Model Pertumbuhan Diameter dan Tinggi Pohon Lima Jenis Dipterocarpaceae di Hutan Penelitian Carita - Banten

Model pertumbuhan lima jenis Dipterocarpaceae dibuat dengan menggunakan model Alder (1980) yaitu Ln Y = a+b (1/A)k dan model-model lain yang tersedia dalam perangkat lunak Curve Expertversi 1.37 yaitu model Hoerl (Y = abXXc), Quadratic Fit (Y = a + bX + cX2 ), Gompertz ( Y = ae –eb-cx). Logistic (Y = a/(1+be-cX) , dan Exponential Association ( Y = a (1 – ebX), dan lain-lain; dimana, Y adalah peubah pertumbuhan diameter (cm) atau tinggi pohon (m); X adalah umur pohon (tahun); e adalah bilangan alam sebesar 2.718; a,b,c,d adalah koefisien regresi. Berdasarkan kriteria simpangan rata-rata relatif (SRR < 10%) dan simpangan agregatif relatif (SAR < 1%), dihasilkan model pertumbuhan diameter pohon dan tinggi pohon untuk masing-masing jenis yang diteliti

Leaf Litter Decomposition and Nutrient Release of Three Native Tree Species in a Drained Tropical Peatland in Riau, Indonesia

The decomposition and its nutrient release were the key ecological process that had a broad role in the forest ecosystem. This study aimed to investigate the leaf litter decomposition rate and its nutrient release of three native tree species of tropical peat swamp forest, namely Macaranga pruinosa, Macaranga gigantea, and Cratoxylum arborescens and one exotic species i.e Acacia crassicarpa. The decomposition and nutrient release were monitored in an experimental plot using litter bag technique. The initial litter quality of each litter and micro-environment properties were also observed. The result showed that the decomposition and its nutrient release were insignificantly different among native tree species and also between native species and Acacia crasssicarpa. The litter decomposition of all tree species was slow; with the range of k was 0.98-1.19 year-1. However, the P and K release from the decomposition of native species litter after four months of incubation were quickly, ranging 70-74% and 88-93%. We were suggested that the high of lignin content in the leaf litter (36-39%) was the main factor that made slow decomposition. These findings could be used as one of the tools in tree species selection for peat swamp forest rehabilitation

Pengaruh Teknik Persiapan Lahan terhadap Serangan Hama Penyakit pada Tegakan Bambang Lanang

Land preparation may affect the infestation of pests and diseases. This study aimed to find out the dynamic of pests and diseases infestation in the bambang lanang stand based on land preparation techniques. Land preparation was done by total clearing, path clearing and circle clearing. Percentage attack and intensity attack of pests and disesases were carried out over two years. Pest infestation was found by Graphium agamemnon L. (Papilionidae; Lepidoptera), Sorolopha cumarotis (Tortricidae; Lepidoptera), and leaf minner. Diseases infestation was found by Colletotrichum sp., Cercospora sp. and Curvularia sp. Pests and diseases infestations tended to go down on all land preparation treatments, in line with the increase of plant age. The lowest plant damage was found in total clearing treatment

Pengaruh Penanaman Beberapa Jenis Pohon Hutan terhadap Kondisi Kesuburan Tanah Andosol

Pembangunan hutan tanaman industri perlu memperhatikan faktor kesuburan tanah, karena tanah yang subur memungkinkan pohon tumbuh dan menghasilkan kayu serta produk lainnya dengan baik. Penelitian mengenai pengaruh penanaman jenis pohon hutan, seperti Agathis loranthifolia, Pinus oocarpa, Shorea platyclados, Alnus Nepalensis, Toona sureni, Casuarina junghuhniana, Khaya anthotheca dan Acacia cassicarpa telah dilakukan pada tanah andosol di dataran tinggi Cikole, Jawa Barat. Pengambilan sampel tanah dilakukan di bawah tegakan yang telah berumur enam tahun pada 3 titik dan dicampur untuk dianalisa sifat kimia dan biologi tanahnya, sedangkan sifat fisik sampel diambil pada dua kedalaman O cm - 15 cm dan 15 cm - 30 cm dengan menggunakan ring sampel. Hasil penelitian menunjukkan bahwa pH tanah di bawah tegakan umumnya masam sama dengan kondisi awal, kecuali untuk jenis S. platyclados sangat masam. Kandungan bahan organik, unsur hara makro dan kapasitas tukar kation pada umumnya sama, sehingga penanaman jenis dapat menstabilkan kondisi tanah. Tekstur tanah setelah penanaman lempung liat berdebu, kecuali T. sureni yang menjadi liat, sedangkan pengaruhnya terhadap porositas, berat jenis dan air tersedia berpengaruh positif. Selain itu, penanaman dapat meningkatkan jurnlah mikroorganisme, jumlah fungi dan respirasi di dalam tanah yang berdampak positif terhadap kesuburan tanah

The Utilization of Bioorganic Mixture Ferns Gleichenia linearis (Burm.) Clarke and Leave Manure Leaves of the Pine merkusii Jungh et de vriese as a Medium Jabon Seedling (Anthocephalus cadamba miq.)

Planting medium that’s commonly used in the nursery ground is a top soil. Top soil that is utilized as a medium for planting is known have some weakness and may result in environment damage when used on an ongoing basis, thus the use of additional materials materials top soil that qualify as planting media needs to be done. One of the materials that can be used as a medium for planting is fern nor diacritical marks (Gleichenia linearis) leaf litter and pine (Pinus merkusii). These materials can be used as a medium for planting after compostion process  to remove content of cellulose and hemicellulose contained in such materials. Nutrient element content is inside planting medium   also be added to handouts fertilizers. Utilization bioorganic as media addition to jabon  seedlings are  known can reduce the use of plant top soil as a medium of 50% and produce seedling growth (5.8 cm high; diameter 0,5 mm) while same either by medium planted in top soil (6,5 cm high; diameter 0,5 mm) while seedling on bioorganic planting medium has on media cropping bioorganik having less good growth (high 4,3 centimeters; diameter 0,4 mm ) gord ratio C/N  still very high that the mineral content that  is not available in the media and cannot be used by plant. Provision of fertilizer Terabuster 1% Bioremedi 2%, also a mixture of Terabuster and Bioremedi, respectively, as many as 20 ml are known to be able to boost the growth of the  jabon seedling about 10-50% compared with non-fertilization, besides fertilizers were also able to increase the percent living seed planting  in jabon Bioorganic medium about 4-21

Effect of drought stress treatment towards growth of seedlings of cempaka wasian, nantu, and mahoni

oai:ojs.jurnal.balithutmakassar.org:article/439Climate change has shortened the rainy season compared to the dry season in North Sulawesi. The El Nino phenomenon occurred in 2015 had an impact on the death of clove plants due to drought. Drought stress testing on several types of forestry plants in the North Sulawesi area is a matter that needs to be done in line with these conditions. Development of cempaka wasian (Magnolia tsiampaca (Miq.) Dandy), nantu (Palaquium obtusifolium Burck), and mahoni (Swietenia macrophylla King) plantations have been carried out by communities in North Sulawesi for a long time and have very good prospects. The research was done by conducting a simulation test at seedling level with treatment to be tested on volume and interval of watering. The watering volume consists of 3 levels, i.e. 100%, 50%, and 25% watering of the field capacity, while the watering intervals included once-daily, 3-day and 5-day watering once for 18 weeks. The results showed that nantu species has better resistance to drought stress conditions compared with mahogany and cempaka wasian

The Changes in Seed Germination Capacity, Seedling Growth, and Leaf Morphology of Ficus variegata Blume Influenced by Gamma-Ray Irradiation

Gamma irradiation treatments have commonly been applied to induce variation in plant genetic improvement programs. The improvement of nyawai (Ficus variegata Blume) is urgently needed mainly to break the seed dormancy, increase seedling growth, and induce variation for selecting desired traits. This research aimed to assess the effect of gamma irradiation doses on seed germination, seedling growth, and leaf morphology of Ficus variegate Blume. This experiment's irradiation doses ranged from 5-240 Gy and were applied to seeds with varying levels of vigor based on the artificial seed aging process. The data displayed a positive relationship between low doses of gamma irradiation and the nyawai seed's endurance. Low irradiation doses, 5 to 30 Gy, are deemed capable of promoting seedling development, leaf retention, and diversity in leaf structure. The higher irradiation doses than 30 Gy decreased seedling growth, leaf number, and seedling survival. In addition, these doses also affect some morphological changes, including seedling height and leaf length and width