Contribution of Harvest Residues to Nutrient Cycling in a Tropical Acacia mangium Willd. Plantation
Contribution of Harvest Residues to Nutrient Cycling in a Tropical Acacia mangium Willd. Plantation
复制标题
热带马占相思收获残留物对养分循环的贡献。
作者：
Nguyen Van Bich;A. Eyles;D. Mendham;T. Dong;D. Ratkowsky;K. Evans;V. Hai;H. Thanh;N. Thinh;C. Mohammed
收获残留物可以发挥至关重要的作用，在森林中的循环保存养分，但很少有人知道这些残留物的分解率和养分释放后，在热带相思树种植园伐木。在这项研究中，我们研究了生物量和养分含量的收获残留物成分（树皮，树叶和树枝）使用垃圾袋技术为1.5年的时间内收获的7岁马占相思种植园在北方越南。收获时，收获残留物的总干生物量为18 t ha−1，包括树皮（8.9 t ha−1），树枝（6.6 t ha−1）和叶子（2.5 t ha−1）。保留树皮现场保存51%的N，29%的P，32%的K，64%的Ca，和24%的Mg含量从收获残留物回收。叶的分解速率最快（k = 1.47年-1; t0.5 = 0.47年），其次是枝（k = 0.54年-1; t0.5 = 1.29年）和树皮（k = 0.22年-1; t0.5 = 3.09年）。在腐解过程中，各养分的流失量为K> Ca > N > P> Mg.收获残留物的分解和相关的养分释放速率可能会为下一轮林分的发展提供大量的养分。
Harvest residues can play a crucial role in conserving nutrients for recycling in forests, but little is known about the rates of decomposition and nutrient release from these residues following logging in tropical acacia plantations. In this study, we examined the biomass and nutrient content of harvest residue components (bark, leaves, and branches) using the litterbag technique for a 1.5-year-period following harvest of a seven-year-old Acacia mangium plantation in Northern Vietnam. At harvest, the total dry biomass of harvest residues was 18 t ha−1 comprising bark (8.9 t ha−1), branches (6.6 t ha−1), and leaves (2.5 t ha−1). The retained bark on site conserved 51% N, 29% P, 32% K, 64% Ca, and 24% Mg content from harvest residues for recycling. Decomposition rate of the leaves was the most rapid (k = 1.47 year−1; t0.5 = 0.47 year), then branches (k = 0.54 year−1; t0.5 = 1.29 year), and bark (k = 0.22 year−1; t0.5 = 3.09 year). During decomposition, the loss of nutrients from harvest residues was K ≈ Ca > N > P> Mg. Decomposition of harvest residues and the associated rate of nutrient release can potentially supply a significant amount of nutrients required for stand development in the next rotation.