Articles

PEMODELAN SPASIAL RESILIENSI EKOSISTEM GUNUNGAPI MERAPI PASCA ERUPSI Soraya, Emma; Wardhana, Wahyu; Sadono, Ronggo
Jurnal Ilmu Kehutanan Vol 10, No 2 (2016)
Publisher : Fakultas Kehutanan Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (262.888 KB) | DOI: 10.22146/jik.16509

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Kemampuan ekosistem hutan di wilayah gunungapi pasca erupsi dapat kembali berfungsi seperti sebelumnya sangat dipengaruhi oleh resiliensi atau daya lentur/lembam ekosistem tersebut. Resiliensi suatu ekosistem dalam studi ini didefinisikan sebagai kemampuan ekosistem untuk bangkit kembali setelah guncangan/gangguan. Tujuan penelitian ini adalah untuk memodelkan sebaran resiliensi spasial ekosistem hutan di kawasan Taman Nasional Gunung Merapi (TNGM) lima tahun pasca erupsi dan intervensi restorasi. Analisis dilakukan dengan pendekatan penginderaan jauh multi temporal dan analisis spasial menggunakan sistem informasi geografis untuk menggambarkan perubahan kondisi ekosistem gunungapi sebelum dan pasca erupsi dan kegiatan restorasi. Hasil pemodelan menunjukkan bahwa setelah lima tahun pasca erupsi, telah terjadi transisi resiliensi/perbaikan ekosistem dari lahan terbuka ke lahan dengan tutupan vegetasi berupa rumput, semak belukar, dan hutan sekunder. Transisi resiliensi ini terjadi baik secara suksesi alami maupun campur tangan manusia dalam bentuk tindakan restorasi. Salah satu catatan hasil dari penelitian ini antara lain adalah keberhasilan kegiatan restorasi untuk mengembalikan kondisi ekosistem seperti sebelum erupsi tidak selalu dapat dideteksi dalam jangka lima tahun setelah erupsi. Kata kunci: Gunungapi Merapi; multi temporal; penginderaan jauh; resiliensi spasial; sistem informasi geografis Spatial Resilience Modelling of Merapi Volcano Ecosystem Post-EruptionThe ability of volcano ecosystem to recover post an eruption to the pre eruption status is affected by its ecological resilience. Resilience of an ecosystem can be defined as the ability of an ecosystem to bounch back after (a) disturbance(s). This study aimed to model spatial resilience of Merapi volcano ecosystem within the area of National Park of Merapi Volcano (TNGM) five years post 2010 eruption and restoration intervention. Analysis was conducted using multi temporal remote sensing and spatial analysis using geographic information system to draw the changes of the ecosystem over time, particularly post eruption and restoration actions. The modelling resulted that five years post eruption, there was resilience transisition/ recovery in volcano ecosystem in TNGM post 2010 eruption. The resilience was shown by the changes from open area to vegetation covers as grass, shrubs, and secondary forests. The transitions occured in term of natural succession as well as human intervention in restoration programs. However, the success of restoration actions to recover the ecosystem to the pre eruption status was not always able to be detected within the period of five years post eruption.
FERTILIZATION EFFECTS ON EARLY GROWTH, ABOVEGROUND BIOMASS, CARBON STORAGE, AND LEAF CHARACTERISTICS OF EUCALYPTUS PELLITA F. MUELL. IN SOUTH SUMATERA Wirabuana, Pandu Yudha Adi Putra; Sadono, Ronggo; Juniarso, Sergian
Jurnal Manajemen Hutan Tropika Vol. 25 No. 3 (2019)
Publisher : Institut Pertanian Bogor (IPB University)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (241.293 KB) | DOI: 10.7226/jtfm.25.3.154

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Fertilization is one of the nutrient management efforts that play an important role in improving the productivity of plantation forests. It was conducted to provide adequate nutrients for the plant at the initial growth period when the availability of soil nutrients is very limited. The optimum dose of fertilization for each plant is different depending on its requirement, climate, and soil properties. This study investigated the influence of fertilization on early growth, aboveground biomass, carbon storage, and leaf characteristics in Eucalyptus pellita in the sixth months after field establishment. An experiment comprising four treatments of fertilization, i.e., 0, 75, 133, and 167 kg ha -1 of triple superphosphate 46% P2O5 was set up using randomized complete block design with five replications. Four indicators were selected to evaluate the early growth of E. pellita, namely survival rate, height, the collar of diameter, and crown projection area. Aboveground biomass and carbon storage of E. pellita were estimated in each component, covering stem, bark, branches, and leaves. The leaf characteristics of E. pellita were described by individual leaf area, individual leaf dry weight, specific leaf area, and leaf area index. Results showed that the different treatment of fertilization did not have a meaningful effect on survival rate, individual leaf area, and specific leaf area. The treatments presented a substantial effect on other indicators such as height, diameter, crown projection area, aboveground biomass, carbon storage, individual leaf dry weight, and leaf area index. Despite the fact that the highest mean of height and collar of diameter were observed in the dose of 167 kg ha -1, the greatest average of aboveground biomass and carbon storage were noted in the rate of 133 kg ha -1. Nevertheless, this study did not find a highly different performance of E. pellita between both treatments statistically.
EFFECTS OF COMPETITION ON THE CROWN WIDTH ALLOMETRY FOR DOMINANT TREES ON GOOD SITES OF VEGETATIVE CLONAL TEAK (TECTONA GRANDIS LINN. F.) IN JAVA, INDONESIA Sadono, Ronggo
Jurnal Manajemen Hutan Tropika Vol. 25 No. 2 (2019)
Publisher : Institut Pertanian Bogor (IPB University)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (14692.209 KB) | DOI: 10.7226/jtfm.25.2.104

Abstract

The vegetative clonal teak is fast-growing, exhibits relatively uniform growth, and is sensitive to crown competition. The crown width dimension correlates positively with the size of the diameter (CW allometry). We investigated the effects of competition on CW allometry for dominant trees on good sites and the prediction accuracy of CW allometry. The data were measured during 2015?2017. The Hegyi index with a fixed 30° search cone method was used to measure competition. The scatter plot of all observations was used to identify the general pattern of CW over diameter, and competition index with both diameter and CW. The data were classified into three groups, ignored, free, and occurred competition data sets. Moreover, the occurred competition data set was categorized into three levels: low, medium, and heavy. The power model was used for parameterization of CW allometry. The dispersion of CW over diameter for all observations exhibited a moderate positive correlation, as well as the competition index with both diameter and CW. For the ignored-competition data set, the CW allometry was able to describe approximately 37.2% of observed CW. Interestingly, however, the prediction accuracy increased to 44.6% for the free competition data set. In contrast, the capability of the CW allometry for the occurred competition data set declined sharply to 9.1%. Among the occurred competition data sets, the heavier the subject trees competed, the lower the CW allometry explained the variations. However, the CW allometry was completely not able to describe the observed CW in the heavy competition level.
SOCIAL AND ECONOMIC VULNERABILITY IN THE SUB-WATERSHED OF KARANG MUMUS, EAST KALIMANTAN PROVINCE Endayani, Sri; Sadono, Ronggo; Kusumandari, Ambar; Hartono, Hartono
Jurnal Manajemen Hutan Tropika Vol. 25 No. 2 (2019)
Publisher : Institut Pertanian Bogor (IPB University)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (107.358 KB) | DOI: 10.7226/jtfm.25.2.93

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Changes in land use influence the social and economic characteristics as well as the environmental problems in a sub-watershed. To support the management of a sub-watershed, land use scenarios (biophysics) must be prepared and community involvement level must be improved. So far, the factors used for monitoring and evaluating sub-watershed performance have not been used thoroughly. This research is aimed at finding out the social and economic vulnerabilities tied to the monitoring and evaluation of sub-watershed performance across the sub-districts. This research uses quantitative methods employed to process primary data (biotic: vegetation and settlement, and abiotic: land, climate, geomorphology, and geology), secondary data (community data sourced from the data of BPS; Central Bureau of Statistics) of East Kalimantan Province; in September 2017), and socio-economic data (direct interviews using questionnaires). The primary data were obtained after processing map interpretation and from observation. The results show that high socio-economic vulnerability occurs in areas of high land use vulnerability. Sub-watershed management will be successful if it is done through a "collaborative management" involving all stakeholders. The scenario simulations of this research can be used as reference materials for regional governments in planning, compiling, and implementing the Regional Spatial Plan policies.
A THREE DECADES ASSESSMENT OF FOREST COVER CHANGES IN THE MOUNTAINOUS TROPICAL FOREST OF TIMOR ISLAND, INDONESIA Pujiono, Eko; Sadono, Ronggo; Hartono, Hartono; Imron, Muhammad Ali
Jurnal Manajemen Hutan Tropika Vol. 25 No. 1 (2019)
Publisher : Institut Pertanian Bogor (IPB University)

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Abstract

The Mutis Timau Forest Complex (MTFC), a remained mountainous tropical forest area in Timor Island, located in Indonesia and Timor-Leste border region, tends to decrease gradually. Unfortunately, declined forest area and their rates are not explained by reliable spatial and quantitative information. This study attempts to assess the extent and rate of forest cover changes in the MTFC during the last 30 years. We used Landsat images on three different dates: 1987, 1999, and 2017. Then, we applied a hybrid classification approach that combines the application of Forest Canopy Density model-obtained from four biophysical indices and supervised classification-maximum likelihood classification to generate land cover maps. Finally, we detected forest cover change by comparing land cover map in different years. Results illustrated that the extent and annual rate of deforestation, forest degradation, forest regrowth, and afforestation during 1987?2017 were 2,232 ha (0.36%), 4,820 ha (1.10%), 1,475 ha (0.69%), and 1,252 ha (0.40%), respectively. Such results are important for the MTFC authority to establish appropriate plan and strategies in forest management activities and can be used to support some policies/programs for combating deforestation and forest degradation.
FIRE REGIME IN A PEATLAND RESTORATION AREA: LESSON FROM CENTRAL KALIMANTAN Larasati, Bekti; Kanzaki, Mamoru; Purwanto, Ris Hadi; Sadono, Ronggo
Jurnal Ilmu Kehutanan Vol 13, No 2 (2019)
Publisher : Fakultas Kehutanan Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1472.384 KB) | DOI: 10.22146/jik.52436

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Peat fires have caused carbon emissions and damage to local and regional communities in Indonesia. An effective fire prevention system is required for mitigating climate change and enabling sustainable development of peatlands. This study examined the fire regime in a peatland restoration area in Central Kalimantan in order to assist the establishment of a fire prevention system. The fire regime was analysed using spatial-temporal analysis, land cover change mapping, and logistic regression analysis. Spatial-temporal analysis was done using monthly Niño 3.4 sea surface temperature anomalies, daily rainfall, and MODIS Active Fire (MCD14DL) hotspots from 2006 to 2015. Land cover change was mapped using Landsat imagery from2014, 2015 and 2016. Logistic regression analysis was conducted to identify significant factors that increase fire risk. The temporal analysis showed that the strongest El Niño occurred in 2015, when the region experienced a 140-days drought period. The highest number of hotspots was also observed in this year, with hotspots concentrated in the latter half of drought period. Moreover, spatial analysis using Kernel Density Estimation (KDE) showed fire recur in degraded areas. The logistic regression analysis used topographic and proximity factors, land cover classes, and soil types as independent variables. It showed that fire in 2014 and 2015 was associated with several land cover classes and was related to historical fire occurrence areas based on KDE results. Several area of peatland forests burned in 2015 and occurred at the forest edge areas located near cultivated or degraded land (e.g. shrubland) and oil palm plantations. Based on the results, the fire regime in the study area is characterized by fires that occurring/recurring in relation to climatic conditions, especially drought periods, and are typically located in cultivated or degraded land cover classes. These parameters should be considered in developing a fire prevention system in the restoration area.Rezim Kebakaran Hutan dan Lahan di Area Restorasi Lahan Gambut: Studi dari Kalimantan TengahIntisariKebakaran di lahan gambut menyebabkan emisi karbon dan kerusakan sistem kehidupan masyarakat lokal dan regional. Sistem pencegahan kebakaran yang efektif diperlukan untuk mitigasi perubahan iklim serta mendorong pembangunan lahan dan hutan yang lestari di kawasan gambut. Studi ini meneliti tentang rezim kebakaran hutan dan lahan di suatu kawasan restorasi gambut di Kalimantan Tengah. Rezim kebakaran hutan dan lahan dianalisis menggunakan analisis spasial-temporal, perubahan tutupan lahan, dan regresi logistik. Analisis spasial-temporal menggunakan parameter nilai rata-rata sea surface temperature (SST) bulanan, curah hujan harian, dan hotspot dari MODIS Active Fire (MCD14DL) tahun 2006-2016. Perubahan tutupan lahan dipetakan dengan analisis citra Landsat tahun 2014, 2015 dan 2016. Regresi logistik digunakan untuk menganalisis faktor yang berpengaruh pada peningkatan resiko kebakaran. Analisis temporal terhadap nilai SST tahun 2006-2016 menunjukkan bahwa El- Niño terparah terjadi di tahun 2015 yang memiliki hari tanpa hujan selama 140 hari berturut-turut dan ditemukan titik hotspot terbanyak. Kernel Density Estimation (KDE) digunakan dalam analisis spasial dan hasilnya menunjukkan bahwa kebakaran terjadi dan dapat berulang di area terdegradasi. Regresi logistik  menggunakan parameter yang terdiri faktor topografis, kedekatan dengan sungai/kanal, tipe penutupan lahan, serta jenis tanah. Hasil analisis menunjukkan bahwa kebarakan tahun 2014 dan 2015 berhubungan dengan beberapa tipe tutupan lahan di area yang secara historis pernah terbakar berdasarkan analisis KDE, sehingga area tersebut terindikasi telah terdegradasi sebelumnya. Beberapa area hutan di lahan gambut juga mengalami kebakaran pada tahun 2015 khususnya di area tepi hutannya. Berdasarkan hasil, rezim kebakaran di area studi dapat dijelaskan bahwa kebakaran terjadi dan dapat berulang karena pengaruh iklim.
PREDIKSI LEBAR TAJUK POHON DOMINAN PADA PERTANAMAN JATI ASAL KEBUN BENIH KLON DI KESATUAN PEMANGKUAN HUTAN NGAWI, JAWA TIMUR Sadono, Ronggo
Jurnal Ilmu Kehutanan Vol 12, No 2 (2018)
Publisher : Fakultas Kehutanan Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1183.339 KB) | DOI: 10.22146/jik.40143

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Penelitian ini bertujuan untuk menentukan model perkembangan lebar tajuk pohon dominan jati asal Kebun Benih Klon pada tegakan berkualitas baik.Penelitian dilakukan di Kesatuan Pemangkuan Hutan Ngawi pada petak tanaman jati asal Kebun Benih Klon bertumbuhan baik pada umur 615 tahun. Petak tanaman bertumbuhan baik ditentukan berdasarkan kriteria persentase keberhasilan tanaman, rata-rata tinggi pohon dan rata-rata diameter batang serta aksesibilitasnya. Pada petak yang memenuhi syarat bertumbuhan baik dipilih sebanyak 30 sampel pohon dominan dan tiap sampel diukur radius tajuk pada empat arah mata angin. Hasil pengukuran radius tajuk digunakan untuk menghitung rata-rata radius tajuk sebagai rata-rata kuadratik 4 arah pengukuran radius tajuk dan lebar tajuk sebagai dua kali rata-rata radius tajuk. Rata-rata aritmatik dari lebar tajuk 30 pohon dominan tiap petak pengukuran digunakan sebagai variabel respons dan umur tegakan sebagai variabel prediktor. Data pengukuran selanjutnya dipilah menjadi dua bagian, yaitu sebagian besar untuk pengembangan model dan satu bagian lagi untuk validasi model. Analisis regresi non linear dengan metode kuadrat terkecil digunakan untuk memilih 4 kandidat model penduga rata-rata lebar tajuk, yaitu model Sigmoid, Power, Schumacher dan Gompertz. Pemilihan model didasarkan atas nilai koefisien determinasi tertinggi dan standard error of the estimate terkecil serta signifikansi uji F dan uji T. Akhirnya, model terbaik diuji kelayakannya dengan kriteria root mean squared error, simpangan agregatif dan simpangan relatif. Model Gompertz adalah model terbaik untuk memprediksi perkembangan rata-rata lebar tajuk pohon dominan, yang dapat dituliskan dengan persamaan:CW = 6,585 Xe-0,705xe-0,091sagedan dapat menjelaskan 79% variasi data. Model tersebut lolos validasi dan layak digunakan untuk memprediksi rata-rata lebar tajuk pohon dominan jati asal Kebun Benih Klon pada tegakan berkualitas baik umur 6 tahun sampai dengan umur 15 tahun di Kesatuan Pemangkuan Hutan Ngawi.Predicting Crown-width of Dominant Trees on Teak Plantation from Clonal Seed Orchards in Ngawi Forest Management Unit, East JavaAbstractThis study aims to determine the model of crown width development of the dominant teak tree planted using seeds from clonal seed orchards. The research was carried out in Ngawi Forest Management Unit on the good quality teak compartment having stands age from 6 to 15 years old. The good quality compartments were determined based on higher stand density, taller average tree height, larger average stem diameter, and good accessibility. In a well-qualified compartment, 30 samples of the dominant tree were selected and each sample was measured for the crown radius in the four radii. The measured crown radius was used to calculate average crown radius as a quadratic mean of 4-crown radii and crown width as double of average crown radius. The arithmetic mean of the crown width of the 30 dominant trees in each measured compartment was used as the response variable and stand age as the predictor variable. The measurement data were then sorted into two parts, namely: mostly for model fitting and the remaining for model validation. Non-linear regression analysis with the least squares method was used to evaluate 4 candidate models of average crown width, namely: Sigmoid, Power, Schumacher, and Gompertz models. The model selection was based on the highest coefficient of determination and the smallest standard error of the estimate and the significance of F test and T test. The best model was eventually validated using the following criteria : root mean squared error, aggregate deviation, and relative deviation. Gompertz model was the best model to predict the average crown width development of dominant teak tree and expressed as:CW = 6.585 Xe-0.705xe-0.091xageand able to explain 79% variation of data. The model was passed based on statistical validation and it was feasible for predicting the average of crown width of dominant teak tree from clonal seed orchards on good quality stand aged 6 to 15 years in Ngawi Forest Management Unit.
TREE ASSOCIATION WITH POMETIA AND ITS STRUCTURE IN LOGGING CONCESSION OF SOUTH PAPUA FOREST Murdjoko, Agustinus; Marsono, Djoko; Sadono, Ronggo; Hadisusanto, Suwarno
Jurnal Manajemen Hutan Tropika Vol. 22 No. 3 (2016)
Publisher : Institut Pertanian Bogor (IPB University)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1177.772 KB)

Abstract

Part of forests in Papua is still as logging concession.  Pometia is one of target species, but there is still a lack of information regarding the ecological condition of this species.  Thus, the objectives of this research were to describe what tree species (small and large individuals) associated with Pometia, how logging and soil properties influence the association and to analyze the structure of Pometia in term of diameter distribution.  Canonical correspondence analysis (CCA) was applied to describe the association and its relationship with environmental factors (soil and litterfall).  The results showed that association of small and large individuals of trees with both Pometia showed a different pattern in which the small individuals had a positive association and had certain tree species as a community. This association resulted from logging activity leading to the change in ecological conditions.  Conversely, the association between large tree species with Pometia acuminata Radlk. and Pometia pinnata J. R. Forst. & G.Forst. showed negative pattern and tree species correlated with both Pometia were different.  Of environmental factors, only C content of litterfall had a positive correlation with large Pometia acuminata  and its community.  Furthermore, the small individuals of Pometia were dynamic as a response to logging in which a number of the small individuals of Pometia tended to increase after logging.
PRELIMINARY STAND TABLE FOR AVERAGE DOMINANT TREES OF JATI PLUS PERHUTANI IN SARADAN, MADIUN, AND NGAWI FOREST DISTRICS Rahmadwiati, Rissa; Sadono, Ronggo; Supriyatno, Nunuk
Jurnal Manajemen Hutan Tropika Vol. 22 No. 1 (2016)
Publisher : Institut Pertanian Bogor (IPB University)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (223.973 KB) | DOI: 10.7226/jtfm.22.1.57

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In order to realize sustainable teak forest management, the strategic plan of forest management is highly needed to establish the growth characteristics model of Jati Plus Perhutani (JPP). The most thing which cannot be ignored to estimate the growth and yield of teak is quantification of site quality differentiation. The objective of this study is to arrange and predict the properly yielded table of the average dominant trees of JPP in the forest management unit of Saradan, Madiun, and Ngawi. The trees sampling had been selected for the age of 6 to 12 years from the best compartment areas in JPP. Growth model and JPP's yield stands were predicted using growth parameters such as diameter (dbh), total height, clear bole height, volume, and growing space. Each parameter was analyzed using SPSS 20 statistical software to determine the best growth model that will then be used to predict the stand table parameters values. The equation was selected from the highest R2 value or the value which is approaching to 1, with low standard error estimation (SEE).  The result shows that best equation model to estimate the growth from tree parameters on medium site of JPP are dominated by S model and the best model for bole height is growth model. The data were taken from an initial observation as a preliminary study, further research is expected to enhance the results of current research to obtain the stand table which can be applied in the future.  
THE FARMERS PERCEPTION ON EFFECTIVENESS OF PRIVATE FOREST REVOLVING FUND DISTRIBUTION AND FACTORS AFFECTING ITS REPAYMENT: CASE IN KATIBUNG SUBDISTRICT, SOUTH LAMPUNG DISTRICT, LAMPUNG PROVINCE Sanudin, S; Awang, San Afri; Sadono, Ronggo; Purwanto, Ris Hadi
Jurnal Manajemen Hutan Tropika Vol. 22 No. 1 (2016)
Publisher : Institut Pertanian Bogor (IPB University)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (262.311 KB) | DOI: 10.7226/jtfm.22.1.47

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Commercial banks are not interested in providing fund for community-based forest plantation development.  Therefore, in this case, non bank institutions such Forest Development Funding Center (pusat pembiayaan pembangunan hutan, PPPH) are highly required.  This paper is aimed to find out the effectiveness of private forest revolving fund distribution and factors affecting its repayment.  The research was conducted during September?December 2014 in 3 Private Forest Farmer Groups in Katibung Sub-District, South Lampung District, Lampung Province.  The data was collected through household surveys and in-depth interviews.  The household surveys were done using structured questionnaires that included questions related to: characteristics of the borrowers, characteristics of private forest, characteristics of loan, and household perceptions on private forest revolving fund.  Household perceptions on private forest revolving fund are pre requirement, loan procedure, loan realization, interest rate, length of repayment periode, and repayment procedure. The effectiveness of private forest revolving fund distribution was analyzed by likert scale and factors affecting repayment of loan was analyzed by logistic regression.  The result showed that: 1) private forest revolving fund in three private forest farmer groups in Katibung Sub-District, South Lampung District was effective, 2) income from non-private forest and amount of loan are factors affecting repayment of private forest revolving fund, 3) the faced problem in private forest revolving fund distribution could be overcame by maximizing the role of PPPH field officers in assisting and facilitating private forest revolving fund debitors candidate.