Samenvatting

The loss of biodiversity is a worldwide problem caused by over exploitation of natural resources, pollution, introduction of invasive species and other problems, human induced. The Netherlands is working on strengthening its natural environment boosting social and economic wellbeing. In Southwest Drenthe, a small population of European tree frogs has been released in the year 2000 near a village called Vledder. Unclear is how the population has dispersed to other pools and what their routes of migration are. This is important as they are a protected species. The area researched was selected within a 10km radius, around the release point just North of Vledder resulting in a research area of 314km2. In this research the aim is to find out what the distribution of the European tree frog is in Vledder and the surrounding area concerning pool vegetation quality, pool characteristics and land use qualities, as well as contributing to find out which landscape structure is preferred by the tree frog for migration, which is also referred to as connectivity.The main research question is “What is the suitability of the landscape and the predictability distribution of the tree frog in Southwest Drenthe and what connectivity opportunities are provided for this species in the near future in the research area?” The research question contributes to more knowledge about the European tree frog species located in Vledder and the surrounding areas in Southwest Drenthe. Sub-questions leading to an answer of the main research question concern occupancy of the tree frog in Southwest Drenthe, relationship between pool characteristics and presence of the tree frog, and the appropriateness of the landscape in terms of migration and connectivity.