02540nas a2200253   4500008004100000245006800041210006800109300001200177520185000189653001302039653001502052653001602067653001402083653001802097653001602115653001102131653003002142653001702172653000902189653002502198100001602223700001302239856003402252       2002                        eng d00aEffects of forest fragmentation on the activity of dung beetles0 aEffects of forest fragmentation on the activity of dung beetles  a165-1793 aThe effect of seed burial by dung beetles on seed survival and seedling establishment in Tetragastris altissima (Burseraceae) was measured on 3 sites of continuous forest and 7 islands in the man-inundated rain forest of Saint-Eugene, French Guiana. Experiments using a total of 250 seeds were performed using wire enclosures open to dung beetles but excluding terrestrial seed predators. Fragmentation had no effect on the rate of dung disappearance at 12, 24 and 48 h because there was a high variability between sites. On average, 24 % of seeds were buried by dung beetles after 72 h, Overall, there was no effect of fragmentation due to variation between sites. Dung burial rates were positively correlated with rarefaction of the dung beetle samples collected on the different sites. They were also positively correlated with weighted abundances of large diurnal tunnellers after 12 h and to total tunnellers after 24 h. Seed burial was positively correlated to weighted abundance of large nocturnal tunnellers and of total tunnellers. The species diversity and abundance were positively related to area that did not involve a correlation between seed burial rates and area. After 72 h, survival rate of protected seeds at ground surface was significantly larger (78 %) than for non protected seeds (22 %), which were attacked by rodents. There was no difference between continuous forest and islands. Eight percent of buried seeds emerged, i.e. 2 % of all seeds deposited. Burial depth significantly affected the rate of emergence of buried seeds. Ninety percent of seeds at surface germinated versus 0 % at 10 and 15 cm. The effects of seed burial by dung beetles on early recruitment of T altissima was low and highly variable between sites in relation with the structure of the community of Scarabaeidae and intensity of seed predation.10aAmazonia10aCOLEOPTERA10acommunities10adispersal10afrench-guiana10alos-tuxtlas10aMexico10amonkeys alouatta-palliata10aScarabaeidae10aseed10atropical rain-forest1 aHingrat, Y.1 aFeer, F.  u<Go to ISI>://00017928480001102494nas a2200313   4500008004100000245011800041210006900159300001200228490000700240520159500247653001001842653001201852653003101864653001501895653001501910653001201925653001901937653002101956653000901977653002501986653004102011100001302052700001602065700001502081700001902096700001502115700001602130856003402146       2001                        eng d00aRecruitment, a multi-stage process with unpredictable result: the case of a Sapotaceasae in French Guianan forest0 aRecruitment a multistage process with unpredictable result the c  a119-1450 v563 aThe net result of the multi-stage recruitment from seed production to seedling establishment was assessed along 3 consecutive years in Chrysophyllum lucentifolium (Sapotaceae) in a mature rain forest of French Guiana. According to year, between 37 and 42 % of seed production was primarily dispersed away from fruiting trees without damage, especially by primates. Seeds dispersed in howler monkeys' (Alouatta seniculus) defecation were serendipitously buried by dung beetles (14%), eaten by terrestrial vertebrates such as rodents, or destroyed by insects or pathogens. The proportion of seeds secondarily dispersed by scatterhoarding rodents Varied from 3 to 17 % according to year. The survival rate of unremoved and uneaten seeds after 20 days, varied from 2 to 56 % according to year and pattern of spatial distribution generated by primary dispersal (clump or scattered). The empirical model based on the seed and seedling fate diagram showed that, according to years, from 6 to 15 % of produced seeds lead to seedling establishment away from parent tree. Variations in patterns of seed removal and predation by rodents were the most crucial factors governing the effectiveness of primary and secondary dispersers and the spatial distribution of seedlings. Between-year variations of recruitment were important and stochastic because the fluctuations of seed production and seed dispersal/predation varied independently. The proposed empirical model has thus no predictive value. However it can be useful for instance to test the effects of seed size and of some faunal perturbations.10afruit10amonkeys10amonkeys alouatta-seniculus10apopulation10ared howler10arodents10aseed-dispersal10aspatial patterns10atree10atropical rain-forest10avouacapoua-americana caesalpiniaceae1 aFeer, F.1 aJulliot, C.1 aSimmen, B.1 aForget, P., M.1 aBayart, F.1 aChauvet, S.  u<Go to ISI>://000169450800002