Numerical Responses of Microarthropods
t)
E
1=
020 u
'61
o
"0
~ 10
79
O+:~~~~~~~,,~~~~~~~~~
AWJJASONDJFWAWJJASONDJFWAWJJASON
nME (months)
Fig. 6.3. Relationship of ecological to standard time. Solid line immature; dashed line pseudomature of Glomeris balcanica. (Stamou et a1.1993b)
evergreen-sclerophyllous formation of southern France (Bigot and Bodot
1973).
To model asymmetric phenologies, Stamou et al. (1993a) defined the unit
of ecological time as the standard-clock time interval during which a constant number of demographic events (births plus deaths) occur. During population explosions, a given number of demographic events (for example ten
births plus deaths) will occur in shorter standard time intervals than during
other times. Thus, when defined demographically, the unit of ecological time
changes during the passage of standard clock time (Fig. 6.3). Increasing parts
of the curve correspond to rapid development in numbers, whereas the plateau indicates negligible changes in population size. Stamou et al. (1993a)
suggested that changes in ecological time parallel changes in the environmental gradients overriding population dynamics in the field. The relationship between the two time units depends upon the demography as well as on
the physiological response of each species to environmental component
variables. Hence, dynamic relationships specific to each population can be
formulated.
6.2
Numerical Responses of Microarthropods
A curve was fitted numerically to census data referring to the phenologies of
11 collembolan and eight oribatid species from Hortiatis (Figs. 6.4, 6.5). As
t)
E
1=
020 u
'61
o
"0
~ 10
79
O+:~~~~~~~,,~~~~~~~~~
AWJJASONDJFWAWJJASONDJFWAWJJASON
nME (months)
Fig. 6.3. Relationship of ecological to standard time. Solid line immature; dashed line pseudomature of Glomeris balcanica. (Stamou et a1.1993b)
evergreen-sclerophyllous formation of southern France (Bigot and Bodot
1973).
To model asymmetric phenologies, Stamou et al. (1993a) defined the unit
of ecological time as the standard-clock time interval during which a constant number of demographic events (births plus deaths) occur. During population explosions, a given number of demographic events (for example ten
births plus deaths) will occur in shorter standard time intervals than during
other times. Thus, when defined demographically, the unit of ecological time
changes during the passage of standard clock time (Fig. 6.3). Increasing parts
of the curve correspond to rapid development in numbers, whereas the plateau indicates negligible changes in population size. Stamou et al. (1993a)
suggested that changes in ecological time parallel changes in the environmental gradients overriding population dynamics in the field. The relationship between the two time units depends upon the demography as well as on
the physiological response of each species to environmental component
variables. Hence, dynamic relationships specific to each population can be
formulated.
6.2
Numerical Responses of Microarthropods
A curve was fitted numerically to census data referring to the phenologies of
11 collembolan and eight oribatid species from Hortiatis (Figs. 6.4, 6.5). As