Mixed-power scaling of whole-plant respiration from seedlings to giant trees.
The scaling of respiratory metabolism with body mass is one of the most pervasive phenomena in biology. Using a single allometric equation to characterize empirical scaling relationships and to evaluate alternative hypotheses about mechanisms has been controversial. We developed a method to directly measure respiration of 271 whole plants, spanning nine orders of magnitude in body mass, from small seedlings to large trees, and from tropical to boreal ecosystems. Our measurements include the roots, which have often been ignored. Rather than a single power-law relationship, our data are fit by a biphasic, mixed-power function. The allometric exponent varies continuously from 1 in the smallest plants to 3/4 in larger saplings and trees. Therefore, our findings support the recent findings of Reich et al. [Reich PB, Tjoelker MG, Machado JL, Oleksyn J (2006) Universal scaling of respiratory metabolism, size, and nitrogen in plants. Nature 439:457-461] and West, Brown, and Enquist [West GB, Brown JH, Enquist BJ (1997) A general model for the origin of allometric scaling laws in biology. Science 276:122 -126.]. The transition from linear to 3/4-power scaling may indicate fundamental physical and physiological constraints on the allocation of plant biomass between photosynthetic and nonphotosynthetic organs over the course of ontogenetic plant growth.
Mori
Shigeta
S
Forestry and Forest Products Research Institute, Matsunosato 1, Tsukuba 305-8687, Japan. moris@ffpri.affrc.go.jp
Yamaji
Keiko
K
Ishida
Atsushi
A
Prokushkin
Stanislav G
SG
Masyagina
Oxana V
OV
Hagihara
Akio
A
Hoque
A T M Rafiqul
AT
Suwa
Rempei
R
Osawa
Akira
A
Nishizono
Tomohiro
T
Ueda
Tatsushiro
T
Kinjo
Masaru
M
Miyagi
Tsuyoshi
T
Kajimoto
Takuya
T
Koike
Takayoshi
T
Matsuura
Yojiro
Y
Toma
Takeshi
T
Zyryanova
Olga A
OA
Abaimov
Anatoly P
AP
Awaya
Yoshio
Y
Araki
Masatake G
MG
Kawasaki
Tatsuro
T
Chiba
Yukihiro
Y
Umari
Marjnah
M
D018533:Biomass; D001901:Botany / Q000379:methods*; D005740:Gases / Q000032:analysis* / Q000378:metabolism; D018526:Plant Transpiration; D036226:Seedlings / Q000737:chemistry* / Q000502:physiology; D014197:Trees / Q000737:chemistry* / Q000502:physiology
D005740:Gases