Kebakaran hutan berdampak terhadap sifat fisika, kimia tanah, biologi tanah, erosi, kapasitas menyimpan air tanah, penghilangan serasah serta humus. Tujuan penelitian ini adalah untuk mengetahui dampak kebakaran hutan terhadap sifat fisik dan sifat kimia di Prevab, Taman Nasional Kutai. Tujuan penelitian didekati dengan membandingkan areal bekas terbakar dan areal tidak terbakar. Pengujian sampel tanah dilakukan di laboratorium, selanjutnya dilakukan analisis data dengan mengacu pada kriteria penilaian sifat fisik dan kimia tanah yang telah ditetapkan. Berdasarkan penelitian ini diperoleh hasil bahwa sampai 19 tahun setelah terbakar, diketahui kebakaran hutan berdampak terhadap sifat fisik tanah, yaitu meningkatnya kerapatan lindak/Bulk Density, penurunan porositas dan permeabilitas tanah serta tekstur tanah dengan fraksi pasir lebih dominan. Sifat kimia tanah memiliki kriteria yang sama antara areal bekas terbakar dan tidak terbakar yaitu pH sangat masam, DHL sangat rendah dan KTK rendah, sedangkan untuk kation-kation basa secara umum lebih tinggi pada areal tidak terbakar dibandingkan dengan areal terbakar, kecuali untuk Kalium (K).

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Biomass studies are important because they are closely related to other study interests. Estimation of the amount of forest stand biomass is highly relevant to the study of biogeochemical cycles. This study aims to determine the amount of biomass and macro nutrient content in teak stands. By calculating the biomass estimation and analyzing the nutrient content it will be known the amount of nutrient accumulation in biomass. The results of this study are: Total of teak stand biomass of 39,26 ton / ha, including stem component as much as 21,64 ton / ha (55%), branch + twig 11,79 ton / ha (30%), bark component 3.71 ton / ha (9%) and leaf component 2.13 ton / ha (5%). The highest N concentration of nutrients in leaf components, for the highest P in branches + twigs, whereas K, Ca and Mg were highest in the bark component. The highest accumulation of nutrient biomass is Ca (194.4 kg / ha), followed by K (189.7 kg / ha), P (92.4 kg / ha), N (53.5 kg / ha) and Mg (48.4 kg / ha).

The open-pit mining process has an impact on soil properties, including the soil physical properties. The physical properties of soil in the rehabilitation area will develop over time. This study aimed to determine the soil physical properties development in the 20 years old rehabilitation area and compare it with the natural forest area. Soil samples test was carried out in the laboratory, and data analysis refers to the criteria for assessing the soil's physical properties. Based on the soil profile observations, it is known that the rehabilitation site has 72 cm root depth; soil consistency and soil structure varies, soil texture is the silty clay loam. The natural site has 117 cm roots depth; soil consistency is predominantly firm (moist conditions) and sticky to very sticky (wet conditions); soil structures are sub-angular blocky and angular blocky, soil texture is sandy loam. The value of soil permeability, soil porosity, and bulk density is in the same class, namely a rather slow permeability, a low bulk density, and a very high porosity.

Biomass studies are important because they are closely related to other study interests. Estimation of the amount of forest stand biomass is highly relevant to the study of biogeochemical cycles. This study aims to determine the amount of biomass and macro nutrient content in teak stands. By calculating the biomass estimation and analyzing the nutrient content it will be known the amount of nutrient accumulation in biomass. The results of this study are: Total of teak stand biomass of 39,26 ton / ha, including stem component as much as 21,64 ton / ha (55%), branch + twig 11,79 ton / ha (30%), bark component 3.71 ton / ha (9%) and leaf component 2.13 ton / ha (5%). The highest N concentration of nutrients in leaf components, for the highest P in branches + twigs, whereas K, Ca and Mg were highest in the bark component. The highest accumulation of nutrient biomass is Ca (194.4 kg / ha), followed by K (189.7 kg / ha), P (92.4 kg / ha), N (53.5 kg / ha) and Mg (48.4 kg / ha).