Waldforschung: Offener Zugang

Waldforschung: Offener Zugang
Offener Zugang

ISSN: 2168-9776


The Effects of Flooding on Forest Floristics and Physical Structure in the Amazon: Results from Two Permanent Plots

Randall W Myster

I investigated how flooding affects floristics and physical structure of forests in the Amazon at the Area de Conservacion Regional Comunal de Tamshiyacu-Tahuayo, Loreto ProvinceIquitos, Peru and at the Yasuni Experimental Station, Yasuni National Park, Ecuador. Iset up and sampled 1 ha permanent plots next to a blackwater river (igapó forest) in Peru and next to a white-water river (várzea forest) in Ecuador. I found (1)16 families in the 1 haigapó plot with Fabaceae the most common family, (2) várzeastems conformed to a reverse J size pattern for stems less than 40 cm dbh but had more large stems, total stems were within other várzea forest ranges with a slightly larger average dbh, trees were clumped at a low level with 45% canopy closure and while the basal area was also within other várzeaforest ranges, above-ground biomass was lower, (3) igapóstems conformed to the reverse J size pattern, total stems were lower than other igapóforest ranges with a slightly larger average dbh, trees were clumped at a higher degree than the várzea forest with 12% canopy closure while the basal area and aboveground biomass was less than both other igapó samplings and the várzea study plot, and (4) flooding produced reduced basal area in igapó, and smaller stems, stem densities and above-ground biomass for both flooded forests. I conclude that both study plots show a reduction of tree stem density and structure (basal area, above-ground biomass) with flooding, which reduces even more as months under water increase. More sampling in these forests is needed, however, before a conclusion about which aspect of the flooding regime –e.g., water quality, flooding duration or frequency – is most important in determining different aspects of forest structure. Permanent plot studies in the Amazon, like this one, provide much needed data for intelligent management decisions and the development of sustainability techniques.