Epiphytic bryophyte communities in New Zealand temperate rainforests along selected altitudinal transects
Lindlar, Anja; Frahm, Jan-Peter
This paper presents the results of an analysis of the epiphytic bryophyte vegetation in New Zealand temperate rainforests. A total of 414 relevés according to the Braun-Blanquet method were sampled on tree trunks along 6 altitudinal transects which are located on a latitudinal gradient in both the South and North Islands. The relevés were analyzed using the divisive classification program Twinspan. As a result the epiphytic bryophyte vegetation could be classified into three phytosociological orders (Cyathophoro-Plagiochiletalia fasciculatae, Jamesoniello-Plagiochiletalia circinalis and Frullanietalia rostratae). These orders are differentiated by climatic parameters and the forest structure of the phorophyte stands. The Cyathophoro-Plagiochiletalia fasciculatae are typical of lowland to montane mixed evergreen rainforest and are formed by shade-epiphyte synusia. The Jamesoniello-Plagiochiletalia circinalis and the Frullanietalia rostratae characterize the epiphytic bryophyte vegetation of humid beech forests in montane to subalpine altitudes with lower average precipitation. Their communities are related to sun-epiphyte synusia. The alliances of these orders show an altitudinal and geographical zonation: the Cyathophoro-Plagiochiletalia fasciculatae include the Dendromastigophorion flagelliferae (lowland s.str.), Lopidio-Metzgerion decipientis (upper lowland), and the Paraschistochilo-Bazzanion adnexae (upper lowland-montane). The montane-subalpine Jamesoniello-Plagiochiletalia circinalis comprise the Mesoto-Frullanion falcilobae (South Island) and the Dicnemo-Macromitrion longipetis (North Island). The Frullanietalia rostratae include only one alliance. They are typical of subalpine beech forest. The trunk epiphytic bryophyte vegetation of the Cyathophoro-Plagiochiletalia fasciculatae shows floristic similarities to the Thysanantho-Bazzanietea tridentis of Southeast Asia and pantropical units like the Lejeunea flavae-Frullanea ericoidis and the Coeno-Plagiochiletea. By contrast the Frullanietalia rostratae resembles the holarctic Frullanio dilatatae-Leucodontetea sciuroidis. The Jamesoniello-Plagiochiletalia circinalis falls in between the two phytogeographical units, combining elements typical of epiphytic bryophyte communities of the tropics and elements of temperate-holarctic areas. Therefore the orders differentiated in this study cannot be assigned to a single class.