The effects of anthropogenic activities and environmental factors on naturalized flora in the Northern Taiwan

• Main Authors: Hao-Ting Sun, 孫豪廷
• Other Authors: Teng-Chiu Lin
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/kx8gnv

碩士 === 國立臺灣師範大學 === 生命科學研究所 === 97 === To approach the effects of anthropogenic activities and environmental factors on local native and naturalized plant communities, this study was conducted in the Northern Taiwan. A total of 2,242 quadrats in 1m2 of 100 plots in 1km2 were sampled according to designated habitat types. Selected anthropogenic and environmental factors were obtained, and biodiversity indices were applied on the field data for further analyses. According to the results, habitat types with higher anthropogenic activities (e.g. roadside, cemetery, crop field) were highly invaded. Plant invasions were facilitated by anthropogenic activities (including both diversity and intensity) as well as environmental factors. Significantly positive relationships were found between anthropogenic activities (e.g. landscape heterogeneity, exploitation intensity, and agriculture factor) and the biodiversity and dominance of naturalized species. On the other hand, exploitation intensity was negatively correlated to native biodiversity. Propagule pressure and disturbances created by anthropogenic activities may be the major mechanism facilitating biodiversity and dominance of naturalized species. II Environmental factors including elevation-temperature and precipitation factors were negatively correlated to naturalized biodiversity but positively correlated to native biodiversity. Native—exotic richness relationships were also examined under different plot characteristics at same spatial scale. Negative relationships (more native less exotic) were found at plots with lower anthropogenic activities, while positive relationships (more native more exotic) were found at plots with higher anthropogenic activities. The mechanisms related to the native—exotic relationship transformation may be biotic resistance in negative relationships and abiotic factors including landscape heterogeneity in positive relationships. This result demonstrated the new evidence of how anthropogenic activities affect plant invasions and also made the current discussions in native—exotic richness relationships more comprehensive. These results can provide valuable direction in the management of naturalized plants.