Habitat Suitability for Javan Gibbon in Mount Salak

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4.3.2.2. Habitat Suitability for Javan Gibbon in Mount Salak

Based on PC loadings, the first component is best describing the contained in lowland and submontane forest area, slope 0 to 15 and more than 45, and distance to road and nonforested land. The second component is best describing primary and secondary forest and contained area with slope 15 to 45. Based on Table 7, weight calculation set the forest maturity i.e. primary and secondary forest and distance from road as the most influenced variable; followed by forest ecosystem, distance to non-forested area and riverwater body. The weights seem ecologically interpreteable. The weight of forest maturity is highest on primary forest, which is already known that primary forest is containing richer gibbon diets foods, providing more cover structural properties in environment that used for certain activities, such as resting cover, sleeping cover, and so forth than the secondary forest. The influence of water supply to the gibbons is small by the fact that gibbon are seldom to come down from the tree canopy. Eventhough, Hadi 2004 noted that communities near to the river have a high species biodiversity. Based on the model outcome, the highly suitable habitat is mainly situated in the eastern and northern part of Mt Salak area, within Desa Tamansari, Gunung Malang, Tenjolaya, and also Pasirjaya, Sutajaya, Pasawahan, and Cisaat. Some part of this class is placed in the western parts, i.e. Parakansalak, Sukakersa, and Sukatani. Suitable habitat area is much more distributed following the orientation of the shape of Mt Salak area, as well as the moderate suitable area. The low suitable is mainly located at the periphery of Mt Salak, surrounds the suitable and highly suitable habitat. The smallest suitable class area less suitable is placed in the northern part. Mostly the suitable and highly suitable habitat spread over the primary forest. In constrast, low suitable area is mainly placed over secondary forest. The distribution data was superimposed into the habitat suitability class map to know the condition of available gibbon distribution from field survey. Figure 42 shows that from 29 gibbon identified groups, 3 and 9 groups are living in high suitable and suitable habitat respectively; 13 groups in moderate suitable, and for each less and low suitable habitat level is lived by 2 javan gibbon groups. 78 Two gibbon groups are living in low suitable habitat, instead of that small portion of the habitat is still supporting their lives. It shows the influence of geographical factors to the model, which are not only considered to biological or ecological factors. The suitability of the habitat entity is decreasing if located near to the inappropriate factors built up area, such as road, settlement, and so forth for survival. That is also explains why many groups are located in the moderate suitable. In this class especially in the western part of Mt. Salak, a complex of power plant company including its road system is established. Figure 53 shows a member of isolated gibbon near Cangkuang base. Figure 53. A Male Gibbon Which Living in the Low-Suitable Habitat Some limitations are identified in this research. The outcome of suitability model depends on the samples unit sampling size and quantity and habitat factors as model input. It is expected that sampling units large enough and taken from more systematic way. Samples data is not sufficient to do validity and sensitivity analysis, therefore the reliability and consistency of the model are not known. The validity somehow is hard to be inspected, since the meaning of suitability correspond to gibbon survival or imply to successful reproduction and dispersion forming a new family group, hence needs a long term research. Such research should have an objective to find out the relationship between demographic parameters which reflects the population progression such as the reproduction rate in each suitability classes with the suitability classes themselves. 79 The input of habitat factors is also limited. More likely, the model would be much more legitimate if it considered the landscape theoryconcepts, such as the edge-effect and contiguity concepts. Edge-effect is the phenomenon shows structural and compositional changes from the edge of natural landscape to its interior that adjacent with unnatural or disturbed patch or landscape. Dessy 1996 showed the fact on natural landscape of national park trespassed by road which caused edge-effect for 40 m width. Unfortunately, the similar research has not been conducted in Mt. Salak. Contiguity is related with the habitat isolation. A fragment of habitat will be more suitable if its surrounding has the same structural and compositional vegetation. In other meaning, the more isolated a habitat, it less suitable for certain species to live. The contiguity concept is not adopted in the model because of technical matter. The current version of SUITSTAT is not provided by the contiguity analysis and hence suggested for further development. 80

V. CONCLUSION AND RECOMMENDATION

5.1. Conclusion

1 This research shows the development a mapping system that used to produce habitat suitability information in vector-based grid format. It is supported by vector-based grid transformation, basic geo-processing tools, ecogeographical data generation, species distribution mapping, weight calculation based on presence species data, and suitability score calculation. Through SUITSTAT, the user is able to dynamically select spatial data which represents habitat factors, modify criteria and constraint, and calculate the score. 2 Based on habitat suitability model which grouped into 5 classes, Mt. Salak area is dominated by suitable class. The area with score more than the moderate suitable class covers 52.39 km 2 or 39.5 from total area 132.78 km 2 . 3 Two javan gibbon groups are located for each low and less and suitable habitat, 13 groups in moderate suitable, 9 groups in the suitable habitat and 3 groups are living in the high suitable habitat.

5.2. Recommendation

This research promotes some idea for further development of this system: 1 Developing a modular system which could combine many algorithms in determining habitat suitability. 2 The system that could read or integrate various spatial data format could be promising since there is no single format to represent habitat data. 3 The further development is more likely better constructed under the available open-source GIS software as the extension consider to the cost effectiveness, the utilization of modular framework, and availability comprehensive geoprocessing function. Some open-source GIS softwares can be used are Quantum GIS http:qgis.org and Jump Project. 4 The future system is that providing information through internet web-based suitability information could be the most challenge. At least, it should apply