01793nas a2200169   4500008004100000245011500041210006900156260000800225300000800233490000700241520126000248653003301508100001601541700001301557700001901570856003401589       2004                        eng d00aSeed fate of two Sapotaceae species in a Guianan rain forest in the context of escape and satiation hypotheses0 aSeed fate of two Sapotaceae species in a Guianan rain forest in   cJan  a1-90 v203 aSeed removal by rodents was investigated for Manilkara huberi and Chrysophyllum lucentifolium in a French Guianan forest. According to the escape hypothesis, seed survival was expected to be greater in populations of low conspecific adult density, while on the contrary, under the satiation hypothesis, it was expected to be greater in populations of high density. The two plots under study showed opposite densities for the two studied tree species. Therefore, according to both hypotheses, seed survival at each plot was expected to be opposite between species. To assess seed fate, seeds were thread-marked in order to relocate them after removal and to determine whether they were consumed or scatterhoarded by rodents. Contrary to what was expected, our results showed that both M. huberi and C. lucentifolium had better survival in the same plot. This suggests that seed fate for both study species was not influenced by the density of conspecific adult trees, but was rather affected by other habitat characteristics, likely the global resource abundance. Variation in seed predation rates of both species seemed largely related to their respective fruiting period, while seatterhoarding rate seemed more affected by intrinsic seed characteristics.10adung beetles forest function1 aChauvet, S.1 aFeer, F.1 aForget, P., M.  u<Go to ISI>://00018895360000102891nas a2200337   4500008004100000245006000041210005700101260000800158300001200166490000700178520199700185653003002182653003102212653001202243653001802255653001502273653001802288653002502306653003102331653001202362653001902374653001902393653000902412653002502421653001402446653001602460653001102476100001302487700001902500856003402519       2002                        eng d00aSpatio-temporal, variations in post-dispersal seed fate0 aSpatiotemporal variations in postdispersal seed fate  cDec  a555-5660 v343 aThe post-dispersal fate of Chrysophyllum lucentifolium (a canopy tree; Sapotaceae) seeds was analyzed in French Guiana over three consecutive years. Experiments using 750 thread- marked seeds were performed to investigate seed removal, predation, and caching by terrestrial vertebrates on howler monkey (Alouatta seniculus) defecation sites, where clumps of intact C lucentifolium seeds were observed. Year-to-year variations in seed fare during the peak fruiting period were considered in relation to overall fruit and seed resource availability estimated by a raked-trail survey. The effect of two forest areas, which differed in soil and floristic composition, was examined with conspecific fruiting tree density as a covariant. Exclosure versus open treatment was used to discriminate small rodents (not larger than a spiny rat) from other vertebrates. The presence of fresh howler dung did not affect seed fate after 20 days as shown by comparisons between defecation sites and control during the first year. There was a significant effect of year on the percentage of seeds remaining after 20 days. Low seed removal in 1995 and 1996 (compared to 1997) corresponded to higher overall fruiting and higher fruiting of C lucentifolium, or the presence of alternative resources for rodents. All effect of forest area was observed on the seed removal rate, which varied with years and protection. Comparatively, an effect of forest area on the percentage of seeds lost was observed in 1996 and an effect of treatment on the percentage of seeds eaten was seen in 1995. The mode of seed caching Suggested that spiny rats were the main seed remover. Results of this study suggest that greater seedling recruitment may Occur when large fruit crop and high howler dispersal co-occur with a lower impact of rodents (i.e., when rodents are saturated by abundant and diversified fruit resources such as in 1995). Such event synchrony, however, is highly unpredictable after only three years of study.10aamericana caesalpiniaceae10aChysophyllum lucentifolium10adensity10aFrench Guiana10afrench-gui10ahowler monkey10ajanzen-connell model10amonkeys alouatta-seniculus10arodents10aseed dispersal10aseed predation10atree10atropical rain-forest10avariation10avouacapoua-10ayearly1 aFeer, F.1 aForget, P., M.  u<Go to ISI>://00018053980000802494nas 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