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All Journal Indonesian Journal of Forestry Research Jurnal Penelitian Hutan dan Konservasi Alam JURNAL BIOLOGI INDONESIA
Djoko Wahjono
Center for Forest Productivity Improvement, Forestry Research and Development Agency
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology

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EFFECT OF POST-LOGGING SILVICULTURAL TREATMENT ON GROWTH RATES OF RESIDUAL STAND IN A TROPICAL FOREST Krisnawati, Haruni; Wahjono, Djoko
Indonesian Journal of Forestry Research Vol 7, No 2 (2010): Journal of Forestry Research
Publisher : Secretariat of Forestry Research and Development Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Post-logging silvicultural treatments are generally performed to improve yields of the remaining tree species by increasing their growth rate. In this study the effects of silvicultural treatment on the growth rates of commercial (dipterocarps and non-dipterocarps) as well as non- commercial tree species in a tropical forest in West Kalimantan were examined and were compared to a control treatment. Silvicultural treatment applied was liberation of future crop trees from lianas and neighbouring competing trees. Treatments were applied to six plots of 80 m x 80 m each. The plots comprised 64 quadrats of 10 m x 10 m to allow better control of measurements. The treatment and control plots were established 6 years after logging. Effects were measured 2,4 and 7 years after treatment application. In all obser vation periods, the growth rates increased with silvicultural treatment. Overall, commercial dipterocarps, commercial non-dipterocarps and non-commercial tree species groups differed in response to silvicultural treatment. The growth rates of commercial tree species in plots that received silvicultural treatment were 62–97% higher than in the control plots. For non-commercial tree species, the increase of growth rates was 20–58%, compared to the control plots. These results indicate that the application of silvicultural treatments after logging could help improve the growth of the residual stands. These provide quantitative information that silvicultural treatments in logged-over forest should be considered as a viable management option and may guide the choice of cutting cycle.
CHANGES IN THE SPECIES COMPOSITION, STAND STRUCTURE AND ABOVEGROUND BIOMASS OF A LOWLAND DIPTEROCARP FOREST IN SAMBOJA, EAST KALIMANTAN Krisnawati, Haruni; Wahjono, Djoko; Imanuddin, Rinaldi
Indonesian Journal of Forestry Research Vol 8, No 1 (2011): Journal of Forestry Research
Publisher : Secretariat of Forestry Research and Development Agency

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Abstract

The dynamics of species composition, stand structure and aboveground biomass were studied over a 4.3-yr period (December 2004 – April 2009) in a lowland dipterocarp forest of Samboja, East Kalimantan. This study was conducted in six permanent sample plots (100 m x 100 m each) distributed over an area of 26.5 ha of Samboja Research Forest. All woody plants = 10 cm dbh (diameter at 1.3 m aboveground) were identified. In December 2004, 2.143 trees were measured in the six plots, consisting of 39 families, 82 genera and 111 species. The condition in April 2009 (after 4.3 yr) was: 2,466 trees, 40 families, 86 genera and 123 species. Most species were found in both occasions. Fourteen new species were registered, which contributed to 9.8% of a net addition of the total number of species found in the six plots. Over the 4.3-yr period, there was also an increase of 15.1% in density, 12.9% in basal area, and 11.6% in aboveground biomass, respectively. The density increased from 357 to 411 trees per ha; the basal area increased from 20.09 to 22.67 m2 ha-1; and the aboveground biomass increased from 286.3 to 319.4 ton ha. The family Dipterocarpaceae was the richest in species (more than 20 species found in both occasions), followed by Euphorbiaceae, Burseraceae, Fabaceae, and Anacardiaceae (more than five species). Most genera (80%) contained just one species, but Shorea with 13 species was the richest. Four families (Dipterocarpaceae, Fabaceae, Myrtaceae and Lauraceae) contained more than 80% of the aboveground biomass in both occasions (75% of them from Dipterocarpaceae family). The increases in species richness and density did not cause any significant differences in the diversity index and diameter distribution. This condition suggested that forest vegetation of the study site maintains its diversity composition and structural features over the period of study.
CHANGES IN THE SPECIES COMPOSITION, STAND STRUCTURE AND ABOVEGROUND BIOMASS OF A LOWLAND DIPTEROCARP FOREST IN SAMBOJA, EAST KALIMANTAN Krisnawati, Haruni; Wahjono, Djoko; Imanuddin, Rinaldi
Indonesian Journal of Forestry Research Vol 8, No 1 (2011): Journal of Forestry Research
Publisher : Secretariat of Forestry Research and Development Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20886/ijfr.2011.8.1.1-16

Abstract

The dynamics of species composition, stand structure and aboveground biomass were studied over a 4.3-yr period (December 2004 – April 2009) in a lowland dipterocarp forest of Samboja, East Kalimantan. This study was conducted in six permanent sample plots (100 m x 100 m each) distributed over an area of 26.5 ha of Samboja Research Forest. All woody plants = 10 cm dbh (diameter at 1.3 m aboveground) were identified. In December 2004, 2.143 trees were measured in the six plots, consisting of 39 families, 82 genera and 111 species. The condition in April 2009 (after 4.3 yr) was: 2,466 trees, 40 families, 86 genera and 123 species. Most species were found in both occasions. Fourteen new species were registered, which contributed to 9.8% of a net addition of the total number of species found in the six plots. Over the 4.3-yr period, there was also an increase of 15.1% in density, 12.9% in basal area, and 11.6% in aboveground biomass, respectively. The density increased from 357 to 411 trees per ha; the basal area increased from 20.09 to 22.67 m2 ha-1; and the aboveground biomass increased from 286.3 to 319.4 ton ha. The family Dipterocarpaceae was the richest in species (more than 20 species found in both occasions), followed by Euphorbiaceae, Burseraceae, Fabaceae, and Anacardiaceae (more than five species). Most genera (80%) contained just one species, but Shorea with 13 species was the richest. Four families (Dipterocarpaceae, Fabaceae, Myrtaceae and Lauraceae) contained more than 80% of the aboveground biomass in both occasions (75% of them from Dipterocarpaceae family). The increases in species richness and density did not cause any significant differences in the diversity index and diameter distribution. This condition suggested that forest vegetation of the study site maintains its diversity composition and structural features over the period of study.
MODEL DINAMIKA STRUKTUR TEGAKAN UNTUK PENDUGAAN HASIL DI PT. INTRACAWOOD MANUFACTURING, KALIMANTAN TIMUR Wahjono, Djoko; Imanuddin, Rinaldi
Jurnal Penelitian Hutan dan Konservasi Alam Vol 4, No 4 (2007): Jurnal Penelitian Hutan dan Konservasi Alam
Publisher : Pusat Penelitian dan Pengembangan Hutan

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Abstract

ABSTRAKPenelitian ini bertujuan untuk mendapatkan model dinamika struktur tegakan yang dapat digunakan dalam memproyeksi pendugaan hasil di hutan alam bekas tebangan, sehingga diharapkan dapat membantu perencanaan produksi terutama dalam pengaturan hasil. Bahan yang digunakan dalam penelitian ini adalah data pengukuran ulang petak-petak ukur permanen (PUP) yang terdapat di kawasan konsesi HPH PT. Intracawood Manufacturing (Unit Sesayap), Kalimantan Timur. PUP tersebut sudah diukur ulang sebanyak tujuh kali pengukuran dalam waktu 10 tahun. Tegakan yang dijadikan obyek penelitian menggambarkan sebaran pohon berdasarkan kelas diameter dan kelompok jenis, meliputi komersial, non komersial, dan semua jenis. Dalam penelitian ini, dicoba untuk mendapatkan model dinamika struktur tegakan dengan memodifikasi persamaan eksponensial hubungan N dan D dengan menambahkan parameter jumlah pohon pada pengukuran awal, jumlah pohon tahun sebelumnya serta waktu. Model dinamika struktur tegakan yang dihasilkan, antara lain :- Komersial: Ndit = (0,34305+Ndit-1 ) e(0,01225 Ln Ndit-1 - 0 ,00261 N0di / t - 0,00101 Di)- Non-Komersial: Ndit = (0,16391+Ndit-1 ) e(0,02388 Ln Ndit-1 - 0 ,01177 N0di / t - 0,00204 Di)- Semua Jenis: Ndit = (0,41258+Ndit-1 ) e(0,01205 Ln Ndit-1 - 0 ,00209 N0di / t - 0,00110 Di)dimana, Ndit adalah jumlah pohon pada kelas diameter i pada waktu t; Ndit-1 adalah jumlah pohon pada kelasdiameter i pada waktu t-1; Di adalah kelas diameter ke i; N0 di adalah jumlah pohon pada kelas diameter ipada awal pengukuran; t adalah tahun pengukuran. Model dinamika struktur tegakan tersebut mempunyai tingkat ketelitian yang tinggi dengan nilai koefisien determinasi (R2) lebih dari 0,998 untuk masing-masingmodel. Hasil proyeksi volume tegakan menunjukkan rata-rata riap volume tegakan pada diameter 50 cm ke atas adalah 2,080 m3/ha/tahun untuk jenis komersial; 0,308 m3/ha/tahun untuk jenis non-komersial; dan 2,372 m3/ha/tahun untuk semua jenis.
DINAMIKA PERUBAHAN PENUTUPAN VEGETASI DAN POTENSI HUTAN BERDASARKAN CITRA LANDSAT DI KALIMANTAN SELATAN Imanuddin, Rinaldi; Wahjono, Djoko
Jurnal Penelitian Hutan dan Konservasi Alam Vol 4, No 3 (2007): Jurnal Penelitian Hutan dan Konservasi Alam
Publisher : Pusat Penelitian dan Pengembangan Hutan

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Abstract

ABSTRAK Untuk menjaga kawasan hutan, terutama ekosistemnya, maka hutan harus dikelola dan dimanfaatkan berdasarkan azas kelestarian. Untuk mewujudkan hal tersebut, maka segala bentuk gangguan terhadap hutan harus dicegah, diberantas, dan atau diminimalisir dengan cara memperkuat tingkat pengawasan terhadap setiap bentuk gangguan tersebut. Penelitian ini bertujuan untuk memperoleh gambaran dan informasi dinamika perubahan lahan dan potensi hutan di HPH/IUPHHK PT. Aya Yayang Indonesia (AYI) Provinsi Kalimantan Selatan berdasarkan citra  landsat  selama  kurun  waktu 10  tahun terakhir. Metodologi yang digunakan dalam penelitian ini pada dasarnya terdiri dari lima tahap pemrosesan, yaitu pengolahan awal citra, pemeriksaan lapangan, klasifikasi citra secara digital, pemetaan penutupan dan penggunaan lahan. Kegiatan analisis data dalam penelitian ini dilakukan dengan menggunakan software ER-mapper versi 6.4 dan ArcView GIS 3.3. Hasil analisis menunjukkan bahwa dinamika perubahan lahan dan potensi tegakan yang terjadi di areal PT. AYI selama kurun waktu 10 tahun terakhir menurun sangat drastis, di mana penurunan luas hutanmencapai 4.654 ha/tahun dan penurunan potensi tegakan mencapai 285.656,58 m3/tahun. 
EFFECT OF POST-LOGGING SILVICULTURAL TREATMENT ON GROWTH RATES OF RESIDUAL STAND IN A TROPICAL FOREST Krisnawati, Haruni; Wahjono, Djoko
Indonesian Journal of Forestry Research Vol 7, No 2 (2010): Journal of Forestry Research
Publisher : Secretariat of Forestry Research and Development Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20886/ijfr.2010.7.2.112-124

Abstract

Post-logging silvicultural treatments are generally performed to improve yields of the remaining tree species by increasing their growth rate. In this study the effects of silvicultural treatment on the growth rates of commercial (dipterocarps and non-dipterocarps) as well as non- commercial tree species in a tropical forest in West Kalimantan were examined and were compared to a control treatment. Silvicultural treatment applied was liberation of future crop trees from lianas and neighbouring competing trees. Treatments were applied to six plots of 80 m x 80 m each. The plots comprised 64 quadrats of 10 m x 10 m to allow better control of measurements. The treatment and control plots were established 6 years after logging. Effects were measured 2,4 and 7 years after treatment application. In all obser vation periods, the growth rates increased with silvicultural treatment. Overall, commercial dipterocarps, commercial non-dipterocarps and non-commercial tree species groups differed in response to silvicultural treatment. The growth rates of commercial tree species in plots that received silvicultural treatment were 62–97% higher than in the control plots. For non-commercial tree species, the increase of growth rates was 20–58%, compared to the control plots. These results indicate that the application of silvicultural treatments after logging could help improve the growth of the residual stands. These provide quantitative information that silvicultural treatments in logged-over forest should be considered as a viable management option and may guide the choice of cutting cycle.
UJI PENGELOMPOKAN JENIS BERDASARKAN MODEL PENDUGA RIAP DIAMETER POHON PADA HUTAN BEKAS TEBANGAN DI PROVINSI JAMBI Wahjono, Djoko; Dewi, Adinda Kusuma
Jurnal Penelitian Hutan dan Konservasi Alam Vol 4, No 4 (2007): Jurnal Penelitian Hutan dan Konservasi Alam
Publisher : Pusat Penelitian dan Pengembangan Hutan

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Abstract

ABSTRAK Penelitian ini bertujuan untuk mendapatkan informasi mengenai kelompok-kelompok jenis yang memiliki model penduga riap diameter sama berdasarkan model paling optimal yang diperoleh dengan menduga hubungan  antara  riap  diameter  dengan  diameter  pohon,  kerapatan  tegakan,  luas  bidang  dasar,  dan interaksinya  pada berbagai jenis pohon pada hutan alam bekas tebangan di konsesi Hak Pengusahaan Hutan (HPH) PT. Putraduta Indah Wood, Jambi. Data yang digunakan dalam penelitian ini adalah data Petak Ukur Permanen (PUP) yang telah dilakukan enam kali pengukuran dengan selang waktu sekitar satu tahun (1995-2000). Pengelompokan jenis dilakukan dengan model-model hipotesis, antara lain: 1) Ln Y = a 0  + a1  Ln D + a2 DN + å,  2) Ln Y = a 0 + a1 Ln D + a 2 D + å,  3) Ln Y = a 0 + a1  Ln D2 + a2 DN +å,  4) Ln Y = a 0 + a1  Ln D + a2 D2 + å,   5) Y = a 0 + a1 D + a2 D2 + å,   6) Y = a 0 + a1 DN + a2 D2 + å,  7) Y = a 0 + a1 Ln D + a2 (Ln D)2 + å,  8) Log (Y + 0,2) = a 0  + a1  log (BA) + a 2  D + a3  log (D) + å. Berdasarkan hasil uji peranan peubah bebas melalui uji F, model yang terpilih untuk pengelompokan jenis adalah Model 1,  Model 2, Model 5, Model 6, dan Model 7.   Berdasarkan perbandingan nilai JKS terkecil dari semua pengelompokan jenis sementara model terpilih, dihasilkan 11 kelompok jenis, yaitu: Kelompok 1 (Xylopia sp.), Kelompok 2 (Ganua motleyana Pierre), Kelompok 3 (Planconia valida Bl + Ilex cymosa Bl), Kelompok 4 (Urandra scorpioides O.Ktze + Castanopsis sp.), Kelompok 5 (Shorea macrantha Brandis), Kelompok 6 (Cantleya cornoculata Howard), Kelompok 7 (Tetramerista glabra Miq + Santiria laevigata BL), Kelompok 8 (Ilex sp.+ Gluta renghas L), Kelompok 9 (Colomus optimus + Dacryoides rostrata H.J.L.), Kelompok 10 (Hydnocarpus gracilis + Eugenia sp.), dan Kelompok 11 (Durio carinatus Mast). Pendugaan riap diameter rata-rata setiap kelompok diperoleh dengan menggunakan model gabungan dari masing-masing kelompok menghasilkan nilai untuk Kelompok 1) 0,392 cm/th dengan selang 0,334-0,449 cm/th,  Kelompok 2) 0,402 cm/th dengan  selang 0,343-0,462 cm/th,    Kelompok 3)  0,380  m/th  dengan  selang  0,321-0,440 cm/th, Kelompok 4) 0,374 cm/th dengan selang 0,313-0,435 cm/th,  Kelompok 5) 0,385 cm/th dengan selang 0,281-0,490 cm/th,  Kelompok 6) 0,354 cm/th dengan selang 0,255-0,452 cm/th, Kelompok 7) 0,360 cm/th dengan selang 0,282-0,438 cm/th,  Kelompok 8) 0,038 cm/th dengan selang 0,03-0,045 cm/th,  Kelompok 9) 0,366 cm/th dengan selang 0,279-0,452 cm/th, Kelompok 10) 0,382 cm/th dengan selang 0,268-0,497 cm/th, dan Kelompok 11) 0,366 cm/th dengan selang 0,178-0,555 cm/th.
The Dynamics of Species Composition Stand Structure and Above Ground Biomass of Undisturbed Forest in East Kalimantan Krisnawati, Haruni; Wahjono, Djoko; Imanuddin, Rinaldi
JURNAL BIOLOGI INDONESIA Vol 8, No 1 (2012): JURNAL BIOLOGI INDONESIA
Publisher : Perhimpunan Biologi Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (255.378 KB) | DOI: 10.14203/jbi.v8i1.3062

Abstract

Dinamika Komposisi Spesies Struktur Pohon dan Biomasa di Hutan Terganggu di Kalimantan Timur. Kajian dinamika komposisi spesies dan biomasanya dilakukan selama 4,3 tahun (Desember 2004 - April 2009) di hutan terganggu Kalimantan Timur. Untuk melakukan kajian di gunakan 6 plot permanen (100x100 m2), yang berada di hutan penelitian Samboja. Semua pohon berdiameter > 10 cm dbh (diukur pada posisi 1,3 m diatas tanah). Pada Desember 2004,tercatat 2143 pohon tersebar di plot tersebut terdiri dari 39 famili, 82 genus dan 111 spesies. Pada pengamatan April 2009 tercatat 2466 pohon terdiri dari 40 famili, 86 genus dan 123 jenis.Sebagian besar spesies yang mendominasi adalah Garcinia nervosa dan Trigonostemon laevigatus tetapi setelah pengamatan pada tahun 2009, keduanya tidak lagi mendominasi. Selama kurun 4,3 tahun terjadi penambahan kepadatan 15,1%, basal area 12,9% dan biomasa 11,6%. Penambahan kepadatan tercatat meningkat dari 357 menjadi 411 pohon/ha. Basal area meningkat mulai dari 20,09 menjadi 22,67 m2 ha-1, sedangkan biomasa meningkat dari 286,3 menjadi 319,4 ton ha-1.Kata kunci: Komposisi, spesies, biomas, hutan terganggu
THE DYNAMICS OF SPECIES COMPOSITION STAND STRUCTURE AND ABOVE GROUND BIOMASS OF UNDISTURBED FOREST IN EAST KALIMANTAN Krisnawati, Haruni; Wahjono, Djoko; Imanuddin, Rinaldi
JURNAL BIOLOGI INDONESIA Vol 8, No 1 (2012): JURNAL BIOLOGI INDONESIA
Publisher : Perhimpunan Biologi Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jbi.v8i1.3062

Abstract

Dinamika Komposisi Spesies Struktur Pohon dan Biomasa di Hutan Terganggu di Kalimantan Timur. Kajian dinamika komposisi spesies dan biomasanya dilakukan selama 4,3 tahun (Desember 2004 - April 2009) di hutan terganggu Kalimantan Timur. Untuk melakukan kajian di gunakan 6 plot permanen (100x100 m2), yang berada di hutan penelitian Samboja. Semua pohon berdiameter > 10 cm dbh (diukur pada posisi 1,3 m diatas tanah). Pada Desember 2004,tercatat 2143 pohon tersebar di plot tersebut terdiri dari 39 famili, 82 genus dan 111 spesies. Pada pengamatan April 2009 tercatat 2466 pohon terdiri dari 40 famili, 86 genus dan 123 jenis.Sebagian besar spesies yang mendominasi adalah Garcinia nervosa dan Trigonostemon laevigatus tetapi setelah pengamatan pada tahun 2009, keduanya tidak lagi mendominasi. Selama kurun 4,3 tahun terjadi penambahan kepadatan 15,1%, basal area 12,9% dan biomasa 11,6%. Penambahan kepadatan tercatat meningkat dari 357 menjadi 411 pohon/ha. Basal area meningkat mulai dari 20,09 menjadi 22,67 m2 ha-1, sedangkan biomasa meningkat dari 286,3 menjadi 319,4 ton ha-1.Kata kunci: Komposisi, spesies, biomas, hutan terganggu
Co-Authors Adinda Kusuma Dewi Haruni Krisnawati Rinaldi Imanuddin