David F. Murray

Climate change and Arctic ecosystems: 2. Modeling, paleodata-model comparisons, and future projections

Large variations in the composition, structure, and function of Arctic ecosystems are determined by climatic gradients, especially of growing-season warmth, soil moisture, and snow cover. A unified circumpolar classification recognizing five types of tundra was developed. The geographic distributions of vegetation types north of 55degreesN, including the position of the forest limit and the distributions of the tundra types, could be predicted from climatology using a small set of plant functional types embedded in the biogeochemistry-biogeography model BIOME4. Several palaeoclimate simulations for the last glacial maximum (LGM) and mid-Holocene were used to explore the possibility of simulating past vegetation patterns, which are independently known based on pollen data. The broad outlines of observed changes in vegetation were captured. LGM simulations showed the major reduction of forest, the great extension of graminoid and forb tundra, and the restriction of low- and high-shrub tundra (although not all models produced sufficiently dry conditions to mimic the full observed change). Mid-Holocene simulations reproduced the contrast between northward forest extension in western and central Siberia and stability of the forest limit in Beringia. Projection of the effect of a continued exponential increase in atmospheric CO2 concentration, based on a transient ocean-atmosphere simulation including sulfate aerosol effects, suggests a potential for larger changes in Arctic ecosystems during the 21st century than have occurred between mid-Holocene and present. Simulated physiological effects of the CO2 increase (to >700 ppm) at high latitudes were slight compared with the effects of the change in climate.

Climate change and Arctic ecosystems: 1. Vegetation changes north of 55°N between the last glacial maximum, mid-Holocene, and present

A unified scheme to assign pollen samples to vegetation types was used to reconstruct vegetation patterns north of 55°N at the last glacial maximum (LGM) and mid-Holocene (6000 years B.P.). The pollen data set assembled for this purpose represents a comprehensive compilation based on the work of many projects and research groups. Five tundra types (cushion forb tundra, graminoid and forb tundra, prostrate dwarf-shrub tundra, erect dwarf-shrub tundra, and low- and high-shrub tundra) were distinguished and mapped on the basis of modern pollen surface samples. The tundra-forest boundary and the distributions of boreal and temperate forest types today were realistically reconstructed. During the mid-Holocene the tundra-forest boundary was north of its present position in some regions, but the pattern of this shift was strongly asymmetrical around the pole, with the largest northward shift in central Siberia (∼200 km), little change in Beringia, and a southward shift in Keewatin and Labrador (∼200 km). Low- and high-shrub tundra extended farther north than today. At the LGM, forests were absent from high latitudes. Graminoid and forb tundra abutted on temperate steppe in northwestern Eurasia while prostrate dwarf-shrub, erect dwarf-shrub, and graminoid and forb tundra formed a mosaic in Beringia. Graminoid and forb tundra is restricted today and does not form a large continuous biome, but the pollen data show that it was far more extensive at the LGM, while low- and high-shrub tundra were greatly reduced, illustrating the potential for climate change to dramatically alter the relative areas occupied by different vegetation types.

Climate change and Arctic ecosystems: 1. Vegetation changes north of 55 degrees N between the last glacial maximum, mid-Holocene, and present

A unified scheme to assign pollen samples to vegetation types was used to reconstruct vegetation patterns north of 55°N at the last glacial maximum (LGM) and mid-Holocene (6000 years B.P.). The pollen data set assembled for this purpose represents a comprehensive compilation based on the work of many projects and research groups. Five tundra types (cushion forb tundra, graminoid and forb tundra, prostrate dwarf-shrub tundra, erect dwarf-shrub tundra, and low- and high-shrub tundra) were distinguished and mapped on the basis of modern pollen surface samples. The tundra-forest boundary and the distributions of boreal and temperate forest types today were realistically reconstructed. During the mid-Holocene the tundra-forest boundary was north of its present position in some regions, but the pattern of this shift was strongly asymmetrical around the pole, with the largest northward shift in central Siberia (∼200 km), little change in Beringia, and a southward shift in Keewatin and Labrador (∼200 km). Low- and high-shrub tundra extended farther north than today. At the LGM, forests were absent from high latitudes. Graminoid and forb tundra abutted on temperate steppe in northwestern Eurasia while prostrate dwarf-shrub, erect dwarf-shrub, and graminoid and forb tundra formed a mosaic in Beringia. Graminoid and forb tundra is restricted today and does not form a large continuous biome, but the pollen data show that it was far more extensive at the LGM, while low- and high-shrub tundra were greatly reduced, illustrating the potential for climate change to dramatically alter the relative areas occupied by different vegetation types.

Causes of Arctic Plant Diversity: Origin and Evolution

The term biodiversity was coined rather recently as a shorthand reference to biological diversity, i.e., for the sum of all taxa of plants and animals (Wilson 1988), yet the study of biodiversity is the oldest branch of biology (Weber and Wittmann 1992). Today, frames of reference other than taxonomic ones have become important as we recognize the need for understanding diversity at various levels of organization, from inclusive to restrictive, from communities to genotypes. Whatever the level of our focus in the hierarchy, we must ultimately have a precise knowledge of the component taxa.

Vegetation, Floristics, and Phytogeography of Northern Alaska

The word tundra means very different things to different people; nevertheless, except for its occasional usage in the vernacular for treeless bogs in the subarctic interior, it denotes both the circumpolar treeless region north (and south) of the latitudinal treeline and the less extensive mountain landscapes above altitudinal treeline. Originally the word tundra was applied to treeless rolling plains of the Eurasian far north, thus connoting a regional climate, a landscape, and a vegetative cover. Since the history of the landscape and biota is not the same throughout tundra regions, since climates vary, and since floras differ from place to place, tundra, as it might apply to vegetation, is an ambiguous term (Griggs, 1934). Depending upon one’s frame of reference, it is possible to develop three basic stereotypes: a steppe-desert, a heathland, and a bog and meadow landscape. All are correct; treelessness is the shared feature.

Toward a new arctic vegetation map: a review of existing maps

Institute of Arctic and Alpine Research, University of Colorado, Boulder, CO 80309, USA; Fax +1 303 492 6388; E-mailDONALD.WALKER@COLORADO.EDU; Botanical Museum, University of Copenhagen, Gothersgade 130, DK-1123, Copenhagen, Denmark; Fax +45 35 32 22 10; Institut fur Okologie der Pflamen, Westfalische-Wilhelms-Universitädt, Hindenburgplatz 55, D-48143 Miinster, Germany; Fax +49 251 838371; Icelandic Museum of Natural History, Hiemmur 3, P.O. Box 5320, IS-125 Reykjavik, Iceland; Fax +354 1 620815; institute of Biology and Geology, Troms^ University, N-9037 Troms0, Norway; Fax +47 77 645600; ^ORUT Group Ltd., N-9005 Troms0, Norway; Tel. +47 776 80150; ^Faculty of Geography, Moscow State University, Moscow 119899, Russia; Fax +7 095 932 8836; University of Alaska Museum, Fairbanks, AK 99775-6960, USA; Fax +1 907 474 5469; ^U.S. Fish and Wildlife Service, 1011 East Tudor Road, Anchorage, AK 99503, USA; Fax +1 907 786 3635; ^Komarov Botanical Institute, 197376 Russia, St. Peterburg, ul. Prof. Popova 2; Fax +7 812 234 4512; ^Canadian Forest Service, Northern Forestry Centre, 5320 122 Street, Edmonton, Alberta, Canada T6H3S5; Fax +1 403 435 7359

Floristics, systematics, and the study of arctic vegetationa commentary

Some remarks are made on the special problem encountered in arctic plant geography and vegetation studies, viz. the circumpolar distribution of many taxa, which may have been described independently in different countries. 80 % of the arctic bryophytes, 70 % of the lichens and 50 % of the vascular plants have a circumpolar distribution and especially amongst the vascular plants there are several cases of confu- sion. Special attention is paid to Dupontia fisheri s.l., Carex aquatilis s.l. and C. bigelowii s.l. Especially for a classifica- tion of vegetation based on floristic data, having a list of accepted plant names and knowing their synonyms is of para- mount importance. An electronic database for arctic vegeta- tion will foster, if not require, more unified approaches to the description of plant communities.

Parrya nauruaq (Brassicaceae), a new species from Alaska

ABSTRACT Parrya nauruaq Al-Shehbaz, J. R. Grant, R. Lipkin, D. F. Murray & C. L. Parker (Brassicaceae) is described from the Seward Peninsula of Alaska. It differs from the other North American species in Parrya R. Brown by its smaller flowers and fruits, and by its fewer seeds per fruit. A key to the four North American species of Parrya is provided.

New names in Papaver section Meconella (Papaveraceae)

Rarnlel (1977: 437) determined that the specimens from Alaska and Yukon represented a taxon (listinct from the Asiatic material she had studied. She proposed Papaver nudicaule subsp. americanurn, for which she supplied a diagnosis but failed to select a type as required by Article 37.1 (Greuter et al., 1994). As holotype I have chosen a specimen complete with leaves, flowers, and fruits, which Rindel had seen and annotated as subspecies

Albert W. Johnson, 1926–2017

I first met Al Johnson in 1959 when I entered the graduate program in wildlife management at the University of Alaska Fairbanks (UAF). My committee saw in my academic record an absence of systematic botany, and I was directed to take Al’s course. I did, and I was captivated by his inspiring presentations in lecture and lab as he opened my eyes to a field of which I then knew little. Inasmuch as the departments were small then, it was natural that faculty and students mixed socially. Thus, I discovered that Al and I shared a fondness for martinis and Mort Sahl, stand-up comic of the time, a satirist of current politics. Although I finished my M.S. in wildlife management, I had been irrevocably transformed to a botanist. Al was a wonderful example of a fine human being, and fortunately for me, a mentor, a relationship that ended only with his recent passing at home of congestive heart failure on September 23, 2017, at age 91. Al grew up in Illinois with good midwestern credentials. He was very much an out-of-doors person, influenced by his rugged paternal grandfather. This led to an interest in natural history and, not surprisingly, to thoughts of studying biology. Soon after his very brief stint in 1945 with the Army Air Corps, he started his postsecondary education at Colorado State University and then graduate studies at the University of Colorado Boulder, taking his Ph.D. with John Marr. His dissertation (Johnson 1956) dealt with the subalpine forest near the field station we knew as Science Lodge or as the Mountain Research Station of the Institute of Arctic and Alpine Research. Marr (1961) thanked his graduate student workers, of which Al was one, for their critical role in establishing a transect of climate stations from Boulder to a ridge top at 12,000 ft. on Niwot Ridge (cf. Salzberg, Elias, and Christensen 2001). A photo of that team can be found in Kindig (2000) in which Al is sporting a cowboy hat and pipe. Al’s first academic post was at the University of Alaska Fairbanks in 1956 with the Department of Biology where he taught for six years. During his tenure on the faculty a proposal named Project Chariot was made by the Atomic Energy Commission (AEC) to use thermonuclear devices to blast an “instant harbor” on the northwest arctic coast of Alaska at Cape Thompson-Ogotoruk Creek. This was the brainchild of Edward Teller, who was looking for peaceful applications for nuclear explosions under AEC’s Plowshare program. Teller and his supporters at both the AEC and the University administration accepted critical assumptions that proved to be wrong. Faculty firmly against the plan became embroiled in a debate with those forces. Al drafted a letter of opposition with faculty co-signers that put the University and AEC on notice. I recall the biology faculty returning from a meeting with AEC officials incensed by what they had been told. What they did Al explaining frost scars to Barbara Murray and Sue Kubanis at Gobblers Knob, Alaska. Photo by David F. Murray. ARCTIC, ANTARCTIC, AND ALPINE RESEARCH 2018, VOL. 50, NO. 1, e1447541 (4 pages) https://doi.org/10.1080/15230430.2018.1447541