Ladislav Mucina

Arctic vegetation is the visible surface expression of Arctic terrestrial systems. It is the key to monitoring and modeling changes to most components of the system, such as shrub distribution; greening patterns, plant and animal habitats and biodiversity, hydrological networks, and snow distribution, as well as the less visible aspects, such as permafrost, soil carbon stocks, and greenhouse-gas emissions.

Currently, there are no standardized approaches to sample, describe, map, and analyze circumpolar patterns of Arctic vegetation across a hierarchy of spatial scales and international boundaries. There is a need for a well-distributed Arctic vegetation observatory network and a set of internationally accepted protocols for sampling, data information systems, classifying, and mapping vegetation to aid in addressing priority research topics for the Fourth International Conference on Arctic Research Planning (ICARP IV) and the The Fifth International Polar Year (IPY5).

The Circumpolar Arctic Vegetation Science Initiative (CAVSI) is a response to these needs and those expressed by ICARP IV Research Priority Team 1 (RPT 1) (Zhang and Rasouli 2025) and Research Priority Team 2 (RPT2) (Bret-Harte 2025), which focus on the role of the Arctic in the global system and observing, reconstructing, and predicting future Arctic climate dynamics and ecosystem responses. CAVSI is also a response to the recommendation by the Arctic Council for long-term biodiversity monitoring to address key gaps in Arctic-system knowledge (Conservation of Arctic Flora and Fauna (CAFF) 2013, Christiansen et al. 2020, Barry 2023). It aligns with several national and international Arctic research plans and policies that involve observation, monitoring, modeling, and prediction, including those of the United States (Office of Science & Technology Policy (OSTP) 2022, United States Army Reserve Command (USARC) 2023) and the international Sustaining Arctic Research Network (Sustaining Arctic Observing Networks (SAON), Starkweather et al. 2021).

This white paper provides a framework for vegetation description and monitoring. It includes: (1) a network of sites across the full range of Arctic climates, phytogeographic regions, local habitats, and disturbance regimes; (2) standardized methods to describe and monitor local floras, vegetation composition, and key environmental factors; (3) a pan-Arctic vegetation plot archive to store legacy and recent plot data; (4) a consistent hierarchical classification and checklist of Arctic vegetation; (5) an archive of Arctic vegetation and landcover maps; (6) applications and ideas for CAVSI IPY5 initiatives; (7) an 11-year timeline for CAVSI activities leading up to and including synthesis from IPY5 activities; and (8) recommendations for priority activities and research related to ICARP IV RPTs 1 and 2.

Anthropogenic biodiversity decline threatens the functioning of ecosystems and the many benefits they provide to humanity1. As well as causing species losses in directly affected locations, human influence might also reduce biodiversity in relatively unmodified vegetation if far-reaching anthropogenic effects trigger local extinctions and hinder recolonization. Here we show that local plant diversity is globally negatively related to the level of anthropogenic activity in the surrounding region. Impoverishment of natural vegetation was evident only when we considered community completeness: the proportion of all suitable species in the region that are present at a site. To estimate community completeness, we compared the number of recorded species with the dark diversity—ecologically suitable species that are absent from a site but present in the surrounding region2. In the sampled regions with a minimal human footprint index, an average of 35% of suitable plant species were present locally, compared with less than 20% in highly affected regions. Besides having the potential to uncover overlooked threats to biodiversity, dark diversity also provides guidance for nature conservation. Species in the dark diversity remain regionally present, and their local populations might be restored through measures that improve connectivity between natural vegetation fragments and reduce threats to population persistence.

The fundamental value of universal nomenclatural systems in biology is that they enable unambiguous scientific communication. However, the stability of these systems is threatened by recent discussions asking for a fairer nomenclature, raising the possibility of bulk revision processes for "inappropriate" names. It is evident that such proposals come from very deep feelings, but we show how they can irreparably damage the foundation of biological communication and, in turn, the sciences that depend on it. There are four essential consequences of objective codes of nomenclature: universality, stability, neutrality, and transculturality. These codes provide fair and impartial guides to the principles governing biological nomenclature and allow unambiguous universal communication in biology. Accordingly, no subjective proposals should be allowed to undermine them.

Plant communities are composed of species that differ both in functional traits and evolutionary histories. As species’ functional traits partly result from their individual evolutionary history, we expect the functional diversity of communities to increase with increasing phylogenetic diversity. This expectation has only been tested at local scales and generally for specific growth forms or specific habitat types, for example, grasslands. Here we compare standardized effect sizes for functional and phylogenetic diversity among 1,781,836 vegetation plots using the global sPlot database. In contrast to expectations, we find functional diversity and phylogenetic diversity to be only weakly and negatively correlated, implying a decoupling between these two facets of diversity. While phylogenetic diversity is higher in forests and reflects recent climatic conditions (1981 to 2010), functional diversity tends to reflect recent and past climatic conditions (21,000 years ago). The independent nature of functional and phylogenetic diversity makes it crucial to consider both aspects of diversity when analysing ecosystem functioning and prioritizing conservation efforts.

This article describes FloraVeg.EU, a new online database with open-access information on European vegetation units (phytosociological syntaxa), vegetated habitats, and plant taxa. It consists of three modules. (1) The Vegetation module includes 149 phytosociological classes, 378 orders and 1305 alliances of an updated version of the EuroVegChecklist modified based on the decisions of the European Vegetation Classification Committee. Vegetation units dominated by vascular plants are characterized by country-based distribution maps and data on the dominant life forms, phenology, soil properties, relationships to vegetation regions, elevational vegetation belts and azonal habitats, successional status, and degree of naturalness. A list of diagnostic taxa is also provided for each class. (2) The Habitats module includes vascular-plant-dominated terrestrial, freshwater, and marine habitat types from the first to the third or fourth highest hierarchical levels of the EUNIS classification. Of these, 249 vegetated habitats are characterized by a brief description, a point-based distribution map, diagnostic, constant, and dominant taxa, and a list of the corresponding alliances. (3) The Species module provides information on 37 characteristics of European vascular plant species and some infrageneric or infraspecific taxa, including functional traits (habitus and growth type, leaf, flower, fruit and seed traits, and trophic mode), taxon origin (native vs alien), and ecological information (environmental relationships, Ellenberg-type indicator values, disturbance indicator values, and relationships to vegetation units and habitat types). Values for at least three variables are available for 36,404 species. Individual taxa, vegetation units, and habitats in these three modules are illustrated by more than 34,000 photographs. The Download section of FloraVeg.EU provides open-access data sets in a spreadsheet format that can be used for analyses. FloraVeg.EU is a new resource with easily accessible data that can be used for research in vegetation science, ecology, and biogeography, as well as for education and conservation applications.

The Fynbos biome (at the continental biome level) is a member of the global warm-temperate Ethesial Zone (zonobiome S1). The dominating feature of the vegetation supported by this biome are species- and endemic-rich shrublands. The occurrence of bioclimatically and pedologically marginal coastal thickets as well as inland fire-shy Cape thickets is briefly discussed. The relationship between pockets of fire-shy afrotemperate forests (belonging to another zonobiome) and the fynbos shrublands are also analysed. The CB Fynbos is here divided into 19 regional biomes, of which most are intrazonal pedobiomes, and two are extrazonal; only four regional biomes (all characterised by renosterveld vegetation) are of true zonal nature. This chapter presents descriptions of all 19 regional biomes.

This book is the first comprehensive account of large-scale ecosystems (biomes) of Southern Africa (defined as area south of the Kunene and Zambezi Rivers). It addresses the diversity of biomes in one of the most biodiverse regions of the world, comprising South Africa, Namibia, Botswana, Zimbabwe, southern part of Mozambique, Eswatini, and Lesotho. It has adopted a novel, hierarchical biome-classification approach. The biomes at four levels of complexity are identified, described, and mapped using modern GIS-assisted mapping technology. The structure of the book and its comprehensive nature makes this product of prime interest to teachers and students of all tertiary education levels as well as to scientists in the fields of ecology, biodiversity science, and bioclimatology. It is poised to serve as a major reference book and handbook for the users in these scientific fields.

The biomes of the zonobiome E2 Tropical Seasonal Zone occupy the largest portion of the tropical and subtropical regions of the world. This zone is also the dominant zonobiome of the studied MBSA. Physiognomically, the biomes of this zone are represented by savanna grasslands and woodlands, as well as Tropical Dry Forests (TDF). In bioclimatic terms, these biomes are characterised by alternation of prolonged dry and wet periods. In the study region we recognise Mesic and Arid Savanna at the rank of global biome, each comprising 25 and 9 regional biomes, respectively. While the savanna units are functionally underpinned by the domination of highly productive C4 grasslands, the TDF is characterised by an overall lack of grassy (or shrubby) understorey beneath a (semi)closed canopy of trees of predominantly low stature. There are two regional biomes of TDF recognised within the study area, namely Southern African Dry Forest and Southern African Dry Thicket. This chapter presents descriptions of all regional biomes of the zonobiome E2.

With over 350 species, Thesium is the largest genus in Santalales. It is found on all continents except Antarctica; however, its highest diversity is in the Cape Floristic Region of South Africa where approximately half the species occur. Thesium samples of ca. 590 collections from throughout its entire geographic range were obtained and nuclear ribosomal ITS sequenced from 396 accessions representing 196 named taxa and 30 currently unnamed taxa for a total of ca. 230 species. In addition, two chloroplast genome spacers ( trnDT , trnLF ) were sequenced from 269 and 315 accessions, respectively. Maximum parsimony, maximum likelihood and Bayesian methods were employed to generate gene trees and infer phylogenies. The value of the morphological characters traditionally used in the taxonomy of the genus and previous infrageneric classifications are discussed. Broad scale relationships were generally congruent among the ITS and the chloroplast trees. For example, both the nuclear and chloroplast trees support the presence of Eurasian and African clades. In contrast, major incongruence was detected between nuclear and chloroplast trees for a number of taxa including the recently described T. nautimontanum that is sister to the entire African clade on the ITS tree. Although the causes of this incongruence are currently unknown, a novel form of chloroplast capture is hypothesized. A hypothesis of the biogeographical history of the genus based on our molecular phylogeny is presented.