nam and Q. mongolica community of Mt. Work showed relatively larger changes in composition. However, in the other sites, few changes were observed. Changes of species richness were not notable except for Mt. Nam, where three species were added in the pine forest, whereas one species disappeared in the oak forest. In the oak forests, mortality rate was as follows (in descending order): Mt. Nam (25.5%), Mt. Jeombong (24.3%), Mt. Worak (16.4%) and Mt. Jiri (0.8%). In the pine forest, the recruitment rate was as follows (in descending order): Mt. Nam (63.7%), Mt. Worak (12.9%), Mt. Jeombong (7.6%) and Mt. Jiri (7.3%). The mortality rate and change rate of basal area were strongly negatively correlated (r = -0.9, P = 0.002), and the recruitment rate and change rate of density were positively correlated (r = 0.77, P = 0.026). In the KNLTER sites, larger vegetation changes were attributed to anthropogenic activities such as salvage logging. Suppression or competition for resources would also affect these changes. Research suggestions such as monitoring to clarify the causes of species mortality were discussed.
Abstract
The Namsan Ecological Tower Site based on a flux tower was equipped with eddy covariance and automatic opening/closing chamber systems to collect long-term continuous measurements of CO_2 flux, such as the net ecosystem exchange (NEE) and soil CO_2 efflux in a cool-temperate Quercus mongolica forest. The mean concentrations of atmospheric CO_2 (705 mg/m^3) during the summer were smaller than those measured (770 mg/m^3) during the winter. The mean CO_2 flux during the summer period was negative (-0.34 mg m^(-2) s^(-1)), while that during the winter period was positive (0.14 mg m^(-2) s^(-1)). CO_2 was deposited from the atmosphere to the surface in the summer. The daily mean value of soil CO_2 efflux increased from spring to summer. The seasonal pattern in the rate of soil CO_2 efflux tightly followed the seasonal pattern in soil temperatures. The Q_(10) values for soil CO_2 efflux varied in a range from 2.12 to 3.26, and increased with increasing soil depth. The maximum value of total carbon uptake (i.e., NEE) during the growing season was -8 g CO_2 m^(-2) day^(-1). At the same time, the rate of soil CO_2 efflux was 6.9 g CO_2 m^(-2) day^(-1). The amplitude of flux variations in NEE was approximately 14% larger than those in soil CO_2 efflux. These results suggest that in cool-temperate regions of the Korean peninsula, the forest ecosystem of Q. mongolica may have a larger atmospheric CO_2 uptake, due primarily to its high photosynthetic capacity and low ecosystem respiration.
Abstract
In this study, litter production, the nutrient concentration of each component of litterfall, and the amount of nutrient input to the forest floor via litterfall were assessed for four years from May 2005 through April 2009 in a Quercus mongolica forest in Mt. Worak National Park. The average amount of leaf litter, branch and bark, reproductive organs (flowers and nuts), and miscellaneous categories for 4 years were 2.921 ± 0.242, 1.112 ± 0.288, 0.625 ± 0.176 and 0.837 ± 0.209 t ha^(-1) y^(-1), respectively. The average percentage of leaf litter, branch and bark, reproductive organs and miscellaneous categories for 4 years were 53.2 ± 7.31, 20.2 ± 4.43, 11.4 ± 2.59 and 15.2 ± 3.35%, respectively. The amount of total litterfall in 2005, 2006, 2007, and 2008 was 5.438, 5.864, 5.669 and 5.009 t ha^(-1) y^(-1), respectively. The average amount of litterfall for 4 years was 5.495 ± 0.368 t ha^(-1) y^(-1). The average amount of N, P, K, Ca, and Mg returned to the forest floor via litterfall for 4 years in this Quercus mongolica forest were 53.4 ± 5.35, 3.8 ± 0.88, 17.8 ± 1.37, 17.2 ± 2.21 and 5.8 ± 0.55 kg ha^(-1) y^(-1), respectively.
Abstract
Coarse woody debris (CWD) mass dynamics in three temperate natural forests, dominated by Quercus mongolica, Abies holophylla, and Pinus densiflora, were studied for 5 to 8 years in a Korea National Long-Term Ecological Research (KNLTER) site located in Mt. Jumbong, Korea. CWD mass (Mg/ha), input rate of CWD mass (Mg ha^(-1) y^(-1)), and decay rate constant (1/y) were 20.6, 1.20, and 0.058 for Q. mongolica forest, 12.2, 0.44, 0.106 for A. holophylla forest, and 5.0, 0.00, and 0.086 for P. densiflora forest, respectively. CWD mass was classified into species, types (log, snag, and stump), and decay classes (I-V). The proportion of logs was higher than that of the other CWD types in Q. mongolica forest because of wind-related mortality, whereas the proportion of logs was similar to the proportion of snags in A. holophylla forest and P. densiflora forest. CWD mass, input rate, decay rate, and distribution reflected the status of forest regeneration and succession for three forests. Mass dynamics were affected interactively by a variety of factors including species, microclimate, and topography, but these effects were hardly distinguishable in this study because of the limited number of comparable sites and pieces of CWD. Thus, further studies will require data regarding long-term microclimate and CWD mass dynamics in a variety of forest types, which could represent diverse environmental factors.
Abstract
In this study, in order to determine how climate change may affect amphibian and reptile communities, we surveyed the numbers of egg clumps and adults of amphibians and the number of reptiles at eight amphibian and nine reptile survey sites in Woraksan National Park from March 2005 to September 2009. We assessed the relationships among six climate factors (annual minimum temperature, annual maximum temperature, monthly mean temperature, monthly mean precipitation, monthly mean temperature during winter, and monthly mean precipitation during winter); species diversity, evenness, and richness indexes for both amphibians and reptiles; and the number of each species and egg clumps of three amphibian species. First, both the amphibian and reptile species indices evidenced sudden changes in 2007, when climate factors in Korea fluctuated substantially. Second, amphibian diversity and evenness were negatively related with annual minimum temperature. Increased monthly mean precipitation had a positive effect in mountain edge sites, but a negative effect in valley sites. Third, reptile species evenness was positively related with monthly mean precipitation. In particular, the monthly mean temperature in the winter season affected the numbers of the Dione's rat snake and the Korean tiger keelback snake. These results indicate that amphibian and reptile communities are responding to climate change in a variety of ways.