| Summary: | 碩士 === 國立東華大學 === 自然資源管理研究所 === 92 === The fecal pellets of twelve rodent species from areas of different altitudes in Taiwan were collected and examined for the presence of spores of arbuscular mycorrhizal fungi (AMF). Numbers of AMF spores per 10 mg dried fecal materials were estimated. Spores were found in feces of all the rodent species examined. There were significant differences between species of lowland and mountain areas in the percentages of spore-positive fecal samples and the amount of spores in feces. Among lowland species, more than 70% fecal samples of Apodemus agrarius, Rattus losea and Bandicota indica were spore-positive and spores were most abundant in Mus musculus. The occurrence and abundance of spores were found to differ significantly in the fecal samples of M. caroli, A. agrarius and B. indica from different regions. Niviventer coxingi, the species from middle elevation area, the amount, but not the occurrence, of spores from southern and eastern Taiwan differed significantly. For species in high mountain areas, spores were most abundant in A. semotus, however, the occurrence and amount of spores did not differ among different vegetation types. In addition, significant differences among vegetation types were found in the amount of spores in Eothenomys melanogaster and in the occurrence of spores in N. culturatus.
Significant species and monthly variation were found in the amount of AMF spores in the feces of M. caroli and A. agrarius collected in Yuemei area of eastern Taiwan. Time series analysis showed significant correlations between monthly precipitation and the amount of fecal spores of the two species in Yuemei (eastern Taiwan) and of N. coxingi in Tengjhih (southern Taiwan) with time lags of 20 and 60 days, respectively.
The results indicated that, if the amount of spores in the environment were determined by precipitation, the twelve rodent species in Taiwan might be active consumers of AMF spores. However, the difference in diet and habitat among rodent species may affect their searching ability of AMF spores. For example, the importance of invertebrate prey in A. agrarius may affect its encounter rates of AMF spores in soil surface. Further studies to investigate the mechanisms for the relation between monthly amount of fecal spores and precipitation are needed.
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