Inland hypersaline lakes and the brine shrimp <i>Artemia</i> as simple models for biodiversity analysis at the population level

Biodiversity can be measured at different hierarchical levels, from genetic diversity within species to diversity of ecosystems, though policy-makers tend to use species richness. The 2010 goal of reducing biodiversity loss, agreed by the subscribers to the Convention on Biological Diversity, requires simple and reliable protocols to evaluate biodiversity at any level in a given ecosystem. Stakeholders, particularly policy makers, need to understand how ecosystem components interact to produce social and economic benefits on the long run, whilst scientists are expected to fulfil this demand by testing and modelling ideally simple (low diversity) ecosystems, and by monitoring key species. This work emphasizes the unique opportunity offered by inland, isolated salt lakes and the brine shrimp Artemia, an example of biodiversity contained at the intra-specific level, as simple models to understand and monitor biodiversity, as well as to assess its predicted positive association with ecosystem stability. In addition to having well identified species and strains and even clones, that allow to test reproductive effects (sexual versus asexual), Artemia benefits from the possibility to set up experimental testing at both laboratory scale and outdoor pond systems, for which a comprehensive cyst bank with sufficient amount of samples from all over the world is available

Biologia reprodutiva de Psychotria spectabilis Steyrm. e Palicourea cf. virens (Poepp & Endl.) Standl. (Rubiaceae) em uma floresta tropical úmida na região de Manaus, AM, Brasil Reproductive biology of Psychotria spectabilis Steyrm. and Palicourea cf. virens (Poepp. & Endl.) Standl. (Rubiaceae) in a moist tropical forest at Manaus, Amazonas State, Brazil

Este estudo descreve a fenologia reprodutiva, morfologia e biologia floral, polinização e sucesso reprodutivo de Psychotria spectabilis e Palicourea cf. virens. Psychotria spectabilis floresceu de setembro a dezembro enquanto Palicourea cf. virens floresceu de maio a outubro. As inflorescências de Psychotria spectabilis são inflorescências terminais do tipo capítulo, com brácteas amarelas, flores brancas e heterostilia associada a diferenças na papila estigmática. Palicourea cf. virens apresenta inflorescências terminais do tipo corimbo, com flores amarelas homostílicas. Os recursos florais oferecidos foram néctar e pólen em ambas as espécies. Os beija-flores Phaethornis bourcieri e o macho de Thalurania furcata foram os principais visitantes florais de Psychotria spectabilis. Palicourea cf. virens também foi visitada por Thalurania furcata, com maior freqüência de visitas pela fêmea desta espécie. A abelha Trigona fulviventris visitou as flores das duas espécies, mas se comportou como pilhadora. O sucesso reprodutivo pré-emergente (SRPE) das duas espécies foi baixo, embora tenham apresentado um alto potencial reprodutivo.<br>This study describes the reproductive phenology, floral biology, pollination and reproductive success of Psychotria spectabilis and Palicourea cf. virens. Psychotria spectabilis flowered from September to December while P. cf. virens flowered from May to October. The terminal inflorescence of Psychotria spectabilis is of the capitate type with yellow bracts, white flowers and heterostyly associated with differences of stigmatic papillae. The terminal inflorescence of Palicourea cf. virens is a corymb with yellow, homostylous flowers. Flower resources include nectar and pollen for both species. The hummingbirds Phaethornis bourcieri and the male of Thalurania furcata were the main floral visitors of Psychotria spectabilis. Palicourea cf. virens was also visited by T. furcata, but the female was the main visitor. Trigona fulviventris visited flowers of both species, but was considered a thief. Pre-emergent reproductive success (PERS) of these two species was low, although they showed high reproductive potential