Judul: Effect of Inundation and Shade Levels on the Growth of Balangeran (Shorea balangeran (Korth.) Burck) in Peat Soil Media in the Nursery
Abstrak: Pembukaan hutan rawa gambut yang tidak terkendali dan pembangunan kanal pada gambut menyebabkan terbukanya hutan dan degradasi lahan gambut. Pada musim kemarau, lahan gambut yang terdegradasi menjadi kering dan rawan kebakaran, sebaliknya pada musim penghujan lahan gambut terdegradasi menjadi rawan banjir. Balangeran (Shorea balangeran) adalah jenis asli lahan gambut yang digunakan pada kegiatan revegetasi atau rehabilitasi lahan gambut terdegradasi dan diharapkan mampu memperbaiki ekosistem gambut yang rusak. Tujuan penelitian ini adalah mengkaji pengaruh pemberian genangan dan naungan terhadap pertumbuhan bibit balangeran pada media dan air gambut artificial. Penelitian ini menggunakan Rancangan Acak Lengkap dengan dua faktor, yaitu genangan dan naungan. Hasil penelitian menunjukkan adanya interaksi perlakuan genangan dan naungan memberikan pengaruh yang signifikan terhadap diameter, berat basah total, nisbah pucuk akar, jumlah akar adventif, kandungan klorofil, dan laju fotosintesis. Perlakuan tunggal genangan maupun naungan berpengaruh nyata terhadap tinggi, dan berat keing total balangeran. Bibit balangeran mampu hidup secara pada berbagai tingkat genangan. Naungan yang tepat untuk pertumbuhan optimal bibit balangeran adalah naungan 30%., Uncontrolled logging and canals development in the peat swamp forests caused open canopy and peatland degradation. In dry season, the degraded peatland become drying and prone to fire, while during rainy season the degraded peatlands vulnerable to floods. Balangeran (Shorea balangeran) is a native peat swamp forest that suitable for revegetation or rehabilitation of degraded peatlands and it is expected to be able to restore the damage peat ecosystems. The purpose of this study is to examine the effect of inundation and shade level on the growth of balangeran seedlings on the peat media. This study used a completely randomized design with two factors, namely inundation, and shade. The results of this study are the interaction of inundation and shade treatment gives a significant influence on the stem diameter, total wet weight, shoot root ratio, number of adventitious roots, chlorophyll content, and photosynthesis rate. A single treatment of inundation and shade affects the height and total dry weight significanly. Balangeran seedlings can live in various levels of inundation. The suitable shade for the optimal growth of balangeran seedlings is the 30% shade.
Keyword: genangan, naungan, revegetasi, Shorea balangeran, inundation, shade, revegetation

Judul: Root Morphophysiology of Seedlings Planted in Nursery with Waterlogging and Shading using Peat Soil
Abstrak: Pemanfaatan lahan gambut saat ini masih memiliki berbagai hambatan, salah satunya adalah mendapatkan tanaman yang toleran pada kondisi lahan gambut yang khas, karakter tanah, dan adanya genangan yang dapat timbul sewaktu-waktu. Analisis morfo-fisiologi akar tanaman yang ditanam pada tanah gambut dengan perlakuan genangan dan naungan yang bervariasi akan memberikan gambaran mengenai respon tanaman pada kondisi di lahan gambut yang direstorasi. Penelitian ini bertujuan untuk menganalisis morfo-fisiologi akar dengan berbagai intensitas penggenangan dan naungan di tanah gambut. Jenis tanaman yang digunakan yaitu Durio zibethinus (durian), Nephelium lappaceum (rambutan), Shorea balangeran (balangeran), dan Cratoxylum arborescens (gerunggang) ditanam pada tanah gambut dan diberikan perlakuan genangan dan naungan dengan berbagai intensitas, selanjutnya dilakukan pengamatan morfo-fisiologi akar yang meliputi kerapatan pembuluh xilem (VD), jumlah sel pembuluh xilem, luas area xilem akar (Axilem), luas total lumen pembuluh xilem (Alumen), diameter ideal lumen pembuluh xilem akar (D), dan konduktivitas hidrolik potensial (Kp) pembuluh xilem akar. Hasil penelitian menunjukkan ada perbedaan morfologi akar antara S. balangeran dan C. arborescens. Perlakuan genangan dan naungan berinteraksi memengaruhi D dan Kp akar S. balangeran, sementara VD pada S. balangeran hanya dipengaruhi oleh genangan. Interaksi genangan dan naungan juga memengaruhi D akar C. arborescens., The utilization of peatlands nowadays is still hindered by many things, one of them is finding plants that can tolerate the extreme conditions caused by the unique peat soil characteristics, and waterlogging that may occur. Morphophysiological analysis of roots from four plant species that were planted in peat soil and treated with various levels of waterlogging and shading was expected to show how plants will respond to the condition of the rewetted peatlands. This study aimed to analyze morpho-physiology characteristics of roots from Durio zibethinus (durian), Nephelium lappaceum (rambutan), Shorea balangeran (red balau), and Cratoxylum arborescens (gerunggang) seedlings planted in peat soil treated with several intensities of waterlogging and shading. Roots of the plants were observed to find morpho-physiological differences in vessel density (VD), the amount of xylem lumen cell, area of xylem (Axylem), a total area of lumens (Alumen), ideal diameter of xylems lumen (D), and the potential hydraulic conductivity (Kp) of roots xylem. The result of this study showed that waterlogging influenced the root morphology of S. balangeran and C. arborescens. Waterlogging treatment affected VD of S. balangeran. The interaction of waterlogging and shading treatments affected D and Kp of S. balangeran but it only affected D of C. arborescens.
Keyword: Cratoxylum arborescens, Durio zibethinus, hydraulic conductivity, kerapatan pembuluh xilem, konduktivitas hidrolik, Nephelium lappaceum, Shorea balangeran, vessel density

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