Overview

1. Comparative measurements of water, energy and carbon fluxes from a forest fragment and pristine forest in Central Amazonia Maria T. F. Monteiro, Javier Tomasella, Ralph Trancoso, Flávio de C. Magina, Rita de C. S. von Randow, Marcos A. Bolson, Alessandro C. de Araújo, Celso von Randow

2. Overview • Motivation • A newly erected flux tower • Preliminary results • Comparison with pristine forest

3. Motivation • Does regional evaporation decrease in fragmented landscapes? • Secondary vegetation in Eastern Amazonia was shown to transpire similar amounts of water into the atmosphere as a primary forest • Model results show that secondary vegetation maintains a water turnover comparable with that of a primary forest, with some evidence of a slightly higher throughfall and possibly also drainage Hölscher et al (1998), Sommer et al (2002, 2003)

4. Motivation (cont.) • The magnitude and spatial pattern of transpiration in small forest patches is SE Asia is strongly influenced by the conditions in surrounding clearings • Transpiration enhancement can occur not only at forest edges, but also well within the patch for trees whose canopies are exposed to advection • Hence, fragmentation of remaining forested areas would partly offset the reduction in regional evaporation due to deforestation (Giambelluca et al, 2003).

5. Motivation (cont.) Source: Gill Instruments, UK

6. Motivation (cont.) • These findings support the statement of Veen et al. (1991) that ‘regional evaporation may be higher in a landscape with many patches of forest (many edges) as compared with a landscape with the same total forest concentrated in large blocks’. • Hence, fragmentation of remaining forest partly reverses the reduction in regional evaporation due to deforestation. The magnitude of this effect is likely to vary according to the regional climate and the degree of dissimilarity among land-cover elements (Giambelluca et al. 2002).

7. Marcelo P. Moreira (2003) A newly erected flux tower • About 80 km N-NE off Manaus, at ZF-3 site • 34 m height (15 m above the average canopy height)

8. A newly erected tower (cont.) • Fluxes of momentum, sensible and latent heat, and CO2 measured continuously since June 2008 • As well as meteorological variables above and beneath the surface • Telematics “on board” so that monitoring and dowloading of data may be performed remotely from anywhere

9. Preliminary results • Wind blows from E-SE during most of the time • Predominantly blowing over secondary vegetation on the plateau

10. Preliminary results (cont.) • Physical drivers (radiation, rainfall)

11. Preliminary results (cont.) • Rn and albedo

12. Preliminary results (cont.) • Rainfall

13. Preliminary results (cont.) • Energy balance closure test is poor and similar to other forest sites in Amazon

14. Preliminary results (cont.) • Friction velocity (u*) follows the same pattern as over other forest sites in Amazonia

15. Preliminary results (cont.) • H, LE and CO2 fluxes

16. Comparisons (still preliminary) • Evaporation rate was about 3.85 mm day-1 • Evaporative fraction was about 0.74

17. Are LUCC spatially “homogeneous pasture-forest mosaics” as assumed by models? Ji-Paraná LUCC patterns 1984-1995 Large properties Fishbone – Small properties Linhares, 2006 Secondary forest area and age estimates in the Legal Amazon 2002. Results of the Prodes project (INPE 2004). A Fractions of remaining primary forest p(PF). B Predicted fractions of deforested areas occupied by secondary forest p(SF). C Predicted secondary-forest mean aget(years). White areas represent missing data (Neef et al. 2006).