Some of the effects of wind upon young Acer pseudoplatanus L. tree seedlings were investigated, including the nature of wind damage to leaves and some of the effects of wind upon CO2 and H2O exchange at different levels of soil water. A controlled environment wind tunnel was used for much of the work but some of the observations of that damage involved outdoor plants. Brown lesions developed on leaves as a result of abrasion when they were exposed to wind. The zones of leaf that were readily damaged changed as the leaf expanded and its topography altered. Young, expanding leaves were more susceptible to damage than older leaves. In the wind tunnel, there was a linear relationship between % damage and windspeed and mean leaf relative growth rate appeared to be reduced by wind. Wind damage led to crushing of epidermal and mesophyll cells and disruption of the epicuticular waxes present on the abaxial leaf surface which was far more readily damaged than the adaxial surface despite apparently protective topographic features. The effects of wind upon CO2 and H2O exchange depended upon the state of leaf development and the availability of soil water. When leaves were fully expanded, day and night leaf conductance to water vapour were increased by wind over a period of several days but when leaves were still expanding, only night time conductance was affected. The effects were reduced at low levels of soil water. Where there were effects of wind they were always at least partially reversible in a subsequent calm period. Photosynthesis was only affected by wind at high levels of soil water, when the rate of photosynthesis of green areas of wind damaged leaves increased - thereby compensating for the loss of photosynthetically active area. There was a linear relationship between % macroscopic damage and cuticular conductance to water vapour. Mesophyll conductance and dark respiration were unaffected by wind and soil water.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:663900 |
| Date | January 1979 |
| Creators | Wilson, Julia |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/14681 |
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