Tropical Grasslands (2000) Volume 34, 125128
Germination and viability of mesquite (Prosopis pallida) seed following ingestion and excretion by feral pigs (Sus scrofa)
B.C. LYNES1 and S.D. CAMPBELL2
1Natural and Rural Systems Management, University of Queensland, Gatton College
A study in northern Queensland aimed to determine if feral pigs disperse viable seeds of the invasive woody weed, Prosopis pallida. Thirty-eight dung samples were collected, 19 from within a dense P. pallida infestation and 19 from an adjacent area that had been mechanically cleared of P. pallida. All seeds were removed from the dung and undamaged seed tested for germination and viability. Mean (± s.e.) dry weight of collected dung samples averaged 51.1 (± 2.9)g, with no difference between infested and cleared sites. Visual estimation of the contents of these samples showed that P. pallida seed pods were the major component of the dung, averaging 69 (± 4)% from samples collected within dense infestation and 57 (± 4)% for those from the adjacent area. Fifty-eight % and 42% of the pig dung samples collected from within and adjacent to the infestation, respectively, contained viable seed. No significant difference (P > 0.05) was found between the number of viable seeds present in dung samples from the two areas; an average of 2.4 seeds per sample was recorded with a range of 0–19. The germinability of this seed was high, with 70% of all viable seed germinating within 21 days and the remainder germinating immediately after scarification.