• 제목/요약/키워드: forest dynamics

검색결과 238건 처리시간 0.025초

생태계교란식물 마늘냉이의 확산과 분포 특성 (Spread and distribution characteristics of ecosystem-disturbing plant Alliaria petiolata(M. Bieb.) Cavara & Grande in Korea)

  • 이연지;홍보람;이규송
    • 환경생물
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    • 제42권1호
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    • pp.62-79
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    • 2024
  • 마늘냉이(Alliaria petiolata)는 미국과 캐나다를 황폐화 시킨 종으로, 생태계 파괴 역할을 하는 것으로 알려져 있다. 본 연구에서 마늘냉이의 국내분포를 확인하였고, 국내에서 가장 큰 개체군이 정착한 삼척지역에서 정밀 분포 현황을 파악하여 정밀 분포도를 작성하였다. 삼척지역의 개체군을 대상으로 생육환경, 생활사 및 개체군 동태를 파악하였다. 마늘냉이는 삼척시에서 총 301지소에서 출현하였고 총 분포면적은 2,957 m2이었다. 일년생 개체는 4월 중순에 발아하여 로제트형태로 월동한 뒤 다음 해 4월 10일부터 24일까지는 영양생장을, 4월 24일부터 5월 7일까지 개화하였다. 종자를 맺은 개체들은 6월부터 사멸하기 시작하였다. 일년생과 이년생의 개체 수는 모두 4월 27일(118일) 전후를 기준으로 증가 후 감소하는 경향을 보였다. 마늘냉이는 초봄 시기에 빛 조건이 양호하고, 낙엽층은 덜 발달하며, 길로부터의 거리가 짧고, 해발고도가 낮은 사면 중하부의 낙엽활엽수림과 숲 가장자리를 선호하였다. 삼척지역에서 적절한 제어조치가 행해지지 않는다면 갈야산 일대의 등산로를 따라서 낙엽활엽수림을 중심으로 확산이 더욱 빠르게 진행될 가능성이 높다고 판단된다. 특히, 임상에 빛이 적은 소나무군락보다 개화기에 빛이 임상에 들어오는 참나무군락으로 확장할 가능성이 클 수 있다.

표고 톱밥재배사의 溫-濕度 變化 動態 (Dynamics of Temperature and Humidity Changes in Lentinula edodes Sawdust Cultivation Sheds)

  • 구창덕;김재수;이화용;유성열;유창현
    • 한국산림과학회지
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    • 제98권6호
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    • pp.748-756
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    • 2009
  • 적정한 종균과 배지를 가지고 표고를 톱밥재배하는 요점은, 표고균은 생장시키면서 오염균은 억제하도록 환경, 특히 온도와 습도를 조절하는 것이다. 톱밥표고 재배사내 온도와 습도 변동을 이해하기 위하여, 대만과 중국 방식의 재배사에서 이들을 측정 기록하고 분석하였다. 대만방식에서 재배사의 온-습도 변화는 5개 특징적 기간(겨울 균사생장기, 봄 버섯발생기, 초여름 버섯발생기, 여름 버섯 비발생기, 가을 버섯발생기)로 구분되었다. 먼저 겨울 균사 생장기는 저온기로 겨울 12월~3월 초순으로 일평균 $-1{\sim}8^{\circ}C$였고, 봄 버섯발생기는 온도상승기로 3월 중순~5월 하순으로서 일평균온도는 $8{\sim}21^{\circ}C$, 밤낮 온도차이는 $15^{\circ}C$였다. 초여름 버섯발생기는 버섯발생에 적온기로 6월 초순~7월초순이며 일평균온도가 $17{\sim}25^{\circ}C$ 였고. 여름 버섯비발생기는 고온다습기로 7월 중순~8월 중순으로 일평균온도 $25{\sim}28^{\circ}C$였다. 가을 버섯발생기는 온도하강기간인 8월 하순~10월 하순으로 일평균온도가 $10{\sim}23^{\circ}C$, 밤낮 온도차이가 $10{\sim}15^{\circ}C$에 이르고, 일평균온도가 $7^{\circ}C$ 이상 하강하였다가 $5^{\circ}C$ 정도 상승하는 날이 5~7일 주기로 반복되었다. 한편 중국식 재배사내 온-습도변화는 겨울동안 차광과 보온 그리고 가온으로 일평균온도를 $-1.9{\sim}5.0^{\circ}C$를 유지하였고, 6월~10월에는 $15{\sim}32^{\circ}C$를 유지하였다. 배지를 배열한 선반 0~150 cm 높이에서 온도 변이폭은 $12-30^{\circ}C$, 습도 변이폭은 40~100% 였다. 표고 톱밥 재배자들은 표고균에게는 유리하면서 오염균에게는 불리하도록, 즉 고온 과습하지 않도록 하루 중에도 수시로 차광과 통풍, 보온 등으로 재배사내 온-습도를 조절하였다.

石灰巖地域 소나무림과 측백나무림의 落葉生産, 分解 및 窒素와 燐의 動態 (Litterfall, decomposition, and nutrient dynamics of litter in red pine (pinus densiflora) and chinese thuja (thuja orientalis) stands in the limestone area)

  • Mun, Hyeong-Tae;Kim, Joon-Ho
    • The Korean Journal of Ecology
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    • 제15권2호
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    • pp.147-155
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    • 1992
  • Litterfall, decomposition, and dynamics of n and p in decomposing litter were investigated for 2 years in red pine ( pinus densiflora) and chinese thuja( thuja orientalis)stands in the limestone area. Average litterfall in red pine and chinese thuja stands were 4, 535kgDM ha-1 yr-1 and 5, 010 kgDM ha-1 yr-1, respectively. Seasonal litterfall in red pine and chinese thuja stands showed peaks in November. concentrations of N and P in the needle litter were lowest in the winter when the greast litterfall occurred, and highest in the summer when the least litterfall occurred. However, those in chinese thuja scale leaf litter showed litter seasonal variation.amount of N and P returned to the forest floor through litterfall were 29.02kgN ha-1 yr-1 , 2.81 kg P ha-1 yr-1 for red pine stand, and 31.06 kg N ha-1 yr-1 , 2.86kgP ha-1 yr-1 for chinese thuja stand, respectively. After 21 mounts elapsed, needle and chinese thuja scale leaf litterbags lost 34.8% and 32.5% of the initial weight, respectively. N concentrations in the docomposing needle and chines thuja scale leaf litter decreased by 19% and 30%, respectively, after 1 month elapsed, and then gradually increased to exceed the initial concentration after 9 months elapsed and then gradually increased to exceed the initial concentration after 9 months elapsed in both of them, P in needle and chines thuja scale leaf litter decreased by 54% and 57% of the initial concentration, respectively, after 1 month elapsed. unlike N, P concentration in the decomposing litter did not exceed that of initial ones. Neyt immobilization period of N and P in decomposing litter did not occur over the study period.

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넓은잎천남성 (Arisaema robustum) 개체군의 동태 (Population Dynamics of Arisaema robustum)

  • 민병미;유진숙
    • The Korean Journal of Ecology
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    • 제21권1호
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    • pp.27-33
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    • 1998
  • Arisaema robustum, which has the ability to change sex, was studied in a temperate broadleaf forest of Sanseong-ri, Joongbu-myeon, Gwangju-gun, Kyonggi Province, Korea. \ulcornerThe study, carried out from 1993 to 1997, focused on population dynamics energy budget among organs, size distribution, mortality, the relationships between sex and size, seed production and germination rate. In terms of energy budget among the organs, the ratio of aboveground to belowground biomass was 36.6 : 63.4 in non-female plants, and 81.4 : 18.6 in female plants. Also, in female plants, the ration of leaf to sexual organ biomass was 39.5 : 41.9. Therefore, the belowground ratio of female plants was lower than that of non-female plants. Plants were classified into 8 levels relative to the amount of leaf area by $100cm^2$. The rates of the smallest and the largest classes were 49% and 1%, respectively, and population distribution by size was relatively stable. The mortality averaged 13.1% per year and decreased in inverse proportion to leaf size (6.6% in the smallest and 0.0% in the largest size classes). Leaf areas were $64.1{\pm}48.5cm^2$ in non-flowering plants, $232.1{\pm}123.9cm^2$ in males and $444.8{\pm}153.9cm^2$ in females. The increase rates of leaf area per year varied from 1.9% in plants changing from female tomale, to 152.4% in plants changing from non-flowering to female. But plants which remained female for 2 years showed a decrease of 34.7%. >From this result, it is thought that the female plants invest more energy to reproduction than to vegetative organs. The correlation coefficient (CC) value between plant size and the number of seeds produced (0.55) was larger than the CC value between plant size and total seed weight (0.73). That is, the larger the plant size, the heavier the seed produced. The germination rate increased along with seed weight, and it was 95% in plants which were over 60mg fresh weight/seed.

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Relationship between Vegetation Composition and Dissolved Nitrogen in Wetlands of Higashi-Hiroshima, West Japan

  • Miandoab, Azam Haidary;Nakane, Kaneyuki
    • Journal of Ecology and Environment
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    • 제30권3호
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    • pp.209-223
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    • 2007
  • Twenty-four wetlands located in Higashi-Hiroshima City in West Japan were selected for this study in order to investigate both the relationship between aquatic plant composition and environmental conditions; and the relationship between changing land use patterns in the catchments and the concentration of different forms of nitrogen in the wetlands. The dominant and subdominant species which comprised the principal vegetation were determined based on a vegetation census conducted in each wetland during the growing season from June to August, 2006. The seasonal variations of water quality factors (pH, electrical conductivity, turbidity, dissolved oxygen, total dissolved solid, and temperature) and different forms of nitrogen such as nitrite, nitrate, ammonium, total nitrogen, dissolved organic nitrogen and dissolved inorganic nitrogen concentrations were analyzed as important indicators of water quality for the surface water of the wetlands. The surveyed wetlands were classified into three types (non-disturbed wetlands, moderately-disturbed wetlands and highly-disturbed wetlands), based on the degree of human disturbance to their catchment areas. An analysis of variance indicated that there was a significant difference among the wetland groups in the annual mean values of electrical conductivity, total dissolved solids, total nitrogen, nitrite, dissolved inorganic nitrogen and dissolved organic nitrogen. Classification of the wetlands into three groups has revealed a pattern of changes in the composition of plant species in the wetlands and a pattern of changes in nitrogen concentrations. A majority of the non-disturbed wetlands were characterized by Brasenia schrebi and Trapa bispinosa as dominant; with Potamogeton fryeri and Iris pesudacorus as sub-dominant species. For most of the moderately-disturbed wetlands, Brasenia schrebi were shown to be a dominant species; Elocheriss kuriguwai and Phragmites australis were observed as sub-dominant species. For a majority of the highly-disturbed wetlands, Typha latifolia and T. angustifolia were observed as dominant species, and Nymphea tetragona as the sub-dominant species in the study area. An analysis of land use and water quality factors indicated that forest area played a considerable role in reducing the concentration of nutrients, and can act as a sink for surface/subsurface nutrient inputs flowing into wetland water, anchor the soil, and lower erosion rates into wetlands.

Distribution pattern and population dynamics of Brown trout (Salmo trutta) and Snow trout (Schizothorax richardsonii) in Punatsangchhu River, Bhutan

  • Rupesh Subedi;Dhan Bdr Gurung;Kinzang Namgay;Laxmi Sagar;Rinchen Dorji;Tshering Pem;Namkha Gyeltshen
    • Fisheries and Aquatic Sciences
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    • 제27권7호
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    • pp.421-433
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    • 2024
  • Among larger species of fish found in Punatsang chhu, Brown trout (Salmo trutta) and Snow trout (Schizothorax richardsonii) are notable species. Snow trout is a native species, whereas Brown trout is an introduced species. Brown trout is noted to have a negative impact on the population of native species worldwide. This study studied the population dynamics and structure of these species to detect if the introduced species affected the native species adversely. The study was conducted on a 30 km stretch of Punatsang chhu including its major and minor tributaries at about their confluences. In total, 56 sample plots of a 200 m sampling stretch were studied with a 200 m distance between each stretch. Length, weight, maturity, and sex data for both species were collected along with the habitat and water parameters. The two species were found to prefer different areas within a single stretch with a rare overlap. Snow trout were found to be distributed widely within the basin whereas Brown trout were only found in altitudes higher than 1,000 masl ($\overline{x}$ = 1,231.77) and in turbid waters (p = 0.009). Recruitment of Snow trout was not good whereas recruitment of Brown trout was good. Length-frequency graphs indicated good inverse J distribution for the Snow trout population and sporadic for Brown trout. There is an effect of Brown trout introduction to the Snow trout living in the study area. Places invaded by Brown trout have a lesser presence of Snow trout compared to places not invaded by these species.

기후변화에 따른 수도권 산림의 순일차생산량과 토양탄소저장량의 시공간적 변화 추정 (Estimation of Spatial-Temporal Net Primary Productivity and Soil Carbon Storage Change in the Capital area of South Korea under Climate Change)

  • 권선순;최선희;이상돈
    • 환경영향평가
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    • 제21권5호
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    • pp.757-765
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    • 2012
  • The purpose of this study was to estimate the spatial-temporal NPP(Net Primary Productivity) and SCS(Soil Carbon Storage) of forest ecosystem under climate change in the capital area of South Korea using Mapss-Century1 (MC1), one of Dynamic Global Vegetation Models (DGVMs). The characteristics of the NPP and SCS changes were simulated based on a biogeochemical module in this model. As results of the simulation, the NPP varies from 2.02 to 7.43 tC $ha^{-1}\;yr^{-1}$ and the SCS varies from 34.55 to 84.81 tC $ha^{-1}$ during 1971~2000 respectively. Spatial mean NPP showed a little decreasing tendency in near future (2021~2050) and then increased in far future (2071~2100) under the condition of increasing air temperature and precipitation which were simulated by the A1B climate change scenario of Intergovernmental Panel on Climate Change (IPCC). But it was estimated that the temporal change of spatial mean NPP indicates 4.62% increasing tendency in which elevation is over 150m in this area. However, spatial mean SCS was decreased in the two future periods under same climate condition.

Basal area effects on a short-term nutrient status of litter fall and needle litter decomposition in a Pinus densiflora stand

  • Kim, Choonsig
    • Journal of Ecology and Environment
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    • 제39권1호
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    • pp.51-60
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    • 2016
  • This study was conducted to examine litter fall, litter decomposition, and a short-term nutrient (C, N, P, K, Ca, and Mg) status for one year at various levels of basal area (21.4, 27.0, 30.8, 37.0, 42.1, and 46.7 m2 ha-1) in approximately 40-yearold red pine (Pinus densiflora S. et Z.) stands in the Hwangmaesan mountain forest in Korea. Monthly fluxes of litter fall components such as needles, broad leaves, branches, bark and total litter fall followed a similar pattern at various levels of basal area. Mean annual needle, bark and total litter fall fluxes were positively correlated with increased basal area (p<0.05), but the woody litter such as branches and cones was not correlated with basal area. Carbon and K concentrations of needle litter were negatively correlated with increased basal area, while nutrient (C, N, P, K, Ca, and Mg) fluxes were positively correlated with the basal area treatments. Remaining mass, N and P concentration and remaining N and P stocks in decomposing needle litter were not affected by the basal area. However, the concentration and stocks remaining of K, Ca, and Mg from decomposing litter were positively correlated with increased basal area during the initial three months of decomposition. The results indicate that basal area has an impact on nutrient cycles through change in litter fall and litter decomposition processes; thus, the dynamics of nutrient cycles based on a stand scale could differ considerably with different levels of basal area in red pine stands.

해송엽(海松葉) Litter의 분해(分解)와 N, P 및 K의 동태(動態) (Decomposition and, Nitrogen, Phosphorus and Potassium Dynamics of Pinus thundbergii Needle Litter)

  • 이명종
    • 한국산림과학회지
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    • 제80권3호
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    • pp.303-310
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    • 1991
  • 해송엽(海松葉) litter의 분해(分解)와 그에 따른 양분방출(養分放出)의 동태(動態)를 일본지방(日本地方)의 해안(海岸) 해송림(海松林)에서 litterbag법(法)으로 조사(調査)하였다. litter의 분해(分解)에 따른 건물중(乾物重)의 소실(消失)은 초기(初期) 1년간(年間)에 빨랐고 그후는 보다 둔화(鈍化)하였으며, 분해(分解) 1년동안의 소실율(消失率)은 약(約) 40%였다. 분해계수(分解係數)는 0.5-6.0, 반감기(半減期)(년(年))는 l.1-l.4의 범위였다. 분해(分解)에 따른 잔존(殘存) litter내의 N과 P의 양분농도(養分濃度)는 경시적(經時的)으로 증가(增加)하는 경향(傾向)이었으나 K의 농도(濃度)는 감소(減少)하였다. K의 양분(養分)의 절대량(絶對量)은 분해(分解)가 진행(進行)하는 동안 현저히 감소하였으나 N의 절대량(絶對量)은 증가하는 경향을 보였다. 분해(分解)에 따른 방출(放出)은 K>P>N의 순(順)이었다. 실험기간중 N의 무기화(無機化) 단계는 나타나지 않았다.

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KA-32T 헬기 시뮬레이터 검증을 위한 비행시험 (KA-32T Helicopter Flight Test for Full Flight Simulator Validation)

  • 최형식;장재원;전대근;전향식
    • 항공우주기술
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    • 제7권1호
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    • pp.1-7
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    • 2008
  • 국토해양부 지원을 통해 수행되는 KA-32 훈련용 헬기시뮬레이터 개발 프로그램의 목적은, FAA AC 120-63의 레벨 C 요구규격을 충족하는 헬기 시뮬레이터를 개발하는 것이다. 한국항공우주연구원(KARI)은 개발 총괄 프로그램을 주관하고 있으며, 또한 비행 역학 모델을 개발하고 시뮬레이터 설계 데이터와 비행 시험 데이터에 기초를 충실도를 검증하는 업무를 담당하고 있다. 대상 헬기는 산림항공관리소에서 운용되고 있는 Kamov KA32T이다. 비행시험은 7월 30일에서 8월 31일까지 익산 산림항공관리소에서 수행되었다. 본 논문은 시뮬레이터 검증을 위한 비행시험데이터 획득에 필요한 장비장착 및 비행시험에 대한 내용을 기술하고 있다.

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