Profundal
As profundal in which is ecology of the habitat of the low zone (lat. Profundus , profound) of standing water , respectively. However, this only refers to the sediment and the layer of water lying above it.
It is differentiated from the overlying littoral , the illuminated soil zone. The boundary between profundal and littoral is described in the compensation level , which is assumed for the depth to which one percent of the photosynthetically active radiation (PAR) can still reach.
Important influencing factors on the community in Profundal are light , temperature , water movement and oxygen saturation of the water.
Influencing factor light
Very little light reaches the profundal (less than one percent PAR), so that no profitable photoautotrophic primary production can take place. The profundal community is therefore predominantly heterotrophic .
Influencing factor temperature
Due to the density anomaly of the water, the temperature in deep profundals is fairly constant around 4 ° C and there are only very slight seasonal fluctuations.
According to the types of circulation, there are also lakes that deviate from this basic rule.
Influencing factor oxygen saturation
The oxygen content is a decisive factor for the residents of Profundal. There is almost always a lack of oxygen here.
Influencing factor water movement
Various water movements occur in the Profundal, for example through bioturbation , but also due to temperature differences between the sediment and the water above it. These movements of the water enable an exchange of substances between water and sediment.
