Sistem Perakaran Bidara Laut (Strychnos lucida R. Br.) untuk Pengendalian Tanah Longsor

One of potential Non Timber Forest Products (NTFPs) in West Nusa Tenggara and Bali is Strychnos lucida R.Br. which is used for medicinal purposes. The species is also potential to use in land rehabilitation of dry land where it offers an additional benefit of landslide control. Part of the plant which has important role in landslide control is root system. Therefore this study aimed to investigate the Strychnos lucida root system in landslide control. The study was held in Bali Barat National Park. Root characteristics observed in the study were the penetration position in the soil, root architecture, and Index of Roots Anchoring (IRA) and Index of Roots Binding (IRB). The result showed that Strychnos lucida root was able to penetrate into deep soil layer and had R-tipe root architecture which can increase shear resistance of soil. Value of IRA and IRB indicated the species had a more vertical roots in every growth stage and a high enough horizontal roots. Based on its root characteristics, Strychnos lucida was able to decrease landslide risk, especially shallow and surface landslide

KUALITAS PERAIRAN MANGROVE DI CIASEM PAMANUKAN, KABUPATEN SUBANG, JAWA BARAT

This study aimed to evaluate the water quality of mangrove ecosystem indegraded mangrove forest areas, either already or not rehabilitated. The research was conducted at the Ciasem protected forest areas, BKPH Ciasem Pamanukan (RPH Poponcol, RPH Bobos, and Tegal Tangkil RPH), Subang regency, West Java province. Observations and measurements of mangrove stands were performed using line transect and sample plots method (Line Transect Plot). Substrate and water samples were taken and analyzed in the laboratory. The results showed that the mangrove ecosystem in Subang was dominated by Avicennia sp and Rhizophora sp. Avicennia more adaptive to the shallow water, while Rhizophora more adaptive to an area closer or direct contact with the sea. Water quality conditions at the three locations were quite varied and still within the quality standard range for mangrove waters, except the BOD and DO parameters that need to be recovered because they out of the standard. Fertility conditions (physics and chemistry) of sediment (substrate) were generally in good condition for plant growth

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

ENHANCING THE PRODUCTIVITY OF DEGRADED LAND THROUGH SOIL AND WATER CONSERVATION TECHNIQUE IN CARITA RESEARCH FOREST, WEST JAVA

Encroachments on Carita Research Forest area have exacerbated the degradation of land due to uncontrolled runoff, erosion and nutrient losses especially on the sloping land with high annual rainfall. To reduce the severity of the degradation the area should be rehabilitated by applying soil and water conservation techniques. The techniques used were the vegetative methods (culture), and a combination of it with mechanical/technical methods. The combination method is expected to be more effective in controlling runoff, erosion and nutrient losses. One important parameter is the efficiency of the distance of the vertical mulch channel, which affects the application cost. This study was aimed to determine the effect of different distances of vertical mulch channels on the plant growth and annual crop yield as well as its effectiveness in controlling runoff, erosion and nutrient losses. The research was conducted in Carita Research Forest from 2005 to 2008, using the randomized block design. Treatments applied were: vertical mulch with six and twelve meter distances of plots of khaya (Khaya anthotheca C.Dc.) and corn ( Zea mays L.) cropping system. Observations included height and diameter growth of khaya, runoff and erosion, and cost per ha. The results showed that six meter of vertical mulch was the most efficient distance. The height and diameter of khaya tree increased by 7% and 31% in six meter distance compared to the control. Moreover, runoff and erosion was reduced by 75% and 37%, and nutrient losses could be trimmed down by three to five times. In addition, six meters distance could also produce corn of 712 kg/ha/year, which was 73% greater than corn production without vertical mulch. On the other hand, the cropping system with six meter distance of vertical mulch required Rp 3,250,000,- per ha, which was Rp 250,000,- more expensive than that without vertical mulch

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

Forty Years of Soil and Water Conservation Policy, Implementation, Research and Development in Indonesia: A Review

Dominated by mountainous topography, high rainfall, and erosion-sensitive soil types, and with the majority of its population living in rural areas as farmers, most of Indonesia’s watersheds are highly vulnerable to erosion. In 1984, the Government of Indonesia established 22 priority watersheds to be handled, which marked the start of formal soil and water conservation activities. Although it has not fully succeeded in improving watershed conditions from all aspects, something which is indicated by fluctuations in the area of degraded land, over the past 40 years the Indonesian government has systematically implemented various soil and water conservation techniques in various areas with the support of policies, laws and regulations, and research and development. These systematic efforts have shown positive results, with a 40% reduction in the area of degraded land over the last 15 years from 2004–2018. This paper reviews policy, implementation, and research and development of soil and water conservation activities in Indonesia over the last 40 years from the 1980s to 2020 and explores the dynamics of the activities

The Dynamics of Vegetation Structure, Composition and Carbon Stock in Peatland Ecosystem of Old Secondary Forest in Riau and South Sumatra Provinces

Lowland tropical rainforests provide an abundance of biodiversity as well as dynamic and stable ecosystems. These forests include tropical peat forests in various locations and forest types that have vegetation structure and composition characteristics, and carbon stocks that still need to be explored more deeply. Research on the structure and the composition of the vegetation and carbon stock in the old secondary peat forest was carried out in the protected areas of Bukit Batu, Riau Province, and Muara Merang, South Sumatra Province. Based on a 1-hectare permanent plot established in Bukit Batu and Muara Merang, 25 subplots of 20 m by 20 m were established in each location for measurement purposes. The results showed that Bukit Batu and Muara Merang had 42 and 36 species belonging to 26 and 20 families, respectively. Bukit Batu had a species diversity index (H’) of 2.93, and the dominant tree species were Palaquium xanthochymum with an importance value index (IVI) = 66.27%, Eugenia sp. (IVI = 32.76%), and Litsea sp. (IVI = 18.39%). The Muara Merang location had a species diversity index (H’) of 2.82, and the dominant tree species were Eugenia sp. (IVI = 60.88%), Alseodaphne insignis (IVI = 26.34%), and Adenanthera pavonina (IVI = 22.11%). In Bukit Batu, forest stands with a diameter of ≥10 cm contained a biomass of 178.10 tonnes/ha and carbon stock of 83.70 tonnes C/ha, which is equal to 307.20 tonnes CO2/ha. Meanwhile, in Muara Merang, it was 190.41 tonnes/ha and 89.49 tonnes C/ha, which is equal to 328.44 tonnes CO2/ha. This research, especially that in Bukit Batu, Riau Province, enriches the data and information available to date and is very useful in supporting restoration practices in Riau Province’s Giam Siak Kecil Biosphere Reserve, which was designated by UNESCO as part of the Man and Biosphere Program

Examining the Socio-Economic and Natural Resource Risks of Food Estate Development on Peatlands: A Strategy for Economic Recovery and Natural Resource Sustainability

Given the huge impact of the COVID-19 pandemic on the food and agriculture sectors, rapid measures are needed to reduce the risk of food crises, especially among the poor and the most vulnerable communities. The government of Indonesia planned to establish the Food Estate National Program to ensure food security. Most of the area will be on peatlands, and as such, the program still faces pros and cons as it might open up opportunities for deforestation, threats to biodiversity, and loss of community livelihoods. We conducted the present research in Central Kalimantan to formulate a food estate (FE) development strategy by taking into account the potential benefits and risks to ensure increases in the local community’s welfare and the sustainability of biodiversity. Data were collected through field surveys, interviews, focus group discussion (FGD), and literature studies. The results show that the operation of a food estate on degraded peatlands has a moderate to high level of risk of negative impacts. Community activities and changes in farming methods through using more inputs and mechanical equipment are the most risky activities in FE development. The low substitutability of peatlands requires mitigation efforts as part of risk management. The operation of food systems on peatlands must be based on a strong sustainability perspective with a main principle of complementary resources. The main strategy is to protect natural resources and replace cultivated exotic plants with potential native peat plants with minimal risk. In addition, the policy and capacity building of farmers towards a business-oriented direction will maximize socioeconomic benefits. Utilization of biodiversity and low-impact cultivation techniques can ensure sustainability