Acta Botanica Hungarica 50(1–2), pp. 171–180, 2008 DOI: 10.1556/ABot.50.2008.1–2.13 CONTRIBUTION TO THE MOSS FLORA OF DERELI, GÝRESUN DISTRICT (TURKEY) T. ÖZDEMÝR 1 and B. KOZ 2 1 Department of Biology, Sciences and Art Faculty, Karadeniz Technical University, 61080 Trabzon, Turkey; E-mail: tozdemir@ktu.edu.tr 2 Department of Biology, Sciences and Arts Faculty, Giresun University 28049 Giresun, Turkey (Received 27 October, 2006; Accepted 30 June, 2007) Field studies were organised for exploring the moss flora of Dereli district of Giresun dur- ing spring–summer period in 2005. Ninety-one specimens were collected in these field studies. After identification of these specimens, five new records for A4 (40–42° N, 38–42° E) were determined according to Henderson’s grid system (1961a). Key words: A4 grid square, Dereli, Giresun, moss flora, Turkey INTRODUCTION Mosses are important components of forest ecosystems. They have im- portant contributions on biological diversity providing wet habitats for many type of living organisms. Bryophyta flora of Turkey has still unexplored parts, therefore recent years Özdemir (1994, 1999, 2000, 2001a, b), Özdemir and Baydar (1997), and Özdemir and Çetin (1999) focused on determination of moss flora of the Black Sea region of Turkey. This study performed for deter- mination of moss flora of Dereli district of Giresun. So far no special work has been performed on the moss flora in Dereli district. Some other works on dif- ferent parts of moss flora of Giresun has been published by Özdemir (1999), Özdemir and Baydar (1997), Özdemir (2001a, b). 0236–6495/$ 20.00 © 2008 Akadémiai Kiadó, Budapest