Predicting individual stem volumes of sugi (Cryptomeria japonica D. Don) plantations in mountainous areas using small-footprint airborne LiDAR     

Tomoaki Takahashi  Kazukiyo Yamamoto  Yoshimichi Senda  Masashi Tsuzuku 《Journal of Forest Research》2005,10(4):305-312

This study investigated which predictor variables with respect to crown properties, derived from small-footprint airborne light detection and ranging (LiDAR) data, together with LiDAR-derived tree height, could be useful in regression models to predict individual stem volumes. Comparisons were also made of the sum of predicted stem volumes for LiDAR-detected trees using the best regression model with field-measured total stem volumes for all trees within stands. The study area was a 48-year-old sugi (Cryptomeria japonica D. Don) plantation in mountainous forest. The topographies of the three stands with different stand characteristics analyzed in this study were steep slope (mean slope ± SD; 37.6° ± 5.8°), gentle slope (15.6° ± 3.7°), and gentle yet rough terrain (16.8° ± 7.8°). In the regression analysis, field-measured stem volumes were regressed against each of the six LiDAR-derived predictor variables with respect to crown properties, such as crown area, volume, and form, together with LiDAR-derived tree height. The model with sunny crown mantle volume (SCV) had the smallest standard error of the estimate obtained from the regression model in each stand. The standard errors (m³) were 0.144, 0.171, and 0.181, corresponding to 23.9%, 21.0%, and 20.6% of the average field-measured stem volume for detected trees in each of these stands, respectively. Furthermore, the sum of the individual stem volumes, predicted by regression models with SCV for the detected trees, occupied 83%–91% of field-measured total stem volumes within each stand, although 69%–86% of the total number of trees were correctly detected by a segmentation procedure using LiDAR data.  相似文献   

Effects of thinning on wind damage in Pinus thunbergii plantation ——Based on theoretlcal derlvation of risk—ratios for assessing wind damage     

ZHUJiao-jun LIFeng-qin CondaYutaka TakeshiMatsuzaki MasashiYamamoto 《林业研究》2003,14(1):1-8

Based on paper of “Theoretical derivation of risk-ratios for assessing wind damage in coastal forest“,wind damage in the pine coasteal forest,which was thinned at four levels in December of 1997,was investigated for four successive growing seasons.Besides wind damage,the wind profiles outside and inside the coastal forest stand and the distributions of optical stratification porosity (OSP) were also observed.Based on these data,risk-ratios of wind damage for both individual trees and stands were estimated according to the methods developed in “Theoretical derivation of risk-ratios for assessing wind damage in a coastal forest“.The results showed that risk-ratios of wind damage,which were calculated from the meen height and diameter only and from the combination of wind and stand sructure profiles,accurately predicted wind damage in the plantation.Relationships between different thinning ratios and incidence of wind damage showed that stand stability decreased soon after the thinning.This was due to the immediate effects of thinning on increasing the canopy roughness and wind load,and on decreasing the sheltering effects from surrounding trees.However,thinning strategies could improve the stability by long-term effects on growthand development of trees against extreme wind.Only canopy damage was recorded during the experimental period,no stem damage was found,even though the maximum 10-min wind speed outside the coastal forest attained 30.2m s^-1.The results obtained in this study indicate that thinning is the most effective silvicultural strategy available for managing coastal forest despite the increased probability of wind damage soon after thinning.  相似文献   

Chemical characteristics of squeezable sap of hydrothermally treated silver birch logs (Betula pendula): effect of treatment time and the quality of the soaking water in pilot scale experiment     

Akio Yamamoto  Anti Rohumaa  Eero Kontturi  Mark Hughes  Tapani Vuorinen 《Wood Science and Technology》2015,49(2):289-302

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Continuum contraction of tension wood fiber induced by repetitive hygrothermal treatment     

Sujan  KC  Yamamoto  Hiroyuki  Matsuo  Miyuki  Yoshida  Masato  Naito  Kazuhiro  Shirai  Tatsuya 《Wood Science and Technology》2015,49(6):1157-1169

Wood Science and Technology - Tension wood, when kiln-dried, is likely to deform hugely, which is probably caused by a gelatinous layer of the gelatinous fiber. To elucidate the mechanism behind...  相似文献   

Isolation and antimicrobial susceptibility of Plesiomonas shigelloides from great cormorants (Phalacrocorax carbo hanedae) in Gifu and Shiga Prefectures,Japan     

Ryota MATSUYAMA  Naotoshi KUNINAGA  Tomoya MORIMOTO  Tetsuya SHIBANO  Akiko SUDO  Kazunari SUDO  Makoto ASANO  Masatsugu SUZUKI  Tetsuo ASAI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2015,77(9):1179-1181

Plesiomonas shigelloides is a causal agent of gastroenteritis, sepsis and meningitis in humans. We examined the prevalence of P. shigelloides among great cormorants (Phalacrocorax carbo hanedae) in Japan and the antimicrobial susceptibility of isolates. P. shigelloides was isolated from 33 (47.8%) of 69 fecal samples from great cormorants in 2014. All 33 isolates were subjected to antimicrobial susceptibility testing using broth microdilution methods, which showed resistance to ampicillin (31 isolates, 93.9%), tetracycline (two isolates, 6.1%) and trimethoprim (one isolate, 3.0%). The high prevalence of P. shigelloides in the great cormorants implicates the possible microbiological risk to public health.  相似文献   

Mitigation of nitrous oxide (N2O) emission from swine wastewater treatment in an aerobic bioreactor packed with carbon fibers          下载免费PDF全文

Takahiro Yamashita  Ryoko Yamamoto‐Ikemoto  Hiroshi Yokoyama  Hirofumi Kawahara  Akifumi Ogino  Takashi Osada 《Animal Science Journal》2015,86(3):358-368

Mitigation of nitrous oxide (N₂O) emission from swine wastewater treatment was demonstrated in an aerobic bioreactor packed with carbon fibers (CF reactor). The CF reactor had a demonstrated advantage in mitigating N₂O emission and avoiding NOx (NO₃ + NO₂) accumulation. The N₂O emission factor was 0.0003 g N₂O‐N/gTN‐load in the CF bioreactor compared to 0.03 gN₂O‐N/gTN‐load in an activated sludge reactor (AS reactor). N₂O and CH₄ emissions from the CF reactor were 42 g‐CO₂ eq/m³/day, while those from the AS reactor were 725 g‐CO₂ eq/m³/day. The dissolved inorganic nitrogen (DIN) in the CF reactor removed an average of 156 mg/L of the NH₄‐N, and accumulated an average of 14 mg/L of the NO₃‐N. In contrast, the DIN in the AS reactor removed an average 144 mg/L of the NH₄‐N and accumulated an average 183 mg/L of the NO₃‐N. NO₂‐N was almost undetectable in both reactors.  相似文献   

Changes in the cellulose crystallinity of moso bamboo cell walls during the growth process by X-ray diffraction techniques     

Keisuke Toba  Takahisa Nakai  Tatsuya Shirai  Hiroyuki Yamamoto 《Journal of Wood Science》2015,61(5):517-524

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Enantioseparation of isoxanthohumol in beer by hydroxypropyl-gamma-cyclodextrin-modified micellar electrokinetic chromatography     

Kodama S  Yamamoto A  Sato A  Suzuki K  Yamashita T  Kemmei T  Taga A  Hayakawa K 《Journal of agricultural and food chemistry》2007,55(16):6547-6552

Chiral resolution of isoxanthohumol (IX) in beer samples was performed by hydroxypropyl-gamma-cyclodextrin-modified micellar electrokinetic chromatography. The optimum running conditions were found to be 20 mM phosphate buffer (pH 7.0) containing 45 mM hydroxypropyl-gamma-cyclodextrin and 100 mM sodium dodecyl sulfate with an effective voltage of +20 kV at 20 degrees C using direct detection at 210, 295, and 370 nm. IX was detected in 12 beer samples and the total levels of (+)- and (-)-IX ranged from 0.15 to 1.4 mg/L. But the amount of xanthohumol (XN) was below the detection limit (0.017 mg/L). Each level of (-)-IX was almost the same as that of (+)-IX, suggesting that IX was a racemic mixture in these beer samples. The racemization of IX in beer could be attributed to the production of a racemic mixture from XN during boiling and to the fact that IX enantiomers were easily interconverted.  相似文献   

Influence of dietary fat level and whole-body adiposity on voluntary energy intake by juvenile rainbow trout Oncorhynchus mykiss (Walbaum) under self-feeding conditions     

T Yamamoto  T Shima  H Furuita  & N Suzuki 《Aquaculture Research》2002,33(9):715-723

The influence of dietary fat level and whole‐body adiposity on voluntary energy intake of juvenile rainbow trout Oncorhynchus mykiss (Walbaum) was examined using self‐feeders. Groups of lean fish [crude fat (CF) = 7%] and fat fish (CF = 11%), pretreated with a commercial diet with or without supplemental pollock oil, were self‐fed one of three fat level diets (CF = 8%, 13.5% and 19%) for 48 days at 17 °C. Final body weight (BW) and total digestible energy (DE) intake (kJ per fish) were positively affected by the initial BW. Relative to the initial BW, however, fat fish consumed less DE than lean fish. Although the effect of dietary fat level was not significant, percentage weight gain and daily DE intake per BW (kJ kg^?1 BW day^?1) of fat fish were significantly lower than those of lean fish (ancova with initial BW as a covariate, P < 0.05). Energy digestibility, feed efficiency and protein retention were improved with the dietary fat level; however, there was no difference resulting from body fat level. The whole‐body fat levels at the end of the experiment increased with the dietary fat level. Between groups self‐fed the same diet, fat levels of the initially fat fish were still higher than those of the lean fish. The results of the present medium‐term study suggest that rainbow trout adjust DE intake from diets with fat levels ranging from 8% to 19%. Although body fat level affects neither energy digestibility nor protein utilization, a high body fat level may reduce DE intake and consequently depress growth.  相似文献   

Localization of Eimeripain,an Eimeria tenella Cathepsin B-Like Cysteine Protease,during Asexual and Sexual Intracellular Development in Chicken Ceca     

Makoto MATSUBAYASHI  Takeshi HATTA  Takeharu MIYOSHI  ANISUZZAMAN  Kazumi SASAI  Kayoko YAMAJI  Kameo SHIMURA  Takashi ISOBE  Kiyoshi KITA  Naotoshi TSUJI 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2014,76(4):531-537

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