• Journal of Ecology and Environment
• /
• 제31권3호
• /
• pp.193-200
• /
• 2008

We obtained quantitative information on leaf unfolding and leaf shedding by observing 45 species of cool temperate deciduous trees in an arboretum over 5 growing seasons. These trees were in leaf (the foliage period) for 207 days on average after 1 April; 50% of leaves had been shed by 192 days after 1 April. Duration from the start of leaf unfolding to 50% leaf shedding was 157 days on average. Leaf unfolding began 35 days on average after 1 April. For leaf unfolding to begin, a$ 51^{\circ}C{\cdot}day$ of cumulated daily mean air temperature above $5^{\circ}C$ from 1 January (modified Kira's warmth index) was needed. Fifty-nine days elapsed between initiation and the final stage of leaf unfolding. The period of net photosynthetic assimilation was 157 days. The species with succeeding- type leaf unfolding associated with the anemochore seed type dominated the early stage of succession, while the species with flush-type leaf unfolding tended to dominate the late stage of succession. Few species were found in regions where late frosts occur after the day when the cumulative temperature for leaf unfolding is achieved. Biological characteristics include time of leaf unfolding, which affects the life history of each species, so that each species occupies its own niche in the stand. We conclude that that leaf phenology, such as timing of leaf unfolding and leaf shedding, is one of the components of each species' ecological characteristics.

• 한국전자파학회:학술대회논문집
• /
• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
• /
• pp.163-168
• /
• 2005

Attenuation in vegetation is important, for both terrestrial and earth-space systems. However, the wide range of conditions and types of foliage makes it difficult to develop a generalized prediction procedure. Currently, there is also a lack of suitably prediction model and measured experimental data for vegetation loss. So in this paper, vegetation loss data for four different tree-species, including Dawn-redwood tree, Plane tree, Pine tree and Fir tree are obtained by measurement in the frequency range of 1.0 $\sim$ 6.0 GHz. The through or scattered component is calculated using a model based upon the theory of RET(Radiative Energy Transfer) and RET modeling parameters are extracted from the measured data.

• 미생물과산업
• /
• 제25권2호
• /
• pp.11-18
• /
• 1999

전북지방에 만연되고 있는 고구마 위축병에 관한 병원성 검정에 따른 결과는 다음과 같다. 1. 본고구마 위축병의 병원은 mycoplasma-like organism(또는 PPLO)으로서 그 형태는 타원형이며 크기는 200~2500범위이다. 2.항생물질 효과는 oxytetracycline이 가장 효과적이다. 3.전자현미경 관찰 결과 mycoplasma-like bodies 는 엽맥 관세포 속에 밀집되여 있고, 항생물질에 의해 모구조의 파괴현상이 나타난다. 4. 감염경로는 접목전염만이 되고, 즙액전염, 곤충전염에서는 감염이 되지 않았다.

• 한국대기환경학회지
• /
• 제14권6호
• /
• pp.537-544
• /
• 1998

We selected Spathiyhyllum patinii and Pachira aqkatica, since the former has high O3 absorption while the latter low absorption, and analyzed physiological factors such as diffusive coefficient, transpiration rate, photosynthetic rate, and CO2 absorption rate, which affected O3 absorption capacity There was significant relationship between gas absorption capacity and the other factors; photosynthetic rate, diffusive resistance, stomatal resistance and CO2 absorption rate. Therefore model formula for estimation of O3 absorption rate in plant was formulated by making use of these factors. There was difference for the estimation of O3 absorption rate according to plant species. In case of Spathiphyllum patinii, photosynthetic rate is an optimal factor for estimation of O3 absorption capacity. On the other hand, stomatal resistance and diffusive resistance are optimal factors of Pachira aquatica among various physiological ones. And we knew that CO2 absorption rate is a potential factor to evaluate gas absorption capacity regardless of plant species. But considering efficiency and practicality, diffusive resistance was the most effective factor for the estimation of O3 gas absorption.

• Asian-Australasian Journal of Animal Sciences
• /
• 제16권5호
• /
• pp.702-705
• /
• 2003

Forest by-product silage (FPS) comprised of foliage, shrubs, and wild grasses was prepared to examine feeding value as sole roughage source for spotted (sika) deer. This diet was compared with imported oak leaf hay (OLH) and a commercial mixed ration (CMR) in digestion balance trials with spotted deer. Dry matter intake was highest (p<0.05) on the OLH, whereas intakes of the FPS and CMR were similar (p>0.05). Digestibility of dry matter was highest (p<0.05) for CMR. Digestibility of crude protein was highest in CMR and lowest in OLH and there were significant differences (p<0.05) among diets. Average daily gain, digestible dry matter intake and digestibility of crude fiber did not differ significantly among diets. Nitrogen intake, urinary and digestible nitrogen were highest (p<0.05) in CMR. However, nitrogen retention was not significantly different. Consequently, FPS is a good roughage source for deer having high digestibility, dry matter intake and availability of nitrogen.

• Asian-Australasian Journal of Animal Sciences
• /
• 제3권2호
• /
• pp.85-89
• /
• 1990

Sixteen Harnai lambs were used in a completely randomized design to study the nutritive value of fourwing saltbush as a winter maintenance browse in comparison to native range grazing with or without protein and energy supplementation at Tomagh Range Livestock Research Station, in Loralai District, Balochistan. The animals were divided into four groups of four lambs each. These four groups were assigned four treatments at random: fourwing saltbush grazing alone, range grazing plus lucerne hay (100 g/head/day), range grazing plus barley grain (100 g/head/day) and range grazing alone for ten weeks. The results indicate that the two range grazing plus supplementation treatments produced weight gains which were not significantly different from each other (p < 0.05). Both of these treatments yielded significantly higher weight gains (p < 0.05) than did range grazing alone except for the last week of the study. Fourwing saltbush grazing provided cumulative weight gains at 3, 4, 6, 7 and 8 weeks which were not significantly different from the range grazing plus lucerne hay treatment and gained an average of 6 percent in body weight over the 10 week period of study. The carrying capacity for sheep of a mature stand of fourwing saltbush was approximately 20 Sheep-kg-days (SKD) of grazing per cubic meter of foliage. Results of this study suggest that under fourwing saltbush grazing alone, lambs do not only maintain their body weights but can also gain weight in winter.

• Journal of Forest and Environmental Science
• /
• 제36권1호
• /
• pp.17-24
• /
• 2020

This study aimed to figure out and compare the increment of biomass by thinning intensity focused on the plantation of the two major coniferous species (Larix kaempferi and Pinus koraiensis) of South Korea. The inventory interval was three years under the effects of three types of thinning treatments; control (no thinning), light (20% thinning) and heavy (40% thinning). The results showed standing biomass increment of both species decreased as thinning intensity increased (heavylight>control). Meanwhile, the lowest of on-site biomass changes occurred in the control plot, and the greatest was in the heavy thinning plot because thinning was involved with leaving the felling residual biomass (leaves, branches and roots) on the site. According to the results from this short-term study, unthinned stands is preferable for maximizing standing biomass as well as carbon sequestration. However long-term investigation should be considered in order to see more clear results.

• 한국응용곤충학회지
• /
• 제20권2호
• /
• pp.83-86
• /
• 1981

아스파라가스 줄기 마름병 (경고병)의 효과적인 방제 대책을 수립하고자 시험한 결과 1. 줄기 마름명은 5월하순부터 발생하여 7월이후 강우와 함께 급격히 증가하였고, 2. 약제살포를 겸하여 모경대치하고 plastic film으로 피복하였을 해가 약제살포만 할때보다 줄기 마름병의 발생이 현저히 줄어들었다. 3. Plastic film으로 피복하였을 때의 $7\~8$월중 토양 수분변화는 아스파라가스의 생육에 적당한 pF 2.9에 비교적 가까은 상태를 유지할 수 있었다. 4. 모경대치를 할 겅우 대조구보다 수량이 떨어졌으나 plastic film을 피복할 경우는 대조구보다 약 $30\%$ 정도 증수되었다.

• Spatial Information Research
• /
• 제13권1호
• /
• pp.19-29
• /
• 2005

본 연구에서 RTK GPS의 매핑 도구로서의 가능성을 알아보고 RTK GPS의 정확도에 영향을 주는 요인을 알아보기 위해 각각 봄과 여름에 동일대상지역에서 두 번의 현장 작업을 수행하였다. 실험결과, 겨울뿐만 아니라 나무숲이 우거진 봄에도 고층건물과 나무숲으로 둘러싸인 일부환경을 제외한 곳에서 RTK GPS로 매핑이 가능하였다. 하지만 RTK GPS의 이용성과 매핑 정확도는 높지 않았다. 따라서 위성신호수신이 용이하지 않은 도심지 등에서 RTK 매핑 시 Total Station 등의 기타 장비에 의한 현장보완측량이 필요할 것으로 사료된다.

• 전기전자학회논문지
• /
• 제18권4호
• /
• pp.536-543
• /
• 2014

Terrain classification is still a challenging issue in image processing, especially with high resolution satellite images. The well-known obstacles include low accuracy in the detection of targets, especially for the case of man-made structures, such as buildings and roads. In this paper, we present an efficient approach to classify and detect building footprints, foliage, grass and road from high resolution grayscale satellite images. Our contribution is to build a strong classifier using AdaBoost based on a combination of co-occurrence and Haar-like features. We expect that the inclusion of Harr-like feature improves the classification performance of the man-made structures, since Haar-like feature is extracted from corner features and rectangle features. Also, the AdaBoost algorithm selects only critical features and generates an extremely efficient classifier. Experimental result indicates that the classification accuracy of AdaBoost classifier is much higher than that of the conventional classifier using back propagation algorithm. Also, the inclusion of Harr-like feature significantly improves the classification accuracy. The accuracy of the proposed method is 98.4% for the target detection and 92.8% for the classification on high resolution satellite images.