Horizontal distribution of phytoplankton in the Kopački Rit floodplain

Istraživanje utjecaja promjena fizikalno-kemijskih čimbenika vode na horizontalnu distribuciju fitoplanktona u Kopačkom ritu provedeno je na tri mikrolokaliteta - Hulovskom kanalu, Kopačkom jezeru i Sakadaškom jezeru, u različitim sezonama 2013/2014. godine. Usporedba fitoplanktonskih zajednica načinjena je s obzirom na biomasu i strukturu zajednica definiranih prema morfo-funkcionalnoj klasifikaciji. Rezultati istraživanja ukazuju na značajne sezonske i hidrološke utjecaje na razvoj fitoplanktona. Prostorno udaljeni te hidromorfološki vrlo različiti vodeni biotopi u poplavnom području mogu imati vrlo sličan sastav fitoplanktonskih zajednica, posebno u uvjetima plavljenja ili neposredno nakon poplava, kada dominiraju dijatomeje iz funkcionalnih skupina D, MP, P i C. Tijekom razdoblja hidrološke stabilnosti u jesen, do izražaja dolaze sezonski utjecaji i specifičnosti svakog pojedinog lokaliteta. U uvjetima velike količine nutrijenata i suspendiranih tvari, dominiraju predstavnici skupina W1, E i Ws. Dobiveni rezultati potvrđuju opravdanost primjene morfo-funkcionalne klasifikacije u svrhu praćenja distribucije fitoplanktona u sustavima rijekapoplavno područje.Investigation of the horizontal distribution of phytoplankton in the Kopački Rit floodplain was done on three microlocalities - Hulovo channel, Lake Kopačko and Lake Sakadaš in November 2013 and in June and August 2014. The influence of physico-chemical parameters on qualitative and quantitative composition of phytoplankton was investigated and species were grouped according to morpho-functional classification. The results point to the significant seasonal and hydrological impact on phytoplankton development. Spatially distant and hydromorphologicallly very different aquatic habitats in the floodplain can have a very similar phytoplankton composition, especially in the conditions of flooding or immediately after the floods, when diatoms from the functional groups D, MP, P and C dominated. During the hydrological stability in fall, the seasonal influences and site-specific variables become more important. Large amounts of nutrients and suspended organic matter favoured the development of W1, E and Ws groups. The results obtained by this study confirm the usefulness of the morpho-functional classification in monitoring the distribution of phytoplankton in river-floodplain systems

Horizontal distribution of phytoplankton in the Kopački Rit floodplain

Istraživanje utjecaja promjena fizikalno-kemijskih čimbenika vode na horizontalnu distribuciju fitoplanktona u Kopačkom ritu provedeno je na tri mikrolokaliteta - Hulovskom kanalu, Kopačkom jezeru i Sakadaškom jezeru, u različitim sezonama 2013/2014. godine. Usporedba fitoplanktonskih zajednica načinjena je s obzirom na biomasu i strukturu zajednica definiranih prema morfo-funkcionalnoj klasifikaciji. Rezultati istraživanja ukazuju na značajne sezonske i hidrološke utjecaje na razvoj fitoplanktona. Prostorno udaljeni te hidromorfološki vrlo različiti vodeni biotopi u poplavnom području mogu imati vrlo sličan sastav fitoplanktonskih zajednica, posebno u uvjetima plavljenja ili neposredno nakon poplava, kada dominiraju dijatomeje iz funkcionalnih skupina D, MP, P i C. Tijekom razdoblja hidrološke stabilnosti u jesen, do izražaja dolaze sezonski utjecaji i specifičnosti svakog pojedinog lokaliteta. U uvjetima velike količine nutrijenata i suspendiranih tvari, dominiraju predstavnici skupina W1, E i Ws. Dobiveni rezultati potvrđuju opravdanost primjene morfo-funkcionalne klasifikacije u svrhu praćenja distribucije fitoplanktona u sustavima rijekapoplavno područje.Investigation of the horizontal distribution of phytoplankton in the Kopački Rit floodplain was done on three microlocalities - Hulovo channel, Lake Kopačko and Lake Sakadaš in November 2013 and in June and August 2014. The influence of physico-chemical parameters on qualitative and quantitative composition of phytoplankton was investigated and species were grouped according to morpho-functional classification. The results point to the significant seasonal and hydrological impact on phytoplankton development. Spatially distant and hydromorphologicallly very different aquatic habitats in the floodplain can have a very similar phytoplankton composition, especially in the conditions of flooding or immediately after the floods, when diatoms from the functional groups D, MP, P and C dominated. During the hydrological stability in fall, the seasonal influences and site-specific variables become more important. Large amounts of nutrients and suspended organic matter favoured the development of W1, E and Ws groups. The results obtained by this study confirm the usefulness of the morpho-functional classification in monitoring the distribution of phytoplankton in river-floodplain systems

INFLUENCE OF SOIL TILLAGE AND LOW HERBICIDE DOSES ON WEED POPULATIONS AND SPRING BARLEY YIELD

The influence of different tillage variants and low herbicide doses of triasulfuron & chlortoluron mixture (Dicuran forte 80 WP) on weed populations and crop yield were studied in spring barley on lessive pseudogley soil in North-Eastern Croatia at the Čačinci locality in 1999. Tillage had no significant influence on annual broad-leaved weed biomass production, which was 22 kg ha-1 , on the average. Chisel ploughing and disk harrowing significantly increased perennial weed biomass by 21 and 44 times, respectively compared to mouldboard ploughing. The average efficacy of total weed biomass control was 95, 89 and 81% at full, onehalf and one-quarter of the recommended herbicide dose, respectively and did not differ very much between tillage treatments. Both reduced herbicide doses ensured very good biomass control of the most abundant weed populations such as Ambrosia artemisiifolia L., Chenopodium album L., Ch. polyspermum L. and Polygonum lapathifolium L. No significant tillage and herbicide dose effects were recorded in barley yields, which ranked from 4.93 t ha-1 in chisel ploughing to 4.48 t ha-1 in disk harrowing. These results suggested a possibility of mouldboard ploughing substitution with reduced tillage practices on lessive pseudogley soil and herbicide dose reduction of triasulfuron & chlortoluron mixture to 50% or more in spring barley