In this study, preservice science teachers' conceptions of trees, forests and deforestation were explored. Thirty-three preservice science teachers who were enrolled in a compulsory ecology course participated in the study. Two open question forms were used to collect data in class hours. A phenomenographic research methodology was used to analyse preservice science teachers' written responses. Outcome space represented the full range of conceptions held by the participants and the relations identified between these conceptions. Participant responses in one of the class activities, i.e. 'Name the Tree', were also used to conclude if the preservice science teachers recognise the trees that they pass daily. Implications for teacher education are considered accordingly.