Ingibjörg S. Jónsdóttir

Ingibjörg S. Jónsdóttir
University of Iceland | HI · Faculty of Life and Environmental Sciences

PhD

About

134
Publications
42,181
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7,772
Citations
Additional affiliations
April 2009 - present
University of Iceland
Position
  • Professor (Full)

Publications

Publications (134)
Preprint
Full-text available
Rangeland ecosystems are changing worldwide with the abandonment of extensive pastoralism practices and greater interest for species coexistence. However, the lack of compiled data on current changes in the abundance and distribution of herbivores challenges rangeland management decisions. Here we gathered and made available for the first time the...
Article
Full-text available
Snow is an important driver of ecosystem processes in cold biomes. Snow accumulation determines ground temperature, light conditions, and moisture availability during winter. It also affects the growing season’s start and end, and plant access to moisture and nutrients. Here, we review the current knowledge of the snow cover’s role for vegetation,...
Article
Full-text available
Snow is an important driver of ecosystem processes in cold biomes. Snow accumulation determines ground temperature, light conditions and moisture availability during winter. It also affects the growing season’s start and end, and plant access to moisture and nutrients. Here, we review the current knowledge of the snow cover’s role for vegetation, p...
Preprint
Full-text available
Global change drivers such as anthropogenic nutrient inputs simultaneously alter biodiversity, species composition, and ecosystem functions such as above ground biomass. These changes are interconnected by complex feedbacks among extinction, invasion, and shifting relative abundance. Here, we use a novel temporal application of the Price equation t...
Article
Full-text available
1. 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...
Article
Bacterial communities form the basis of biogeochemical processes and determine plant growth and health. Mosses harbour diverse bacterial communities that are involved in nitrogen fixation and carbon cycling. Global climate change is causing changes in aboveground plant biomass and shifting species composition in the Arctic, but little is known abou...
Article
Full-text available
The effects of altered nutrient supplies and herbivore density on species diversity vary with spatial scale, because coexistence mechanisms are scale dependent. This scale dependence may alter the shape of the species–area relationship (SAR), which can be described by changes in species richness (S) as a power function of the sample area (A): S = c...
Article
Full-text available
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...
Article
Amidst the globally accelerated plans to increase geothermal energy utilization, knowledge of ecological responses to power plant emissions is limited. The aim of this study is to investigate ecosystem accumulation of elements emitted from power plants in the Hengill geothermal field in Southwest Iceland, in relation to patterns of plant growth and...
Article
Full-text available
The relative contribution of bryophytes to plant diversity, primary productivity, and ecosystem functioning increases towards colder climates. Bryophytes respond to environmental changes at the species level, but because bryophyte species are relatively difficult to identify, they are often lumped into one functional group. Consequently, bryophyte...
Article
Loss of vegetation and soil erosion are symptoms of widespread rangeland degradation across most of the Icelandic highlands. Areas at different stages of degradation coexist as a mosaic that includes both vegetated heathlands, and exposed gravelly deserts. Revegetation efforts have included fertilizer applications and grazing exclusion to increase...
Article
Full-text available
Rapid climate warming is altering Arctic and alpine tundra ecosystem structure and function, including shifts in plant phenology. While the advancement of green up and flowering are well-documented, it remains unclear whether all phenophases, particularly those later in the season, will shift in unison or respond divergently to warming. Here, we pr...
Article
Full-text available
In a rapidly warming tundra, ecosystems will undergo major environmental changes which are predicted to significantly alter below–ground processes, such as decomposition of plant litter. Making use of International Tundra Experiment sites (ITEX), established approximately two decades ago, we examined long–term impacts of warming on decomposition. W...
Article
Full-text available
Observations of changes in phenology have provided some of the strongest signals of the effects of climate change on terrestrial ecosystems. The International Tundra Experiment (ITEX), initiated in the early 1990s, established a common protocol to measure plant phenology in tundra study areas across the globe. Today, this valuable collection of phe...
Article
Full-text available
The Arctic is warming twice as fast as the rest of the planet, leading to rapid changes in species composition and plant functional trait variation. Landscape-level maps of vegetation composition and trait distributions are required to expand spatially-limited plot studies, overcome sampling biases associated with the most accessible research areas...
Article
Vegetation change of the Arctic tundra due to global warming is a well-known process, but the implication for the belowground microbial communities, key in nutrient cycling and decomposition, is poorly understood. We characterized the fungal and bacterial abundances in litter and soil layers across 16 warming experimental sites at 12 circumpolar lo...
Article
Full-text available
Understanding and predicting large-scale ecological responses to global environmental change requires comparative studies across geographic scales with coordinated efforts and standardized methodologies. We designed, applied and assessed standardized protocols to measure tundra herbivory at three spatial scales: plot, site (habitat), and study area...
Article
Full-text available
Tundra plant communities are often shaped by topography. Contrasting wind exposure, slopes of different inclination and landforms of different curvature affect habitat conditions and shape plant diversity patterns. The majority of tundra is also grazed by ungulates, which may alter topographically induced plant diversity patterns, but such effects...
Article
Full-text available
Lichens are traditionally defined as a symbiosis between a fungus and a green alga and or a cyanobacterium. This idea has been challenged by the discovery of bacterial communities inhabiting the lichen thalli. These bacteria are thought to contribute to the survival of lichens under extreme and changing environmental conditions. How these changing...
Article
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...
Article
Full-text available
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...
Preprint
Full-text available
Lichens are traditionally defined as a symbiosis between a fungus and a green alga and or a cyanobacterium. This idea has been challenged by the discovery of bacterial communities inhabiting the lichen thalli. These bacteria are thought to contribute to the survival of lichens under extreme and changing environmental conditions. How these changing...
Presentation
Full-text available
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...
Article
Full-text available
Vegetation change has consequences for terrestrial ecosystem structure and functioning and may involve climate feedbacks. Hence, when monitoring ecosystem states and changes thereof, the vegetation is often a primary monitoring target. Here, we summarize current understanding of vegetation change in the High Arctic—the World’s most rapidly warming...
Article
Full-text available
Warming can alter the biogeochemistry and ecology of soils. These alterations can be particularly large in high northern latitude ecosystems, which are experiencing the most intense warming globally. In this meta‐analysis, we investigated global trends in how experimental warming is altering the biogeochemistry of the most common limiting nutrient...
Preprint
Full-text available
Bacterial communities form the basis of biogeochemical processes and determine plant growth and health. Mosses, an abundant plant group in Arctic ecosystems, harbour diverse bacterial communities that are involved in nitrogen fixation and carbon cycling. Global climate change is causing changes in aboveground plant biomass and shifting species comp...
Article
Full-text available
Invertebrate herbivores depend on external temperature for growth and metabolism. Continued warming in tundra ecosystems is proposed to result in increased invertebrate herbivory. However, empirical data about how current levels of invertebrate herbivory vary across the Arctic is limited and generally restricted to a single host plant or a small gr...
Presentation
Full-text available
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
Article
Full-text available
In the version of this Article originally published, the following sentence was missing from the Acknowledgements: “This work was supported by the Norwegian Research Council SnoEco project, grant number 230970”. This text has now been added.
Presentation
Full-text available
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
Article
Full-text available
Advancing phenology is one of the most visible effects of climate change on plant communities, and has been especially pronounced in temperature-limited tundra ecosystems. However, phenological responses have been shown to differ greatly between species, with some species shifting phenology more than others. We analysed a database of 42,689 tundra...
Article
Changes in Arctic vegetation can have important implications for trophic interactions and ecosystem functioning leading to climate feedbacks. Plot-based vegetation surveys provide detailed insight into vegetation changes at sites around the Arctic and improve our ability to predict the impacts of environmental change on tundra ecosystems. Here, we...
Article
Full-text available
The tundra is warming more rapidly than any other biome on Earth, and the potential ramifications are far-reaching because of global feedback effects between vegetation and climate. A better understanding of how environmental factors shape plant structure and function is crucial for predicting the consequences of environmental change for ecosystem...
Article
Full-text available
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...
Poster
Full-text available
The Herbivory Network (http://herbivory.biology.ualberta.ca) is an international research network that brings together scientists from Arctic and alpine regions to investigate the role of herbivores in these changing ecosystems. Plant-herbivore interactions are central to the functioning of tundra ecosystems, through their effects on biodiversity,...
Poster
Full-text available
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)
Presentation
Full-text available
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
Article
Aims: 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 develop...
Poster
Full-text available
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)
Article
Full-text available
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...
Presentation
Full-text available
Carbon cycling, Carbon fluxes, NDVI, Summer warming, Spring goose herbivory, Grubbing, Pink-footed geese, Ecosystem types (habitat-types), Plant communities, ITEX, Svalbard, High-Arctic
Presentation
Full-text available
Plant-herbivore interactions, Nutrient dynamics, Nitrogen, Phosphorus, Plant Functional Types, Arctic tundra, Rangifer (reindeer/caribou), Small rodents, Seasonality, Near Infrared Reflectance Spectroscopy
Article
Land degradation and extensive soil erosion are serious environmental concerns in Iceland. Natural processes associated with a harsh climate and frequent volcanic activity have shaped Icelandic landscapes. However, following human settlement and the introduction of livestock in the 9th century the extent of soil erosion rapidly escalated. Despite i...
Presentation
Full-text available
Plant-herbivore interactions, Nutrient dynamics, Nitrogen, Phosphorus, Plant Functional Types, Arctic tundra, Rangifer (reindeer/caribou), Small rodents, Seasonality, Near Infrared Reflectance Spectroscopy
Poster
Full-text available
The priorities of the Herbivory Network (http://herbivory.biology.ualberta.ca) are to integrate study sites, methodologies and metrics used in previous work; to coordinate data collection and ensure meaningful comparisons across studies; to develop new research questions and synthesize knowledge on the role of herbivory in northern and alpine ecosy...
Article
Full-text available
Warmer temperatures are accelerating the phenology of organisms around the world. Temperature sensitivity of phenology might be greater in colder, higher-latitude sites than in warmer regions, in part because small changes in temperature constitute greater relative changes in thermal balance at colder sites. To test this hypothesis, we examined up...
Article
Understanding the forces shaping biodiversity patterns, particularly for groups of organisms with key functional roles, will help predict the responses of ecosystems to environmental changes. Our aim was to evaluate the relative role of different drivers in shaping the diversity patterns of vertebrate herbivores, a group of organisms exerting a str...
Article
Full-text available
Snow is a critically important and rapidly changing feature of the Arctic. However, snow-cover and snowpack conditions change through time pose challenges for measuring and prediction of snow. Plausible scenarios of how Arctic snow cover will respond to changing Arctic climate are important for impact assessments and adaptation strategies. Although...
Article
Full-text available
Sheep grazing is an important part of agriculture in the North Atlantic region, defined here as the Faroe Islands, Greenland, Iceland, Norway and Scotland. This process has played a key role in shaping the landscape and biodiversity of the region, sometimes with major environmental consequences, and has also been instrumental in the development of...
Article
Full-text available
Plant-herbivore interactions are central to the functioning of tundra ecosystems, but their outcomes vary over space and time. Accurate forecasting of ecosystem responses to ongoing environmental changes requires a better understanding of the processes responsible for this heterogeneity. To effectively address this complexity at a global scale, coo...
Article
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 genet...
Poster
Full-text available
We compared the frequency of leaf damage by invertebrates during summer 2014 in plots subjected or not, to long-term passive warming at 6 sites participating in the International Tundra Experiment (ITEX) using a standardized protocol. Presence of leaf damage was assessed at the plant community level using a modified point-intercept method. Herbivor...
Article
Abstract Aim Previous research on how climatic niches vary across species ranges has focused on a limited number of species, mostly invasive, and has not, to date, been very conclusive. Here we assess the degree of niche conservatism between distant populations of native alpine plant species that have been separated for thousands of years. Locatio...
Article
Full-text available
In ecology, expert knowledge on habitat characteristics is often used to define sampling units such as study sites. Ecologists are especially prone to such approaches when prior sampling frames are not accessible. Here we ask to what extent can different approaches to the definition of sampling units influence the conclusions that are drawn from an...