Analisis Kandungan Lignin pada Heartwood dan Sapwood Acacia auriculiformis A. Cunn. ex Benth.

BUDI SANTOSO SITOPUTRA, Dr. Tri Rini Nuringtyas, S.Si., M. Sc.

2014 | Skripsi | BIOLOGI

Kayu merupakan biomaterial dari tumbuhan yang bermanfaat sebagai sumber energi terbarukan (kayu bakar). Untuk dapat dimanfaatkan sebagai sumber energi yang efisien, kayu memiliki persyaratan fisika dan kimia tertentu seperti nilai kalor, kandungan karbon terikat serta senyawa tertentu dalam kayu, seperti kandungan lignin dan ekstraktif. Penelitian ini memakai 38 famili tanaman Akasia Acacia auriculiformis A Cunn. ex Benth. yang ditanam di KHDTK Wonogiri, Jawa Tengah. Kayu tanaman ini memiliki heartwood dan sapwood yang mudah dibedakan dengan jelas. Kedua bagian kayu ini diketahui memiliki karakter anatomi dan kandungan kimia kayu, termasuk lignin yang berbeda. Pada penelitian ini dilakukan pengambilan sampel sebanyak dua periode, yaitu seleksi 2 dan 3 dengan umur tanaman berturut-turut 2,5 tahun dan 3 tahun. Sampel diuji kadar ligninnya pada heartwood dan sapwood dengan metode Chesson-Datta (1981) terkoreksi kadar abu. Hasil penelitian menunjukkan bahwa kadar lignin A. auriculiformis dalam satu individu lebih tinggi di bagian heartwood. Hasil ini berlaku untuk seleksi 2 dan seleksi 3. Kadar lignin pada heartwood dan sapwood serta kadar lignin total individu pada seleksi 2 dan 3, dengan selisih umur 6 bulan, menunjukkan tren kenaikan. Perbedaan yang signifikan terjadi pada kandungan lignin heartwood dan sapwood, tetapi tidak ada beda nyata pada kandungan lignin total antara seleksi 2 dan 3. Hasil analisis variansi menunjukkan beda nyata antar famili tertentu untuk karakter kandungan lignin sapwood seleksi 3, biomassa batang, proporsi heartwood serta sapwood untuk seleksi 2 dan 3. Korelasi signifikan ditemukan pada korelasi negatif kadar lignin sapwood dan diameter batang seleksi 2, korelasi negatif antara proporsi sapwood dan kandungan lignin sapwood seleksi 3, serta korelasi negatif antara diameter batang dan proporsi sapwood seleksi 3.

As a biomaterial formed by a plant, wood has many usage in human life. One of them is as a renewable energy resource, such as firewood. Wood which is good for energy resource purpose requires certain physical and chemical characters, such as, calorific value, fixed carbon, and special compound in the wood, like lignin and extractives content. This study uses 38 family of Acacia auriculiformis A Cunn ex Benth. grown in KHDTK Wonogiri, Central Java. Acacia auriculiformis wood’s could be distinguished easily for its heartwood and sapwood. Heartwood and sapwood are parts of wood that have different anatomy character and its chemical composition, including lignin. In this research, the heartwood’s and sapwood’s lignin content were measured using Chesson-Datta method (1981) corrected by ash content. The result showed that lignin content of A. auriculiformis in an individu was higher in its heartwood. This result is valid for the second and third selection. The heartwood’s, sapwood’s and individual lignin content from the second selection to the third selection, with 6 months difference in age, showed an increment. Significant difference was observed between heartwood’s and sapwood’s lignin content but there were no significant difference between the second selection’s and third selection’s individual lignin content. Analysis of variance showed that there were a significant difference between certain family in the biomass character together with its sapwood and heartwood proportion in both selection, and sapwood’s lignin content in the third selection. Also there were significant negative correlation between second selection sapwood’s lignin content with its stem diameter, between sapwood proportion with its lignin content at the third selection, and between the third selection’s stem diameter with its sapwood proportion.

Kata Kunci : Acacia auriculiformis A Cunn ex Benth, kadar lignin, metode Chesson- Datta, heartwood, sapwood