-In order to provide adequate guidelines in freshwater management, managers need reliable bioindicators that can respond differently to varied stressors. Managers also have to consider hierarchical structure of environmental factors. Thus, our research aims to test the independence of taxa responses along environmental gradients and to examine in what order natural and anthropogenic factors constrain the structure of littoral benthic assemblages. The rank of explained variance of littoral benthic assemblage's variable group hierarchy was: land use > landscape characteristics > eutrophication > fish stocking > hydromorphological alteration. We determined nine gradients (two natural and seven stressor gradients), separated into five groups based on statistically significant differences in responsiveness of taxa. Apart from responsiveness to natural factors, littoral benthic invertebrates could be used as bioindicators for stressors reflecting urbanization, eutrophication, hydromorphological alteration and fish stocking. The taxonomical composition of littoral benthic invertebrates, especially when taxa with preference for certain relatively narrow environmental conditions along gradients are present, can be used to identify effects of key stressors. Our findings have profound implications for ecological assessment and management of lakes, as they indicate that benthic invertebrates can be used when the effects of multiple stressors need to be disentangled.Keywords: macroinvertebrates / multiple stressors / bioindication / lakes / multihabitat sampling Résumé -Est-ce que les invertébrés benthiques d'un littoral lacustre réagissent différemment à l'eutrophisation, la modification hydromorphologique, l'utilisation des terres et l'empoissonnement ?Afin de fournir des lignes directrices adéquates en matière de gestion d'écosystèmes d'eau douce, les gestionnaires ont besoin de bioindicateurs fiables qui puissent répondre différemment à des facteurs de stress variés. Les gestionnaires ont également à considérer la structure hiérarchique des facteurs environnementaux. Ainsi, notre recherche vise à tester l'indépendance des réponses des taxons le long de gradients environnementaux et d'examiner dans quel ordre les facteurs naturels et anthropiques influent sur la structure des assemblages benthiques littoraux. L'ordre dans la variance expliquée du groupe des variables de l'assemblage benthique littoral était : l'utilisation des terres > les caractéristiques du paysage > l'eutrophisation > l'empoissonnement > l'altération hydromorphologique. Nous avons déterminé neuf gradients (deux naturels et sept gradients de stress), séparés en cinq groupes en fonction des différences statistiquement significatives dans la réactivité des taxons. En dehors de la réactivité à des facteurs naturels, les invertébrés benthiques du littoral pourraient être utilisés comme bioindicateurs pour les facteurs de stress reflétant l'urbanisation, l'eutrophisation, l'altération hydromorphologique et l'empoissonnement. La composition taxinomiq...

Urbanization poses serious extinction risks, yet some species thrive in urban environments. This may be due to a pronounced developmental plasticity in these taxa, since phenotypically, plastic organisms may better adjust to unpredictable urban food resources. We studied phenotypic plasticity in Nuctenea umbratica, a common European forest and urban vegetation spider. We subjected spiderlings to low (LF), medium (MF) and high (HF) food treatments and documented their growth and developmental trajectories into adulthood. Spiders from the three treatments had comparable numbers of instars and growth ratios, but differed in developmental periods. Longest developing LF spiders (♀ = 390, ♂ = 320 days) had the smallest adults, but MF (♀ = 300, ♂ = 240 days) and HF (♀ = 240, ♂ = 210 days) spiders reached comparable adult sizes through shorter development. While males and females had comparable instar numbers, females had longer development, higher growth ratios, adult sizes and mass; and while males adjusted their moulting to food availability, female moulting depended on specific mass, not food treatment. We discussed the patterns of Nuctenea sex-specific development and compared our results with published data on two other Holarctic urban colonizers (Larinioides sclopetarius, Zygiella x-notata) exhibiting high plasticity and fast generation turn-over. We conclude that despite relatively unconstrained developmental time in the laboratory enabling Nuctenea to achieve maximal mass and size-main female fitness proxies-their relatively fixed growth ratio and long generation turn-over may explain their lower success in urban environments.

Based on the responses of our sample (N = 310) of adolescents and young adults from Slovenia (students of secondary and tertiary schools, university students) to a number of tasks covering reproduction, from the molecular to organismal levels, it can be concluded that their knowledge is seriously flawed. Correlations of knowledge between individual tasks are low, or even negative, showing patchiness and missed connections between different aspects of reproduction. Our study confirms the well-known difficulties in building a consistent body of knowledge on the genetic–inheritance axis while expanding it to the anatomy and physiology of reproduction. It is crucial to stress the quality of elementary school biology, and science (biology) courses in secondary schools because, for most people, this will be the last formal contact with some important topics that could influence their life decisions.

IZVLEČEK Pomen makrofitov v jezerskem ekosistemuV preglednem članku povzemamo temeljne značilnosti makrofitov v jezerskem ekosistemu. Makrofiti so povezoval ni člen med sedimentom, vodo in ozračjem. Vodne rastline vplivajo na zgradbo habitata, prav tako pa so vir avtohtonih snovi, ki so osnova za prehranjevalni splet. Rast vodnih rast lin je odvisna od mnogih okoljskih dejavnikov, ki so med seboj povezani svetloba, temperatura, vodni tok, globina ipd. Za prehod od velike kalnosti do prosojnosti vode v jeze ru sta značilni spremembi v prevladi skupin primarnih pro ducentov in vrst v celotnem prehranjevalnem spletu, kjer namesto prevladujočega fitoplanktona postanejo prevla dujoči primarni producenti submerzni makrofiti ali peri fitonske alge. Makrofiti so pomembni tudi za vrednotenje človekovega vpliva na jezerski ekosistem ter posredno pri izvajanju upravljavskih načrtov za vode.Ključne besede: makrofiti, jezera, fitoplankton, ekološko stanje ABSTRACT The importance of macrophytes in lake ecosystemIn a review paper we summarized the basic features of macrophytes in lake system. Macrophytes present link be tween sediment, water and atmosphere. Primarily aquatic plants determine the structure of habitat and present the vital source of autochthonous matter as a base for food web. The growth of aquatic plants depends on a number of envi ronmental factors, which are linked light, temperature, water flow, depth etc. Transition from high turbidity to the transparency of the water in the lake is characterized by a change in the dominance of primary producers and species throughout the food web, where instead of the dominant phytoplankton the dominant primary producers becomes submerged macrophytes or periphytic algae. Macrophytes are important for evaluating human impact on lake ecosys tems and indirectly in the management plans for water. Makrofiti imajo pomembno vlogo v vodnih ekosiste mih (Flint & Madsen 1995, Luo et al. 2016, saj so povezovalni člen med sedimentom, vodo in ozračjem. S tvorjenjem mikrohabitatov za perifiton, mest za od laganja jajčec rib in skrivališč mnogih organizmov, vplivajo na večjo biodiverziteto in heterogenost vodne ga ekosistema (Klaassen & Nolet 2007, Lampert & Sommer 2007. S svojim koreninskim sistemom in listi absorbirajo hranila in na ta način čistijo vodo (Zhou et al. 2017) ter istočasno povečujejo koncentracijo hranil ko odmrejo in razpadejo. Lahko delujejo kot indika torji kakovosti vode in sodelujejo pri kroženju hranil. Vključeni so v ekosistemske procese kot so biominera lizacija, transpiracija, izpust biogenih plinov v ozračje in sedimentacija (Carpenter & Lodge 1986). Izločajo tudi alelopatske snovi, ki vplivajo na prehranjevalni splet. Zavirajo rast fitoplanktona, bakterioplanktona (Mulderij et al. 2006) in epifitskih alg , Cerbin et al. 2007, Gross et al. 2007, Wu et al. 2007. Raziskovalci so ugotovili, da alelopatski učinki makrofitov lahko vplivajo na velik del sprememb raz položljivega ogljika v jezerih (Hilt & Gross 2008, Hilt 2006, Jürgens & Jeppesen 1998, Cerbin et al. 20...