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|Horna de Zimmermann, V: Carbon Release from Woody Parts of Trees from a Seasonally Flooded Amazon Forest near Manaus, Brasil in Bayreuther Institut für Terrestrische Ökosystemforschung (BITÖK): Bayreuther Forum Ökologie, Selbstverlag, 94, 1-137 (2002)|
Large areas of tropical lowlands in the Amazon Basin are covered with seasonally flooded forests, locally termed as "Varzea". These forests have a high photosynthetic uptake capacity but seem to have also a large carbon release to the atmosphere since the observed wood productivity is low in spite of favorable climate and nutrient supply. This study looks into the seasonal dynamics and quantitative aspects of carbon release from those tropical forests.
Carbon dioxide release from woody tree surfaces was studied on sixteen indivuiduals of eight tree species in a Varzea forest near Manaus, Brazil. Five deciduous tree species (Albizia multiflora, Tabebuia barbata, Pseudobombax munguba, Crataeva benthamii, Vitex cymosa) and three evergreen tree species (Nectandra amazonum, Laetia corymbulosa, Pouteria glomerata) were compared. Consecutive daily courses of carbon release were measured during one annual cycle using stem and branch chambers and a differential infrared gas analyzer system.
All tree species showed maximum rates of CO2- release from the lower stem area during early flooding between February and April. The CO2 release from branches was tied to leaf phenology and increased to very high levels during new leaf development. Seasonal stand carbon release from above-ground woody parts was positively and linearly correlated with tree basal area. Annual stand carbon release from biomass was estimated to be five to six times higher than stand values reported for non-flooded neotropical forests.
The results of this study document for the first time, for a systematic and representative temporal and spatial sample size, that Varzea forest trees have exceptionally high carbon dioxide release rates during flooding.
- Article: BFÖ 94: Horna de Zimmermann, V: Carbon Release from Woody Parts of Trees from a Seasonally Flooded Amazon Forest near Manaus, Brasil