Assessment of Life Form and Adaptive Capacity of Coral Reef Ecosystem in Tanjung Tiram Waters, Southeast Sulawesi

<b>Background and Objective:</b> The coastal areas of Southeast Sulawesi are households of rich coastal ecosystems, which provide precious ecosystem services for society, but recent conditions might be suffered by various natural and anthropogenic pressures. This study aimed to elucidate the life forms and adaptive capacity of the coral reefs ecosystem in the Tanjung Tiram waters, as one of the potential tourist places in Southeast Sulawesi. <b>Materials and Methods:</b> Observation of the life form and adaptive capacity of coral reefs was carried out using the LIT (line intercept transect) method. The adaptive capacity components of the coral reef ecosystem were assessed including: (1) Coral reef dimensional index (IDCR), (2) Coral cover (%), (3) Dominance of life forms, (4) Number of life form species, (5) Number of reef fish species, (6) Depth of coral reefs and (7) Distance of coral reef ecosystems from residential areas. <b>Results:</b> The life forms of coral reefs consist of <i>Acropora</i> and non-<i>Acropora</i> corals. Adaptive capacity components of coral reefs showed different categories, such as the coral reef dimensional index belonging to the "Low" category, while mostly other adaptive capacity parameters including coral cover, the coral life forms and the number of coral fish belong to the "Moderate" category except for the number of life-form species of coral reefs is in the high category. The distance of the coral reef ecosystem is very near to human settlements of Tanjung Tiram Village and thus coral reef ecosystems are affected by human activities. <b>Conclusion:</b> Overall, the adaptive capacity of the coral reef ecosystem in Tanjung Tiram waters was a moderate category, thus, efforts must be made such as by coral transplantation, conservation, etc., to increase the coral reefs' adaptive capacity in the coastal regions of Southeast Sulawesi.

The self-thinning process in mangrove Kandelia obovata stands

The self-thinning process was monitored in crowded Kandelia obovata Sheue, Liu & Yong stands over four years. The frequency distribution of tree phytomass was an L-shape, which was kept over the experimental period. Spearman's rank correlation coefficient for phytomass decreased as the time span of the comparison became longer, a result which indicates that the rank of phytomass changes as stands grow. Death of trees resulted from one-sided competition, i.e., death occurred in lower-rank trees. Surviving trees continued to grow. Whatever the current spatial distribution of the trees, death occurred randomly and the spatial distribution gradually became close to random as stands grew. The self-thinning exponent was 1.46, which can be regarded as evidence in favor of the 3/2 power law of self-thinning. Relative growth rate, RGR, decreased in proportion to decreasing relative mortality rate, RMR, with a proportionality constant of 1.57, which was not significantly different from the slope of the self-thinning exponent. This experimental result probably justifies the assumption that the ratio of RGR to RMR in the mean phytomass-density trajectory for any self-thinning population with different densities becomes constant as the growth stage progresses.

Characterization of salt tolerance in ectoine-transformed tobacco plants (Nicotiana tabaccum): photosynthesis, osmotic adjustment, and nitrogen partitioning

Ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid) biosynthetic genes (ect. ABC) from Halomonas elongata were introduced to tobacco plants using an Agrobacterium-mediated gene delivery system. The genes for ectoine biosynthesis were integrated in a stable manner into the tobacco genome and the corresponding transcripts were expressed. The concentration of ectoine under salt-stress conditions was higher in the roots than in leaves. A close relationship was found between stomatal conductance and the amount of transported nitrogen, suggesting that water transport through the xylem in the stem and transpiration may be involved in nitrogen transport to leaves. The data indicate that the turgor values of the ectoine transgenic lines increased with increasing salt concentration. The data revealed two ways in which ectoine enhanced salinity tolerance of tobacco plants. First, ectoine improved the maintenance of root function so that water is taken up consistently and supplied to shoots under saline conditions. Second, ectoine enhanced the nitrogen supply to leaves by increasing transpiration and by protecting Rubisco proteins from deleterious effects of salt, thereby improving the rate of photosynthesis.