Landscape-scale variation in structure and biomass of Amazonian seasonally flooded and unflooded forests

摘要: Abstract Accurate estimates of current forest carbon stocks are required for efforts to reduce emissions from tropical deforestation and degradation. The relative contributions different vegetation types potential poorly understood in highly heterogeneous mosaics, further field-based measurements necessary severely undersampled regions improve regional scale extrapolations based on remote sensing. We assessed the aboveground biomass (AGB) two contiguous western Brazilian Amazonian protected areas totalling 886,176 ha, which contain vast expanses seasonally flooded varzea (VZ) along floodplain Jurua river adjacent terra firme (TF) farther inland. Estimates were equations incorporating wood specific gravity (WSG) tree height addition DBH, derived a network 200 plots 0.1 ha (=20 ha) sampled across unflooded forest. A large number small stratified by type allowed more representative sample, encompassing considerable variation structure composition both within between types. Mean basal area per plot was higher than (VZ: 37.6 ± 1.2 m2 ha−1; TF: 32.4 ± 0.9 m2 ha−1) but AGB lower 281.9 ± 12.0 Mg ha−1; 358.4 ± 14.4 Mg ha−1) due WSG height. Linear mixed effects models showed overriding effect AGB, roles water stress historical signature selective logging pressure, particularly forests. ALOS ScanSAR generated categories flood duration provided relevant description SRTM elevation data; subjected longer duration. Varzea forests store significant levels despite their lighter-wooded trees canopy stature, yet heavily settled rural Amazonians, increasingly vulnerable logging. This study helps understand how baseline environmental gradients human disturbances these unique affect storage value, highlights importance outside existing areas.