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Subject: Agroforestry × Author: KAU × Author: Subu, R Unnithan × End date: 2017 × Start date: 2015 ×
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    ThesisItemOpen Access
    Diversity, structure and standing stock of timber in the homegardens of Thrissur district, Kerala
    (Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2017) Subu, R Unnithan; KAU; Kunhamu, T K
    Tropical homegardens are time-tested land use systems which have evolved through generations of crop intensification. Homegardens of Kerala are traditional agricultural systems that were closely related to the livelihood and nutritional security of small and marginal farmers of Kerala. A study was carried out to investigate the functional and structural status of the homegardens in Thrissur District, Kerala. Study was conducted in selected homegardens of 10 panchayths and one peri urban area of Thrissur district. The study was based on comparison of homegardens of three size classes such as small (<0.2 ha), medium (0.2-0.4 ha) and large (>0.4 ha) from three eco regions (highland, midland and coastal land) and one peri urban area (municipality). A total of 330 homesteads were selected from selected panchayths based on a stratified random sampling. There was a great variability in diversity, abundance and standing stock of different tree species belongs to different use categories among three homegarden size classes and across different eco regions. There were 163 total species present in the entire Thrissur district that included 122 trees species and 41 agricultural crop species. Contrary to earlier studies, consistent decline in diversity was observed with decrease in homegarden size. Highest number of taxa was observed from large homegardens (102 species) which was followed by medium (95 species) and small (85 species). Population pressure and skewed land availability may have negatively affected the species diversity in homegardens. Most abundant functional group of trees found in surveyed homegardens were medicinal trees (62 species) followed by timber species (53 species). Economically important functional groups such as timber, fodder, fuel, green manure and other MPTs were abundant in large homesteads. Eco-region wise comparison of tree diversity suggested high diversity in the midland and highland regions while lower in coastal land and peri-urban areas. Mangifera indica was the predominant timber tree species in terms of abundance and standing stock in Thrissur district with a total stand number and standing stock projected to the Thrissur district as 15,98,849 and 18,84,356.3 m3 respectively. Other dominant timber trees in terms of standing stock were Artocarpus heterophyllus, Tectona grandis, Swietenia macrophylla, etc. Standing stock per hectare of total timber species identified in Thrissur district was 55.12 m3 ha-1 and projected standing stock of all timber species in the district was 81,38,931.6 m3. Vertical diversity of the studied homegardens suggested high species richness associated with middle storey. Also all three strata of large homegardens were more diverse than medium and small homegardens irrespective of eco-region. In total there were 41 species of agricultural crops and medicinal plants identified from selected homegardens. Musa sps., Areca catechu and Cocos nucifera were the predominant species of all size holds. Simpson Index and Shannon Diversity Indices of agricultural crops of all size holds showed no large difference. Attempts to study the socio-economic factors of homegarden functioning revealed land fragmentation as the principal agent of their decline. The most frequent constraints of homegardens included high wage of the labourers involved in homegarden maintenance, less labour availability, large expense/less profit, pest and disease, etc. Wood quality assessment of Tectona grandis, Artocarpus heterophyllus and Swietenia macrophylla using NDT showed that oven dry specific gravity (SPGo.d) has no influence on eco-regions and tree size classes. The dynamic modulus of elasticity (MOEdyn) showed significant differences for Artocarpus heterophyllus and Swietenia macrophylla across eco-regions. However, this was not prominent for Tectona grandis. On the whole, the functional and structural analysis of the homegardens in Thrissur district of Kerala revealed their potential contribution to the agro-biodiversity. However concerted efforts are required to revitalize these unique traditional agricultural practices in terms of their ecological and economic viability.
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    ThesisItemOpen Access
    Diversity, structure and standing stock of timber in the homegardens of Thrissur district, Kerala
    (Department of Silviculture and Agroforestry, College of Forestry, Vellanikkara, 2017) Subu, R Unnithan; KAU; Kunhamu, T K