DIVERSITY, STRUCTURE AND STANDING STOCK OF WOOD IN THE HOMEGARDENS OFKERALA IN PENINSULAR INDIA

A survey was conducted in 17 selected thaluks (revenue sub-divisions) of Kerala state to elucidate the floristic structure, composition and the extent of similarities and diversities in the composition of homeg ardens of Kerala, with particular reference to small (below 0.4 ha), m edium (0.4 to 2 ha) and large (> 2.0 ha) holding size categories. Besi des attempts were also made to characterize the potential of homegarde ns to supply commercial timber and fuelwood. Two hundred and fifty two farmers were selected through a stratified random process. In additio n to gathering general information on crop and livestock production en terprises, all scattered trees and shrubs (greater-than-or-equal-to 15 cm girth at breast height) on the homestead and border trees except p alms and rubber were enumerated. There was tremendous variability both in the number of trees and shrubs present and species diversity of th e selected homesteads in different provinces. The small, medium and la rge sized holdings also exhibited profound variability in the number o f woody taxa and individuals present. In total, 127 woody species (Gir th at Breast Height (GBH) greater-than-or-equal-to 15 cm) were encount ered. The mean number of woody taxa found in the homegardens ranged fr om 11 for Pathanapuram to 39 in Perinthalmanna. Floristic diversity wa s higher in the smaller homesteads. It decreased with increasing the s ize of holdings. Mean Simpson's diversity index for the homesteads ran ged from 0.251 (Kochi) to 0.739 (Kottarakkara) suggesting that florist ic diversity of homegardens was moderate to low compared to a value ov er 0.90 for the species-rich evergreen forests of the Western Ghats. T he Sorensen's similarity indexes suggested a moderately high degree of similarity for the different tree species encountered in the homestea ds of Kerala. No clear cut planting pattern was discernible in the hom egardens of Kerala. The homegarden trees and shrubs were either scatte red throughout the homestead or on farm boundaries. Farmers tend to pr efer timber trees such as ailanthus (highest frequency) and teak besid es fruit trees such as mango, jack, cashew and the like. Major homegar den species were represented in all diameter classes. The diameter str ucture, however, exhibited a slightly skewed (+) distribution pattern, having the highest frequency in the 20-30 cm classes ensuring adequat e regeneration status and in that process making homegardens a sustain able as well as dynamic land use system. Standing stock of timber and firewood in the homestead of different thaluks are presented. Average commercial standing stock of homesteads ranged from 6.6 to 50.8 m3 ha- 1 and fuel wood volume was of the order of 23 to 86 m3 ha-1. Implicit in the high commercial timber volume and fuel wood volume is that a su bstantial proportion of the society's wood demands are met from the ho mesteads. Palms, however, constituted the dominant component of standi ng commercial timber and fuel wood volumes accounting as much as 63% a nd 72%, respectively, of the total wood in these categories.