Pre-harvest Tree and Vine Biomass in a Rainforest in NW Mato Grosso, Brazil
Ted
R.
Feldpausch, Cornell University, Ithaca, NY USA, trf2@cornell.edu
(Presenting)
Stefan
Jirka, Cornell University, Ithaca, NY USA, sj42@cornell.edu
Susan
J.
Riha, Cornell University, Ithaca, NY USA, sjr4@cornell.edu
Carlos
Alberto Moraes
Passos, Universidade Federal de Mato Grosso, Cuiabá, Brazil, capassos@terra.com.br
Johannes
Lehmann, Cornell University, Ithaca, NY USA, cl273@cornell.edu
Franklin
Jasper, Rohden Indústia Lígnea Ltda, Juruena, Brazil, stuhler@terra.com.br
Erick
C.M.
Fernandes, The World Bank, ESSD-ARD, Washington, DC USA, efernandes@worldbank.org
Andrew
J.
McDonald, Cornell University, ajm9@cornell.edu
Selective logging has become a dominant land-use in Brazilian Amazônia. Published data on forest biomass in southern Amazônia is sparse. As part of a larger study to evaluate the effect of reduced impact logging on C dynamics and nutrient stocks, forest structure, and forest regeneration potential, we conducted a pre-harvest campaign to estimate tree and vine biomass in a parcel of managed forest in northwestern Mato Grosso. The diameter at breast height (DBH) of all commercially harvestable trees ≥30 cm DBH (40+ native species) was measured in 50x50 m cells in a 1000 ha management unit. We calculated biomass, stem density, and basal area for each cell, and then used kriging interpolation to generate three dimensional wire-frame maps for the area. Potential commercial biomass, 50.2±24.5 Mg ha-1, was highly variable across the 1000 ha area. To more intensively compare pre- and post-logging biomass and forest structure, we used these maps to locate stratified sampling transects (10x1000 m) within the management units and measured all stems ≥10 cm DBH. Total tree biomass (≥10cm DBH) was 301.5±50.2 Mg ha-1, with commercial biomass (≥30 cm DBH) on average 17% of the total. Tree stems with 10-30 cm DBH, often not measured in biomass estimates, represented 84% of all tree stems and 32% of the total biomass. In nested transects (2x1000 m) we measured DBH of all vines and estimated biomass (13.3±6.5 Mg ha-1) as 4.4% of the total measured biomass. Two non-commercial tree species Amescla (Trattinickia burserifolia (Mart.) Willd.) and Breu (Protium heptaphyllum (Aubl.) March.), represented 17% of the total biomass and 37% of the stems. Using geostatistical analysis, we plan to estimate tree and vine biomass as a function of DBH size classes, soil, and landscape position over a larger area of the forest.