We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Leaf fracture toughness and sclerophylly: their correlations and ecological implications.
- Authors
Choong, M. F.; Lucas, P. W.; Ong, J. S. Y.; Pereira, B.; Tan, H. T. W.; Turner, I. M.
- Abstract
The fracture toughness of sun-leaves of 42 tropical tree species growing in Singapore was measured along a 'least tough' path using an instrumented cutting technique. Punch-and-die (penetrometer) tests were also conducted. Intercostal material was analyzed for crude fibre and crude protein (total nitrogen concentration × 6.25) and the ratio of the two, the index of selerophylly, calculated for each species. Leaf anatomy was examined and specific leaf area was calculated. Thirty-seven of the species were from three definable plant communities, namely mangroves, trema belukar (secondary forest on undegraded sites) and adinandra belukar (secondary forest on highly degraded soils). There was a highly significant positive correlation between fracture toughness and index of selerophylly for the 42 species (R2 = 0.43, P < 0001) brought about largely by a high correlation between toughness and crude fibre content. Fracture toughness was not correlated with lamina tissue dorsi-ventral thickness but high toughness was clearly associated with the presence of sclerenchyma bundle sheaths and sheath extensions. Analysis of the fracture path for 26 leaves of ten mangrove species showed a high correlation between the area fraction occupied by veins and fracture toughness if one species, Avicenmia rumphiana, was excluded. The regression equation for the other nine species gave estimates of the fracture toughness of vein tissue and lamina matrix of 6053 and 327 J m-2 respectively. Punch-and-die test results only correlated well with the cutting tests when values were divided by lamina thickness.
- Subjects
TREES; TROPICAL agriculture; LEAVES; PLANT anatomy; NITROGEN; EPITHELIUM
- Publication
New Phytologist, 1992, Vol 121, Issue 4, p597
- ISSN
0028-646X
- Publication type
Article
- DOI
10.1111/j.1469-8137.1992.tb01131.x