Material Ecocriticism and Sylvan Agency in Speculative Fiction: The Forests of the World links the examination of fictional forests and arboreal characters of speculative fiction with the literary approach of material ecocriticism and a conceptualization of a sylvan agency. Aiming to establish and situate the investigation of sylvan agency firmly within the context of material ecocriticism, this book offers a framework for reading fictional forests with an ecocritical, and particularly eco-sylvan, lens and applies it to the analysis of the sylvan realm, arboreal characters and the relationship between human characters and their fictional forests in speculative fiction. Drawing on the re-negotiation of matter and material agency, the comprehensive study of the sylvan realm establishes a sylvan and arboreal agency in speculative fiction, ranging from classics, such as J. R. R. Tolkien's fantasy The Lord of the Rings (1954-55) or Ursula Le Guin's science-fiction novella The Word for World is Forest (1961), to contemporary texts, such as James Cameron's Avatar (2010) or Ali Shaw's The Trees (2016). The author argues for a re-negotiation of a sylvan agency and facilitation of an eco-sylvan awareness in times of environmental crisis.