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    Author(s): Michael Keller; Michael Palace; Gregory P. Asner; Rodrigo Jr. Pereira; Jose Natalino M. Silva
    Date: 2004
    Source: Global Change Biology 10, :784–795,
    Publication Series: Miscellaneous Publication
    PDF: Download Publication  (475 B)


    Coarse woody debris (CWD) is an important component of the carbon cycle in tropical forests. We measured the volume and density of fallen CWD at two sites, Cauaxi and Tapajós in the Eastern Amazon. At both sites we studied undisturbed forests (UFs) and logged forests 1 year after harvest. Conventional logging (CL) and reduced impact logging (RIL) were used for management on areas where the geometric volumes of logs harvested was about 25–30m3 ha-1. Density for five classes of fallen CWD for large material (410 cm diameter) ranged from 0.71 to 0.28Mg m-3 depending upon the degree of decomposition. Density of wood within large fallen logs varied with position relative to the ground and with distance from the center of the log. Densities for materials with diameters from 2 to 5 and 5 to 10 cm were 0.36 and 0.45 Mg m-3, respectively. The average mass ( ± SE) of fallen CWD at Cauaxi was 55.2 (4.7), 74.7 (0.6), and 107.8 (10.5) Mg ha-1 for duplicate UF, RIL, and CL sites, respectively. At Tapajós, the average mass of fallen CWD was 50.7 (1.1) Mg ha-1 for UF and 76.2 (10.2) Mg ha-1 for RIL for duplicate sites compared with 282Mg ha-1 for live aboveground biomass. Small- and medium-sized material (<10 cm dia.) accounted for 8–18% of the total fallen CWD mass. The large amount of fallen CWD at these UF sites relative to standing aboveground biomass suggests either that the forests have recently been subjected to a pulse of high mortality or that they normally suffer a high mortality rate in the range of 0.03 per year. Accounting for background CWD in UF, CL management produced 2.7 times as much CWD as RIL management. Excess CWD at logging sites would generate a substantial CO2 emission given the high rates of decay in moist tropical forests.

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    Keller, Michael; Palace, Michael; Asner, Gregory P.; Pereira, Rodrigo Jr.; Silva, Jose Natalino M. 2004. Coarse woody debris in undisturbed and logged forests in the eastern Brazilian Amazon. Global Change Biology 10, :784–795,


    Amazon, coarse woody debris, reduced impact logging, selective logging, tropical forest, wood density

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