Abstract booklet - gtö – Society for Tropical Ecology

208 SCIENTIFIC POSTER SESSION | FOYERSCIENTIFIC POSTER SESSION | FOYER209Topic: East African mountain forests: functional ecology and sustainablemanagementTopic: The Andean biodiversity hotspot and its future: biodiversity, ecosystemfunctioning and ecosystem services under environmental changeDO TROPICAL EVERGREEN CONIFER TREES GROW CONTINUOUSLY?- INTERCONTINENTAL COMPARISON OF PODOCARPACEAE FAMILYJulia Krepkowski 1 , Franziska Volland 1 , Achim Bräuning 1 , AsterGebrekirstos 2CHARACTERISATION OF SOME NATIVE ARBUSCULARMYCORRHIZAL (AM) FUNGI FORMING SYMBIOSES WITH TREESNATIVE TO SOUTH ECUADORClaudia Krüger 1 , Arthur Schüßler 1WEDNESDAY | FOYER1University of Erlangen, Erlangen, DE, jkrep@geographie.uni-erlangen.de, 2 WorldAgroforestry Centre, Nairobi, KEThe evergreen conifer family Podocarpaceae occurs under varying tropicalclimate conditions. We compare the impact of climate seasonality on growthdynamics of indigenous Ethiopian Podocarpus falcatus and EcuadorianPrumnopytis montana, both occurring in tropical montaine forests. Microscopicthin sections of microcores of the outermost centimetre of the tree stem anddendrometer data were used to analyze cambial activity. Samples of P. falcatuscould be correlated to the bimodal, but highly variable rainfall pattern atthe Ethiopian study site. We found that P. falcatus shows a period of cambialdormancy during the dry season, however it is able to interrupt its dormancyduring sufficient rain events. Juvenile P. falcatus trees have a straight stem, butover the years parts of the cambium are inactivated inducing a lobate growthform leading to wedging and missing rings. For better understanding of treegrowth changes during the biography of P. falcatus, we tried to reconstruct thegrowth history of a fallen tree. Counting of visible tree-ring boundaries andprobably annually formed wood density variations on stem disks and incrementcores indicate tree ages of around 450 years, which is verified by radiocarbondating.In contrast to the seasonal climate in the Ethiopian study area, climate in theEcuadorian mountain forest is humid all around the year, however, occasionaldry periods may occur during September to November (‘veranillo del Niño’).These dry spells initiate growth interruptions in Prumnopytis montana indicatedby stem shrinkage. As shown by wood anatomy, the formation of density bandsis associated with dry weather conditions. We conclude that growth activity ofboth Podocarpaceae species in the two study regions is directly controlled bymoisture availability, and plant internal processes seem to play a minor role forgrowth dynamics.1LMU München, Planegg-Martinsried, DE, claudia.krueger@lrz.uni-muenchen.deIn former studies of the Ecuadorian mountain rainforest in the Reserva Biológicade San Francisco (research area of the DFG RU402 and RU816) it was shown,that uncharacterized arbuscular mycorrhizal fungi (AMF, Glomeromycota) fromthe considered ecosystem improve the growth performance of nursery grownnative tree seedlings (Urgiles et al. 2009, New Forest 38: 229-239). AMF fromthose nursery grown trees and also from afforestation plots were isolated andcharacterized. The goal was to later utilize them in the tree nursery as a defined’cocktail’ of AMF to inoculate seedlings of native, potential crop trees, suchas Cedrela montana, Heliocarpus americanus and Tabebuia chrysantha and toanalyse, which of the AMF species from the applied cocktail persist during a sixmonths nursery phase and after outplanting on reforestation plots, and whichAMF have an impact on the growth of certain tree species.Here, we characterise the used AMF morphologically and by a DNA barcodingapproach using the complete SSU and ITS rDNA regions and 800 bp of the LSUrDNA (in total 3.3 kb; Krüger et al. 2009, New Phytol. 183: 212-223; Stockinger etal. 2010, New Phytol. 187: 461-474). We established a number of defined AMFcultures, whereas most of them are single spore isolates. Eventually, we couldculture and characterise six different native AMF species, from phylogeneticallyvery distinct clades, including two or three new species. The detailed molecularphylogeny of the species is also shown.Wednesday WEDNESDAY 16:00 | FOYER | FoyergtöSociety for Tropical Ecology | Gesellschaft für Tropenökologie e.V. Status and future of tropical biodiversity | Frankfurt, 21 - 24 February 2011gtö