
Kari Anne BråthenUiT - Arctic University of Norway, former University or Tromsø · Department of Arctic and Marine Biology
Kari Anne Bråthen
Professor
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135
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Publications (135)
Boreal and tundra plant communities are expected to change in biodiversity due to increasing global change pressures such as climate warming. One long-term scenario is increasing compositional similarity, i.e., biotic homogenization, which has been relatively little studied in high-latitude plant communities. Here, we study how the composition and...
Certain graminoids can be successful in grasslands to the extent it is a phenomenon called "the Viking Syndrome". Nevertheless, forbs also make up a substantial part of vascular plant diversity in grasslands and are important resources of mammalian herbivores. Here we assess the hypothesis that forb recruitment is constrained by dominant graminoids...
Climate change negatively impacts reindeer grazing in Fennoscandia, with the encroachment of Empetrum nigrum (crowberry) being a significant, yet largely unrecognized problem. Crowberry encroachment affects the neighboring palatable vegetation negatively, homogenizing the pasture and decreasing ecosystem biodiversity. Current husbandry management a...
Environmental changes, such as climate warming and higher herbivory pressure, are altering the carbon balance of Arctic ecosystems; yet, how these drivers modify the carbon balance among different habitats remains uncertain. This hampers our ability to predict changes in the carbon sink strength of tundra ecosystems. We investigated how spring goos...
Arctic rodents influence tundra plant communities by altering species diversity, structure, and nutrient dynamics. These dynamics are intensified during rodent population peaks. Plants are known to induce defenses in response to rodent herbivory. However, changes in plant tissue digestibility may also play a role in deterring rodents or impacting t...
Ongoing Arctic greening can increase productivity and reindeer pasture quality in the tundra. However, greening may also entail proliferation of unpalatable species, with consequences for pastoral social-ecological systems. Here we show extensive greening across 20 reindeer districts in Norway between 2003 and 2020, which has reduced pasture divers...
Heathlands are extensive systems often dominated by slow‐growing and long‐lived woody plants. These systems require longer‐term studies to capture if and how they are changing over time. In 2020, we resurveyed species richness and cover of vascular plant communities in 139 heathlands along the coastline of northern Fennoscandia, first surveyed duri...
Little is currently known about how climate modulates the relationship between plant diversity and soil organic carbon and the mechanisms involved. Yet, this knowledge is of crucial importance in times of climate change and biodiversity loss. Here, we show that plant diversity is positively correlated with soil carbon content and soil carbon-to-nit...
Given the current rates of climate change, with associated shifts in herbivore population densities, understanding the role of different herbivores in ecosystem functioning is critical for predicting ecosystem responses. Here, we examined how migratory geese and resident, non‐migratory reindeer—two dominating yet functionally contrasting herbivores...
Environmental changes can rapidly alter standing biomass in tundra plant communities; yet, to what extent can they modify plant‐community nutrient levels? Nutrient levels and their changes can affect biomass production, nutrient cycling rates and nutrient availability to herbivores. We examined how environmental perturbations alter Arctic plant‐com...
Small rodents are prevalent and functionally important across the world's biomes,
making their monitoring salient for ecosystem management, conservation, forestry,
and agriculture. There is a growing need for cost-effective and noninvasive methods
for large-scale, intensive sampling. Fecal pellet counts readily provide relative abundance indices, a...
Plant biodiversity, which is fundamental for the delivery of ecosystem services, is in decline. Yet, knowledge about how plant biodiversity is perceived and appreciated is scarce.
We studied biologists' and laypeople's perception and appreciation for plant communities that differ in plant biodiversity, using ranges of plant biodiversity known to af...
Plant-soil feedbacks (PSF) play a substantial role in determining plant performance in native and foreign habitats. Yet, PSF strength may be altered by climatic parameters, creating synergies. Here, we assess performance of alpine grassland species in their native and in foreign soils in an experiment including different climates.
Using soil and se...
Given the current and anticipated rates of global change, with associated shifts in herbivore population densities, understanding the role of different herbivores in shaping ecosystem structure and processes is critical for predicting ecosystem responses. Here, we examined the controls exerted by migratory geese and resident, non-migratory ungulate...
Population size has increasingly been taken as the driver of past human environmental impact worldwide, and particularly in the Arctic. However, sedimentary ancient DNA (sedaDNA), pollen and archaeological data show that over the last 12,000 years, paleoeconomy and culture determined human impacts on the terrestrial ecology of Arctic Norway. The la...
What drives ecosystem buildup, diversity, and stability? We assess species arrival and ecosystem changes across 16 millennia by combining regional-scale plant sedimentary ancient DNA from Fennoscandia with near-complete DNA and trait databases. We show that postglacial arrival time varies within and between plant growth forms. Further, arrival time...
Spatial variation in plant chemical defence towards herbivores can help us understand variation in herbivore top–down control of shrubs in the Arctic and possibly also shrub responses to global warming. Less defended, non‐resinous shrubs could be more influenced by herbivores than more defended, resinous shrubs. However, sparse field measurements l...
Fungi are highly diverse organisms, which provide multiple ecosystem services. However, compared with charismatic animals and plants, the distribution patterns and conservation needs of fungi have been little explored. Here we used high‐resolution sequencing to assess endemicity patterns, global change vulnerability and conservation priority areas...
Small rodents are prevalent and functionally important across world’s biomes, making their monitoring salient for ecosystem management, conservation, forestry and agriculture. Yet, there is a dearth of cost-effective and non-invasive methods for large-scale, intensive sampling. As one such method, fecal pellet counts readily provide relative abunda...
Fungi play pivotal roles in ecosystem functioning, but little is known about their global patterns of diversity, endemicity, vulnerability to global change drivers and conservation priority areas. We applied the high-resolution PacBio sequencing technique to identify fungi based on a long DNA marker that revealed a high proportion of hitherto unkno...
Ongoing Arctic greening can increase productivity and reindeer pasture quality in the tundra. However, greening may also entail proliferation of unpalatable species, with distinct consequences for pastoral socio-ecological systems (SES).
We show extensive greening across 20 reindeer districts in northern Norway between 2003 and 2020. The allelopath...
Fungi are highly important biotic components of terrestrial ecosystems, but we still have a very limited understanding about their diversity and distribution. This data article releases a global soil fungal dataset of the Global Soil Mycobiome consortium (GSMc) to boost further research in fungal diversity, biogeography and macroecology. The datase...
Herbivore‐induced changes in both leaf silicon‐based defence and nutrient levels are potential mechanisms through which grazers alter the quality of their own grass supply. In tundra grasslands, herbivores have been shown to increase nutrient contents of grasses; yet, it is an open question whether they also increase grass silicon‐based defence lev...
Chemical responses of tundra vegetation and tundra soil to environmental changes are likely to differ, with implications for ecosystem functioning; yet they are rarely compared. Here, we aimed at comparing sensitivity and magnitude of short-term carbon and nitrogen responses of three main tundra-ecosystem compartments: vascular plants, mosses, and...
The grassland biome supports an enormous diversity of life and includes ecosystems used extensively by humans. Although graminoids lend grasslands their characteristic appearance, forbs are largely responsible for their taxonomic, phylogenetic, and functional diversity. In terms of abundance, however, forbs often play a subordinate role relative to...
1. Stable isotopes analysis (SIA) of carbon and nitrogen provides valuable information about trophic interactions and animal feeding habits.
2. We used near-infrared reflectance spectroscopy (NIRS) and support vector machines
(SVM) to develop a model for screening isotopic ratios of carbon and nitrogen (δ13C and δ15N) in samples from living animals...
The effects of climate change on species richness are debated but can be informed by the past. Here, we generated a sedimentary ancient DNA dataset covering 10 lakes and applied novel methods for data harmonization. We assessed the impact of Holocene climate changes and nutrients on terrestrial plant richness in northern Fennoscandia. We find that...
Climate change is expected to increase the frequency and intensity of extreme events in northern ecosystems. The outcome of these events across the landscape, might be mediated by species effects, such as niche construction, with likely consequences on vegetation resilience. To test this hypothesis, we simulated an extreme event by removing abovegr...
The effects of climate change on species richness is debated but can be informed by the past. Here, we assess the impact of Holocene climate changes and nutrients on terrestrial plant richness across multiple sites from northern Fennoscandia using new sedimentary ancient DNA (sedaDNA) data quality control methods. We find that richness increased st...
Ungulate trampling modifies soils and interlinked ecosystem functions across biomes. Until today, most research has focused on temperate ecosystems and mineral soils while trampling effects on cold and organic matter‐rich tundra soils remain largely unknown.
We aimed to develop a general model of trampling effects on soil structure, biota, microcli...
Altered species composition caused by environmental and climatic change can affect the transfer of plant residues among communities. Whereas transferred residues are typically considered a resource in recipient systems, residues of allelopathic species may instead cause interference.
Evergreen dwarf shrubs, specifically the allelopathic species Emp...
The leaf is an essential unit for measures of plant ecological traits. Yet, measures of plant chemical traits are often achieved by merging several leaves, masking potential foliar variation within and among plant individuals. This is also the case with cost‐effective measures derived using near‐infrared reflectance spectroscopy (NIRS). The calibra...
In the long‐term, herbivores can alter nutrient dynamics in terrestrial ecosystems by changing the functional composition of plant communities. Here, we ask to what extent herbivores can affect plant‐community nutrient dynamics in the short‐term. We provide theoretical expectations for immediate effects of herbivores on tundra‐grassland plant‐commu...
The leaf is an essential unit for measures of plant ecological traits. Yet, measures of plant chemical traits are often achieved by merging several leaves, masking potential foliar variation within and among plant individuals. This is also the case with cost-effective measures derived using Near-infrared reflectance spectroscopy (NIRS). The calibra...
Spring herbivory (grubbing),
Pink-footed geese,
Summer warming,
Nutrient contents,
Plant quality,
Nutrient pools,
Plant/forage quantity,
Nitrogen,
Phosphorus,
Plant biomass,
Plant Functional Types (PFTs),
Vegetation-types (habitat-types),
Plant communities,
High-Arctic,
Svalbard,
International Tundra Experiment (ITEX),
Near Infrared Reflectance Spe...
Spring herbivory (grubbing), Pink-footed geese, Summer warming, Ecosystem compartments, Vascular plants, Mosses, Soil, Nitrogen, Nutrient contents, Vegetation-types (Habitat-types), Plant communities, International Tundra Experiment (ITEX), High-Arctic, Svalbard
Climate change is modifying temperature and precipitation regimes across all seasons in northern ecosystems. Summer temperatures are higher, growing seasons extend into spring and fall and snow cover conditions are more variable during winter. The resistance of dominant tundra species to these season-specific changes, with each season potentially h...
Near-infrared spectroscopy (NIRS) is a high-throughput technology with potential to infer nitrogen (N), phosphorus (P) and carbon (C) content of all vascular plants based on empirical calibrations with chemical analysis, but is currently limited to the sample populations upon which it is based. Here we provide a first step towards a global arctic-a...
Mammalian herbivores shape the structure and function of many nutrient-limited or low-productive terrestrial ecosystems through modification of plant communities and plant–soil feedbacks. In the tundra biome, mammalian herbivores may both accelerate and decelerate plant biomass growth, microbial activity and nutrient cycling, that is, ecosystem pro...
Species distributions are driven by abiotic conditions that filter species with specific traits and physiological tolerances and match them with their suitable environment. Plant–plant interactions can constrict (through competition) or loosen (through facilitation) the strength of these environmental filters, which in turn inhibit or enhance estab...
Spring herbivory (grubbing),
Pink-footed geese,
Summer warming,
Ecosystem compartments,
Vascular plants,
Mosses,
Soil,
Nitrogen,
Nutrient contents,
Vegetation-types (Habitat-types),
Plant communities,
International Tundra Experiment (ITEX),
High-Arctic,
Svalbard
We present a Holocene record of floristic diversity and environmental change for the central Varanger Peninsula, Finnmark, based on ancient DNA extracted from the sediments of a small lake (sedaDNA). The record covers the period c. 10 700 to 3300 cal. a BP and is complemented by pollen data. Measures of species richness, sample evenness, and beta-d...
Variability in biotic interaction strength is an integral part of food web functioning.
However, the consequences of the spatial and temporal variability of biotic interactions
are poorly known, in particular for predicting species abundance and distribution.
The amplitude of rodent population cycles (i.e., peak-phase abundances) has
been hypothesi...
The above mentioned article was originally scheduled for publication in the special issue on Ecology of Tundra Arthropods with guest editors Toke T. Høye . Lauren E. Culler. Erroneously, the article was published in Polar Biology, Volume 40, Issue 11, November, 2017. The publisher sincerely apologizes to the guest editors and the authors for the in...
Goose herbivory (grubbing),
Pink-footed geese,
Summer warming,
Plant nutrient dynamics,
Nitrogen,
Phosphorus,
Seasonality,
International Tundra Experiment (ITEX),
Plant communities,
Vegetation-types (Habitat-types),
High-Arctic,
Svalbard,
Near Infrared Reflectance Spectroscopy (NIRS)
Spring herbivory (grubbing),
Pink-footed geese,
Summer warming,
Vegetation-types (Habitat-types),
Plant communities,
Carbon fluxes,
Net Ecosystem Exchange (NEE),
Gross Primary/Ecosystem Productivity (GPP, GEP),
Ecosystem respiration (Reco),
High-Arctic,
Svalbard
Spring goose herbivory,
Pink-footed geese,
Vegetation types (habitat-types),
Plant communities,
High-Arctic,
Summer warming,
Litter decomposition,
Carbon fluxes,
Plant nutrient dynamics,
Tea Bag Index (TBI)
Chronic, low intensity herbivory by invertebrates, termed background herbivory, has been understudied
in tundra, yet its impacts are likely to increase in a warmer Arctic. The magnitude of these changes is however
hard to predict as we know little about the drivers of current levels of invertebrate herbivory in tundra. We assessed the intensity of...
In the face of climate change, populations have two survival options - they can remain in situ and tolerate the new climatic conditions ("stay"), or they can move to track their climatic niches ("go"). For sessile and small-stature organisms like alpine plants, staying requires broad climatic tolerances, realized niche shifts due to changing biotic...
Carbon cycling,
Carbon fluxes,
NDVI,
Summer warming,
Spring goose herbivory,
Grubbing,
Pink-footed geese,
Ecosystem types (habitat-types),
Plant communities,
ITEX,
Svalbard,
High-Arctic
Plant-herbivore interactions, Nutrient dynamics, Nitrogen, Phosphorus, Plant Functional Types, Arctic tundra, Rangifer (reindeer/caribou), Small rodents, Seasonality, Near Infrared Reflectance Spectroscopy
Rangifer (caribou/reindeer) management has been suggested to mitigate the temperature-driven transition of arctic tundra into a shrubland state, yet how is uncertain. Here we study this much focused ecosystem state transition in riparian areas, where palatable willows (Salix) are dominant tall shrubs and highly responsive to climate change. For the...
The current study reports the first comprehensive evaluation of a class of allelopathic terrestrial natural products as antifoulants in a marine setting. To investigate the antifouling potential of the natural dihydrostilbene scaffold, a library of 22 synthetic dihydrostilbenes with varying substitution patterns, many of which occur naturally in te...
Organisms that modify the environment (niche constructors) are likely candidates to mediate the effects of climate warming. Here we assess tundra plant community changes along a temperature gradient and how these are modified in the presence of the common allelopathic dwarf shrub Empetrum nigrum and the large herbivore Rangifer tarandus.We develope...
Plant-herbivore interactions,
Nutrient dynamics,
Nitrogen,
Phosphorus,
Plant Functional Types,
Arctic tundra,
Rangifer (reindeer/caribou),
Small rodents,
Seasonality,
Near Infrared Reflectance Spectroscopy
Gender-related inequalities in scientific careers are widespread, evidenced by the attrition of women along the different stages of the promotion ladder. We studied the interwoven personal and professional trajectories of researchers in ecology and compared these trajectories between France and Norway. Given their differing welfare state policies a...