9 research outputs found
Changes on Soil Chemical Characteristics of The Reclamation Ex-Mining Land As A Model at The PT. Antam UBPE Pongkor
High mining activity in the forested land had damaged the forest, that reclamation is necessary to restore the forest conditions as before. This research aims at finding out changes on soil chemistry, and the concentration of Pb and Fe in the soil, and the 10 years old planted rosewood, pine, and walnut trees at the reclamation ex-gold mining land as a model of PT. Antam UBPE Pongkor. Soil analysis at 0–5 cm, 5–15 cm and 15–30 cm depth showed increase soil quality, especially in C-organic content at 0–5 cm, which is much higher than the deeper depth. C-organic content of rosewood stand was 2.08%, pine was 1.04% and walnut was 0.95%. The 10 years old planted trees had absorbed Pb and Fe, of which the highest Pb content was found in walnut roots at 13 ppm, while the highest Fe content was in pine roots at 4933 ppm.Keywords: C-organic, Fe, Pb, reclamation, soil chemistr
GIS BASED FLOOD HAZARD AND VULNERABILITY MAPPING: A CASE STUDY OF TIDAL AND RIVER FLOODS IN DOWNSTREAM OF CIASEM WATERSHED, SUBANG-WEST JAVA
Flood events in downstream of Ciasem watershed are believed to occur due to degradation of watershed and mangrove cover. This paper studies the flood hazard and vulnerability caused by tidal and river flood, mainly on vegetation and built up areas as the main element of risk. The observation was focused at downstream of Ciasem watershed, located in MuaraVillage, Blanakan subdistrict, north coastal region of Subang District. Tidal flood hazard was mapped using iteration process in ILWIS 3.4 software while river flood hazard map was made up incorporating elevation, slope and river characteristics using hydrological tools (HEC-geo RAS and HEC-RAS) in ArcGIS 10 software. Those hazard maps were then utilized to determine element of risk covering vegetation and built up areas. Result showed that tidal inundation started to happen in the western area dominated by fish ponds as the main element of  risk.When sea level rose up to 90 cm height, settlement areas were experiencing inundation by tidal flood. Ciasem River began to over flowwhen the river discharge exceeded 160 m3/sec and inundated the paddy fields, fish ponds and settlements. This study indicated that fish ponds and paddy fields having high vulnerability to the flood event while that of settlements and roads depend on the construction materials. Flood disaster risk should be reduced by continuing the land rehabilitation activity, restoring mangrove vegetation, implementing government regulations on management and establishment of aquaculture in mangrove, and carefully considering the construction of coastal protection barriers
EFFECT OF CHARCOAL APPLICATION ON THE EARLY GROWTH STAGE OF Acacia mangium and Michelia montana
Charcoal, or black coloured carbon-predominated stuff, is produced during incomplete combustion of woody plant biomass. Charcoal application to the soil can improve chemical and nutritional nature thereby inducing better plant growth and development. However, the utilization of charcoal in forestry sector, especially industrial plantation, has not been introduced due to the absence of available information. Indicator species used in this study are Acacia mangium and Michelia montana. A. mangium is one of the most important species grown in industrial plantations in Indonesia. Meanwhile M. montana is critical endemic species in Gunung Halimun National Park. Glasshouse research was designed to examine the effectiveness of charcoal incorporation into marginal soils on the growth of 6-month-old Acacia mangium and 6-month-old Michelia montana. Charcoal treatments were 0,10, 15 and 20% (v/v) for A. mangium, while 0, 5, 10, 15 and 20 % (v/v) for M. montana. Representative samples of Orthic Acrisol (i.e. Very fine, mixed, semiactive, isohyperthermic, and Typic Paleudult) were collected from B horizon. A completely randomized design with four replications (for A. mangium) and five replications (for M. montana) was employed to examine the effect of charcoal application on the plant growth and some important chemical properties of the corresponding soil. Charcoal additions to the soil significantly increased height, diameter, and leaf and stem biomass weight of A. mangium, and significantly increased height, diameter, and total biomass weight of M. montana seedlings in comparison to those of a control. Increasing the amount of charcoal higher than 10% level, however, have little effect on A. mangium growth. On the other hand, increasing the amount of charcoal higher than 10% is still effective on M. montana growth. This study indicated that charcoal application at the rates of 10 % for A. mangium and 15 % for M. montana would be adequate to improve the availability of soil nutrients, and hence significantly induce a better plant growth response
Developing biomass allometric equations for small trees in mixed-species forests of tropical rainforest ecozone
Allometric equations for the small trees that dominate many forests recovering from disturbance, such as fire, are relatively rare, increasing the uncertainty of aboveground biomass (AGB) estimates in young regrowth forests. In this study we sampled 516 small trees (diameter leaves > branches. AGB estimates based on allometric equations developed for larger trees, sourced from the literature, overestimated small tree biomass by up to 25% when compared with AGB estimates from equations developed in this study. The allometric models of small trees and the root-to-shoot ratio values obtained in this study will improve biomass estimates for young regrowth forests of Indonesia and the tropical region in general
ANALISIS HASIL TANGKAPAN FINGERLING IKAN SIDAT (Anguilla spp. ) DENGAN ALAT TANGKAP BUBU BAMBU DI MUARA SUNGAI JENGGALU KOTA BENGKULU
Muara SUngai Jenggalu merupakan salah satu sungai yang ada di Bengkulu yang termasuk
ke dalam habitat jenis Anguilla spp. sebab parameter kualitas air masih dalam keadaan baik bagi kelangsungan hidup ikan sidat tersebut . Hasil tangkapan ikan sidat dengan menggunakan bubu bambu semakin berkurang serta banyaknya permintaan dan kurangnya produksi anakan dari alam untuk budi daya. Penelitian ini bert
berujuan untuk menganalisis komposisi jumlah hasil tangk apan fingerlingsidat , dan menghitung produktivitas dan sel ektivitas hasil tangkapan bubu berbahan bambu di Muara Sungai Jenggalu, Kota Bengkulu. Penelitian ini menggun akan metode experimental fishing, yakni uji coba pengop erasian 20 unit bubu bambu dengan menggunakan objek penel itianya ngtertangkap sebagai sampel . Hasil penelitian menunjukkan Persentase HTU ( Hasil Tangkapan Utama ) berjumlah 4% dan HTS ( Hasil Tangkapan Sampingan ) berj umlah 96%, nilai produktifitas alat tangkap bubu bambu yaitu 46,067 gram / unit serta selektifitas bubu bambu termasuk ke dalam kriteria sangat rendah .
Kata Kunci : Sidat , Bubu Bambu, Muara Sungai , Komposisi Hasil Tangkapan
Effect of species grouping and site variables on aboveground biomass models for lowland tropical forests of the Indo-Malay region
Key message: This study assessed the effect of ecological variables on tree allometry and provides more accurate aboveground biomass (AGB) models through the involvement of large samples representing major islands, biogeographical zones and various succession and degradation levels of natural lowland forests in the Indo-Malay region. The only additional variable that significantly and largely contributed to explaining AGB variation is grouping based on wood-density classes. Context: There is a need for an AGB equation at tree level for the lowland tropical forests of the Indo-Malay region. In this respect, the influence of geographical, climatic and ecological gradients needs to be assessed. Aims: The overall aim of this research is to provide a regional-scale analysis of allometric models for tree AGB of lowland tropical forests in the Indo-Malay region. Methods: A dataset of 1300 harvested trees (5 cm ≤ trunk diameter ≤ 172 cm) was collected from a wide range of succession and degradation levels of natural lowland forests through direct measurement and an intensive literature search of principally grey publications. We performed ANCOVA to assess possible irregular datasets from the 43 study sites. After ANCOVA, a 1201-tree dataset was selected for the development of allometric equations. We tested whether the variables related to climate, geographical region and species grouping affected tree allometry in the lowland forest of the Indo-Malay region. Results: Climatic and major taxon-based variables were not significant in explaining AGB variations. Biogeographical zone was a significant variable explaining AGB variation, but it made only a minor contribution on the accuracy of AGB models. The biogeographical effect on AGB variation is more indirect than its effect on species and stand characteristics. In contrast, the integration of wood-density classes improved the models significantly. Conclusion: Our AGB models outperformed existing local models and will be useful for improving the accuracy on the estimation of greenhouse gas emissions from deforestation and forest degradation in tropical forests. However, more samples of large trees are required to improve our understanding of biomass distribution across various forest types and along geographical and elevation gradients.We are grateful to GIZ and KFW Forclime for supporting
field-data collection. The support of the Australia Award Scholarship is
gratefully acknowledged
A Review on Sustainability of Watershed Management in Indonesia
This paper provides an overview of the implementation and obstacles of watershed management, and the alternative solutions based on a synoptic review of related studies and experiences across Indonesia. The review found that problems in the institutional aspect were hierarchical confusion, discrepancy, and asynchrony among regulations, and weak (participation, synchronization, and coordination) among watershed management stakeholders. The weaknesses in the planning stage are integration among sectors, a lack of community participation, and limited readiness to integrate watershed planning into regional planning. Stakeholders’ involvement is also a critical factor in successful implementation of degraded watershed rehabilitation, including in peatland and mangrove areas. Failure should be minimized by providing adequate information on degraded watershed characteristics, appropriate species choices, and effective mechanical construction for soil and water conservation. Community participation as the main factor in driving watershed management should be achieved by strengthening public awareness of the importance of a sustainable watershed and providing access for the community to be involved in each stage of watershed management. Another problem is data gaps which are essential to address from the planning to evaluation stages. The gaps can be bridged by using remotely sensed data and by applying hydrological-based simulation models. Simplified criteria for watershed assessment may also be required, depending on site-specific issues and the watershed scale
Effect of species grouping and site variables on aboveground biomass models for lowland tropical forests of the Indo-Malay region
A Chronicle of Indonesia’s Forest Management: A Long Step towards Environmental Sustainability and Community Welfare
Indonesia is the largest archipelagic country in the world, with 17,000 islands of varying sizes and elevations, from lowlands to very high mountains, stretching more than 5000 km eastward from Sabang in Aceh to Merauke in Papua. Although occupying only 1.3% of the world’s land area, Indonesia possesses the third-largest rainforest and the second-highest level of biodiversity, with very high species diversity and endemism. However, during the last two decades, Indonesia has been known as a country with a high level of deforestation, a producer of smoke from burning forests and land, and a producer of carbon emissions. The aim of this paper is to review the environmental history and the long process of Indonesian forest management towards achieving environmental sustainability and community welfare. To do this, we analyze the milestones of Indonesian forest management history, present and future challenges, and provide strategic recommendations toward a viable Sustainable Forest Management (SFM) system. Our review showed that the history of forestry management in Indonesia has evolved through a long process, especially related to contestation over the control of natural resources and supporting policies and regulations. During the process, many efforts have been applied to reduce the deforestation rate, such as a moratorium on permitting primary natural forest and peat land, land rehabilitation and soil conservation, environmental protection, and other significant regulations. Therefore, these efforts should be maintained and improved continuously in the future due to their significant positive impacts on a variety of forest areas toward the achievement of viable SFM. Finally, we conclude that the Indonesian government has struggled to formulate sustainable forest management policies that balance economic, ecological, and social needs, among others, through developing and implementing social forestry instruments, developing and implementing human resource capacity, increasing community literacy, strengthening forest governance by eliminating ambiguity and overlapping regulations, simplification of bureaucracy, revitalization of traditional wisdom, and fair law enforcement