We investigated the culm form for one of the largest bamboo species, Phyllostachys pubescens Mazel ex Houz. in relation to the me- chanical constraint principles, i.e., elastic, stress and geometric similarity. The fi...We investigated the culm form for one of the largest bamboo species, Phyllostachys pubescens Mazel ex Houz. in relation to the me- chanical constraint principles, i.e., elastic, stress and geometric similarity. The fine-resolution analysis of the culm taper indicated that the culm for P. pubescens consisted of three or four segments with various forms, except for the butt swell. This implied that the taper of the whole culm for P. pubescens could be expressed by neither of these principles. The regression slope between culm height and diameter at breast height on the double logarithmic coordinates was 0.629, which was significantly different from the values predicted from these principles. In conclusion, none of these mechanical constraint principles can express the culm taper and height-diameter relationship, and there may be a need for a more complicated model to express the culm form for P. pubescens.展开更多
The hollow cylindrical culm is one of the most remarkable morphological characters of most bamboo species.In relation to its hollow structure,there are two different attributes of the culm volume in bamboo:the apparen...The hollow cylindrical culm is one of the most remarkable morphological characters of most bamboo species.In relation to its hollow structure,there are two different attributes of the culm volume in bamboo:the apparent culm volume(va:the total culm volume including the hollow portion)and the woody culm volume(vw:the volume of the woody walls of the culm).The ratio of vw to va is defined as the reduction factor for culm volume(fv).The quantity fv is useful to quantify the biomass resources of bamboo culms as well as to evaluate the carbon stock of bamboo forests.However,the direct measurement of fv requires destructive sampling,which consumes time and labor.Hence,an alternative method for obtaining fv is desired.In this study,we examined fv in five species of the genus Phyllostachys and proposed alternative methods to estimate fv.Our data showed that fv varied by species,some of which exhibited a dependency of fv on culm sizes.These findings indicate that the intraspecific and interspecific variation in fv should be considered carefully when converting va into vw by fv.Based on our results,we propose here six approaches for predicting fv and we discuss their advantages and disadvantages.Our results are intended to facilitate evaluation of the carbon sequestration capacity of bamboo forests and the commercial utilization of bamboo culms.展开更多
基金supported in part by the Sumitomo Foundation (Grant no. 083062)
文摘We investigated the culm form for one of the largest bamboo species, Phyllostachys pubescens Mazel ex Houz. in relation to the me- chanical constraint principles, i.e., elastic, stress and geometric similarity. The fine-resolution analysis of the culm taper indicated that the culm for P. pubescens consisted of three or four segments with various forms, except for the butt swell. This implied that the taper of the whole culm for P. pubescens could be expressed by neither of these principles. The regression slope between culm height and diameter at breast height on the double logarithmic coordinates was 0.629, which was significantly different from the values predicted from these principles. In conclusion, none of these mechanical constraint principles can express the culm taper and height-diameter relationship, and there may be a need for a more complicated model to express the culm form for P. pubescens.
基金supported by JSPS KAKENHI(Grant Numbers:15KK0220,JP16K12823,JP16K14948,25390147,18H03818,18H02244 and 18KT0027)
文摘The hollow cylindrical culm is one of the most remarkable morphological characters of most bamboo species.In relation to its hollow structure,there are two different attributes of the culm volume in bamboo:the apparent culm volume(va:the total culm volume including the hollow portion)and the woody culm volume(vw:the volume of the woody walls of the culm).The ratio of vw to va is defined as the reduction factor for culm volume(fv).The quantity fv is useful to quantify the biomass resources of bamboo culms as well as to evaluate the carbon stock of bamboo forests.However,the direct measurement of fv requires destructive sampling,which consumes time and labor.Hence,an alternative method for obtaining fv is desired.In this study,we examined fv in five species of the genus Phyllostachys and proposed alternative methods to estimate fv.Our data showed that fv varied by species,some of which exhibited a dependency of fv on culm sizes.These findings indicate that the intraspecific and interspecific variation in fv should be considered carefully when converting va into vw by fv.Based on our results,we propose here six approaches for predicting fv and we discuss their advantages and disadvantages.Our results are intended to facilitate evaluation of the carbon sequestration capacity of bamboo forests and the commercial utilization of bamboo culms.
