engleski

Paspalum paspaloides evapotranspiration effect on water content in mediterranean kastic pond – implications for management

We aimed to determine the effect of bio-fouling of the pond with the plant Paspalum paspaloides on the water loss by evapotranspiration. The experiment was conducted in NATURA2000 area candidate. These ponds are the habitat of Mauremys rivulata, critically endangered in Croatia largely due to habitat loss. Water temperature, evaporation and evapotranspiration, were measured weighing water loss four times a day in August 2007 and 2008. Bio-fouling and free water surface were estimated in percents on site since year 2004. Average evaporation was 4, 89 gmin-1m-2 and evapotranspiration 9, 17 gmin-1m-2. The water loss due to bio-fouling was higher than loss due to evaporation, on every occasion. Total amount of water lost from the pond was the greatest in the year 2006 when bio-fouling was the most extensive, estimated to be 168, 028 l. Decrease of estimated water lost during August 2007 can be explained by removing the grass from the pond and small total water content. In the August 2008 the pond was desiccated with all of the grass removed. Emigration and decrement of free-range farming in Croatian coastal outback leave the ponds to fast succession benefi ted by Mediterranean climate. To preserve them, water loss should be controlled by proper plant management.

karstic pond; management; evapotranspiration; succession

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