Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.593432
Title: Effect of shade on growth of lowland forest tree seedlings in Papua New Guinea
Author: Siaguru, Philip
Awarding Body: University of Aberdeen
Current Institution: University of Aberdeen
Date of Award: 1992
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Abstract:
This study was in two parts and involved two years of field research and nursery work in Madang and Lae respectively, in northern Papua New Guinea. The effect of different intensities of sunlight on the growth of twelve tropical lowland forest timber trees as studied using neutral shade in a nursery and artificial canopy gaps in natural forest. The twelve tree species were Albizia falcataria (*), Canarium schlecteri (*), Celtis latifolia (*), Intsia bijuga (+), Maniltoa psilogyne (+), Microcos grandiflora (*), Neonauclea sp (*). Pometia pinnata (* +), Pterocarpus indicus (* +), Terminalia complenata (* +), Terminalia impediens (* +) and Terminalia sepicana (*) . The species marked (*) were monitored in nursery conditions, those with (+) in natural forest. Seeds of the studied tree species were collected from the forest in Madang and were germinated and acclimated under 54&'37 RLI (Relative Light Intensity) in the Lae nursery. After about 2 weeks the plants were transferred to six shade houses at 4, 11, 31, 54, 74 &'38 100&'37 RLI. Height growth, leaf production, biomass growth and seedling mortality were measured. Seedling mortality was highest for some plants in 4&'37 RLI, while most plants attained maximum growth between 30-70&'37 RLI. Growth generally declined in full sun which was partly due to solarization, partly to herbivory, and partly to a pot effect. Clear differences were observed between the species which were ranked on a gradient from the most shade tolerant to the least : C. latifolia, M. grandiflora, P. pinnata, C. schlechteri, T. sepicana, T. impediens, Neonauclea sp., T. complenata and A. falcataria . The research in natural forest at Madang ran concurrently with the nursery research. Seeds of the tree species were collected from the forest in Madang and were germinated and acclimated under 28&'37 RLI in the village nursery in Madang. After about 6 weeks of acclimation, the plants were planted out into the light treatments (1, 29, 63, 84 &'38 100&'37 RLI) created by felling trees to open up the canopy. Pre-existing seedlings together with transplanted seedlings were assessed for height growth, biomass growth, seedling mortality and leaf production. Tree species growing under 1&'37 RLI showed significantly lower growth than at 29&'37 RLI, which was close to the maximum growth, for most species. Species were ranked on a gradient from the most shade tolerant to the least for transplanted seedlings : I. bijuga, P. pinnata, T. complenata, T. impediens and P. indicus ; and pre-existing seedlings : C. latifolia, M. psilogyne and P. pinnata . All tree species studied under natural and nursery conditions attained maximum growth in light levels below full sun.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.593432  DOI: Not available
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