| BIOTIC FACTOR |
RESPONSE |
| |
|
| Intense predation by: |
|
|
-Invertebrates
|
Predominance of large Cladocera e.g. Eurycercus
sp., large Daphnia; morphological adaptation to invertebrate
predation. |
|
- Vertebrates
|
|
Zooplanktivores
|
Predominance of small or adapted Cladocera; possibly
an increased abundance of cladoceran remains in the sediment. |
Piscivores
|
A response similar to that of intense invertebrate predation,
because of reduced number of zooplanktivores. |
| |
|
| Increase in algal biomass caused by: |
|
| - Increased nutrients |
Lower species diversity of chydorids; increased abundance
of planktonic Bosmina and Chydorus sphaericus and other
species favouring turbid water conditions. |
| - Slower water renewal |
Maintenance of species diversity, with increased abundance
of sedimentary remains. |
| |
|
| Increase in macrophytes caused by: |
|
| - Increased water transparency |
Increased diversity and abundance of chydorids; possibly
the loss of larger Cladocera because of increased visibility
to vertebrate predators |
| - Change in water level |
Increased diversity and abundance of chydorids if area
of littoral region is increased. |