Ecology and Bio-prospecting of Bamboo in Mount Baung Natural Park, Pasuruan, East Java

Abstract

Bamboo is one of plant taxa comprising various species with high economic potential. Bamboo is a member of Bambusoideae of the Poaceae family. There are 1250 bamboo species in the world, 135 of them are in Indonesia. Not all bamboo species are well known, and only some of them can be found in Java Island. Land use changes reduce bamboo natural habitats in Indonesia. One of the bamboo forests in East Java is found at a conservation area namely Mount Baung Natural Park. The information of bamboo diversity, population structure and the relationship between bamboo and its biotic and abiotic factors in Mount Baung Natural Park is not well known. The aims of the research were to study the ecology of bamboo, the relationship between bamboo growth and its biotic and abiotic factors, and the bio-prospection aspect of this taxon in Mount Baung Natural Park, Pasuruan, East Java. This research was carried out at four different locations from September 2011 to Mei 2012. Those locations were Preserved Area, Rehabilitation Area, Limited Usage Area, and Intensive Usage Area. Data collection was conducted by analyzing the bamboo populations using sampled plots along the transects that were determined by stratified random samplings within four purposive sampled areas. The collected botanical data consisted of the bamboo scientific names, the number of clumps per plot and the diameter of clumps. The environmental data consisted of altitude, solar radiation, temperature-humidity, and soil pH. Soil samples were analyzed at the Soil Chemical Laboratory, Center for Research of Land Resources, Bogor. The abundances and densities of bamboo expressed an importance value index, namely the resultant of the sum of Relative Density, Relative Frequency, and Relative Dominance. The determination of habitat characteristics (i.e. determining the most related factors in relation to the presence of bamboo in their community) were analyzed by statistical correlations using the software STATISTICA Minitab 14. The principal component analysis (PCA) and cluster analysis were performed to determine relationships between abiotic/biotic components and bamboo’s occurrences. Canonical Correspondence Analysis (CCA) was used to determine component relationships. Cluster analysis was used to analyze the similarity of the environmental conditions of the bamboo habitat. Index Cultural Significance (ICS) was performed to determine the bamboo bio-prospecting of bamboo. There were seven species of bamboo in Mount Baung Natural Park, Pasuruan, namely Bambusa blumeana, Bambusa vulgaris, Dendrocalamus asper, Schizostachyum iraten, Gigantochloa apus, Gigantochloa atter and Dinochloa matmat. D. matmat was not described detail in this These due to the very limited number ( < 1%) of individual occurence. Among the six bamboo species, B. blumeana possessed nearly ideal population structure. Bambusa blumeana had the highest important value index 127,97%. The structure of bamboo population was classified based on the clump diameter classes which were: A (< 5 m), B (5-10 m) and C (> 10 m). Based on this category, the bamboo in Mount Baung Natural Park belonged to A phase class. Based on the soil analysis, the location had good soil characteristics and was feasible for bamboo growth, namely silty clay loam, medium CEC (Cation Exchange Capacity) ranging from 10,90 to 18,52 cmol kg-1, and high Phosphorus (P), Potassium (K), and base saturation. P is an edafic factor significantly contributing to B. blumeana and B. vulgaris growth and while Sodium (Na) and Manganese (Mn) affecting to G.apus growth. Cluster analysis showed that there were two groups of bamboo which had similar habitat. First group consisted of B. blumeana - B.vulgaris, and the other one consisted of D. asper - G. atter - G. apus - S. iraten. Ordination analysis showed that B. blumeana was affected mainly by slope and altitude. Bamboo blumeana or Gesing bamboo which can be found in Limited, and Intensive Usage areas had the highest important values index and ICS as well as very high usage intensity and exclusive values. This indicateed that Gesing bamboo is a dominant species over the other species at Mount Baung Natural Park. Therefore B. blumeana species must be protected, managed, and conserved proverly. The other bamboo species D. asper, which had low important value index but high ICS, required conservation attention. The absence of conservation actions will lead to the extinction of bamboo population in the Mount.