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AbstrakEkosistem hutan gambut tropika merupakan penyimpan karbon potensial, tetapi konversi lahan dan penebangan tidak lestari menyebabkan ekosistem ini juga menjadi sumber emisi karbon ke atmosfer. Pengaruh perubahan penutupan lahan dan pembangunan drainase terhadap dinamika muka air, penurunan tanah dan kehilangan karbon masih belum banyak diketahui pada tipologi gambut pesisir dengan bentang lahan yang sempit. Penelitian dilaksanakan pada berbagai tipe penutupan lahan gambut di Trumon dan Singkil, Provinsi Aceh mulai Mei 2013 hingga Oktober 2014. Penyimpanan dan kehilangan karbon dihitung berdasarkan bobot isi, kadar abu, karbon organik tanah, dan kedalaman tanah. Hasil penelitian menunjukkan perubahan penutupan lahan dan pembangunan drainase mempengaruhi tata air, penurunan tanah, dan kehilangan karbon sebesar 38,54 -58,52%. Penurunan permukaan tanah tertinggi sebesar 5,6 cm/tahun terjadi pada lahan dengan bobot isi rendah dan intensitas drainase yang tinggi. Kehilangan karbon dari degradasi lahan gambut melepaskan sekitar1,352 ton CO2 eq/ha/tahun. Kata kunci: drainase, gambut tropika, kedalaman muka air, kehilangan karbon, penurunan permukaan tanah. Abstract

Perum Perhutani has an important role in providing food and wood for people. Diversity and diversification of food will reduce the need for one type of food, namely rice as a staple food. Some tuber and rhizome are source of alternative foodstuffs, such as taro and arrowroot. This study aimed to determine the suitability and productivity of arrowroot and taro planted under old superior teak clones with several levels of stand density. Arrowroot and taro were planted under 14-year-old teak stands with 4 levels of density. Both plants were planted in the form of an array, measuring of 3m x 15m, with a spacing of 75cm x 75cm between plants. They were arranged in Randomized Completely with Block Design (RCBD) placed in 4 blocks of observation as replications.  The results showed that under superior teak clone had the potential to be planted with arrowroot and taro. Teak stand density influenced significantly some characteristics of arrowroot (leaves number, leaves area, stem height, stem diameter, root length) and taro (stem diameter, tuber diameter). Arrowroot productivity per hectare increased with low density of teak stands, accounted for 55, 59, 80, and 88 kg respectively. Meanwhile, taro productivity from very high to low teak density were 365, 301, 523, and 426 kg/ha. The novelty of this study is that there is no record of intercropping studies on old superior teak clones, so this is among the first studies. The benefit of from this research result, it could be employed by Perhutani to support the Indonesian government in the national food security program

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Pertumbuhan tanaman dipengaruhi oleh faktor genetik dan faktor lingkungan. Salah satu faktor lingkungan yang sangat memengaruhi pertumbuhan adalah sifat kimia dan fisika tanah. Beberapa famili jati yang ditanam pada lokasi yang berbeda diduga mempunyai respon pertumbuhan yang berbeda pula. Penelitian ini bertujuan untuk mengetahui respon pertumbuhan (tinggi dan diameter) tanaman jati dari 30 famili yang ditanam pada dua lokasi yang berbeda, secara khusus untuk mengetahui pengaruh karakteristik sifat kimia dan fisika tanah pada pertumbuhan jati di dua lokasi tersebut. Metode penelitian yang dilakukan untuk mengukur pertumbuhan 30 famili jati yaitu tinggi total tanaman dan diameter setinggi dada. Sampel tanah diambil dengan terlebih dahulu membuat lubang profil tanah berukuran 1 m × 1 m dengan kedalaman 1 meter kemudian sampel diambil dari kedalaman 0-10 cm, 10-20 cm, 20-40 cm, dan 40-60 cm. Sifat kimia yang diamati adalah pH H2O, C Organik, N total, P, K, Ca, dan Mg tersedia serta Kapasitas Pertukaran Kation (KPK), sedangkan sifat fisik yang diukur adalah tekstur. Analisis statistik dilakukan dengan melakukan uji-t. Hasil penelitian menunjukkan parameter diameter tanaman, semua (30) famili tanaman jati menunjukkan perbedaan yang nyata di antara dua lokasi, sedangkan parameter tinggi hanya sebagian kecil famili yang berbeda nyata. Karakter kimia dan fisik tanah juga menunjukkan perbedaan nyata di antara dua lokasi. Parameter kimia tanah yaitu pH H2O, K, Ca, dan Mg tersedia, berbeda nyata antara 2 lokasi sedangkan kandungan C Organik, P tersedia dan KPK tidak berbeda nyata. Sementara dari sifat fisiknya, kandungan lempung dan debu pada dua lokasi berbeda nyata, sedangkan kandungan pasirnya tidak berbeda secara nyata. Perbedaan-perbedaan tersebut menunjukkan beberapa sifat tanah memang memengaruhi respon tanaman jati dalam hal pertumbuhan baik tinggi maupun diameternya. The Effect of Soil Chemical and Physical Characteristics on Growth of 30 Families of Teak (Tectona grandis) in a 10-year-old Progeny TestAbstractSome environmental factors that greatly affect plant growth are soil’s physical and chemical properties. Some teak families planted at different locations alleged to have different growth responses. This study aimed to investigate the growth response of teak (height and diameter) from 30 families, and to determine the effect of soil chemical and physical characteristics on teak growth in two different locations. Teaks were measured for total height and diameter at breast height. Soil pits (size: 1 m x 1 m and 1 m in depth) were dug and samples were taken from 0-10 cm, 10-20 cm, 20-40 cm and 40-60 cm in depth. Soil characteristics measurement were conducted on pH (H2O), organic carbon, total Nitrogen, available P, K, Ca, and Mg, also the Cation Exchange Capacity (CEC). Further, soil physical properties been measured was soil texture. Statistical analysis was performed by t- test. The results showed that teak’s diameter of all 30 families, showed significant differences between the two locations, while only a small proportion of height parameters significantly differed among families. Chemical and physical characters of the soil also showed differences between the two locations. Soil pH (H2O), available K, Ca, and Mg, were significantly differed between the two locations while the content of organic C, available P and the CEC were not significantly differed. For the soil physical properties, content of clay and silt in two location significantly differed whereas the sand content did not differ significantly. These differences indicate that some properties of the soil were affecting the growth response of teak famili in terms of both height and diameter.