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

• 대한공간정보학회지
• /
• 제21권3호
• /
• pp.11-17
• /
• 2013

사회 변화에 따라 산지이용 수요가 증가하고 다양화되면서 산림을 훼손하고, 타 용도로 활용하는 산지의 면적이 증가하고 있다. 이에 최근 훼손된 산지의 면적을 효과적으로 확인하기 위하여 두 시기의 항공사진을 활용한 훼손 산지 변화탐지 기법을 연구하였다. 본 연구에서 개발한 기법은 객체기반 변화탐지 형식으로, 영상 혼합 - 객체 분할 - 객체 병합 - 노이즈 제거 - 훼손지 추출의 5가지 단계로 진행되었다. 훼손 산지에 적합한 객체생성 수준을 선정하고, 객체를 분할 병합하는 과정을 통해 객체 간의 관계와 각 객체가 지닌 분광 특성 및 정황적(Contextual) 정보를 활용하여 신규 훼손 산지를 추출하였다. 시범 영역 테스트 결과, 전체 판독범위의 12%에 해당하는 훼손 산지를 추출하였고 육안판독 훼손산지의 평균 96%를 포함함으로써, 육안판독 전 후의 보완 자료로서의 가치와 자동추출의 가능성을 확인하였다.

• Journal of Forest and Environmental Science
• /
• 제31권3호
• /
• pp.225-234
• /
• 2015

Mangroves are important coastal ecosystems and are located at the inter-tidal zones of tropical and sub-tropical belts. The global mangrove forests are declining dramatically because of the conversion of forests to shrimp farming, over-exploitation, pollution and freshwater diversion. The Bangladesh Forest Department initiated mangrove afforestation throughout the coastal belts of Bangladesh in 1966 to provide better protection for the coastal communities. Up to 1990, 120,000 ha of mangroves had been planted and it is one of the largest coastal afforestaton programs in the world. The objective of this study is to exploit the spatial extent of mangrove plantation and their dynamics of changes over the last two decades using multispectral Landsat imagery. The study area covers the coastal areas of Bangladesh that is extended over the eastern part of Sundarbans up to Teknaf, the southern tip of mainland Bangladesh. Mangrove plantations were interpreted visually on computer screen and interactive delineation of forest boundary was done. The mangrove plantation area has been estimated as 32,725, 47,636 and 43,166 ha for the year of 1989, 2000 and 2010, respectively. Mangrove deforestation by human activity has increased almost six times in the recent decade in comparison to the previous one. The mangrove forest loss due to coastal erosion has slightly declined in the 2000s. Mangroves have been lost primarily because of agricultural expansion. The result of this investigation will be helpful to understand the dynamics of mangrove plantation and the main drivers of changes in this coastal ecosystem.

• Journal of Forest and Environmental Science
• /
• 제38권1호
• /
• pp.1-11
• /
• 2022

The Dutch colonial government introduced social forestry at the end of the 19th century with a commitment to controlling forest resources in the Dutch East Indies. This program was a response to the rampant deforestation which had resulted in forest degradation and poverty of the population around the forest. This study examined the practice of social forestry in the late colonial period which had not been done much. From a historical perspective, social forestry practices in Indonesia before independence could be explained more comprehensively. This study uses a historical method which includes four stages: heuristic, source criticism, interpretation, and historiography (composing historical stories). Sources of information were explored through studies of archival documents and contemporary artefacts, especially official colonial government reports and contemporary newspapers/magazines. Data from various sources are then compared and tested for validity to obtain data validity. The next stage is to build facts based on data obtained and then interpreted using the social science theories. Finally, compiling a historical (historiographical) story about social forestry during the late colonial period. The results showed that colonial forestry during the colonial period was still limited in terms of area and method, namely in the area of teak forest and involving villagers through the intercropping system. Farmers involved in these activities are called pesanggem who earn income from forest land being rejuvenated. However, the relationship between pesanggem and the forestry service has not been well institutionalized, consequently the pesanggem is often disadvantaged. Including certainty of ownership and ownership of forest land never gained clarity and even became a source of conflict.

• Journal of Forest and Environmental Science
• /
• 제32권2호
• /
• pp.120-128
• /
• 2016

Forest sequesters large terrestrial carbon which is stored in the biomass of tree and plays a key role in reducing atmospheric carbon. Thus, the objectives of the present study were to assess the growing stock, above ground biomass and carbon in trees of Ponda watershed of Rajouri district (J&K). IRS-P6 LISS-III satellite data of October 2010 was used for preparation of land use/land cover map and forest density map of the study area by visual interpretation. The growing stock estimation was done for the study area as well as for the sample plots laid in forest and agriculture fields. The growing stock and biomass of trees were estimated using species specific volume equations and using specific gravity of wood, respectively. The total growing stock in the study area was estimated to be $0.25million\;m^3$ which varied between $85.94m^3/ha$ in open pine to $11.58m^3/ha$ in degraded pine forest. However in agriculture area, growing stock volume density of $14.85m^3/ha$ was recorded. Similarly, out of the total biomass (0.012 million tons) and carbon (0.056 million tons) in the study area, open pine forest accounted for the highest values of 43.74 t/ha and 19.68 t/ha and lowest values of 5.68 t/ha and 2.55 t/ha, respectively for the degraded pine forest. The biomass and carbon density in agriculture area obtained was 5.49 t/ha and 2.47 t/ha, respectively. In all the three forest classes Pinus roxburghii showed highest average values of growing stock volume density, biomass and carbon.

• 한국산림과학회지
• /
• 제101권3호
• /
• pp.469-479
• /
• 2012

본 연구의 목적은 숲길프로그램에 대한 이용객의 선호와 이용 행태, 숲길에 따른 이용특성을 파악하는 것이다. 숲길프로그램 참여의사, 선호하는 산림휴양활동, 프로그램 내용과 실질적인 프로그램 운영방식에 대한 이용객의 요구를 살펴보았다. 숲길프로그램이 필요하다는 응답이 높게 나타났고 산림휴양활동, 숲길프로그램 내용, 운영방식은 이용대상, 이용행태, 숲길에 따라 차이를 보였다. 20대는 활동성이 높은 자연체험 프로그램, 중 노년층은 건강 프로그램을 선호하였다. 프로그램 운영은 현장에서 진행하는 정기 프로그램을 선호하였고, 운영시간은 1~3시간이 적절한 것으로 나타났다. 숲길별로 살펴보면 북한산 둘레길은 산림치유 등 건강프로그램 위주의 1~2시간 진행되는 정기 프로그램이 적합할 것으로 생각되며 울진숲길은 기존의 가이드방식에 자연감수성을 키울 수 있는 다양한 체험활동의 도입이 필요할 것으로 보인다. 지리산 둘레길은 젊은 층의 이용이 많고 다른 숲길에 비해 트레킹을 중심으로한 프로그램개발이 필요하다.

• Clinical Endoscopy
• /
• 제55권3호
• /
• pp.426-433
• /
• 2022

Background/Aims: Cholangiogram interpretation is not used as a key performance indicator (KPI) of endoscopic retrograde cholangiopancreatography (ERCP) training, and national societies recommend different minimum numbers per annum to maintain competence. This study aimed to determine the relationship between correct ERCP cholangiogram interpretation and experience. Methods: One hundred fifty ERCPists were surveyed to appropriately interpret ERCP cholangiographic findings. There were three groups of 50 participants each: "Trainees," "Consultants group 1" (performed >75 ERCPs per year), and "Consultants group 2" (performed >100 ERCPs per year). Results: Trainees was inferior to Consultants groups 1 and 2 in identifying all findings except choledocholithiasis outside the intrahepatic duct on the initial or completion/occlusion cholangiogram. Consultants group 1 was inferior to Consultants group 2 in identifying Strasberg type A bile leaks (odds ratio [OR], 0.86; 95% confidence interval [CI], 0.77-0.96), Strasberg type B (OR, 0.84; 95% CI, 0.74-0.95), and Bismuth type 2 hilar strictures (OR, 0.81; 95% CI, 0.69-0.95). Conclusions: This investigation supports the notion that cholangiogram interpretation improves with increased annual ERCP case volumes. Thus, a higher annual volume of procedures performed may improve the ability to correctly interpret particularly difficult findings. Cholangiogram interpretation, in addition to bile duct cannulation, could be considered as another KPI of ERCP training.

• 한국융합학회논문지
• /
• 제13권1호
• /
• pp.417-424
• /
• 2022

본 연구에서는 산림교육전문가들이 자연(숲)과 사람(방문객)을 매개하는 연결자 역할을 충분히 발휘할 수 있게 하기 위한 심리학 기반 자연탐구역량 교육과정을 개발하고자 하였다. 자연에서 자신의 감각과 정서를 자각하고 명명하며 자연 관련 기억과 자연탐구지능을 발굴하여 자연에서 몰입하고 디폴트 모드 네트워크를 활성화하는 내용을 중심으로 즐거운 생활, 슬기로운 생활, 의미있는 생활의 3개로 구성된 교육과정을 고안하였다. 전문가 자문을 통해 보완한 교육과정에 따라 구성한 교육을 산림교육전문가의 직무교육으로 시행하고 참가자를 대상으로 이해도와 활용 가능성 등을 조사하여 수정하였다. 최종적으로 자연탐구역량을 정서, 인지, 실천의 3개 영역의 심리학적 개념으로 구성한 교육과정을 완성하였다. 향후 지속적 평가를 통해 본 교육과정을 발전시켜 산림교육전문가들이 자연탐구역량을 강화하여 향상된 산림교육서비스를 제공할 수 있기를 기대한다.

• 한국산림과학회지
• /
• 제94권2호통권159호
• /
• pp.61-66
• /
• 2005

This research is based on a visitor survey at Jogyesan Provincial Park in Jeonnam, and its implications for interpretive planning. The research population was the set of weekend and holiday visitors, 20 years of age and older, to Jogyesan Provincial Park in Jeonnam, during the summer of 2003. A questionnaire was offered to every tenth person entering the park on every other weekend day and both holidays (June 1 and September 30). It was obvious that the interpretive program at Jogyesan Provincial Park, to meet the expectations of its visitors, should provide: (1) visitors with opportunities to experience the out-of-doors and learn about the cultural, historical and natural surroundings; (2) opportunities for the visitors to relax and escape from the normal and work environment; and (3) opportunities for the visitors to experience an atmosphere which enables them to achieve and self-actualize. In the area of interpretive programs, expectations are usually priorities, except for mountain climbing and exercise. Enhancing achievement and self-actualization is rarely a consideration and needs more emphasis in the future interpretive programs and plans.

• 환경영향평가
• /
• 제8권3호
• /
• pp.77-90
• /
• 1999

The degree of green naturality (DGN) has played a key role for maintaining the environmental quality from inappropriate developments, although the quality and effectiveness of the mapping of DGN has been under debate. In this study, spatial distribution of degree of green naturality was initially estimated from forest stand maps that were produced from the aerial photo interpretation and extensive field survey. Once the boundary of initial classes of DGN were defined, it were overlaid with normalized difference vegetation index (NDVI) data that were derived from the recently obtained Landsat Thematic Mapper data. NDVI was calculated for each pixel from the radiometrically corrected satellite image. There were no significant differences in mean values of vegetation index among the initial DGN classes. However, the satellite derived vegetation index was very effective to delineate the developed and damaged forest lands and to adjust the initial value of DGN according to the distribution of NDVI within each class.