Structure of intertidal and subtidal assemblages in Arctic vs temperate boulder shores

• Main Authors: Piotr Kukliński, David K. A. Barnes, Instytut Oceanologii, Polska Akademia Nauk
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Key words; Arctic; North Atlantic; boulder−fields; biodiversity; assemblages similarity
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.619.7048; http://www.polar.pan.pl/ppr29/PPR29-203.pdf

Abstract: Several studies suggest that assemblages in intertidal zones that experience fre− quent physical extremes (e.g. wave−impacts) should be highly dependent on the regional in− put of propagules. Therefore with higher disturbance in the intertidal zone, higher depend− ence on the species pool from nearby assemblages (e.g. subtidal) should be observed. Here we examine adult community structure to investigate levels of similarity among marine as− semblages of Arctic intertidal zones compared with those in adjacent subtidal areas. Addi− tionally we compare Arctic results with similar data from a temperate area. We selected boulder fields as a model habitat and we predicted that subtidal and intertidal diversity would change differently under varying disturbance regimes. Multivariate analysis of data from Arctic and temperate North Atlantic indicates that in the Arctic, intertidal and subtidal assemblages were more similar to each other than were temperate intertidal and subtidal as− semblages. We suggest this is not because of species differences but that the temperate areas are less disturbed. The wave and ice battered, highly disturbed intertidal assemblages of the Arctic were composed of a subset of nearby subtidal assemblages with similar dominance structure. Intertidal specialist species were not found in the Arctic samples. In contrast, tem− perate intertidal boulder−field assemblages had a completely different dominance structure to the adjacent subtidal. Furthermore, temperate intertidal assemblages were composed of different (specialist) species often not found in the subtidal zone. We conclude that more disturbed environments, such as our Arctic study sites, are more dependent on outside sources of recruitment.