Temperature is the key factor controlling population dynamics of Brachionus angularis in Lake Jinghu during Summer and Autumn

Figures & data

Figure 1. Physicochemical conditions at the two stations of Lake Jinghu between July 24 and October 21 in 2008.

Figure 2. Dynamics of population density, egg ratio, death rate, birth rate, and growth rate of B. angularis at the two stations of Lake Jinghu between 24 July and 21 October 2008.

Table 1. Product–moment correlations between population density and egg ratio (e), population growth rate (r), birth rate (b), and death rate (d) of B. angularis with and without a time lag of one sampling interval (four days).

Population parameter	Without a time lag		With time lag
	Station I	Station II	Station I	Station II
e	0.365	0.673**	0.254	0.309
r	−0.375	−0.445	0.328	0.539**
b	0.318	0.592**	0.318	0.396
d	0.450	−0.717**	0.069	−0.036
Notes: All data were tested for normality using the one-sample Kolmogrov–Smirnov procedure, and population density in station II was log-transformed.
*p < 0.05, **p < 0.01.

Table 2. Correlation coefficients between population density and environmental variables.

Environmental variables	Without a time lag		With time lag
	Station I	Station II	Station I	Station II
Water temperature	0.323	0.715*	0.431*	0.774**
Chl a	−0.22	−0.089	−0.164	−0.047
Chl a < 25 µm	−0.166	−0.038	−0.190	−0.159
Transparency	0.179	−0.347	0.257	−0.276
DO	−0.298	−0.295	−0.333	0.028
pH	−0.458	−0.265	−0.336	−0.16
Other microfilter feeders	0.487*	0.639**	0.183	0.524*
Asplanchna spp.	−0.361	−0.122	−0.2	−0.015
Notes: All data were tested for normality using the one-sample Kolmogrov–Smirnov procedure, and population density in station II was log-transformed.
*p < 0.05, **p < 0.01.