Endozoochory by native and exotic herbivores in dry areas: consequences for germination and survival of Prosopis seeds

CAMPOS CLAUDIA; PECO BEGOÑA; CAMPOS VALERIA; MALO JUAN; GIANNONI STELLA; SUAREZ FRANCISCO

SEED SCIENCE RESEARCH

Cambridge University Press

Lugar: New York; Año: 2008 vol. 18 p. 91 - 100

0960-2585

Mammalian herbivores can play a role in theendozoochorous dispersal of Prosopis seeds in thearid zones of Argentina, and the introduction of exoticmammals can change relevant parameters of the plant’s reproductive ecology. Our specific goals were to quantify the seeds of Prosopis flexuosa, P. chilensis and P. torquata contained in the faeces of native mara (Dolichotis patagonum), guanaco (Lama guanicoe) and exotic donkey (Equus asinus) and hare (Lepus europaeus) mammals, and to determine the mortality, germination percentage and germination speed of seeds borne in faeces, compared to those collected from trees. In 2006, seeds were collected directly from trees or removed from mammal faeces. Seeds were counted and classified as apparently healthy or damaged. P. torquata and P. flexuosa seeds were found in the dung of guanaco, hare and mara, whereas only P. flexuosa seeds appeared in donkey faeces. P. chilensis seeds were only found in guanaco faeces. There was a notable relative abundance of seeds contained in small herbivore faeces in comparison to the large herbivores. The passage through the digestive tract of animals modified seed germination capacity and speed, with great variability between animal species. Guanacos had greater effects than donkeys on mortality, germination percentage and germination speed. Differences between the effects of both smaller-sized herbivores on seeds were much smaller.