Interactions of the Cerrado Palms Butia paraguayensis and Syagrus petraea with Parasitic and Pollinating Insects

The two cerrado palms Butia paraguayensis and Syagrus petraea were studied with regard to parasitizing and pollinating insects that visit their reproductive organs. At the study site in Botucatu, São Paulo State, both species occurred together, while at the study site in Indianópolis, Minas Gerais state, only S. petraea was growing. Bees of the subfamily Meliponinae and Halictinae were the main pollinators of B. paraguayensis and several beetles and flies were additional pollinators. The visiting beetles divided up in more exclusive parasites, such as the weevils Tripusus leiospathae and Petalochilus lineolatus, and the Colydiidae Bitoma palmarum, which bored and oviposited the closed spathe and whose larvae fed on the flower buds, as well as species of the weevil Microstrates, which bred in staminate flowers. Differently, the curculionids Anchylorhynchus bicolor, Parisoschoenus sp., Dialomia sp., and species of Mystrops (Nitidulididae) behaved as parasites and pollinators. On the other hand, S. petraea shows more evident adaptations for pollination by beetles. This species has Trigona spinipes as prominent bee pollinator, but otherwise beetles dominated as visitors, being them either parasites, pollinators or both. Although several identical beetle genera occur on both palms, at the species level they are different, as for example Anchylorhynchus camposi on S. petraea. At the two distant study sites of S. petraea in Botucatu and Indianópolis, several species, especially of the parasitic insects, are identical, indicating that parasitism is a stronger bond than pollination in this species which is characterized by a generalist pollination mode

Brazilian montane rainforest expansion induced by Heinrich Stadial 1 event

The origin of modern disjunct plant distributions in the Brazilian Highlands with strong floristic affinities to distant montane rainforests of isolated mountaintops in the northeast and northern Amazonia and the Guyana Shield remains unknown. We tested the hypothesis that these unexplained biogeographical patterns reflect former ecosystem rearrangements sustained by widespread plant migrations possibly due to climatic patterns that are very dissimilar from present-day conditions. To address this issue, we mapped the presence of the montane arboreal taxa Araucaria, Podocarpus, Drimys, Hedyosmum, Ilex, Myrsine, Symplocos, and Weinmannia, and cool-adapted plants in the families Myrtaceae, Ericaceae, and Arecaceae (palms) in 29 palynological records during Heinrich Stadial 1 Event, encompassing a latitudinal range of 30°S to 0°S. In addition, Principal Component Analysis and Species Distribution Modelling were used to represent past and modern habitat suitability for Podocarpus and Araucaria. The data reveals two long-distance patterns of plant migration connecting south/southeast to northeastern Brazil and Amazonia with a third short route extending from one of them. Their paleofloristic compositions suggest a climatic scenario of abundant rainfall and relative lower continental surface temperatures, possibly intensified by the effects of polar air incursions forming cold fronts into the Brazilian Highlands. Although these taxa are sensitive to changes in temperature, the combined pollen and speleothems proxy data indicate that this montane rainforest expansion during Heinrich Stadial 1 Event was triggered mainly by a less seasonal rainfall regime from the subtropics to the equatorial region.This work was funded by FAPESP research grant 2015/50683-2 to P.E. De Oliveira, VULPES Project, Belmount Forum