LITTERFALL, LITTER TURNOVER AND SOIL RESPIRATION IN TWO PINE FOREST PLANTATIONS IN CENTRAL JAVA, INDONESIA

• Published in: Journal of tropical forest science Vol. 6; no. 3; pp. 310 - 322
• Main Author: Gunadi, Bintoro
• Format: Journal Article
• Language: English
• Published: Forest Research Institute Malaysia (FRIM) 01-03-1994
• Subjects: Agrology; Coniferous forests; Dry seasons; Forest litter; Forest soils; Plant litter; Plantations; Rain; Rainy seasons; Tropical forests
• ISSN: 0128-1283

Litterfall, litter turnover and soil respiration were studied for one year in two forest plantations of Pinus merkusii, one on the slopes of Mount Merapi (at 800 m) and another on the slopes of Mount Merbabu (at 1050 m) in Central Java. The dominant component of total litterfall differed per site. At the Merapi site total litterfall was 9 t ha⁻¹ y⁻¹ , nearly 60% of which consisted of female cones. At the Merbabu site total litterfall was 4 t ha⁻¹ y⁻¹ and needles were the dominant component (63%). At the Merapi site, litter turnover during the dry season (Kd=0.08) was four times that in the wet season (kw = 0.20). Because of litter removal by the local people at Merbabu, derived litter turnover values were not realistic. The removal also decreased litter standing crop and significantly reduced the CO₂ efflux from the litter and soil (0.19 - 0.35 gm⁻²h⁻¹). The CO₂ production at Merapi was 0.37 - 0.45 g m⁻²h⁻¹. There was no relationship between CO₂ production and rainfall at Merapi because moisture was not limiting to the mulch effect of the litter standing crop. At Merbabu, where the water content of the litter reached very low values by the end of the dry season (7.2%), there was a positive relationship between CO₂ production and rainfall. Guguran sarap, pembalikan sarap dan respirasi tanih dikaji selama satu tahun di dua hutan ladang Pinus merkusii. Kajian telah dijalankan di Bukit Merapi (pada ketinggian 800 m) dan Bukit Merbabu (pada ketinggian 1050 m), Java Tengah. Komponen dominan jumlah pengguguran sarap berubah mengikut tempat kajian. Pada tapak Bukit Merapi, jumlah gugur sarap ialah 9 t ha ⁻¹ y⁻¹ yang mana hampir 60% daripadanya terdiri dari kon betina. Di Bukit Merbabu pula, jumlah gugur sarap adalah sebanyak 4 t ha⁻¹ y⁻¹ dan komponen dominannya (63%) terdiri dari jejarum. Pembalikan sarap di Bukit Merapi pada musim kering (kd = 0.80) adalah empat kali lebih banyak di bandingkan dengan pembalikan sarap pada musim hujan (kw = 0.20). Oleh kerana, aktiviti pengumpulan sarap oleh penduduk tempatan di Merbabu nilai pembalikan sarap yang di perolehi adalah tidak realistik. Kesan pembuangan ini telah mengurangkan sarap dirían tanaman dan mengurangkan effluk CO₂ dari sarap dan tanih (0.19 - 0.35 g m⁻² h⁻¹). Pengeluaran CO₂ di Merapi adalah 0.37 - 0.45 g m⁻² h⁻¹. Tidak ada hubungan antara pengeluaran CO₂ dengan penurunan hujan di Merapi kerana tahap kelembapan tidak menghad kesan sungkup pada dirian sarap tanaman. Di Merbabu pula di mana nilai kandungan air sarap menurun pada penghujung semasa musim kering (7.2%) terdapat perhubungan positif antara pengeluaran CO₂ dengan penurunan hujan.