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Holá, Michaela, 2012. Spatial and Temporal Variation in the Quality of Summer Foods for Herbivores along a Latitudinal Gradient. Second cycle, A2E. Umeå: SLU, Dept. of Wildlife, Fish and Environmental Studies

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Abstract

The spatial and temporal variation in nutritional quality of plants consumed by herbivores is considered as one of the main factors governing their feeding patterns and influencing their productivity. Plant nutrients vary in space and time both within and among plant species, at fine scales, and across large geographical scales, creating a heterogeneous environment where herbivores have to cope with variation in food quality at different spatiotemporal scales. As a response to this variation, herbivores make trade-offs between acquisition of digestible nutrients (e.g. nitrogen) and reduction of digestibility-reducing compounds (e.g. plant defence compounds like phenolics or tannins). Since little is known where the major sources of variation that herbivores face are and how these may be compared in a natural system, I analysed spatial and temporal variation in food quality (i.e. the concentration of nitrogen, fiber, total phenolics and condensed tannins) at three levels: local, regional and yearly scales. Two important plant species, downy birch (Betula pubescens) and fireweed (Epilobium angustifolium), in the summer diet of moose (Alces alces) were collected for three subsequent years along a latitudinal gradient of varying environmental conditions spanning across Sweden and assessed with near infrared reflectance spectroscopy. The degree of variation in nutritional aspects of food quality was of similar importance at all three spatiotemporal scales. In addition, there was a clear latitudinal gradient of these nutrients, where nitrogen and fiber increased towards the south in both species, and defence compounds increased towards the north in fireweed. My findings may have important implications for researchers dealing with multiple sources of variation in large scale questions, like climate change and its effects on plant-herbivore interactions.

Main title:Spatial and Temporal Variation in the Quality of Summer Foods for Herbivores along a Latitudinal Gradient
Authors:Holá, Michaela
Supervisor:Ball, John P
Examiner:Roberge, Jean-Michel
Series:Examensarbete i ämnet biologi / Sveriges lantbruksuniversitet, Institutionen för vilt, fisk och miljö
Volume/Sequential designation:2012:7
Year of Publication:2012
Level and depth descriptor:Second cycle, A2E
Student's programme affiliation:SM003 Management of Fish and Wildlife Populations - Master's Programme 120 HEC
Department:(S) > Dept. of Wildlife, Fish and Environmental Studies
Keywords:nutrient variability, Betula pubescens, Epilobium angustifolium , near infrared reflectance spectroscopy, Sweden, Spatiotemporal scales
URN:NBN:urn:nbn:se:slu:epsilon-s-2812
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-s-2812
Subjects:Plant physiology - Nutrition
Animal feeding
Language:English
Deposited On:11 Oct 2013 09:45
Metadata Last Modified:11 Oct 2013 09:45

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