Endah Dwi Hastuti

Growth characteristics of mangrove seedling in silvofishery pond – the allometric relationship of height, diameter and leaf abundance

Dynamic environment condition of the silvofishery pond should provide an effect on the growth of mangrove seedling. This research aimed to observe the morphometric growth rate of mangrove seedling of Avicennia marina and Rhizophora mucronata planted in the silvofishery pond and to analyze the morphometric growth relationship of height, diameter and leaf number development of mangrove seedling. The research was conducted through field experiment involving mangrove species of A. marina and R. mucronata for 18 months during March 2015 to September 2016, both single structured and mixed structure. The observation was conducted every 13 weeks including seedling height, diameter and number of leaves. Data analysis was conducted by regression to provide the statistical relation between the growth of diameter – height, diameter – number of leaves and height – number of leaves. The result showed that the growth rate of A. marina in single structured pond was ranged from 0.38 – 3.00 cm.wk-1, 0.0015 – 0.0969 cm.wk−1 and 0.1 – 13.7 leaves.wk−1 respectively for height, diameter and number of leaves, while in mixed structure was 0.23 – 1.69 cm.wk−1, 0.0169 – 0.0731 cm.wk−1 and 0.5 – 14.0 leaves.wk-. The growth of R. mucronata respectively in single and mixed structure were 0.08 – 2.00 cm.wk−1 and 0.15 – 2.62 cm.wk−1, 0.0031 – 0.1369 cm.wk−1 and 0.0008 – 0.0831 cm.wk−1 and 0.0 – 1.9 leaves.wk−1 and 0.0 – 1.6 leaves.wk-1respectively for height, diameter and number of leaves. Data analysis showed that the growth of seedling height of Avicennia in the mixed structure was significantly affected by its diameter growth and the number of leaves of Avicennia in single structured was significantly affected by its diameter. While the height, diameter and number of leaves of R. mucronata both in mixed and single structured silvofishery ponds were independent to each other. This research concluded that mangrove seedling growth is varied among species and growth environment.

Nutrient Accumulation in the Sediment of Silvofishery Ponds in Semarang

Information concerning the functionality of mangrove within silvofishery ponds is needed, especially relating to the accumulation rate of organic materials and nutrients. This research studied the effect of mangrove structure on the accumulation rate of nutrients within silvifishery ponds. The research, conducted in May 2016, used canals of width 1, 2, and 3 m, with mangrove species Avicennia marina and Rhizophora mucronata , alone or in combination. Nutrients measured were nitrogen, phosphorus and organic matter, in the sediment of the treatment ponds, through soil sampling followed by laboratory analysis. The respective analysis methods used were Kjehdahl, spectrophotometry, and ashing. Data analysis was conducted using factorial ANOVA. The highest nitrogen concentration was detected in the treatment with 15 stands of mixed mangrove species (0.63 ± 0.04 %), the treatment with 10 stands of mixed mangroves showed the highest phosphorus concentration (62.86 ± 12.31 mg/kg), and the highest organic matter concentration (2.55 ± 0.67 %) was seen with 10 stands of R. mucronata . The highest average value based on partial group showed that R. mucronata had the highest nitrogen accumulation at 0.56 ± 0.07 %; for phosphorus, the mixed species pond (62 . 02 ± 7 . 84 mg/kg); and for organic matter, R. mucronata (2.41 ± 0.39 %) .

Effect of Glycerol Concentration and Heating Treatment on Delignification and Bioethanol Production of Sago Dregs

The purpose of this paper was to find the suitable condition between glycerol concentration and heating time treatment in the process of delignification and bioethanol production. The production of bioethanol consisted of 3 main stages: hydrolysis, fermentation, and distillation. The best result was obtained by a glycerol concentration of 90% and 15 minutes of heating time. It was used to delignify the lignocellulose biomass waste of the sago dregs originally containing 36.56% of lignin, 37.6% of -cellulose and 39.51% of holocellulose. Then after being delignificated by 90% of glycerol concentration with 15 minutes heating time, the lignin content decreased to 19.3%, while -cellulose increased to 39.64% and holocellulose also increased to 62.18%. After the delignification was successful, it was followed by the bioethanol production to produce 25% of bioethanol. This research is expected to overcome the problem of the energy crisis, food crisis, and environmental pollution by the sago dregs.