Mission 2007 - Hydrocarbon Potential Evaluation Team

Brief Introduction

Seeing from the above map, the main distribution of vegetation in the Arctic National Wildlife Refuge is characterized as having mainly herbaceous classes of plants, which include sedges, mosses and few shrubs. In this region, as well as the whole Alaskan arctic region, bryophytes (commonly known as "mosses") and lichens are shown to be important in the tundra communities in terms of their cover, production and phytomass. They are generally not freely consumed by herbivores, though they are the main producers in the tundra region; many mosses are slow to decompose, resulting in high phytomass to production ratios indicative of slow turnover. The accumulating bryophyte phytomass has high thermal insulating, water-holding and cation exchange capacities. Thus, it exerts a powerful influence on soil temperature and water regimes and on nutrient cycling, and it forms a carbon sink of significance in terms of global warming.

The altitude that ANWR is located mroe or less belongs to the the region of "mild-polar" region, in which the summer is warmer than the cool-polar region with conditions less arid, but the winter is still severe. In this region, there is extensive grassheath, dwarf-shrub heath, mire and other closed phanerogamic vegetation. Mosses and lichens are extensively abundant in this region. Further south there are taller shrubs too co-existing with the bryophyte vegetation. A few examples are as follows:

Bryophytes:        Aulacomnium, Sphagnum,Tomenthypnum spp.
Lichens:           Cladonia, Peltigera, Cetraria spp.
Shrubs:               Alnus, Salix spp.

Mosses contribute significantly to above-ground production and phytomass in the region. In the extensive, relatively dry tussock tundra in Alaska, the production of mosses is around 70gm^-2 but in the wetter areas, as near the coastal part of ANWR, the production can be as high as 164gm^-2, because moss production generally increases with water availability and marine shore is usually more plentiful in nutrients. Lichens are generally less productive than mosses, but they contribute substantial phytomass in lichen heaths and woodlands.