The Origin and Affinity of the Biota of the Kodiak Island Group, Alaska 
Robert E. Vincent 1 
Kodiak Island occupies an important biogeo- 
graphical position. Situated along the north- 
western border of the Gulf of Alaska, this island 
and its neighboring lesser islands have biogeo- 
graphic relationships that radiate in three direc- 
tions: westward along the Aleutian Islands, 
northward toward interior Alaska, and southeast- 
ward toward the temperate Pacific Coastal and 
Rocky Mountain regions of North America. The 
Aleutian and Bering Strait migration routes tend 
to funnel through this strategic area. Further- 
more, the Island Group was probably severely 
glaciated during at least the later part of the 
Pleistocene. Karlstrom ( I960) found geological 
evidence of a small late Pleistocene refuge on 
southwestern Kodiak Island. Nearly all subse- 
quent biota, besides that which may have per- 
sisted on the refuge or on nunataks, would have 
had to originate as reinvaders from adjacent 
land or sea areas. A third peculiar feature in 
addition to location and glacial history is the 
possible significance of major habitat change 
caused by an encroaching timber line across the 
northeastern part of Kodiak Island. 
A working hypothesis based solely upon geo- 
graphic consideration could be proposed: that 
the biota of Kodiak Island is fashioned from 
elements of the three diverse regions with which 
it has geographic relationships. The purpose of 
this paper is to consider the relationship of the 
Kodiak Island Group biota to that of mainland 
Alaska. This should suggest what areas contrib- 
ute heavily to the fauna and flora and indicate 
if geographic location is supported biogeo- 
graphically. 
A study of postglacial immigration of the 
Kodiak biota can be enlightening to the proc- 
esses of intercontinental migrations, reinvasion 
following extermination, and centers of post- 
glacial dispersion. The Bering land connection 
and the Aleutian chain of islands have been 
1 Department of Conservation, University of Michi- 
gan, Ann Arbor. Present address: Colorado Coopera- 
tive Fishery Unit, Colorado State University, Fort Col- 
lins, Colorado. Manuscript received December 6, 1962. 
migration routes from Asia. After Pleistocene 
glaciation, northwestern Alaska was a major 
reservoir of plants and animals to reoccupy 
nearly barren areas, as Kodiak Island is pre- 
sumed to have been. 
METHODS 
Because the indigenous mammal and fresh- 
water fish fauna is sparse, it is necessary to 
place major emphasis upon plants. Hultens 
Flora of Alaska and Yukon (1941) was used 
as the source for vascular plant distribution 
records. It is realized that Hultens comprehen- 
sive work does not include all Alaskan species, 
nor are ranges as completely known as would 
be desirable. There are many areas within this 
vast state where few botanical collections have 
been made; range extensions and adjustments 
are being recorded annually. Yet, even within 
the limitation of knowledge concerning the 
flora of Alaska, the general trends and salient 
features should be little affected by addition of 
a few species or minor range adjustments. 
Alaska can be divided into five subregions 
( exclusive of Kodiak ) for purposes of grouping 
plant distribution records. These subregions are: 
Southeastern Alaska (northwestward to 
Yakutat) 
Kenai Peninsula-Cook Inlet area 
Alaska Peninsula (Iliamna to Cold Bay) 
Aleutian Islands 
Interior Alaska (all Alaska north and 
east of Bristol Bay and the Alaska Range) 
Each of these subdivisions is a fairly well natu- 
rally defined unit, except for the large interior 
region. This area encompasses nearly all of the 
true arctic and much of the boreal zone in 
Alaska. Those species recorded by Hulten from 
southwestern Yukon were included in the in- 
terior subregion, for this area is the geographic 
connection between interior and southeastern 
Alaska. 
In this study species that have been recorded 
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