Judul: Studi Pertumbuhan Tanaman Revegetasi Pasca Tambang Batu Bara di PT Arutmin Indonesia Site Batulicin Kalimantan Selatan
Abstrak: Soil characteristics on post coal mining land is generaly have a high acidity, density, and content of phytotoxic compounds wich potentially causing stunt plants. This study examines the characteristics of the soil and crop growth performance at post coal mining land revegetation of PT Arutmin Indonesia Site Batulicin South Borneo and the correlation between its soil character with plant growth performance at this site. The study was conducted by measuring the height and diameter of acacia and sengon from 26 plots, and conducting soil analysis of chemical and physical soil properties from each plot. This study found some stunt plant, soil density is a factor that most often appears in problem level at this site, and is a factor that has a significant correlation with plant growth performance.
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Judul: Evaluasi Keberhasilan Tanaman Hasil Revegetasi di Lahan Pasca Tambang Batubara Site Lati PT Berau Coal Kalimantan Timur
Abstrak: Mining activities in the forest areas is done through the lend use of forest areas. The activities of mining must always be followed by reclamation and revegetation to restore the condition of damaged forest area as a result of mining efforts and forest areas can serve again in line with aimed. Revegetation is an effort to repair and restore the damaged vegetation by planting and maintenance activities on the grounds of forest areas former use. Evaluation needs to be done to find out the status of successful revegetation has been done by mining company. Purposes of this research are to assess the successful status of revegetation on post-mining land based on survival rate and plants performance of Acacia mangium on Block Q3 East Elevation 60 Lati Site of PT Berau Coal East Kalimantan. Observation also held to find out the causes of ineffective growth by result of soil analysis on post-mining land, and also to give recommendations of revegetation improvements. The result showed that the success of revegetation status on Block Q3 East Elevation 60 Lati Site is not successful based on survival rate and performance of planted plants. It is caused by the average values of growth and health plant percentage which lower than 80%. The average value of growth percentage is 79,31% and health plant percentage is 71,62%. The main factor of this condition is failure characteristics of soil revegetation which unsupport properly for the growth of plants. The level of soil acidity which appertain very acid soil can cause some important problems and it can be harmful to plants. Soil amendment and replanting vegetation should be done to improve revegetation on Block Q3 East Elevation 60 Lati Site PT Berau Coal East Kalimantan.
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Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology