The Effects of Different Linear Habitats on Small Mammal Abundance and Diversity within Lowland Agricultural Landscape

摘要

Farmland biodiversity has declined due to changes in agriculture. Such changes have also seen the increase in field sizes which reduces the amount of linear boundary features which are important for habitat for many small mammal species. Certain characteristics of linear boundaries may influence small mammal species abundance and diversity due to the provisions of food, shelter and their role in species dispersal. The aim of this study was to compare two different linear features comprising of different features and to observe which of these certain features affects different small mammal species. The two linear features compared were an established hedgerow, some 170 metres in length with a width of two metres and a compiled woody fence feature which was only 30 metre in length with a width of 0.5 metre. Data was collected over a month by the use of Longworth traps that were placed five metres apart along the trapping line, all small mammals caught were recorded based on species, sex and weight. All the data collected was analysed in Microsoft Excel and Past statistics software. The overall unique species homogeneity was calculated by the use of Chi-squared, as well as both the Simpson and Shannon diversity indexes being calculated too. Species sex and weight were analysed by the use of the Mann-Whitney U test. Overall, three small mammal species (Wood Mouse, Bank Vole and Yellow- Necked Mouse) were caught during this study. All three of these species were caught in the wood fence feature however just wood mouse was caught in the hedgerow. Unique individual capture was found to be little over three times higher in the wood fence feature than the hedgerow and the overall abundance and diversity found at the wood fence feature habitat was found to be statistically significant (P=0.0264) compared to the established hedgerow while species weight comparisons were statistically insignificant (P=0.4). Results from a trapping density showed the correlation between a particular characteristic of the linear features and the ecology of certain small mammal species. During the study the hedgerow gradually lost vegetation due to plant phenology this factor didn’t affect wood mice but may be the explanation why Bank Voles and Yellow Necked Mice were absent since they are known to be negatively influenced by increased numbers of gaps present. Increased trapping density was caught on points with higher levels of low-lying dense vegetation and provisions of food. In Conclusion, the wood fence feature had greater abundance and diversity of small mammals and had characteristics which are beneficial and can be utilized in the conservation of these species.