Interactive effect of under-canopy irradiance and temperature fluctuations on leaf antioxidants.

Robson, T. M. (Handledare), Loehr, J. A. (Bihandledare), Brelsford, C. (Bihandledare)

Aktivitet: ExaminationstyperHandledning av annat kunskapsprov (pro gradu, licentiatavhandling)


Winter temperature fluctuations in forests depend on canopy cover controlling the daytime irradiance and night-time loss of infra-red radiation to the sky. These fluctuations affect the antioxidant accumulation of wintergreen plants as they try to counteract abiotic stress. These plants look to utilise favourable conditions in the early spring to flower before canopy tree leaf flush.
1. To assess how the temperature fluctuations in forest stands of differing tree functional types and leaf area index (LAI) interact with irradiance to affect leaf antioxidant production (anthocyanins and flavonoids) by wintergreen and early-spring ephemeral understorey plants. The native understorey forbs Hepatica nobalis, Fragaria vesca or Oxalis acetocella might represent good species on which to test the leaf antioxidant production response to temperature as all have winter-green leaves.
2. To assess how spring seasonal changes affect the time-course accumulation of leaf antioxidants in these plants under different canopies.
3. To experimentally manipulate the environment to create a treatments of larger temperature fluctuations during winter and early spring for understorey plants under controlled conditions in a greenhouse or growth chamber, in to order test the response of leaf antioxidants to the sort of conditions that might be expected under future climate change, and to segregate responses to light from responses to temperature. As well as the native species, an exotic understorey species such as Fuchsia which is known to produce a large anthocyanin response would be a candidate to these controlled manipulations.
Period24 jan 2017 - 30 jun 2017
ExaminandMathilde Poissenot
Examination vidUniv Strasbourg, Strasbourg, France