鸟类和蚂蚁对桃金娘种子传播的初步研究

Seed dispersal of the pioneer shrub Rhodomyrtus tomentosa by frugivorous birds and ants

在中国科学院鹤山丘陵综合开放试验站观察研究了鸟类和蚂蚁对桃金娘 (Rhodomyrtustomentosa)种子的传播。据野外观察和网捕法所捕鸟的情况可知 :红耳鹎 (Pycnonotusjocosus)和白头鹎 (P .sinensis)两种鸟传播桃金娘种子 ,白头鹎比红耳鹎的数量多。在网捕到的红耳鹎和白头鹎的粪便中收集到的桃金娘种子分别为 8.0± 3.0粒/只和 10 .0± 2 .0粒 /只。在显微镜下观察经过鸟消化道的桃金娘种子都没有破损。传播桃金娘种子的蚂蚁有全异巨首蚁 (Pheidologetiondiversus)和梅花山大头蚁 (Pheidolemeihuashanensis)。它们传播的最远距离分别为 4m和 5m ,平均为 1.1± 0 .0 9m和 1.3± 0 .0 7m。全异巨首蚁占样地蚂蚁个体总数的 6 0 .0 % ;梅花山大头蚁占个体总数的8.1% ;余下的为其他种蚂蚁。每个全异巨首蚁蚁巢平均贮藏桃金娘种子 195 .0± 82 .9粒 ,其中 73.2 %是完好种子。每个梅花山大头蚁蚁巢平均贮藏 2 8.8± 11.4粒种子 ,全部是完好种子。林窗、闲置的空旷地、植物群落交错带都有桃金娘实生苗。

Field work was done in Heshan city, Guangdong Province on seed dispersal of Rhodomyrtus tomentosa by frugivorous birds and ants. R. tomentosa is a very common pioneer species in the South China, and its pulp is rich in glucide and fat. Pycnonotus jocosus and P. sinensis were the birds that ate R. tomentosa fruits and dispersed the seeds in the study area, and the later was more than the former in number during the observation period. The seed number of this shrub in the feces of P. jocosus and P. sinensis caught in mist nets were 8.0±3.0 and 10.0 ±2.0, respectively. Two species of ants, Pheidologetion diversus and Paratrechina flavipes, were observed eating R. tomentosa pulp. Pheidologetion diversus and another ant species Pheidole meihuashanensis were observed carrying the seeds. The longest distances of movement by Pheidologetion diversus and Pheidole meihuashanensis were 4 m and 5 m, respectively, and the mean distances of dispersal by these agents were 1.1±0.09 m and 1.3±0.07 m, respectively. 657 ants were collected in the study area by pitfall trapping, comprising 394 Pheidologetion diversus (60.0%), 144 Paratrechina flavipes (21.9%), 53 Pheidole meihuashanensis (8.1%) and other species. The average number of stored seeds in a Pheidologetion diversus nest was 195.0±82.9, among which 73.2% were intact. And the average number of stored seeds in a Pheidole meihuashanensis nest was 28.8±11.4, all of which were intact. The seedlings of R. tomentosa could be found at canopy gaps, on bare land and at the forest edge. There were also many seedlings near ant's nests wherever sunlight was high.