Heat damage in sclerophylls is influenced by their leaf properties and plant environment
Mediterranean southwestern Australia experienced two successive days of extreme (>45 deg C) maximum temperatures and hot winds during the summer of 1991, resulting in adult mortality and extensive crown damage in a sclerophyllous mallee-heathland. To investigate the relationship between leaf attr...
| Main Authors: | , , , , |
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| Format: | Journal Article |
| Published: |
2004
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| Online Access: | http://hdl.handle.net/20.500.11937/22718 |
| _version_ | 1848750948413865984 |
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| author | Groom, Philip Lamont, Byron Leighton, Sylvia Leighton, Pattie Burrows, Chantal |
| author_facet | Groom, Philip Lamont, Byron Leighton, Sylvia Leighton, Pattie Burrows, Chantal |
| author_sort | Groom, Philip |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Mediterranean southwestern Australia experienced two successive days of extreme (>45 deg C) maximum temperatures and hot winds during the summer of 1991, resulting in adult mortality and extensive crown damage in a sclerophyllous mallee-heathland. To investigate the relationship between leaf attributes, plant environment, and heat tolerance in sclerophylls, measurements of plant height, leaf clustering, leaf morphology (thickness, dry density, area, perimeter/area ratio), percentage crown damage, and percentage mortality, and categories of exposure to wind, shade, and bare soils were recorded for 40 heat-damaged and 14 undamaged co-occurring species. Analyzing the entire dataset by principal components analysis showed that undamaged species had thicker leaves (on average 61% thicker) than species with damaged leave and were more exposed to wind, sun, and bare soil. Thicker leaves are a common respone to hot, dry, and more exposed environments and are more heat tolerant than thinner leaves. A separate analysis of the Proteaceae (25 damaged and six undamaged species) showed a similar trend to the overall dataset. An analysis of the Myrtaceae (10 damaged and three undamaged species) showed that wind exposure and level of shading were the most important variables influencing the degree of leaf damage. Percentage leaf damage was significantly correlated with percentage adult mortality, but not with the ability of a species to regrow (percentage of plants producing new shoots). Differences between undamaged and damaged species may be a result of preconditioning, whereby species growing in more exposed habitats were pre-adapted to tolerate periods of heat stress. It is unlikely that the study species were able to reduce leaf temperatures via transpirational cooling during the hottest part of the 2-d heatwave. The ability of a species to tolerate extreme temperature events will be determined by the interaction between leaf heat loads, leaf heat-storing capacity, and the degree of exposure to environmental elements. |
| first_indexed | 2025-11-14T07:44:56Z |
| format | Journal Article |
| id | curtin-20.500.11937-22718 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:44:56Z |
| publishDate | 2004 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-227182017-01-30T12:33:13Z Heat damage in sclerophylls is influenced by their leaf properties and plant environment Groom, Philip Lamont, Byron Leighton, Sylvia Leighton, Pattie Burrows, Chantal Mediterranean southwestern Australia experienced two successive days of extreme (>45 deg C) maximum temperatures and hot winds during the summer of 1991, resulting in adult mortality and extensive crown damage in a sclerophyllous mallee-heathland. To investigate the relationship between leaf attributes, plant environment, and heat tolerance in sclerophylls, measurements of plant height, leaf clustering, leaf morphology (thickness, dry density, area, perimeter/area ratio), percentage crown damage, and percentage mortality, and categories of exposure to wind, shade, and bare soils were recorded for 40 heat-damaged and 14 undamaged co-occurring species. Analyzing the entire dataset by principal components analysis showed that undamaged species had thicker leaves (on average 61% thicker) than species with damaged leave and were more exposed to wind, sun, and bare soil. Thicker leaves are a common respone to hot, dry, and more exposed environments and are more heat tolerant than thinner leaves. A separate analysis of the Proteaceae (25 damaged and six undamaged species) showed a similar trend to the overall dataset. An analysis of the Myrtaceae (10 damaged and three undamaged species) showed that wind exposure and level of shading were the most important variables influencing the degree of leaf damage. Percentage leaf damage was significantly correlated with percentage adult mortality, but not with the ability of a species to regrow (percentage of plants producing new shoots). Differences between undamaged and damaged species may be a result of preconditioning, whereby species growing in more exposed habitats were pre-adapted to tolerate periods of heat stress. It is unlikely that the study species were able to reduce leaf temperatures via transpirational cooling during the hottest part of the 2-d heatwave. The ability of a species to tolerate extreme temperature events will be determined by the interaction between leaf heat loads, leaf heat-storing capacity, and the degree of exposure to environmental elements. 2004 Journal Article http://hdl.handle.net/20.500.11937/22718 fulltext |
| spellingShingle | Groom, Philip Lamont, Byron Leighton, Sylvia Leighton, Pattie Burrows, Chantal Heat damage in sclerophylls is influenced by their leaf properties and plant environment |
| title | Heat damage in sclerophylls is influenced by their leaf properties and plant environment |
| title_full | Heat damage in sclerophylls is influenced by their leaf properties and plant environment |
| title_fullStr | Heat damage in sclerophylls is influenced by their leaf properties and plant environment |
| title_full_unstemmed | Heat damage in sclerophylls is influenced by their leaf properties and plant environment |
| title_short | Heat damage in sclerophylls is influenced by their leaf properties and plant environment |
| title_sort | heat damage in sclerophylls is influenced by their leaf properties and plant environment |
| url | http://hdl.handle.net/20.500.11937/22718 |