Essays about: "Food webs"

Showing result 21 - 25 of 37 essays containing the words Food webs.

1. 21. Diversity of ecosystems : Variation in network structure among food webs

   University essay from Linköpings universitet/Biologi

   Author : Björn Eriksson; [2016]
   Keywords : biodiversity; ecosystems; ecosystem diversity; food webs; network structure;

   Abstract : Biodiversity loss is one of the major threats to humanity. This has led to an increasing amount of research on biodiversity on genetic and species levels. Studies of diversity at the ecosystem level has however been neglected. An important aspect of ecosystems is food webs that describe the predation-prey interactions between species. READ MORE

3. 22. Analysis of Per- and Polyfluoroalkyl Substances (PFASs) in African Darter (Anhinga rufa) Eggs along Vaal River, South Africa : Comparison of Homologue and Isomer Profiles

   University essay from Örebro universitet/Institutionen för naturvetenskap och teknik

   Author : Felicia Fredriksson; [2016]
   Keywords : Per- and polyfluoroalkyl substances PFASs ; Perfluorooctane sulfonate PFOS ; linear and branched isomers; African Darter; Vaal River; bird eggs; Per- och polyfluoralkylerade substanser PFASs ; perfluoroktansulfonat PFOS ; linjära och grenade isomerer; African Darter; Vaal River; fågelägg;

   Abstract : Per- and polyfluoroalkyl substances (PFASs) are a group of toxic and persistent organic compounds. Their properties make them extremely resistant and they have been shown to have bioaccumulation and toxic properties in the environment and also to biomagnify in both aquatic and terrestrial food webs. READ MORE

4. 23. Spring ice melt effect on benthic oxygen production

   University essay from Umeå universitet/Institutionen för ekologi, miljö och geovetenskap

   Author : Tommy Karlsson; [2015]
   Keywords : Benthic; Oxygen; Ice release; Ecology;

   Abstract : In biology, the winter season is less studied than other seasons partly due to technical and logistical difficulties. The Arctic region is undergoing rapid changes with shorter and warmer winters, shorter snow duration and considerable changes in snow and ice cover as a result. READ MORE

5. 24. Resource use by macroinvertebrates within boreal stream food webs

   University essay from Umeå universitet/Institutionen för ekologi, miljö och geovetenskap

   Author : Emelie Landström; [2015]
   Keywords : Allochthonous; Autochthonous; Food webs; Boreal; Streams; Deuterium; Carbon;

   Abstract : Stream food webs are supported by carbon produced within the stream (autochthonous) and from terrestrial environments (allochthonous). Allochthonous carbon (C) inputs are assumed to be the dominant C source supporting food webs within small streams, but few direct estimates of resource use in small streams have been made, especially in boreal streams. READ MORE

6. 25. Ecotoxicological effects on a food-web exposed to pharmaceuticals : Uptake and effects of oxazepam, fexofenadine and a mixture of both in algae, zooplankton and sticklebacks.

   University essay from Umeå universitet/Institutionen för ekologi, miljö och geovetenskap

   Author : Anna Sundelin; [2015]
   Keywords : Bioconcentration; Bioaccumulation; Behaviour; Pharmaceutical mixtures.;

   Abstract : Complex mixtures of biologically active pharmaceutical residues continuously enter aquatic environments via wastewater, where it can affect species through preserved human drug targets or cause unexpected effects in non-target species. Benzodiazepines and antihistamines are two highly consumed groups of pharmaceuticals that have been shown to bioconcentrate in aquatic organisms and induce behavioural alterations affecting individual fitness. READ MORE