An increasing number of inland Common Tern
Sterna hirundo
populations nowadays breed in artificial habitats. Inland breeding Common Terns still intensively use rivers while foraging, but the ...characteristics of their preferred foraging habitats are not well known. In this study we combined telemetric field research and river hydrology modelling to investigate whether Common Terns breeding near Zagreb show a preference for shallow river topography. Our results show that Common Terns breeding close to a preferred foraging area visit shallower parts of the river more when foraging than a random distribution of points along the river would suggest. Furthermore, we show that terns breeding on an artificial island further away from a preferred foraging area exhibit higher distance and duration of foraging trips. They also have a larger foraging range and shorter nest presence. The observed changes in foraging and nesting efforts may affect breeding success as well as adult fitness and survival, influencing the health of the entire population. These findings facilitate the identification of preferred feeding areas as those shallower than 1 m, and indicate that positioning artificial breeding sites closer to these areas could increase population fitness. Furthermore, our results offer useful input for river restoration projects, as well as for analysing the environmental impact of interventions in the riverbed.
Water Framework Directive (WFD) guidance documents from 2019 provide a comprehensive review of methods and guidelines to improve the comparability of heavily modified water bodies (HMWBs) in the ...European Union. However, there is currently no common, single methodology for monitoring HMWBs and artificial water bodies (AWBs) or for determining maximum (MEP) and good ecological potential (GEP). This study presents the first assessment of hydromorphological conditions of HMWBs and AWBs in Croatia based on type-specific indicators. The typology of HMWBs and AWBs was based on distinct hydromorphological characteristics and modifications in order to be easily related to the uses of the water bodies. The classes of hydromorphological potential were graded from the theoretical MEP, which was determined by the score scale as the tolerated deviation from natural reference conditions, considering potential mitigation measures. The use of the water body and/or the effects on the wider environment were considered while determining MEP and choosing indicators included in monitoring and assessment. In the case of AWBs, the parameters dependent on natural reference conditions, which are non-existent, were omitted from the assessment. Only 27% of HMWBs and 2 out of 51 AWBs achieved good potential for all three hydromorphological elements. The most significant hydromorphological modifications include channelization, straightening, deepening and removal of riparian vegetation due to flood-protection management practices. In order to achieve the environmental objectives set out by the WFD, the Croatian water management system has to start implementing mitigation measures, especially related to natural flood management.
U krapinsko zagorskom kraju sve su češće pojave manjka oborina i vode u tlu za normalan rast i razvoj usjeva. U cilju primjene natapanja i intenzivne poljoprivredne proizvodnje , u članku analiziramo ...u prvom redu sadašnju i potencijalnu pogodnost poljoprivrednog zemljišta za natapanje do 500 m.n.m., nagiba terena 0-16%, ukupno neto površine 50.075 ha, zatim stanje posjeda-poljoprivrednih gospodarstava i mogućnosti izbora kultura. Poljoprivredne površine županije obuhvaćaju oko 58 % teritorija. Obrađuje se oko 50%. U privatnom vlasništvu je oko 99%. Osnovno obilježje poljoprivrednih gospodarstava je usitnjenost i rascjepkanost posjeda. Od zasijanih kultura prevladavaju žitarice (71%), krmno bilje (16,8%), krumpir (8,2%), povrće (4%), dok je pod ugarom i neobrađenih oranica i vrtova oko 3% poljoprivredne površine. U 2016. godini je natapano 19,35 hektara ratarskih i povrtnih kultura i voća na 51 ARKOD parceli i u 29 gospodarstava. Prema utvrđenom stupnju pogodnosti tla za natapanje i nagibu terena, preporučamo po načelu intenzivne poljoprivrede agro ili/i hidrotehničke mjere uređenja poljoprivrednog zemljišta, okrupnjavanje posjeda, tržišno održivi izbor poljoprivrednih kultura i odgovarajuće načine gospodarenja-korištenja poljoprivrednog zemljišta s natapanjem.
Conducting hydromorphological assessments for evaluating the ecological status of rivers is a key requirement of the Directive 2000/60/EC (Water Framework Directive – WFD) within European Union (EU) ...Member States. This paper aims at understanding how this requirement was implemented, through an original comparative review of methodologies for rivers' hydromorphological assessment in three EU Member States, which joined the EU at different times, and with many differences in terms of hydrographic features, socio-economic and water management systems: France, Romania, and Croatia. More precisely, the paper aims at identifying and understanding the main principles guiding the hydromorphological assessment methodologies, elements and data used, giving an overview of the results of hydromorphological river status assessment, and concluding on the stage of hydromorphological assessment implementation. France developed numerous methodologies for physical habitat survey since the 1990s and it is currently conducting a rigorous hydromorphological field survey, but it does not yet have any national methodology for rivers' hydromorphological status assessment, nevertheless foreseen for the next cycle of the WFD. Besides, Romania and Croatia have already started the assessment of the hydromorphological status of rivers within the two cycles of the River Basin Management Plans and are making efforts to improve the hydromorphological monitoring activity. The methods generally differ in indicators, data used, and spatial scale of analysis, which makes it difficult to compare the results of the assessments. Despite a common water policy, the methodological dissimilarities seem to be rather usual between EU Member States. Therefore, the standardization of methodologies appears to be necessary, but the current results could be useful for setting priorities for river restoration and for achieving a better status at a national scale.
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•Methods for rivers' hydromorphological assessment were compared in 3 EU countries.•Differences concerning parameters used, data and scale of analysis were identified.•In lack of intercalibration, comparing results of river assessments is risky.•Constant progress in approaching national hydromorphological assessment was found.
The environmental and faunistic research conducted included defining the composition and distribution of caddisflies collected using ultraviolet (UV) light trap at 11 stations along the Cetina River, ...from the spring to the mouth, and also along its tributaries the Ruda River and the Grab River with two sampling stations each, and the Rumin River with one station. The research was conducted in the period from August 2004 until August 2005 on the Cetina and the Ruda rivers, and from April 2007 to September 2007 on the Grab and the Rumin rivers. A total of 71 caddisfly species and 10,048 individuals were recorded in the study area. Results of the composition and structure of caddisflies were processed with statistical methods using the NMDS analysis. There were differences in the composition of caddisflies in the upper, middle and lower reaches. The paper also presents some ecological features of caddisflies, such as seasonal dynamics and diversity of caddisflies communities. Results of this work contribute to faunistic and ecological knowledge of Croatian caddisflies.
In this paper new data on distribution and new taxonomic status of the caddisfly Triaenodes ochreellus lefkas are given. DNA barcoding data are also included into defining new status of the species ...Triaenodes lefkas stat. nov. Data from DNA barcoding analyses of 60 specimens from the genus Triaenodes from the BOLD database show certain taxonomic peculiarities in specimens of T. unanimis from Japan.
Poriječje rijeke Ilove u Središnjoj Hrvatskoj pod znatnim je antropogenim utjecajem zbog brojnih hidrotehničkih radova, izgradnje kanalâ i ribnjakâ. Do sada u poriječju Ilove nisu istraživane ...posljedice izgradnje tih hidrotehničkih objekata i uređenja vodotokâ na njihovu hidromorfologiju. Nakon povijesnog pregleda značajnijih hidrotehničkih radova u radu su prikazani rezultati istraživanja morfoloških značajki vodotokâ u poriječju Ilove prema smjernicama Okvirne direktive EU-a o vodama i Metodologije monitoringa i ocjenjivanja hidromorfoloških pokazatelja Hrvatskih voda.
Analizirana su ukupno 534 km vodotokâ i određeno je 48 vodnih tijela za koja je utvrđeno morfološko stanje. Ukupno 38,5 % duljine vodotokâ, odnosno 21 vodno tijelo u poriječju Ilove, ne zadovoljava ciljeve prema Okvirnoj direktivi EU-a o vodama jer je dobilo ocjenu umjereno promijenjeno, loše ili vrlo loše morfološko stanje. Zabrinjavajuće je da su loše ocjene, uz dionice u naselju i oko njega, dobile i mnoge dionice izvan naselja.
U dravsko-plitvičkoj aluvijalnoj nizini na oko 26.594 hektara dijela varaždinske županije, dominiraju obradive površine. Od toga je zapušteno 1.103 hektara. Poljoprivredno zemljište je na automorfnim ...antropogeniziranim i hidromorfnim djelomično hidromelioriranim tlima. Automorfna tla su vlažena vrlo brzom procjednom oborinskom vodom. Hidromorfna tla su vlažena procjednom vodom različitih brzina i/ili podzemnom vodom različite dubine. U priobalju i zaobalju gornjeg i srednjeg toka rijeke Plitvice, vrlo su slabo osjetljiva poljoprivredna tla na propuštanje onečišćivača (klasa I). Slabo osjetljiva tla na propuštanje onečišćivača (klasa II) i umjereno osjetljiva poljoprivredna tla (klasa III), dominiraju na istočnom području plitvičko dravske aluvijalne nizine. Na sjeverozapadu nizine su pretežno poljoprivredna obradiva tla umjerene (klasa III) i jake (klasa IV) osjetljivosti na propuštanje onečišćivača, slika 1 i tablica 2. Podzemna voda u aluvijalnom vodonosnom sloju dravsko-plitvičke nizine jako je ranjiva na onečišćenje nitratima. Na kontrolnim poljima Bartolovec i Nova Ves u četverogodišnjem razdoblju istraživanja,najveća jednokratna koncentracija nitrata u procijeđenoj vodi iz gravitacijskih lizimetara bila je 314,5 mg NO3-/l odnosno amonijačnog dušika 3,8 mg NH4+/l. U procijeđenoj vodi iz tenziometarskih lizimetara najviše nitrata je bilo jednokratno 338,5 mg NO3-/l i 3,0 amonijačnog dušika, tablice 7-10.
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