Secondary dispersal is an important stage in the life cycle of tree species, determining the fate of a high proportion of all seeds. For small-seeded species both physical and biological processes may influence the secondary fate of seeds, however the relative importance of these processes is not well known. Seeds of the pioneer tree species Cecropia insignis (seed mass 0.5 mg), Trema micrantha...

Intraspecific variation in pollen deposition and number of pollen tubes per style is rarely quantified, but is essential for assessing the occurrence of pollen limitation and pollen competition and their evolutionary implications. Moreover, pollen deposition, pollen tube growth, and the fate of fertilized ovules are rarely distinguished in field studies. Here we present such a study in eight na...

Seed mass in species-rich moist tropical forests often varies over six or more orders of magnitude (Foster, 1982; Foster and Janson, 1985; Hammond and Brown, 1995). Most of these species, including some with the minutest seeds (Metcalfe, 1996; Metcalfe and Grubb, 1997), can be classified as ‘shade-tolerant’ with the ability to establish beneath a closed canopy. Seeds of the shade-tolerators var...

Leaves from mature Griffonia simplicifolia plants were examined for the presence of leaf lectins possessing sugar binding specificities similar to the four known seed lectins (GS-I, GS-II, GS-III, GS-IV). Three (GS-I, -II, -IV) of the four known G. simplicifolia seed lectins were present in the leaves. Leaf G. simplicifolia lectins I and IV were similar to the respective seed lectins. Leaf GS-I...

The three primate species of Santa Rosa National Park, Costa Rica (Ateles geoffroyi, Alouatta palliata, Cebus capucinus) have diets in which fruits are major components. All three primate species defecated seeds of many fruiting species; the majority of which (60%) germinated under experimental conditions. The sampling of seed traps placed throughout he forest indicated that, on average, 392 la...

Seed dispersal is one of the vehicles of gene flow in plants. If a seed carrying transgene(s) is dispersed into the environment, the fate can be determined by its persistence in the soil bank, which can also vary in different ecotypes of a species and the physical environment of the soil including temperature and moisture. This study aimed at investigating ecotypic differences in wild sorghum f...

Post-dispersal seed predation and endozoochorous seed dispersal are two antagonistic processes in relation to plant recruitment, but rely on similar preconditions such as feeding behavior of seed consumers and seed traits. In agricultural landscapes, rodents are considered important seed predators, thereby potentially providing regulating ecosystem services in terms of biological weed control. ...

KOCAQALISKAN I., DEMIR Y. & KABAR, K. 1995. A study on polyphenol oxidase activity during seed germination. Phyton (Horn, Austria) 35 (1): 37-43. English with German summary. In this work, polphenol oxidase (PPO) activities, when used four different substrates (dopa,catechol,caffeic acid, tyrosine) oxidizing activities, during seed germination of six different plants were studied in the embryos...

Fragmentation influences the population dynamics and community composition of vertebrate animals. Fragmentation effects on rodent species in forests may, in turn, affect seed predation and dispersal of many plant species. Previous studies have usually addressed this question by monitoring a single species, and their results are contradictory. Very few studies have discussed the fragmentation ef...

BACKGROUND AND AIMS Myrmecochory is a conspicuous feature of several sclerophyll ecosystems around the world but it has received little attention in the semi-arid areas of South America. This study addresses the importance of seed dispersal by ants in a 2500-km(2) area of the Caatinga ecosystem (north-east Brazil) and investigates ant-derived benefits to the plant through myrmecochory. METHOD...