Produksi dan dekomposisi serasah pada hutan mangrove Segara Anakan Cilacap, jawa Tengah

KORJA, I Nengah, Drs. Sunarto Hardjosuwarno

2002 | Tesis | S2 Biologi

Kajian tipe komunitas, struktur, komposisi, produksi dan dekomposisi serasah menipakan masalah penting pada komunitas hutan mangrove Segara Anakan. Terdapat empat tipe komunitas hutan mangrove pada erea kajian. Dua merupakan komunitas muda (tipe I dan IT), satu komunitas umur sedang ( tipe TIT) dan yang terakhir komunitas tua (tipe IV). Penelitian ini bertujuan untuk mengetahui stniktur, komposisi,produksi dan laju dekomposisi serasah. Metode kuadrat digunakan unhk menentukan struktur dan komposisi komunitas hutan mangrove. Litter trap untuk menentukan produksi serasah dipasang selama 8 bulan. Plot kuadrat dan litter trap dipasang secara subyektif, Metode kantong serasah untuk menentukan laju dekomposisi serasah dilakukan selama 7 bulan. Hasil penelitian menunjukkan pada komunitas tipe I tidak ditemukan kelas pohon, tetapi pada komunitas lain ditemukan. Populasi berdasarkan kelas diameter batang pada komunitas 11, Ill dan IV menunjukkan kurva berupa huruf J berbalik, jumlah individu diameter kecil lebih banyak dibandingkan dengan individu diameter lebih besar. Total produksi serasah hutan mangrove area kajian 13,38 ton/ha/tahun. Pengaruh curah hujan dan salinitas terhadap produksi serasah tergantung pada tipe komunitas. Curah hujan dan produksi serasah pada komunitas I berkorelasi negatif, tetapi dengan komunitas 11, Ill dan IV berkorelasi positif. Salinitas dan produksi serasah komunitas 1 berkorelasi positif, tetapi dengan komunitas IT, I11 dan IV berkorelasi negatif dan semua berkorelasi tidak signifikan. Kedalaman berpengaruh terhadap laju dekomposisi dan laju dekomposisi paling cepat terjadi pada permukaan tanah. Dalam k t m satu tahun serah terdekomposisi secara keselwuhan. Laju dekomposisi paling cepat terjadi pada serasah Avicennia alba diikuti Bmguiera gymnorrhrza dan Aegiceras corniculatum . Total sumbangan bahan organlk tiga jenis mangrove tersebut 1 1,99 tonhdtahun.

The study on mangrove forest types, structure, composition, litter production and decompositi are important in mangrove forest community at Segara Anakan. There were four mangrove forest types based on different age were selected as sample study, Two of them were young type communities (type 1 and ll), one was intermediate community (type Ill), and the last was older community (type IV). The aims of this study are to identify the structure, composition, litter production, the rate of litter decomposition. Quadrate method was used to determine the structure and composition of the communities. To determine the litter production was done litter trap in the period of eight months. Quadrate plots and litter traps were placed subjectively. Litter bag method was used to determine decomposition rate of litter in different depths of soil and was done in the period of seven months. Result of the study shows that in the community type I no tree found, but in the other types there are trees. Population based on stem diameter classes of community type 11,111 and iV show negatively rectangular curves. So the amount of smaller stem diameter trees is greater than the bigger. Total litter production of the mangrove forest is 1338 tonlhalyear. The influence of rain fall and salinity on litter fall is varied depend on the community types. In the community type I the correlation of rain fall is negative but in type IT, III and IV are positive. The correlation of salinity in community type I is positive but in the community type 11, 111 and 1V are negative and all of the correlation are not significant. The decomposition rate is affected by soil depth and the rate of litter decomposition indicate that the fastest rate is on the surface of the soil. The litter is completely decomposed in one year. The fastest rate of decomposition is the litter of Avrcennza alha followed by Bmprera gvmnorrhrza and Aegiceras comicdatum. The total contribution of organic matter is 11.99 ton/year.

Kata Kunci : Mangrove,Produksi dan Dekomposisi Serasah,Segara Anakan, Type community, litter production, decomposition of litter, mangrove forest, Segara Anakan