Jurnal Wasian

Number Vol 7 (1), 2020

1-14
The Volume Model of Tree Species Group in Peat Swamp Forest at Logging Concession Area of Tingang Karya Mandiri, Central Kalimantan

Authors: Muhammad Abdul Qirom, Acep Akbar

Abstract

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Number of views: 216

Tropical peat swamp forest (PSF) has a high species diversity and value including timber value. The valuation of timber is approached by calculating the stand volume. However, the volume model at PSF is not available for every species and species groups in specific site. This study aims to obtain a volume estimation model of species groups of tree species in peat swamp forest in Central Kalimantan. The model development and validation used 120 sample trees of the dipterocarpaceae and non-dipterocarpacae species. The distribution of sample trees is 70 % for the development model and 30 % for the validation stage. Modeling used linear and non-linear models). The selection of the best model used several criteria including: coefficient of determination, relative deviation (SR <8 %) and aggregation (SA <1 %), presumptive bias (s and RSE: Root Square Errors), AIC (Akaike's Information criteriation), and NRMSE (Normalized Root Mean Square Errors). The results of this study indicated the Berkhout/diameter model as a single variable was very good in estimating the volume of trees at all levels namely species groups and all species except dipterocarpaceae groups. This model had a high coefficient of determination (R2 >95 %). The models compiled met the SA and SR criteria so that the models were very accurate in estimating tree volume at the tree level, as individuals and stands. The implication of this research was that the whole species model can be used to estimate the volume of trees in peat swamp forest.

15-24
Study of Light Intensity in Riparian Zone of Teak Production Forest in KHDTK Cemoro Modang

Authors: Agung Wahyu Nugroho, Heru Dwi Riyanto, Heru Dwi Riyanto

Abstract

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Number of views: 256

Vegetation is one of the factors that influence the protection function of the riparian zone. Riparian vegetation in teak production forests is dominated by teak plantation with low species diversity. Rehabilitation is needed to increase the role of vegetation in protecting riparian zone. Data and information of light intensity is required to support the success of rehabilitation. Light intensity is a significant factor for photosynthesis which impacts on the survival, growth and adaptation of a vegetation. The varying light intensity in the riparian zone due to diverse land cover becomes a challenge in rehabilitating this area. This study aims to identify light intensity in riparian zone of Modang River and Cemoro River in the teak production forest. Recognizing light characteristics will help in species selection to rehabilitate this area. Primary and secondary data were used in this study. Direct measurement of light intensity was carried out along riparian zone of the Modang and Cemoro Rivers by systematic sampling. A sampling plot measuring 20 x 20 meter was used as the location of the sampling point with a total of 36 plots. Climate data are obtained from field observations through the nearest climatology station. The results showed that different canopy cover causing light intensity of Modang and Cemoro rivers varies. Canopy cover in this area can be divided into canopy cover of teak forest of various ages (production plants), johar (previous rehabilitation plants), and logged-over areas. The selection of tolerant and intolerant trees is important to use as consideration for rehabilitation, in addition to other silvicultural and socio-economic considerations of the local community.

25-38
Analysis of Vulnerability Levels to the Flash Flood Based on Social Economic and Institutional Factors in Wasior, Teluk Wondama, West Papua

Authors: Baharinawati Wilhan Hastanti, Freddy Jontara Hutapea

Abstract

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Number of views: 216

One form of disaster mitigation is to know the vulnerability of areas that are at risk of disaster socially and economically. Studies on vulnerability to flash floods are necessary, as it might prevent material losses and fatalities. Wasior District at Teluk Wondama Regency experienced a flash flood in 2010 causing negative impacts such as fatalities and large material losses. To anticipate flash floods that might occur in the future, studies to evaluate the vulnerability to the flash flood are needed. This study aimed to: 1) analyze the level of vulnerability to flash floods in Wasior based on socioeconomic factors post the 2010 flash floods, 2) analyze the level of vulnerability to flash floods in Wasior based on institutional factors. The method used in this study was a combination of qualitative and quantitative methods. Data collection was conducted by observation, interview, and documentation. Data were analyzed by: 1) identifying the socioeconomic indicators of the community and institutions around the watershed, 2) providing weighting scores to the social economic criteria and institutional criteria from the most vulnerable to the least vulnerable, 3) assessing the level of community and institution vulnerabilities in the study site to the impact of flash floods based on the calculation of the weighting scores of socio-economic and institutional indicators. The results showed that the level of socioeconomic vulnerability to flash floods were categorized as moderate (total score 2.084), while the level of institutional vulnerability was low (total score 2.251). The results of this study can be used as a basis for considerations in the implementation of flash flood mitigation in Wasior.

39-63
The Plants Extract Toxicity Againts Achatina fulica (Ferussac, 1821) in Nyawai Ficus variegata (Blume)

Authors: Fajar Lestari, Beny Rahmanto

Abstract

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Number of views: 176

One of the problems in developing Nyawai plants is the attack of snail pests Achatina fulica (Ferussac, 1821) at seedling level of the plants. Plant damage caused by these pests is quite large and causes seedling death. One of the control efforts that can be done is utilizing biomaterials which have molluscicidal properties (can kill mollusks). This study aimed to determine the toxicity of some extracts of biomaterial to control Achatina fulica (Ferussac, 1821) pests. The research was conducted on a laboratory scale. The study used a factorial random design with 3 replications. The treatment consisted of four biomaterials namely sembung (Blumea balsamifera), gadung (Discorea hispida), tuba (Derris eliptica and betel nut (Areca catechu) with each concentration of 10.25.50 g/l. Each concentration used 4 snails as a test sample. The parameters observed were snail mortality, and Lethal Concentration (LC50 and LC95). The results showed that the gadung tuber extract had the highest toxicity as indicated by mortality of 75 % and the lowest LC95 value of 80.63 g/l. While the lowest toxicity is betel nut with mortality of 49.75 % and the highest LC95 value is 567.75 g/l. The Toxicity of tuba, pinang, and sembung are highest on 50 g/l concentration, excepted the gadung extract. In gadung extract, the highest toxicity was obtained on 10 g/l concentration. However, the application was consideration to the attack intensity of Achatina fulica (Ferussac, 1821) because the toxicity effect of biomaterial pesticide was slower than chemical molluscicide.

51-36
Processing and Added Value of Bamboo in Tasikmalaya, West Java

Authors: Tri Sulistyati Widyaningsih, Eva Fauziyah, Devy Priambodo Kuswantoro

Abstract

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Number of views: 202

Bamboo is a multipurpose plant that has been used by the people for generations. This study aimed to describe the processing of bamboo and analyze its added value in Tasikmalaya Regency, West Java. Data was collected in April -December 2016 through interviews using questionnaires and field observations of bamboo craftsmen, and then were processed and analyzed quantitatively and descriptively. The community processed bamboo into woven products such as ayakan, boboko, haseupan, hihid, picnic basket, nyiru, pipiti, and parcel, as well as non-woven products such as piggy banks, key chains, glasses, wall clocks, lampshades, invitation boxes, bowl, cup, frame, teapot, letterbox, and tissue box. The average added value of woven products was IDR 131,197.21 or 9.11 % of the non-woven products, which was IDR 1,439,742.42. The average added value ratio of woven products is 0,83 and 0,90 for non-woven products. Bamboo woven business for household products is mostly done because the market has formed, stable, and has a wider scope even though it has lower added value. The market of non-woven products is smaller and specific even though it has a higher added value. A bamboo stem is only valued IDR 10,000 – 50,000, so it should be sold in processed products rather than the original form.

65-72
The Invigoration Techniques of Nyamplung (Calophyllum inophyllum L.) Seeds During the Storage

Authors: Naning Yuniarti

Abstract

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Number of views: 239

Nyamplung (Calophyllum inophyllum L.) is one of forestry plant that has double benefits (economic and ecological). One of the problems faced in the development of nyamplung is its recalcitrant seed, which can not be stored for long periods. To increase the viability of nyamplung seed during storage, seed invigoration techniques are required. Invigoration is the treatment given to seeds before planting with the aim of improving germination and growth of sprouts. The purpose of this research is to know the proper invigoration technique on nyamplung seed during storage. The experimental design of the research was used Completely Randomized Design (CRDL) with factorial. There are 2 factors treatments: the first factor of: Invigoration treatment (control, osmoconditioning with soaking in aquades for 24 hours, osmoconditioning with immersion in PEG-6000 concentration 15 % for 24 hours, matriconditioning with moisture of newspaper (CD) for 2 hours, and matriconditioning with moisture ash scrub for 2 hours) and savings period factor the second factor of period of storage (0, 1, and 2 months). The research was conducted with replication is 4 times, @ each with 50 seeds of seed. The observation of germination is done after normal sprout growth, which it has of a pair of leaves. The parameters observed were germination and germination rate. The results showed that the proper invigoration technique on nyamplung seed during storage was the treatment of matriconditioning with moisture of newspaper (CD) for 2 hours. With this treatment it can increase the viability of seed nyamplung (germination) at 42 % and vigor seed (germination rate) at 0,56 % /etmal. results at the end of the abstract. The longer the storage period will cause the value of germination and the speed of germination to decrease.