Factors affecting tree diameter growth

Abstract

Tree diameter growth is sensitive to environmental variations and can influence forest community dynamics. As tropical tree diameter growth is not well characterised in the Indian tropics, an attempt was made to identify important intrinsic and extrinsic factors affecting tree growth in the dry deciduous forest of Mudumalai, southern India. Data were obtained from trees ≥1cm in diameter within a 50-hectare permanent vegetation-monitoring plot at Mudumalai, which was measured at four-year intervals between 1988 and 2000. In addition, a comparison was made between the factors influencing growth at the dry forest of Mudumalai versus those at the tropical moist deciduous forest of Barro Colorado Island (BCI), Panama.

At Mudumalai, species identity explained approximately 16% of growth rate variation in the community, while tree size and height-based growth forms were less important. Most trees also showed a positive association between growth and rainfall variations. Habitat, topography and neighbour density generally had inconsistent influences on growth. Only the most dominant species, Lagerstroemia microcarpa, showed consistent effects of spatial variables.

Comparison of Mudumalai tree growth rates with those at BCI showed a similar influence of temporal environmental variations at both plots. However, the influence of tree size was much stronger and widespread at BCI. Overall, different factors showed a moderate influence on diameter growth at the drier forest in Mudumalai, whereas light availability may be a dominant influence at the wetter forest in BCI.

Speaker

Cheryl D. Nath, IFP

Organisers

Department of Ecology, “Managing Biodiversity in Mountain Landscapes” programme, French Institute of Pondicherry

Venue

Jawaharlal Nehru Conference Hall, French Institute of Pondicherry, 11, Saint Louis Street, Pondicherry - 605001

Time

16h30