• Journal of Ecology and Environment
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• 제38권4호
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• pp.461-476
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• 2015

Global warming has accelerated glacial retreat in the high Arctic. The exposed glacier foreland is an ideal place to study chronosequential changes in ecosystems. Although vegetation succession in the glacier forelands has been studied intensively, little is known about the microbial community structure in these environments. Therefore, this study focused on how glacial retreat influences the bacterial community structure and its relationship with soil properties. This study was conducted in the foreland of the Midtre Lovénbreen glacier in Svalbard (78.9°N). Seven soil samples of different ages were collected and analyzed for moisture content, pH, soil organic carbon and total nitrogen contents, and soil organic matter fractionation. In addition, the structure of the bacterial community was determined via pyrosequencing analysis of 16S rRNA genes. The physical and chemical properties of soil varied significantly along the distance from the glacier; with increasing distance, more amounts of clay and soil organic carbon contents were observed. In addition, Cyanobacteria, Firmicutes, and Actinobacteria were dominant in soil samples taken close to the glacier, whereas Acidobacteria were abundant further away from the glacier. Diversity indices indicated that the bacterial community changed from homogeneous to heterogeneous structure along the glacier chronosequence/distance from the glacier. Although the bacterial community structure differed on basis of the presence or absence of plants, the soil properties varied depending on soil age. These findings suggest that bacterial succession occurs over time in glacier forelands but on a timescale that is different from that of soil development.

• 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.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제4권1호
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• pp.16-27
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• 2023

Primary succession on bare rocks is a challenge for invaders, including one of which was plants. The invasion of bare rock by exotic species raises the question of whether their presence hinders or facilitates succession. This study aimed to determine the role of exotic species in primary succession in six overburden (OB) coal mines using a chronosequence approach. Vegetation analysis was undertaken using line transects. Measurements were carried out on the absolute and relative coverage of each species. Native and exotic species were identified and grouped using information from local communities, identification books, and websites. The relationship between time and number of species, time, and relative dominance of exotic and native species was analyzed using Pearson's correlation. Species number and dominance data were analyzed descriptively. The number of native species from the six OB heaps was higher (57) than that from exotic heaps (50). Neither the number of species nor the coverage showed a significant relationship with time. Exotic species predominated throughout the age of the embankment but tended to decrease over time. Temporary dominance by exotic species plays a role in assisting primary succession in the OB. This process might be prolonged without the temporary dominance of exotic species during early primary succession.

• The Korean Journal of Ecology
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• 제23권2호
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• pp.83-88
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• 2000

When interpreting change over time in forest ecosystems, distinguishing the effects of forest succession from the effects of environmental stress can be difficult. The result may be a simplistic interpretation. citing a specific successional or environmental cause of forest change when both types may be occurring. We present two case studies of changes in the forest floor in northern hardwoods. First, the belief that 50% of soil organic matter is lost in the first 20 years after logging was based on a study comparing northern hardwood stands of different ages. We resampled a series of 13 such stands after an interval of 15 years, and found that the young stands were not, in fact. losing organic matter as rapidly as predicted from the original chronosequence study. The pattern of higher organic matter content in the forest floors of older stands compared to young stands could be equally well explained by changes in logging practices over the last century as by the aging of the stand. The observed pattern of forest floor organic matter as a function of stand age was previously interpreted as a successional pattern, ignoring changes in treatment history. In the second case study, observed losses of base cations from the forest floor were attributed to cation depletion caused by acid rain and declining calcium deposition. We found that young stands were gaining base cations in the forest floor; losses of base cations were restricted to older stands. Differences in litter chemistry in stands of different ages may explain some of the pattern in cation gains and losses. In this case, the contribution of successional processes to cation loss had been overlooked in favor of environmental stress as the dominant mechanism behind the observed changes. Studies of environmental stress use repeated measures over time. but often don't consider stand age as a factor. Studies of successional change often assume that environmental factors remain constant. We were able to consider both forest succession and external factors because we repeatedly sampled stands of different ages.

• Journal of Forest and Environmental Science
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• 제32권3호
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• pp.302-310
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• 2016

The loss and degradation in tropical forest region are some of the current global concern. Hence, these issues elevated the role of rehabilitated forests in providing ecological products and services. The information on the carbon stock is important in relation to global carbon and biomass use, but lacking from the tropical region. This paper reports the assessment of tree and soil carbon stock in a chronosequence rehabilitated tropical forest stands in Malaysia. The study site was at the UPM-Mitsubishi Forest Rehabilitation Project, UPMKB. $20{\times}20m$ plot was established each and assessed in 2009 at 1-, 10- and 19-year-old sites while an adjacent ${\pm}23-year-old$ natural regenerating secondary forest plot was established for comparison. The overall total carbon stock was in the order of 19-year-old>${\pm}23-year-old$>10-year-old>1-year-old. When forest carbon stock is low, the soil component plays an important role in the carbon storage. The forest carbon recovery is crucial to increase soil carbon stock. The variations in the carbon stock showed the different stages of the forest recovery. Species survived after 19-years of planting are potential species for carbon sequestration activities in rehabilitated forest. Human intervention in rehabilitating degraded forest areas through tree planting initiatives is crucial towards recovering the forest ecological role especially in forest carbon stock capacity.

• 한국광물학회지
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• 제1권1호
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• pp.32-39
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• 1988

The effect of soil forming factors on the pedogenesis of basaltic volcanic ash soils and the influence of allophane material on soil properties have been investigated on 5 chronosequence soils situated from at the near sea coast up to the foot slope of Mt. Halla in Jeju Island. Time seems to be the important soil forming factor which today differentiates soil of the Island. Songag and Donghong soils developed in lower elevations are older and somewhat less influenced by ash shower. However, soils developed at higher elevations, Pyeongdae and Heugag, are rather younger and strongly influence by the ash. It is also proved that the parent materials are very heterogeneous. They mainly are basaltic with some contamination of acidic volcanic ashes and continental aeolian deposits where a considerable amount of quartz encountered in most soils studied. Many physico-chemical properties of soil, such NaF pH, phosphate sorption power, pH and extractable acidity are parameters to differentiate andepts and non-andeptic soils.

• 한국광물학회지
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• 제1권1호
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• pp.40-47
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• 1988

Mineralogy of sand, silt and clay fractions from the five chronosequence soils of Jeju Island is studied with the X-ray, TEM and SEM techniques. Soils of Songag and Donghong situated at lower elevations are generally developed on relatively of ash or alluvial deposits and contain mainly ferromagnesian minerals and feldspars, with some quartz, mica and volcanic glass. Crystalline minerals are dominant in the clay fraction; halloysite and vermiculite are abundant but small amounts of allophane are present. Clay migration results in well developed ferrigargillan, Soils of Pyeongdae and Heugag located at higher elevations are developed on relatively young volcanic ash with some contamination of continental aeolian dust probably containing quartz which may be come from acid ash shower. The absence of clay illuivation is due to the dominance of allophane. This clay mineral is associated with some gibbsite, imogolite and halloysite.

• 환경생물
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• 제32권3호
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• pp.211-215
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• 2014

본 연구에서는 미국 뉴햄프셔주 13개 임분의 낙엽활엽수림에서 5년간(1994~1996, 2003~2004) 낙엽량 측정을 위한 최소 필요 표본수를 알아보았다. 임분별 최소 필요 표본수는 오차범위 10%에서는 현재의 15개 트랩수와 비슷했으나, 1994년과 1995년은 타 년도에 비해 약 2배인 30개의 트랩수가 필요하였다. 오차범위 20%에서는 5년간 13개 모든 임분에서 필요한 트랩수는 10개미만으로 나타났다. 임분별로 최소 필요 표본수는 차이가 있었는데 특히 경사가 급하고 해발고도가 높은 임분에서 더 많은 트랩이 설치되어야 하며, 임분 연령이나 낙엽량과는 관계가 없음이 나타났다. 결론적으로 낙엽량 측정을 위한 최소 필요 표본수를 산정할 경우, 본 연구에서와 같이 다년간의 샘플링이 필요하며, 임분의 지형적 특성 역시 고려해야 함을 알 수 있었다.

• 한국산림과학회지
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• 제100권2호
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• pp.240-245
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• 2011

강원도 남부 지역의 발달단계가 다른 소나무림 벌채지에서 16년 동안의 식생 변화를 연구하였다. 교란 후, 천이 궤적 및 환경 변화를 온도, 상대습도, 서열분석(Detrended Correspondence Analysis, DCA), Multiple Responses Permutation Procedure(MRPP) 및 지표종 분석(Indicator Species Analysis, ISPAN) 등을 통하여 분석하였다. 벌채 직후, 수관열림도는 대조구와 비교하여 세 배(1yr 68.3% 및 R1 23.0%)로 급격히 증가한 후 감소하였으나, 상대습도는 비교적 작은 변화(약 6% 감소)를 나타내었다. DCA 결과, 벌채 후 초기에는 종조성이 이질적으로 변화하였으나, 점차 벌채 이전(대조구)의 것과 유사하게 발달하였다. MRPP 결과, 각 발달 단계(1yr, 3yr, 10yr 및 16yr)의 종 조성은 대조구(R1, R3, R10 및 R16)의 것과 유의한 차이를 보였다. 1yr 및 3yr에서는 목본성 종이, 10yr 및 16yr에서는 초본 종들이 주요 종으로 분석되어, 교란 직후에는 목본성 종들이 활발한 재생을 나타내며, 이후 초본 식생이 발달하는 것을 보였다. 연구 대상지역의 천이는 초기 식물상 조성 모델로 설명할 수 있을 것으로 판단된다.