Agriculture Reference
In-Depth Information
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Calendar Month
Fig. 2.2 Three temporal patterns of shoot elongation of tree species in a deciduous broad-leaved
forest in Niigata, Japan. Shoot elongation and bud development are relativized to their maximum
size (100%) and plotted against calendar months . (After Maruyama 1978; redrawn by Kikuzawa)
1984, 1988), or determinate (Kozlowski 1971; Marks 1975; Lechowicz 1984) shoot
growth. Populus is an example of a succeeding-type (Maruyama 1978; Kikuzawa
1983, 1984, 1988) or indeterminate (Kozlowski 1971; Marks 1975; Lechowicz
1984) shoot growth in which the shoot elongates and leaves emerge over a rela-
tively long period. The period of indeterminate shoot growth can be fairly short, as
in Lindera , or quite extended, as in Populus (Maruyama 1978; Kikuzawa 1983).
The noteworthy contrasts between these determinate and indeterminate modes of
shoot growth, respectively, are (1) the episodic versus ongoing extension growth
and leaf emergence and (2) the temporal separation versus overlap of bud development
from extension and leaf emergence. The same two basic patterns of shoot growth
prevail in tropical forests (Koriba 1947a,b, 1958; Lowman 1992), in savanna species
in the western Himalayas (Zhang et al. 2007), in herbaceous plants (Kikuzawa
2003), and in ferns (Hamilton 1990). These patterns of shoot growth and leaf emer-
gence should be observed in any type of vegetation in the world because they arise
in the developmental controls on shoot growth, not the diverse environmental factors
that trigger the onset of growth (Kikuzawa et al. 1998).
Box 2.1 Bud Scale
Buds are a plant structure protecting vulnerable meristematic tissues and
embryonic leaves from cold or desiccation during a dormant period. The
modified, scale-like leaves that form the outer layers of many buds are called
bud scales. Buds form at the base of existing leaves and do not develop into
leaves until the parent leaf falls.
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