Essays about: "food webs"

Showing result 26 - 30 of 37 essays containing the words food webs.

  1. 26. How does nutrients and light affect algal growth in Swedish headwater streams? : A study using nutrient diffusing substrate and natural gradients of light

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

    Author : Jannika Andersson; [2014]
    Keywords : : boreal streams; algal productivity; N limitation; nutrient diffusing substrate; incident light;

    Abstract : Gaining knowledge about what factors determine benthic algal biomass and productivity is vital for understanding food webs in aquatic systems, especially in woodland streams with naturally low rates of primary productivity. The aim of this study was to investigate what factors determine algal growth in Swedish headwater streams. READ MORE

  3. 27. Biodiversity at the ecosystem level : structural variation among food webs in temperate and tropical areas

    University essay from Linköpings universitet/Biologi; Linköpings universitet/Tekniska högskolan

    Author : Björn Eriksson; [2014]
    Keywords : Biodiversity; Ecology; Euclidean distance; Food webs; Latitude; Network characters;

    Abstract : Biodiversity is a fundamental part of the functioning of ecosystems and their ability to provide ecosystem services. It has been shown that a high biodiversity increases the robustness of an ecosystem according to the insurance hypothesis. READ MORE

  4. 28. Structural variation across food webs as a measure of biodiversity at the ecosystem level

    University essay from Institutionen för fysik, kemi och biologi; Tekniska högskolan

    Author : Rickard Pettersson; [2013]
    Keywords : Biodiversity; Euclidian distance; Food webs; Network characteristics;

    Abstract : Biodiversity can be measured in several ways and on several levels. In this study a framework is developed to use topological differences in the food webs describing ecosystems to quantify differences between ecosystems. This is then used in an attempt to describe biodiversity at the ecosystem level. READ MORE

  5. 29. An ecological study of the migration, food composition and relative abundance of three-spined stickleback (Gasterosteus aculeatus) in a shallow area in Kalmar Sound.

    University essay from Linnéuniversitetet/Institutionen för biologi och miljö (BOM)

    Author : Peter Söderling; [2013]
    Keywords : Three-spined stickleback; Gasterosteus aculeatus; migration; abundance; population; decline; increase; food; prey; predate; pike; perch; roach; spring; spawn; recruitment; shallow; Kalmar; Baltic; Storspigg; spigg; vandring; förekomst; population; populationsökning; populationsminskning; föda; byte; predera; predator; gädda; abborre; mört; vår; vårlekande; föryngring; lek; grunt; Kalmar; Kalmarsund; Östersjön;

    Abstract : The populations of three–spined sticklebacks (Gasterosteus aculeatus) in the Baltic Sea have increased tenfold over the last decade. A large increase in abundance can alter the offshore and coastal food webs. READ MORE

  6. 30. The effect of visibility and predators on foraging efficiency in littoral and pelagic perch

    University essay from Uppsala universitet/Limnologi

    Author : Konrad Karlsson; [2012]
    Keywords : Resource polymorphism; Perca fluviatilis; phenotypic plasticity; habitat coupling; prey preference;

    Abstract : Phenotypic plasticity in Eurasian perch (Perca fluviatilis) can be driven by a trade-off for ecological specialisation to littoral and pelagic resources. Previous studies on perch have found that this specialisation can have different effects on linkage between the littoral and pelagic food web depending on water transparency. READ MORE