• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.28 no.2
• /
• pp.272-279
• /
• 1983

Canopy structure and light interception were investigated as related to forage growth and dry matter production in four swards; pure orchardgrass, pure ladino clover, orchard-ladino mixture, and multi-mixture that was consisted of four grasses and three legumes. In spring, multi-mixture stand had the highest LAI, while ladino clover pure stand had low LAI but the highest leaf volume density(L$_{v}$ ). In fall, both pure orchardgrass and orchard-ladino mixture had higher LAI and L$_{v}$ than others. Orchard pure stand was an electophile canopy with K, light extinction coefficient, of 0.29-0.43, pure ladino clover a planophile canopy with K of 0.72, and both mixtures a plagiophile canopy with K of 0.43-0.58. Dry matter yields had highly significant correlation with LAI in all stands. Optimum LAI for pure orchardgrass was estimated above 6.0 and for pure ladino clover, orchard-ladino mixture and multi-mixture were about 3.8,5.0 and 8.0, respectively. Conclusion was made that multi-mixture and orchard-ladino mixture had better canopy structure to improve light penetration and forage yield than pure stands.

• ALGAE
• /
• v.32 no.1
• /
• pp.41-46
• /
• 2017

In rocky intertidal habitats, abiotic stress due to desiccation and thermal extremes increases with elevation because of tides. A study in Atlantic Canada showed that, at low elevations where conditions are benign due to the brief low tides, fucoid algal canopies (Ascophyllum nodosum and Fucus spp.) do not affect the structure of benthic communities. However, at middle and high elevations, where low tides last longer, fucoid canopies limit abiotic extremes and increase the richness (number of invertebrate and algal species, except fucoids) of benthic communities. Using the data from that study, this paper compares the intensity of facilitation and its importance (relative to all other sources of variation in richness) between middle and high elevations, which represent intermediate and high stress, respectively. Facilitation intensity was calculated as the percent increase in benthic richness between quadrats with low and high canopy cover, while the importance of facilitation was calculated as the percentage of variation in richness explained by canopy cover. Data for 689 quadrats spanning 350 km of coastline were used. Both the intensity and importance of facilitation were greater at middle elevations than at high elevations. As canopies do not affect benthic communities at low elevations, this study suggests that the facilitation-stress relationship at the community level is unimodal for this marine system. Such a pattern was found for some terrestrial systems dominated by canopy-forming plants. Thus, it might be ubiquitous in nature and, as further studies refine it, it might help to predict community-level facilitation depending on environmental stress.

• Journal of Korean Society of Forest Science
• /
• v.88 no.1
• /
• pp.38-46
• /
• 1999

Canopy structure conductances of a Norway spruce forest in the Solling Hills(Central Germany) and Central Forest Biosphere Reserve(320km to the north-west from Moscow) were derived from LE(latent heat flux) and H(sensible heat flux) fluxes measured(by Eddy correlation technique and energy balance method) and modelled(by one dimensional non-steady-state) SVAT(soil-vegetation-atmosphere-transfer) model(SLODSVAT) using a rearranged Penman-Monteith equation("Big-leaf" approximation) during June 1996. They were compared with canopy stomatal conductances estimated by consecutive intergrating the stomatal conductance of individual needles over the whole canopy("bottom-up" approach) using SLODSVAT model. The result indicate a significant difference between the canopy surface conductances derived from measured and modelled fluxes("top-down" approach) and the stomatal conductances modelled by the SLODSVAT("bottom-up" approach). This difference was influenced by some nonphysiological factors within the forest canopy(e.g. aerodynamic and boundary layer resistances, radiation budget, evapotranspiration from the forest understorey). In general, canopy surface conductances derived from measured and modelled fluxes exceeded canopy stomatal conductance during the whole modelled period, The contribution of the understorey's evapotranspiration to the total forest evapotranspiration was small (up to 5-9% of the total LE flux) and was not depended on total radiation balance of forest canopy. Ignoring contribution of the understorey's evapotranspiration resulted in an overestimation of the canopy surface conductance for a spruce forest up to 2mm/s(about 10-15%).

• Journal of Korean Society of Forest Science
• /
• v.96 no.2
• /
• pp.227-234
• /
• 2007

The forest canopy gap has been well known as a substantial process of forest cyclic regeneration and important role in stand structure, dynamics, and biodiversity of the forest ecosystem. Based on 3,600 $5m{\times}5m$ square grids in a 9ha permanent experimental plot, the study was conducted to evaluate the regeneration pattern of woody species by developmental stage {seedlings (<1 m of height), saplingI (>1 m of height, <2 cm of DBH), and saplingII (2 cm$<200m^2$), $201-400m^2$, $400-600m^2$, $601-800m^2$, and $>800m^2$) in the mixed broadleaved-Korean pine forest. The results indicated that the regenerating trees of Populus ussuriensis occurred only in the canopy gap area, considered to be a typical gap-dependent species. The regeneration of Ulmus japonica, Ulmus laciniata, and Maackia amurensis could be generally satisfied with the gap size of $201-600m^2$, Betula costata and Prunus padus with gap size of $401-800m^2$, Picea koraiensis with gap size of $201-800m^2$, Fraxinus mandshurica and Syringa reticulata var. mandshurica with smaller than $800m^2$, respectively. Acer ukurunduense and Acer tegmentosum were likely to have no problem with the gap size to make gap regeneration. Acer mono and Tilia amurensis looked more capable of regenerating in the closed canopy disregarding the upper crown condition. The regeneration of Pinus koraiensis and Abies nephrolepis had no trouble under the canopy condition in less than $800m^2$of gap size. The density of regenerating shrubs was rather high, especially under the closed canopy, considered to be associated with great amount of regeneration production in such shade tolerant species as Lonicera maackii, Corylus mandshurica, Euonymus pauciflorus, and Philadelphus schrenkii under the closed canopy. Pearson correlation coefficient was computed to compare the similarity among non-gap area and five gap size classes by developmental stages for trees and shrubs. The similarity coefficients among closed canopy and the gap size classes were mostly significantly correlated to each other with a few exceptions.

• Korean Journal of Environment and Ecology
• /
• v.11 no.4
• /
• pp.493-505
• /
• 1998

To study vegetation structure and distance between trees of Pinus densiflora forest in Chayang-chon area, Soraksan National Park, thirty-nine plots(10m$\times$10m) were established. They were classified into two communities by TWINSPAN and DCA technique. In the Community I, P. densiflora(DBH 35~75cm, height 9~16m, age 60~80) dominated in canopy and were predicted to be changed by deciduous broad-leaved trees also. In the Community II, P. densiflora(DBH 9~26.5cm, height 9~16m, age 30~50m) dominated in canopy. It seemed that the community II would maintain P. densiflora community for a long time since P. densiflora dominated in both canopy and understory. Shonnon's diversity index was higher in the community II(1.4247) than in the community I(1.2978). The distantes between canopy trees were 4.92$\pm $2.14m in the community I and 2.41$\pm $0.97m in the community II. The regression between DBH in canpy and ecological distance was Y(Distance) = 0.06355$\times $(DBH)+1.51613.

• Korean Journal of Environment and Ecology
• /
• v.11 no.4
• /
• pp.486-492
• /
• 1998

The forests of Osaek-Taech'ongbong-Shinhungsa district in Soraksan National Park was studied to investigate forest structure of tree strata in relation to aspect and altitude of the slope. Excepting the main ridge area which has tyoical environmental condition, tree siwe in canopy of the wouthern slope was smaller, density in canopy of the southern slope was higher and species diversity in tree stratum of the southern slope was lower as compared those of the northern slope of same elevation belts. Elevation trend was found for forest structure of the southern slope where geographical features were similar among elevation belts. With incleasing elevation of the southern slope, basal area of canopy and understory increased. With increasing elevation of the southern slope, importance values of Quercus mongolica, Styrax obassia, and Lindera obtusiloba decreased while those of Pinus koraiensis, Betula ercani, Acer tschonoskii var. rubripes and Rhododendron schlippenbachii increased. According to cluster and ordination analysis, the studied forests was classifide into Quercus mongolica community at the low, middle and high elevation belts of the southern slope and the low and middle elevation belts of the northern slope, Betula ermani community at the elevation belt of the northern slope, and Abies koreana community at the top area.

• Journal of Photoscience
• /
• v.9 no.2
• /
• pp.166-169
• /
• 2002

This paper is a part of the research into effects of increased UV-B (Ultraviolet-B, 280-320nm) upon the ecosystem of field wheat. Based on a 3-year project with intensified UV-B influencing the crop, observation and calculation were made of such factors and parameters as the morphology of a single wheat plant including its leaf area, leaf base angle and proportion of spacing between joints. The results show that the enhanced UV-B signifantly decreased wheat's SSLA, and the increased percentage of the lower LAI is associated with the change in leaf base angle and proportion of spacing between joints.

• Journal of Plant Biology
• /
• v.17 no.3
• /
• pp.118-126
• /
• 1974

Mulberry plants cultivated in mid-Korea were studied on the growth habitat, canopy type, productive structure and vertical light intensity in relation to the quality of mulberry leaves for sericulture. The growth in length of new branch of summer cut mulberry in spring was vigorous on the uppermost of old shoot. Numbers of leaves on a branch were barely 4 leaves on lower than 20th branch from base, but those were 13 leaves on higher than 24th branch. Area of leaves completely expanded was broad on high branch, but narrow on low one. The form of canopy, the type of productive structure and the vertical light distribution depend upon varieties of cultivated mulberry plants were classified according to characteristic of each variety in two groups, respectively; globular and columnar form in canopy, broad leaves and narrow leaves types in productive structure, and seriously obstructured the light and fairly transmitted the light into lower leaf stratum invertical light distribution. Out of varieties of mulberry investigated, Suwon No. 4 and Rosang were belong to the former characters, but Illchiroe and Kaeryangsubun were to the latters. The values of leaf dry matter index and dry matter production produced by leaves were increased in direct proportion to the height of leaf stratum; the leaf dry matter index of the uppermost leaf was twice as much that of the lowest, and the dry matter production by the highest leaf was 17 times compared with that by the lowest leaf. It is assumed that the meagre leaves occurred in the lower leaf stratum of Suwon No. 4 and Rosang were caused to diminished the dry matter index and dry matter production in the under leaves of plant, which were affected by receiving the weak light.

• The Korean Journal of Ecology
• /
• v.16 no.4
• /
• pp.459-476
• /
• 1993

Vegetational structure and successional sere were investigated for the evergreen and nearby deciduous broad-leaved forests in inland areas (Turyunsan, Pulgapsan) and south- western island areas (Hongdo, Chindo). The evergreen broad-leaved forests of the four areas showed a sera1 stage with an age structure mostly under fifty years old. Dominant evergreen broad-leaved species in canopy layer were Castanopsis cuspidata var. sieboldii, Machilus thunbergii, Quercus acuta, Q. stenophylla, Q. glauca, and Ncolitsea serzceu. Succession of the forest vegetation in the surveyed areas was proceeding from deciduous broad-leaved trees to evergreen broad-leaved trees. The species of climax stage were assumed to be Machilus thunbergii, iVeolitseu sericea and Dendropanax morbifera in canopy layer, Aucuba japonica and Machilus japonica in subtree and shrub layer.

• Korean Journal of Environment and Ecology
• /
• v.18 no.3
• /
• pp.279-287
• /
• 2004

To investigate the vegetation structure of the section of Nakdong-jeongmaek from Gajisan to Neungdongsan, fifty plots of 100$m^2$ at ten locations were set up. In accordance with the requirements of DCA(detrended correspondance analysis), which is an ordination technique, the sites were chosen contiguously with each other. The vegetation structure analysis showed Quercus dentata, Pinus densiflora, Q. mongolica to be the major species at canopy layer, Rhododendron schlippenbachii at the layer below the canopy and Tripterygium regelii at the shrub level. Shannon's diversity index was 1.5315～2.4005 per unit area of 500$m^2$. It appeared that the Quercus dentata forest of this ridge section of Nakdong-jeongmaek is about 30 or 40 years old.