Castellanos-Barliza Jeiner, León Peláez Juan Diego
Universidad Nacional de Colombia, Sede Medellín, Facultad de Ciencias Agropecuarias, Medellín, Colombia, Calle 59A 63-20, 14-330.
Rev Biol Trop. 2011 Mar;59(1):113-28.
Several factors control the decomposition in terrestrial ecosystems such as humidity, temperature, quality of litter and microbial activity. We investigated the effects of rainfall and soil plowing prior to the establishment of Acacia mangium plantations, using the litterbag technique, during a six month period, in forests plantations in Bajo Cauca region, Colombia. The annual decomposition constants (k) of simple exponential model, oscillated between 1.24 and 1.80, meanwhile k1 y k2 decomposition constants of double exponential model were 0.88-1.81 and 0.58-7.01. At the end of the study, the mean residual dry matter (RDM) was 47% of the initial value for the three sites. We found a slow N, Ca and Mg release pattern from the A. mangium leaf litter, meanwhile, phosphorus (P) showed a dominant immobilization phase, suggesting its low availability in soils. Chemical leaf litter quality parameters (e.g. N and P concentrations, C/N, N/P ratios and phenols content) showed an important influence on decomposition rates. The results of this study indicated that rainfall plays an important role on the decomposition process, but not soil plowing.
有几个因素控制着陆地生态系统中的分解过程，如湿度、温度、凋落物质量和微生物活性。我们在哥伦比亚巴约考卡地区的森林种植园中，使用凋落物袋技术，在六个月的时间里，研究了马占相思人工林建立之前降雨和土壤耕作的影响。简单指数模型的年分解常数（k）在1.24至1.80之间波动，同时，双指数模型的k1和k2分解常数分别为0.88 - 1.81和0.58 - 7.01。在研究结束时，三个地点的平均残余干物质（RDM）为初始值的47%。我们发现马占相思树叶凋落物中氮、钙和镁的释放模式较为缓慢，同时，磷（P）呈现出主要的固定化阶段，表明其在土壤中的有效性较低。化学凋落物质量参数（如氮和磷浓度、碳氮比、氮磷比和酚类含量）对分解速率有重要影响。本研究结果表明，降雨对分解过程起重要作用，但土壤耕作并非如此。
