Study of the relationships between arthropods and environmental factors at the centre islands from different spatial scales

• Main Authors: An-Cheng Lin, 林安正
• Other Authors: 尤少彬
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/68963075909561555898

碩士 === 國立中興大學 === 生命科學系所 === 94 === The centre islands which are isolated biotope in landscapes have distinctive habitat boundary and simple flora. The centre islands are ideal mesocosm for studying the relationships between arthropods and their environmental factors. This study investigated the arthropod community of the centre islands from large and small spatial scales. Large spatial scales deal with island biogeography and habitat fragmentation which study the variations of arthropods community within patches of landscapes. Small spatial scales deal with mid-domain effect and microhabitat which study the variations of arthropods community within microhabitats of patches. The purposes of this study are: (1) Compare the relationships between arthropod species and area of the centre islands and habitats in order to test the hypothesis that habitat areas have better explanation for species richness. (2) To investigate what is the impact of greenery area outside the centre islands on the species richness of the centre islands. (3) Investigate the relationships between the area of centre islands and the species richness of higher trophic, rarity and poor dispersal arthropods.(4) To test the mid-domain effect theory on arthropod diversity of the centre islands (5) To identify the relationships between arthropod community and the environmental factors of microhabitats. The arthropods were collected with 183 pitfall traps installed on 34 centre islands for 11 days in the spring of 2004 at the campus of National Chung-Hsing University at Taichung in Taiwan. A total of 66285 arthropods were captured, with a total of 633 morphospecies. There was a higher correlation coefficient between species richness and habitat area of centre islands than the correlation coefficient between the species richness and the geographic area of centre islands. Therefore, habitat areas had better explanation for the variation of species richness than the geographic area of centre islands. However, negative correlation was found between species richness and the greenery area outside centre islands. Species richness decreased with the increase of the greenery areas outside the centre islands. Positive species-area relationships have been found for the higher trophic and rare species. However, I did not find the pattern for poor dispersal species. The mid-domain effect was not valid for the most part of Arthropods. However, the theory may fit with the species with high dispersal capability. Sward coverage, shrub coverage, area of centre island and greenery area outside the centre islands are the key factors influenced the species richness of Arthropod communities. Besides the negative correlation between the species richness and the greenery area outside centre islands, the species richness has the positive correlation with other three factors. Regarding the impact of microhabitat factors on the arthropod community assembling, Sward coverage affected the abundance of carnivorous and herbivorous arthropods. Shrub coverage has a significant influence on the abundance of saprophage arthropods. The area of centre islands and greenery areas outside the centre islands had significant influence on the species richness of the ground-active carnivores and omnivores. The streetlamp illumination also had significantly effect on the arthropod assemblage. This study collected 626 morphospecies and yet many species still have not been collected. Therefore, the centre islands of campus deserve a sound management system for conserving the species diversity of the biotope.