Principal, Government Girls Degree College, Adalhat 331 302, Mirzapur, India
Foliar demand and resource economy of nutrients in dry tropical forest species
Article first published online: 18 JAN 2010
2001 IAVS - the International Association of Vegetation Science
Journal of Vegetation Science
Volume 12, Issue 1, pages 5–14, February 2001
How to Cite
Lal, C.B., Annapurna, C., Raghubanshi, A.S. and Singh, J.S. (2001), Foliar demand and resource economy of nutrients in dry tropical forest species. Journal of Vegetation Science, 12: 5–14. doi: 10.1111/j.1654-1103.2001.tb02612.x
- Issue published online: 18 JAN 2010
- Article first published online: 18 JAN 2010
- Received 2 June 1999; Revision received 3 April 2000; Final revision received 30 May 2000; Accepted 5 June 2000.
- Leaf area;
- Leaf mass;
- Nutrient budget;
- Nutrient resorption;
Important phenological activities in seasonally dry tropical forest species occur within the hot-dry period when soil water is limiting, while the subsequent wet period is utilized for carbon accumulation. Leaf emergence and leaf area expansion in most of these tree species precedes the rainy season when the weather is very dry and hot and the soil cannot support nutrient uptake by the plants. The nutrient requirement for leaf expansion during the dry summer period, however, is substantial in these species. We tested the hypothesis that the nutrients withdrawn from the senescing leaves support the emergence and expansion of leaves in dry tropical woody species to a significant extent. We examined the leaf traits (with parameters such as leaf life span, leaf nutrient content and retranslocation of nutrients during senescence) in eight selected tree species in northern India. The concentrations of N, P and K declined in the senescing foliage while those of Na and Ca increased. Time series observations on foliar nutrients indicated a substantial amount of nutrient resorption before senescence and a ‘tight nutrient budgeting’. The resorbed N-mass could potentially support 50 to 100% and 46 to 80% of the leaf growth in terms of area and weight, respectively, across the eight species studied. Corresponding values for P were 29 to 100% and 20 to 91%, for K 29 to 100% and 20 to 57%, for Na 3 to 100% and 1 to 54%, and for Ca 0 to 32% and 0 to 30%. The species differed significantly with respect to their efficiency in nutrient resorption. Such interspecific differences in leaf nutrient economy enhance the conservative utilization of soil nutrients by the dry forest community. This reflects an adaptational strategy of the species growing on seasonally dry, nutrient-poor soils as they tend to depend more or less on efficient internal cycling and, thus, utilize the retranslocated nutrients for the production of new foliage biomass in summer when the availability of soil moisture and nutrients is severely limited.