Haida Gwaii Beach Debris Project  2017 – 2018 

Arboreal Biodiversity Across Spatial Scales Project (A.B.A.S.S.)  2006 – 2012

Walbran Valley Canopy Project  2004 – 2008

Biodiversity in Coastal Temperate Rainforests

Worldwide, coastal temperate rainforests are rare; originally covering less than 1% of the Earth’s land surface, they accumulate and store more organic matter than any other forest type. The coastal temperate rainforest on the west coast of North America also contain the tallest trees in the world. High up in the canopy of these trees, mosses, lichens and other epiphytes create habitat for a myriad of understudied invertebrate groups.

In 2004 I initiated a series of investigations into the factors which structure arboreal (canopy) and terrestrial (forest floor) invertebrate assemblages.  These studies revealed high biodiversity among the acarine suborder Oribatida (a.k.a. oribatid mites); many of which are undescribed and new to science. Additionally, many oribatid mite species occurring in the canopy are not found on the forest floor, and most species within these forest are limited in their distribution to North American coastal temperate rainforests.

The factors which shape canopy oribatid mite communities are related to habitat availability, moisture limitation and random dispersal events of individual species. Our results suggest dispersal limitation associated with physical tree-to-tree dispersal barriers at small spatial scales, but stochastic long-distance dispersal events associated with wind and passive aerial vectors contribute to the maintenance of biodiversity at larger spatial scales. High biodiversity on the forest floor is attributed to high habitat heterogeneity in these systems.

In 2017 I spent my sabbatical on Haida Gwaii sampling beach debris to examine long-distance trans-oceanic dispersal of terrestrial oribatid mites.  I document unique oribatid mite communities associated with tide-line beach debris and the occurrence of several putative Japanese species. Previous explanations of Haida Gwaii’s unique flora and fauna have been attributed to a proximity to the Beringian land bridge and the accumulated evidence of near-offshore glacial refugia during the last glacial period. However, my research also suggests that stochastic, trans-Pacific rafting events contribute to the biodiversity and biogeography of soil communities on the west coast of North America. 

Species Descriptions from the West Coast Research