Mangrove community plays an important role to the mangrove ecosystem and its ecosystem and its surrounding as a source of organic substances and to be overviewed from its role and function, mangrove woods is a very potential natural resource. Homever, some problems rise as a common problem in all whole Java in several aspects of the ecosystem which are: functionality changes of the mangrove forest to be fishery area, housing/residential area, and some other purposes. The study was intended to know the parameters of the ecosystem’s condition including pH, salinity, sediment, structure and the composition of the mangrove vegetation, and existing biotas. In addition, the aim of this study is hoped to be a base of consideration and the source of information for the planned power plant.
The study was conducted in September, 14 and 17, 2007 at three locations in Ujung Piring which are: Jambu, Blebak, and Sekuro. Each of the location is then divided to three stations (Mueller-Dumbois and Ellenberg, 1974) and for every station, a plot measured 10x10 m was produced and subplots of 5x5 m and 1x1 m was made.
The mangrove species composition found in Ujung Piring, Jepara, is composed on 9 species that is joining five family, they are: Lumnitzera racemosa, Ceriops decandra, C. tagal, Rhizopora apiculata, R. stylosa, R. mucronata, Sonneratia alba, Excoecaria agallocha, and Pemphis acidula. For the three categories that is studied (tree, sapling, seedling) in Jambu, where there is no species that is dominant. In Jambu, it is found that the domination of R. apiculata is certain with the Dominance Index (C) of 0.59 and is found at every station at the study area (highest at 833.3 ind/ha and lowest at 233.3 ind/ha), and the importance value coming from the range of 182.9%-200%. For the category of sapling R. apiculata is still the most easy to find everywhere and is dominating in Jambu, where in Blebak, most of the species of sapling living at the rate of individual density of 2133.3 ind/ha. In general both of the uniformity and diversity rate is categorized as low.
During this study, the writer found a species which its spreading is not common in Indonesia, the species is P. acidula. Also in this research there are also some macro benthoses which is found there are 6 species of crustaceae class: Cilibanarius sp. Metaplax sp, Coenobita sp, Metopograpsus sp, Uca sp,and Paracleistostoma sp., it is also found 4 species of gastropod which are Cerithidea cingulata, Clypeomorus moniliferus, Terebralia sp. and Terebralia sp1.
The result of the research showed that the environment of mangrove is quite good for the spreading and growth of mangrove, because in the location, mangrove grows at the salinity decree of 28-32‰, has a flat topography, and the providence of sediments (in which, it is predicted there is a contain of sulphate reduction in Jambu, that is marked by silty black sediment with strong smell of reduced carbonate (CO32-) like methane gas (CH4) and ammonia (NH3), in Blebak, it is predicted that the presence of Sulphate (SO42-) reduction is existed, marked from the silty sand with blackish–gray sand characteristic, and in the third location, Sekuro it is predicted that in the site, contains a presence of Nitrate (NO3-) reduction; marked with the presence of sandy reef with yellow-brown coloring.
The causes why the mangrove was only found in sum of nine species which is grouped to five families were: housing problem, usage of mangrove woods as fuel, and opening of the mangrove forest as fishery area. Now, the problem is worsening within the plan of establishment of power plant is commenced in Ujung Piring due to the recent demonstration. It is now a question for the sake of the Mother Nature; whether or not we are going to save the mangrove or will we disturb the order of this good for mangrove-living and development environment. For the sake of our environment, for the sake of the Indonesia, and for the sake of Mother Nature, Let us make a notion of saying no towards the planned power plant in Ujung Piring.