• 제목/요약/키워드: Ferns

검색결과 73건 처리시간 0.022초

Habitat Suitability Modeling of Endangered Cyathea spinulosa (Wall. ex Hook.) in Central Nepal

  • Padam Bahadur Budha;Kumod Lekhak;Subin Kalu;Ichchha Thapa
    • Journal of Forest and Environmental Science
    • /
    • 제39권2호
    • /
    • pp.65-72
    • /
    • 2023
  • The endangered species of Cyathea spinulosa (tree ferns) are among the least concerned ferns of Nepal that bring threats to them and their habitat. A way to reduce such threats is by maintaining a database of species' whereabouts and generating a scientific understanding the habitat preferences. This will eventually help in the formulation of conservation plans for the species. This research aimed to characterize the suitable habitat of C. spinulosa by enumerating the location of species in the Panchase Forests of central Nepal. The statistical index method was applied to relate the occurrence locations of species with various environmental factors for the development of indices. The suitable habitat of C. spinulosa (more and most suitable categories) covered 119 km2 and accounted for 43% of the total area studied. 74.4% of occurrence locations of C. spinulosa were recorded from these habitats. The habitat characteristics suitable for C. spinulosa were: proximity to streams (high moisture), land covered by forested area (shady area), mid-elevations of hills about 1,000 m to 2,000 m (sub-tropical climate), slope gradient of 20° to 40° (steep slopes), and northern to eastern aspects. These habitat characteristics could be considered for in-situ protection of tree ferns and designating the conservation plots.

Loran-C 한국체인(9930)에의 EUROFIX 시스템 구축 (The Construction of EUROFIX system into the Korean Loran-C Chain(9930))

  • 김민정;김경태
    • 한국항해학회지
    • /
    • 제25권4호
    • /
    • pp.335-345
    • /
    • 2001
  • While recognizing that Loran-C is very important as a back-up for satellite systems, the introduction of EUROFIX, that it uses Loran-C system, was proposed and admitted at 9th FERNS(Far East Radio Navigation System) Meeting. But, the FERNS countries should consider whether the cost-effectiveness of the system could be improved by making use of its communication facilities to integrate more closely with satellite systems. And, the members were requested to give this proposal consideration before the l0th session of the Council. or this matter, Korea planned to demonstrate transmitting EUROFIX signals from Pohang Loran-C station (Master of 9930 Chain) during the l0th FERNS Meetings. Therefore, this thesis describes the analysis of EUROFIX datalink and progress of EUROFIX construction work. This thesis is the report with regard to the sequence of this demonstration of EUROFIX in Korea.

  • PDF

Enumeration of edible and useful ferns (Pteridophytes) in the Bhutan Himalayas

  • Rinchen DORJI;Choki GYELTSHEN;PHUENTSHO PHUENTSHO;Karma Ugyen WANGMO;Kencho DORJI
    • 식물분류학회지
    • /
    • 제52권4호
    • /
    • pp.235-245
    • /
    • 2022
  • Bhutan is endowed with rich biodiversity with several edible and useful fern species. Ferns have been used by local communities for centuries as vegetables, ethnobotanical artifacts, and as medicines. Owing to the limited study of edible and useful pteridophytes in the country, the knowledgebase remains poor. In this study, we attempt to document edible and useful fern species in the country scientifically while also providing an annotated checklist.

광릉숲 양치식물의 분포와 생활형 (The Distribution and Life-form of Ferns in Gwangneung Forest)

  • 이강협;여경택;정승선
    • 한국자원식물학회지
    • /
    • 제19권5호
    • /
    • pp.592-597
    • /
    • 2006
  • 광릉숲 양치식물을 중심으로 한 집중적인 조사를 통하여 이 지역에 분포하는 양치식물을 정확히 밝히고자 하였다. 광릉숲에는 9과 17속 43종 3변종 총 46종류의 양치식물이 분포하고 있으며, 지역별 출현식물을 보면, 쇠뜨기, 고사리삼 등 26종류가 광릉숲 전지역에 걸쳐 분포하는 것으로 나타났으며, 꿩고비, 지리개관중 등 5종류가 소리봉 일대를 중심으로 하여 한정 분포하는 것으로 나타났다. 또, 산림동물원 계곡부를 중심으로 낚시고사리, 광릉족제비고사리 등이 분포하였고, 왕지네고사리, 참새발고사리 등은 외국수목원 일대에 국한된 분포역을 형성하고 있었다. 생활형을 보면, 휴면형(Domancy form)은 H(Hemicryptophyte)의 비율이 56.5%로 가장 높았으며, HH(Hydatophyte)가 2.2%로 가장 낮은 값을 보였다. 번식형(Propagation form)의 지하기관형(Radicoid form)은 대부분이 근경이 짧게 분지하고 가장 좁은 범위의 연결체를 갖는 $R_3$으로 39.1%이며, 근경이 옆으로 벋고 약간 넓은 범위의 연결체를 갖는 $R_2$가 2.2%이었고, 산포기관형(Disseminule form)은 모두 포자가 바람이나 물에 의해 운반되는 $D_1$이었다. 생육형(Growth form)은 t(Tussock)와 e(Erect)가 각각 67.4%와 32.6%로 나타나 광릉숲 양치식물의 대표적인 생활형은 $H-R_{3}-D_{1}-t$로 정리되었다. 광릉숲의 양치식물계수(Ptph.-Q.)는 1.28로 한반도 중부지역과 비교하였을 때 상대적으로 다소 높은 수치를 보이고 있어, 이 지역이 학술림으로서 안정적으로 보전 관리되고 있음을 알수 있다.

Ferns 알고리즘 기반 밝기 및 회전 변화에 강인한 영상검색 시스템 설계 및 구현 (Design and Implementation of Video Search System robust to Brightness and Rotation Changes Based on Ferns Algorithm)

  • 윤석환;심재성;박석천
    • 한국멀티미디어학회논문지
    • /
    • 제19권9호
    • /
    • pp.1679-1689
    • /
    • 2016
  • Recently, due to the rapid development of multimedia technologies, as image data has been extensive and large-scaled, the problem of increasing the time needed to retrieve the desired image is gradually critical. Image retrieval system that allows users to quickly and accurately search for the desired image information has been researched for a long time. However, in the case of content-based image retrieval representative Color Histogram, Color Coherence Vectors (CCV), Scale Invariant Feature Transform (SIFT) used in sensitive to changes in brightness, rotation, there is a problem that can occur misrecognized division off the power. In this paper, in order to evaluate the video retrieval system proposed, no change in brightness, respectively 0°, 90°, 180°, 270° rotated brightness up based on the case of changing, when the brightness down the results were compared with the performance evaluation of the system is an average of about 2% to provide the difference in performance due to changes in brightness, color histogram is an average of about 12.5%, CCV is an average of about 12.25%, it appeared in the SIFT is an average of about 8.5%, Thus, the proposed system of the variation width of the smallest in average about 2%, was confirmed to be robust to changes in the brightness and rotation than the existing systems.

고사리 산업화를 위한 인공종자 개발 및 생산 (Synthetic Seed Development and Production for Industrialization of Eastern Bracken)

  • 장보국;조주성;이철희
    • 한국자원식물학회:학술대회논문집
    • /
    • 한국자원식물학회 2021년도 춘계학술대회
    • /
    • pp.11-11
    • /
    • 2021
  • Ferns have been consumed as food in many countries for centuries. As rich sources of protein, fiber, minerals, vitamins, essential amino acids, and fatty acids, ferns provide important nutrients to humans. Eastern bracken (Pteridium aquilinum var. latiusculum (Desv.) Underw. ex A. Heller) is the most popular edible fern in South Korea where, additionally, it has long been used as an edible wild leaf vegetable. Recently, the production of eastern brackens in South Korea (2018) has reached 14,032 tons, for an annual revenue of 83.5 billion won, and even more eastern brackens are marketed if imports are taken into account as well. Most of the common ferns can be propagated using spores. However, fern farmers cultivate seedlings through traditional propagation methods, such as root pruning or rhizome division. These propagation methods exhibit limitations in forming roots and growing-points and are labor intensive. Quality seedlings of eastern bracken can be obtained through spore propagation, but the spores are fine and difficult to handle in the field. In addition, it would require appropriate environmental control. The production of synthetic seeds using encapsulation technology is easy to establish and it can be used to achieve high productivity at low cost. Synthetic seeds contain explants embedded into a seed foam, and they overcome the limitations of micropropagation and offer the possibility of using plug seedlings. Synthetic seed matrix, such as sodium alginate, has the advantages of low cost, low toxicity, and gel stability. The present study aimed to develop and produce synthetic seeds for the commercial exploitation of eastern bracken. Furthermore, we verified spore germination and the extent of gametophyte and sporophyte development achieved with our new synthetic seeds, whose production was intended to solve current problems with the handling, storage, and transportation of eastern bracken.

  • PDF