The causes of changing species composition between regions are probably (1) the harsh climate in the eastern part of the study area reducing the probability of successful transmission of digeneans with complicated life cycles, and (2) the distribution of different final hosts.
(The causes of changing species composition between regions; are probably; 1) the harsh climate in the eastern part of the study area reducing the probability of successful transmission of digeneans with complicated life cycles, and (2) the distribution of different final hosts) (the study area; reducing; the probability of successful transmission of digeneans with complicated life cycles)
The causes of changing species composition between regions the study area
are probably reducing
1) the harsh climate in the eastern part of the study area reducing the probability of successful transmission of digeneans with complicated life cycles, and (2) the distribution of different final hosts
the probability of successful transmission of digeneans with complicated life cycles