蚂蚁觅食与搬运行为对阜平黄堇和小花黄堇种子散布的影响

Abstract

蚂蚁是无脊椎动物中重要的种子传播者，蚂蚁散布影响植物种子的传播和扩散，进而会影响种苗的空间分布格局。在野外研究了蚂蚁觅食及搬运行为对阜平黄堇（<em>Corydalis wilfordii</em> Regel）和小花黄堇（<em>C. racemosa</em> （Thunb.） Pers.）种子散布的影响。结果显示，双针棱胸蚁和束胸平结蚁是两种植物种子的共同搬运者，前者行使群体募集，后者行使简单协作募集。在搬运阜平黄堇种子时，双针棱胸蚁在原地或搬运途中取食油质体后抛弃的种子约占种子总数的56%，而拖至蚁巢的种子约占种子总数的44%，平均搬运距离为（1.85±0.24）m，搬运效率为（43.8±7.5）粒/h；而束胸平结蚁将完整种子全部直接搬运至蚁巢，平均搬运距离为0.45 m，搬运效率为（7.3±2.2）粒/h。在搬运小花黄堇种子时，双针棱胸蚁和束胸平结蚁均将完整种子全部直接搬运至蚁巢，平均搬运距离分别为（6.27±4.40）m和（6.65±1.64）m，搬运效率分别为（34.2±6.5）粒/h和（10.6±3.2）粒/h。这说明行使群体募集的蚂蚁比行使简单协作募集的蚂蚁有较高的搬运效率，蚂蚁散布导致阜平黄堇和小花黄堇种子到达蚁巢的数量和搬运距离不同，而这种不同与相应搬运蚂蚁的觅食对策、搬运行为和种子特征有关。阜平黄堇种子比小花黄堇种子大，但阜平黄堇的油质体质量比小于小花黄堇的油质体质量比，讨论了种子特征对蚂蚁散布的影响。;Ant-mediated seed dispersal is ecologically important and geographically widespread. Previous studies revealed that seed-carrying ant may impact the rate of seed removal and dispersal distance, and the resultant short-term fate of seed, i.e. the seed location where the ants release after ant manipulation. The impact of ant recruitment and behaviour on seed dispersal of the cogeneric plant taxa, however, is relatively little known. We investigated the ant-mediated effect on seed dispersal of two cogeneric plants, <em>Corydalis wilfordii</em> and <em>C. racemosa</em> (Papaveraceae), in a subtropical evergreen forest at the Jiugongshan mountain (Hubei Province, China). The seed size of <em>C. wilfordii</em> is larger than that of <em>C. racemosa</em>, while the elaiosome/seed mass ratio of <em>C. wilfordii</em> is greater than that of <em>C. racemosa</em> . Being the mutual ant dispersers of the two <em>Corydalis</em> taxa, <em>Pristomyrmex pungens</em> (with mass recruitment mode, i.e. to recruit a large number of ants to remove seeds when one ant found seed) and <em>Prenolepis sphingthorax</em> (with simple cooperative recruitmen mode, i.e. to recruit 5-30 ants to remove seeds when one ant found seed) played a varied role in seed dispersal of two plants. <em>Pristomyrmex pungens</em> carried about 44% of the <em>C. wilfordii</em> seeds transported by it to the nests, with the average dispersal distance of 1.85 m and the removal number of seeds per hour of 43.8, while the rest seeds were removed elaiosomes <em>in situ</em> and/or on the way to the nest. <em>Prenolepis sphingthorax</em> carried all seeds of the <em>C. wilfordii</em> to nests, with the average dispersal distance of 0.45 m and the removal number of seeds per hour of 7.3. In addition, both <em>Pristomyrmex pungens</em> and <em>Prenolepis sphingthorax</em> carried the all seeds of <em>C. racemosa</em> to the nests, with the average dispersal distance of 6.27 m and 6.65 m, and removal number of seeds per hour of 34.2 and 10.6 respectively. The results suggested that seed removal rate of ant with mass recruitment was higher than that of ant with simple cooperative recruitment. The seed dispersal distance and short-term seed fate differed between the two studied plants, depending on ant foraging strategies and behavior and seed characteristics. The discussion of the role of seed characteristics was also presented in the paper.