Efekat višestrukih stresora na multitrofički biodiverzitet barskih ekosistema
Author
Stamenković, OliveraMentor
Stojković-Piperac, MilicaCommittee members
Milošević, ĐurađSimić, Vladica
Cvijanović, Dušanka
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Show full item recordAbstract
This study deals with the effects of multiple anthropogenic activities
(i.e. stressors) on the richness and abundance of phytoplankton,
macrophytes, zooplankton, benthic and epiphytic macroinvertebrates,
and fishes, and their trophic groups. Multiple anthropogenic stressors
were integrated in one measure by calculating anthropogenic stress
index. The aim was to compare the responses of different pond
communities to anthropogenic impact, disentangle the potential
mechanisms responsible for variations in pond biodiversity (direct,
water-chemistry mediated, and cascading effects), and to quantify
pond net-community response to anthropogenic impact. In addition,
the importance of pond natural variability on the variations of
biodiversity of pond hydrobiocenoses was analysed.
All communities were sampled in September 2016, from the 18 study
sites distributed across the six permanent ponds that differ in origin,
connectedness, the intensity of a river impact, and the level of p...ond
coverage in surrounding area.
The effects of anthropogenic stressors varied across the distinct pond
communities, from negative effects on the richness and abundance of
macrophytes and on the richness of epiphytic macroinvertebrates, via
neutral effects on benthic macroinvertebrates, to positive effects on
fish abundance through predominance of the invasive species. The
natural pond variability affected the pond communities and water
chemistry in the majority of cases and it is expected to alter the
effects of anthropogenic stressors on pond communities.
The underlying mechanisms of anthropogenic stressors clearly
differed among different trophic levels. Direct effects were mainly
detected witihin primary producers, while the consumers were mainly
affected indirectly: the increase of nutrient concentrations in water
affected abundance and richness of invertebrate trophic groups, while
cascading effects were the most influential drivers of multitrophic
diversity in the fish community. Despite the variable responses of
different communities and their trophic groups, the total netcommunity
effect of the anthropogenic stressors was negative.