Survival and germination of three hard-seeded Acacia species after simulated cattle ingestion: The importance of the seed coat structure

Acacia pendula (Weeping Myall) in the Hunter Valley of New South Wales: early explorers’ journals, database records and habitat assessments raise doubts over naturally occurring populations.

“…This process, endozoochory, allows for the acidic conditions and enzymes present in the rumen and large intestine of mammals to scarify the seed surface, such that seed germination is possible after the deposition of faeces in favourable environments (Haameyer et al 2010). In their study on Argentinean Acacia species, Venier et al (2012) concluded that the structure of the seed coat in hard seeded species is crucial to the success of endozoochory, supporting the results of earlier studies on other legumes (e.g. Gardener et al 1993;Danthu et al 1996;Shayo & Uden 1998).…”

Western lowland gorilla seed dispersal: Are seeds adapted to long gut retention times?

“…Rather, this variation is likely due to inter-specific differences in the rate at which seed coat scarification by gastrointestinal fluids translates into an increased permeability, thus enhancing germinability, or the removal of much of the protective endocarp damaging the embryo (Traveset, 1998). It would be expected for seeds with thin and soft coats to experience higher scarification, altering germinability (positively or negatively) more strongly than hard and thick coated seeds (Tewksbury et al, 2008;Traveset and Verdú, 2002;Venier et al, 2012). However, we did not observe this pattern here as the species with the thinnest and softest seed coat (T. acuminata) of the four related species exhibited no change in germinability after gut passage, whereas the germinability of two out of the other three, which all have relatively thick seed coats, was negatively (P. longifolia) and positively (P. microcarpa) affected.…”

Inter- and intra-population variability in physical dormancy along a precipitation gradient

“…Seeds of this species present PY due to a very thick and compact seed coat with a sclerified parenchyma (Funes & Venier 2006;Venier et al 2012a). It is not clear how this species breaks PY in nature, however previous studies suggested that passing through the digestive tract of cattle might break seed dormancy in this species (Venier et al 2012b) while fire and other native dispersal agents such as foxes might not be involved in this process (Ferreras et al 2015). In this region, V. aroma is present in different plant communities along a precipitation gradient ranging from 306 to 710 mm.…”