The Alaska Arctic Vegetation Archive (AVA-AK)

The Alaska Arctic Vegetation Archive (AVA-AK, GIVD-ID: NA-US-014) is a free, publically available database archive of vegetation-plot data from the Arctic tundra region of northern Alaska. The archive currently contains 24 datasets with 3,026 non-overlapping plots. Of these, 74% have geolocation data with 25-m or better precision. Species cover data and header data are stored in a Turboveg database. A standardized Pan Arctic Species List provides a consistent nomenclature for vascular plants, bryophytes, and lichens in the archive. A web-based online Alaska Arctic Geoecological Atlas (AGA-AK) allows viewing and downloading the species data in a variety of formats, and provides access to a wide variety of ancillary data. We conducted a preliminary cluster analysis of the first 16 datasets (1,613 plots) to examine how the spectrum of derived clusters is related to the suite of datasets, habitat types, and environmental gradients. Here, we present the contents of the archive, assess its strengths and weaknesses, and provide three supplementary files that include the data dictionary, a list of habitat types, an overview of the datasets, and details of the cluster analysis

Vegetation of Europe: hierarchical floristic classification system of vascular plant, bryophyte, lichen, and algal communities

Vegetation classification consistent with the Braun-Blanquet approach is widely used in Europe for applied vegetation science, conservation planning and land management. During the long history of syntaxonomy, many concepts and names of vegetation units have been proposed, but there has been no single classification system integrating these units. Here we (1) present a comprehensive, hierarchical, syntaxonomic system of alliances, orders and classes of Braun-Blanquet syntaxonomy for vascular plant, bryophyte and lichen, and algal communities of Europe; (2) briefly characterize in ecological and geographic terms accepted syntaxonomic concepts; (3) link available synonyms to these accepted concepts; and (4) provide a list of diagnostic species for all classes. Location: European mainland, Greenland, Arctic archipelagos (including Iceland, Svalbard, Novaya Zemlya), Canary Islands, Madeira, Azores, Caucasus, Cyprus. Methods: We evaluated approximately 10 000 bibliographic sources to create a comprehensive list of previously proposed syntaxonomic units. These units were evaluated by experts for their floristic and ecological distinctness, clarity of geographic distribution and compliance with the nomenclature code. Accepted units were compiled into three systems of classes, orders and alliances (EuroVegChecklist, EVC) for communities dominated by vascular plants (EVC1), bryophytes and lichens (EVC2) and algae (EVC3). Results: EVC1 includes 109 classes, 300 orders and 1108 alliances; EVC2 includes 27 classes, 53 orders and 137 alliances, and EVC3 includes 13 classes, 24 orders and 53 alliances. In total 13 448 taxa were assigned as indicator species to classes of EVC1, 2087 to classes of EVC2 and 368 to classes of EVC3. Accepted syntaxonomic concepts are summarized in a series of appendices, and detailed information on each is accessible through the software tool EuroVegBrowser. Conclusions: This paper features the first comprehensive and critical account of European syntaxa and synthesizes more than 100 yr of classification effort by European phytosociologists. It aims to document and stabilize the concepts and nomenclature of syntaxa for practical uses, such as calibration of habitat classification used by the European Union, standardization of terminology for environmental assessment, management and conservation of nature areas, landscape planning and education. The presented classification systems provide a baseline for future development and revision of European syntaxonomy.info:eu-repo/semantics/publishedVersio

Multi-decadal changes in tundra environments and ecosystems: Synthesis of the International Polar Year-Back to the Future Project (IPY-BTF).

Understanding the responses of tundra systems to global change has global implications. Most tundra regions lack sustained environmental monitoring and one of the only ways to document multi-decadal change is to resample historic research sites. The International Polar Year (IPY) provided a unique opportunity for such research through the Back to the Future (BTF) project (IPY project #512). This article synthesizes the results from 13 papers within this Ambio Special Issue. Abiotic changes include glacial recession in the Altai Mountains, Russia; increased snow depth and hardness, permafrost warming, and increased growing season length in sub-arctic Sweden; drying of ponds in Greenland; increased nutrient availability in Alaskan tundra ponds, and warming at most locations studied. Biotic changes ranged from relatively minor plant community change at two sites in Greenland to moderate change in the Yukon, and to dramatic increases in shrub and tree density on Herschel Island, and in sub-arctic Sweden. The population of geese tripled at one site in northeast Greenland where biomass in non-grazed plots doubled. A model parameterized using results from a BTF study forecasts substantial declines in all snowbeds and increases in shrub tundra on Niwot Ridge, Colorado over the next century. In general, results support and provide improved capacities for validating experimental manipulation, remote sensing, and modeling studies

The regional species richness and genetic diversity of Arctic vegetation reflect both past glaciations and current climate

AIM : The Arctic has experienced marked climatic differences between glacial and interglacial periods and is now subject to a rapidly warming climate. Knowledge of the effects of historical processes on current patterns of diversity may aid predictions of the responses of vegetation to future climate change. We aim to test whether plant species and genetic diversity patterns are correlated with time since deglaciation at regional and local scales. We also investigate whether species richness is correlated with genetic diversity in vascular plants. LOCATION : Circumarctic. METHODS : We investigated species richness of the vascular plant flora of 21 floristic provinces and examined local species richness in 6215 vegetation plots distributed across the Arctic. We assessed levels of genetic diversity inferred from amplified fragment length polymorphism variation across populations of 23 common Arctic species. Correlations between diversity measures and landscape age (time since deglaciation) as well as variables characterizing current climate were analysed using spatially explicit simultaneous autoregressive models. RESULTS : lts Regional species richness of vascular plants and genetic diversity were correlated with each other, and both showed a positive relationship with landscape age. Plot species richness showed differing responses for vascular plants, bryophytes and lichens. At this finer scale, the richness of vascular plants was not significantly related to landscape age, which had a small effect size compared to the models of bryophyte and lichen richness. MAIN CONCLUSION : Our study suggests that imprints of past glaciations in Arctic vegetation diversity patterns at the regional scale are still detectable today. Since Arctic vegetation is still limited by post-glacial migration lag, it will most probably also exhibit lags in response to current and future climate change. Our results also suggest that local species richness at the plot scale is more determined by local habitat factors.Compilation of the species richness data was made possible through the TFI Networks grant to CD, “Effect Studies and Adaptation to Climate Change,” under the Norforsk initiative (2011 – 2014) which supported two CBIONET-AVA workshops held in Denmark during 2013. The genetic studies were funded by the Research Council of Norway (grant nos. 150322/720 and 170952/V40 to CB).http://http://onlinelibrary.wiley.com/journal/10.1111/(ISSN)1466-82382017-04-30hb2016Plant Production and Soil Scienc

Vegetation and altitudinal zonation in continental West Greenland

Following the principles of the Braun-Blanquet approach a detailed investigation of the vegetation types of mountains in continental West Greenland is presented. The vegetation types are analysed regarding their subdivision into subassociations, variants and elevation forms, as well as the prevailing environmental conditions of their habitats. Special attention is paid to bryophytes and lichens as these play an important role in arctic plant communities and ecosystems. Based on 394 relevés the following communities are dealt with: Calamagrostio lapponicae-Salicetum glaucae ass. nov., Hylocomio splendentis-Cassiopetum tetragonae, Empetro hermaphroditi-Betuletum nanae, Ledo decumbentis-Betuletum nanae (all Loiseleurio-Vaccinietea), Carici nardinae-Dryadetum integrifoliae, Thuidio abietini-Kobresietum myosuroides ass. nov., Rhododendro lapponici-Vaccinietum microphylli, Tortello arcticae-Caricetum rupestris ass. nov., Saxifrago nathorstii-Kobresietum simpliciusculae (all Carici-Kobresietea), Plagiomnio elliptici-Salicetum glaucae ass. nov. (Salicetea purpureae), Cerastium arcticum-Poa community, Pediculari flammeae-Caricetum bigelowii ass. nov. (both Salicetea herbaceae), Caricetum saxatilis, Caricetum rariflorae (both Scheuchzerio-Caricetea) and Racomitrium lanuginosum community (Thlaspietea rotundifolii).  Moreover, the importance of all vegetation types in the study area (incl. Phippsietum algidae-concinnae, Cassiopetum hypnoidis, a.o.) regarding the characterization and delimitation of altitudinal vegetation belts is assessed. For this purpose, their altitudinal distribution, elevation forms, change in habitat-type preferences and the substitution of communities along the altitudinal gradient as well as altitudinal indicator values of selected species are discussed. It resulted that the existence of three altitudinal belts with boundaries at 400 and 800 m a.s.l. can be confirmed and that a variety of the considered criteria is necessary for a comprehensive distinction of these vegetation belts. Furthermore, it was shown that differences between vegetation in mid and high altitudes are more pronounced than between low and mid altitudes. The lowlands and mid altitudes are dominated by erect dwarf-shrub heath vegetation. The associations Rhododendro-Vaccinietum and Ledo-Betuletum are mainly restricted to these altitudes. Mid altitudes are differentiated from the lowlands by elevation forms and change in habitat-type preferences of vegetation types as well as by occurrence of snowbed communities and absence of shrub vegetation. High altitudes are dominated by graminoid and prostrate dwarf-shrub vegetation of the classes Salicetea herbaceae and Carici-Kobresietea. They are differentiated from mid altitudes not only by elevation forms and change in habitat-type preferences of plant communities, but also by substitution of vegetation types. Tortello-Caricetum, Pediculari-Caricetum and Racomitrium lanuginosum community are restricted to these altitudes

The Drabo corymbosae-Papaveretea dahliani − a new vegetation class of the High Arctic polar deserts.

A new class and a new order (Drabo corymbosae-Papaveretea dahliani and Saxifrago oppositifoliae-Papaveretalia dahliani) have been described, and the Papaverion dahliani validated. This is vegetation of zonal habitats in lowlands of the High Arctic subzone A (or Arctic herb, cushion forb or polar desert subzone) and of ecologically equivalent sites at high altitudes on the mountain plateaus of the High Arctic. The new class spans three continents – North America (Canadian Arctic Archipelago and Greenland), Europe (parts of Svalbard and Franz Josef Land), and Asia, including northern regions of Chelyuskin Peninsula (Taymir Peninsula), Severnaya Zemlya Archipelago and De Longa Islands

Nomenklaturni popravki in novi sintaksoni arktične, alpinske in oro-mediteranske vegetacije

During preparation of the European checklist of vegetation units (EuroVegChecklist), it became clear that some earlier described syntaxa need to be typified in order to stabilize nomenclature and some new syntaxa need to be described. Here we propose nomenclature adjustments and formal description of four new alliances for the Arctic, alpine and oro-Mediterranean vegetation of Europe, Greenland and Anatolia. First, we typify the class Juncetea trifidi. Second, we describe four new alliances, such as the Puccinellion nuttallianae (Low-Arctic salt steppes of Greenland; class Saxifrago tricuspidatae-Calamagrostietea purpurascentis), Dryado octopetalae-Caricion arctisibiricae (Arctic tundra vegetation of north-eastern European Russia; class Carici rupestris-Kobresietea bellardii), Leontopodio nivalis-Elynion myosuroidis (southern European alpine tundra vegetation; class Carici rupestris-Kobresietea bellardii) and Lagotido uralensis-Caricion ensifoliae (alpine tundra vegetation of the Southern Ural Mountains; class Juncetea trifidi). Two new associations are described within the first two of these alliances. Finally, we present an interpretation of the alliance Muscario-Scillion nivalis.Med pripravo evropskega seznama vegetacijskih enot (EuroVegChecklist) je postalo jasno, da je potrebno za utrditev nomenklature nekatere zgodnejše opise sintaksonov veljavno tipizirati oziroma opisati nove sintaksone. V članku predlagamo nomenklaturne popravke in formalne opise štirih novih zvez za arktično, alpinsko in oromediteransko vegetacijo Evrope, Grenlandije in Anatolije. Najprej smo tipifizirali razred Juncetea trifidi. Kot drugo smo opisali štiri nove zveze: Puccinellion nuttallianae (nizke arktične slane stepe Grenlandije; razred Saxifrago tricuspidatae-Calamagrostietea purpurascentis), Dryado octopetalae-Caricion arctisibiricae (vegetacija arktične tundre severovzhodne evropske Rusije; razred Carici rupestris-Kobresietea bellardii), Leontopodio nivalis-Elynion myosuroidis (vegetacija južnoevropske alpinske tundre; razred Carici rupestris-Kobresietea bellardii) in Lagotido uralensis-Caricion ensifoliae (vegetacija alpinske tundre gorovja južnega Urala; razred Juncetea trifidi). V teh zvezah smo opisali dve novi asociaciji. Na koncu predstavljamo interpretacijo zveze Muscario-Scillion nivalis

Circumpolar Arctic Vegetation Classification

An Arctic Vegetation Classification (AVC) is needed to address issues related to rapid Arctic-wide changes to climate, land-use, and biodiversity. Location: The 7.1 million km2 Arctic tundra biome. Approach and conclusions: The purpose, scope and conceptual framework for an Arctic Vegetation Archive (AVA) and Classification (AVC) were developed during numerous workshops starting in 1992. The AVA and AVC are modeled after the European vegetation archive (EVA) and classification (EVC). The AVA will use Turboveg for data management. The EVC will use a Braun-Blanquet (Br.-Bl.) classification approach. There are approximately 31,000 Arctic plots that could be included in the AVA. An Alaska AVA (AVA-AK, 24 datasets, 3026 plots) is a prototype for archives in other parts of the Arctic. The plan is to eventually merge data from otherregions of the Arctic into a single Turboveg v3 database. We present the pros and cons of using the Br.-Bl. classification approach compared to the EcoVeg (US) and Biogeoclimatic Ecological Classification (Canada) approaches. The main advantages are that the Br.-Bl. approach already has been widely used in all regions of the Arctic, and many described, well-accepted vegetation classes have a pan-Arctic distribution. A crosswalk comparison of Dryas octopetala communities described according to the EcoVeg and the Braun-Blanquet approaches indicates that the non-parallel hierarchies of the two approaches make crosswalks difficult above the plantcommunity level. A preliminary Arctic prodromus contains a list of typical Arctic habitat types with associated described syntaxa from Europe, Greenland, western North America, and Alaska. Numerical clustering methods are used to provide an overview of the variability of habitat types across the range of datasets and to determine their relationship to previously described Braun-Blanquet syntaxa. We emphasize the need for continued maintenance of the Pan-Arctic Species List, and additional plot data to fully sample the variability across bioclimatic subzones, phytogeographic regions, and habitats in the Arctic. This will require standardized methods of plot-data collection, inclusion of physiogonomic information in the numeric analysis approaches to create formal definitions for vegetation units, and new methods of data sharing between the AVA and national vegetation- plot databases