Las áreas boscosas de várzea en la Amazonia Central son periódicamente inundadas por ríos de aguas blancas ricos en sedimentos, que por lo tanto tienen suelos ricos y alta producción primaria. Han sido descritas 250 especies de árboles como típicas, muchas de ellas tienen baja densidad forestal. A pesar que la producción total de madera no es tan alta como en el bosque templado, los bosques de várzea han sido explotados desde finales del siglo pasado. La fácil accesibilidad y el alto número de individuos de una especie por área es ventajosa. Los recursos naturales como la producción de petróleo, jabón, resinas, fibras textiles, taninos, colorantes y medicinas, perfumes, látex y frutas son de importancia local y comercial. La madera de construcción tiene mucha importancia desde principios de siglo, cuando fue usada para la producción de energía en las embarcaio...

Amazonian várzea forests are characterized by a high diversity of species and adaptations against extended flooding. Waterlogging and submergence can last up to 210 days per year, with a water column of up to 6-7 m. The present paper gives an insight into the current knowledge of morpho-anatomical, phenological and physiological responses to flooding in várzea trees, into patterns of regeneration and seedling recruitment, and into differences found along the flooding gradient, and between populations of selected species. This knowledge may serve as a basic tool for forest management. The high selective logging already caused a substitution of timber species, with high damages in the remaining stands, calling for rigorous management plans. Since the regular inundation induces the formation of annual rings, and tree growth responds to the prolonged vegetation period with signifi...

Senna reticulata (Willd.) H. S. Irwin & Barneby (Fabaceae) is a pioneer tree which colonizes open areas in Amazonian floodplains. It is very abundant throughout Amazonia along the nutrientrich whitewater rivers, and can be considered to be one of the most efficient colonizers of open areas. It possesses a very high tolerance towards flooding of the roots and stem, and performs extremely high photosynthetic assimilation and fast growth despite prolonged waterlogging. Efficient seed dispersal and the ability of resprouting after a period of unfavourable conditions add to its effectiveness. These features led the local people to consider Senna reticulata a noxious woody weed called ‘matapasto’ (“pasture killer”) although in the successional sequence it represents a short-lived woody stage which enhances the establishment of highly diverse forests.

Despite precautions, the spontaneous invasion of undesired arthropod pests in greenhouses seems to be unavoidable. Secondary plants can be employed in biological control to enhance the proliferation of desired natural enemies of arthropod pests. However, these additional plants may also attract pests which in turn attack the crop plants. The present study is part of a long-term experiment to test eight species of banker plants (BPs) and their efficiency for biological protection against the spider mite Tetranychus urticae, employing the predatory mite Amblyseius californicus as natural enemy. Our goal was to find the best suited local plant species to be used as BPs, which enhances the reproduction and continuous release of the predators in a greenhouse. In the present paper, we document the spontaneous invasion of arthropods on eight species of BPs in a time span of three months, in a g...