Plant-pollinator interactions in the alpine: Landscape heterogeneity acts as a potential buffer against climate-change induced mismatch in the pollinator-generalist Ranunculus acris

Phenology changes are a common response to global warming and the timing of phenological events is important for symbiotic interactions, such as pollination. If symbiotic species respond differently to global warming, this could lead to loss of facilitative interactions due to phenological mismatches between species. Global warming is faster and stronger in alpine regions, which could induce stronger asynchrony in plant-pollinator interactions in alpine habitats. However, most alpine plant species are pollinator-generalists and thus are expected to be less vulnerable to plant-pollinator mismatches. This study investigates plant-pollinator interactions in the pollinator-generalist plant species Ranunculus acris L. along a snowmelt gradient in the alpine area of Finse in western Norway over two growing seasons (2016 and 2017). The snowmelt gradient creates patches with different times of snowmelt, and thus onset of flowering. I use the spatial distribution of flowering and pollinator activity to investigate whether sub-populations with different times of flowering experience different synchrony with their pollinators, assessing the potential for temporal plant-pollinator mismatches. In addition, I conduct a hand-pollination experiment to investigate whether a sub-population’s synchrony with its pollinators affects plant reproductive ability. Plant-pollinator mismatch was not detected between R. acris and its pollinators in any of the snowmelt stages or years. Pollinator visitation rate was constant throughout the seasons of both years, but pollinator activity was lower for individuals flowering later in the season in 2017. Reproductive output was not found to be pollen limited, although lower achene mass correlates with lower pollinator visitation rates in late-flowering individuals in 2017. I conclude that this pollinator-generalist is well synchronised with its pollinators, and that early flowering might be related to higher reproductive success, meaning that earlier snowmelt and flowering should not be problematic for this species, but later snowmelt and flowering might. In addition, I suggest that the patchiness of this kind of heterogeneous alpine landscape contributes to flowers always being available to insects, and for pollinators to move between the patches of highest flower abundance, which lowers the risk of temporal plant-pollinator mismatch.Masteroppgave i biologiMAMN-BIOBIO39

Plant-pollinator interactions in the alpine: Landscape heterogeneity acts as a potential buffer against climate-change induced mismatch in the pollinator-generalist Ranunculus acris

Phenology changes are a common response to global warming and the timing of phenological events is important for symbiotic interactions, such as pollination. If symbiotic species respond differently to global warming, this could lead to loss of facilitative interactions due to phenological mismatches between species. Global warming is faster and stronger in alpine regions, which could induce stronger asynchrony in plant-pollinator interactions in alpine habitats. However, most alpine plant species are pollinator-generalists and thus are expected to be less vulnerable to plant-pollinator mismatches. This study investigates plant-pollinator interactions in the pollinator-generalist plant species Ranunculus acris L. along a snowmelt gradient in the alpine area of Finse in western Norway over two growing seasons (2016 and 2017). The snowmelt gradient creates patches with different times of snowmelt, and thus onset of flowering. I use the spatial distribution of flowering and pollinator activity to investigate whether sub-populations with different times of flowering experience different synchrony with their pollinators, assessing the potential for temporal plant-pollinator mismatches. In addition, I conduct a hand-pollination experiment to investigate whether a sub-population’s synchrony with its pollinators affects plant reproductive ability. Plant-pollinator mismatch was not detected between R. acris and its pollinators in any of the snowmelt stages or years. Pollinator visitation rate was constant throughout the seasons of both years, but pollinator activity was lower for individuals flowering later in the season in 2017. Reproductive output was not found to be pollen limited, although lower achene mass correlates with lower pollinator visitation rates in late-flowering individuals in 2017. I conclude that this pollinator-generalist is well synchronised with its pollinators, and that early flowering might be related to higher reproductive success, meaning that earlier snowmelt and flowering should not be problematic for this species, but later snowmelt and flowering might. In addition, I suggest that the patchiness of this kind of heterogeneous alpine landscape contributes to flowers always being available to insects, and for pollinators to move between the patches of highest flower abundance, which lowers the risk of temporal plant-pollinator mismatch

The role of plant functional groups mediating climate impacts on carbon and biodiversity of alpine grasslands

Plant removal experiments allow assessment of the role of biotic interactions among species or functional groups in community assembly and ecosystem functioning. When replicated along climate gradients, they can assess changes in interactions among species or functional groups with climate. Across twelve sites in the Vestland Climate Grid (VCG) spanning 4°C in growing season temperature and 2000 mm in mean annual precipitation across boreal and alpine regions of Western Norway, we conducted a fully factorial plant functional group removal experiment (graminoids, forbs, bryophytes). Over six years, we recorded biomass removed, soil microclimate, plant community composition and structure, seedling recruitment, ecosystem carbon fuxes, and refectance in 384 experimental and control plots. The dataset consists of 5,412 biomass records, 360 species-level biomass records, 1,084,970 soil temperature records, 4,771 soil moisture records, 17,181 plant records covering 206 taxa, 16,656 seedling records, 3,696 ecosystem carbon fux measurements, and 1,244 refectance measurements. The data can be combined with longer-term climate data and plant population, community, ecosystem, and functional trait data collected within the VCG.publishedVersio

Plant traits and associated data from a warming experiment, a seabird colony, and along elevation in Svalbard.

The Arctic is warming at a rate four times the global average, while also being exposed to other global environmental changes, resulting in widespread vegetation and ecosystem change. Integrating functional trait-based approaches with multi-level vegetation, ecosystem, and landscape data enables a holistic understanding of the drivers and consequences of these changes. In two High Arctic study systems near Longyearbyen, Svalbard, a 20-year ITEX warming experiment and elevational gradients with and without nutrient input from nesting seabirds, we collected data on vegetation composition and structure, plant functional traits, ecosystem fluxes, multispectral remote sensing, and microclimate. The dataset contains 1,962 plant records and 16,160 trait measurements from 34 vascular plant taxa, for 9 of which these are the first published trait data. By integrating these comprehensive data, we bridge knowledge gaps and expand trait data coverage, including on intraspecific trait variation. These data can offer insights into ecosystem functioning and provide baselines to assess climate and environmental change impacts. Such knowledge is crucial for effective conservation and management in these vulnerable regions

Plant traits and associated data from a warming experiment, a seabird colony, and along elevation in Svalbard.

Acknowledgements: This research was conducted at the University Centre in Svalbard (UNIS), which provided background knowledge of the study sites and systems, accommodation, lab space, and logistical support for lab and field work during the PFTC4 course. Funding provided by the Norwegian Center for International Cooperation in Education (SIU) and the Research Council of Norway (grants 2013/10074, HNP2015/10037, INTPART 274831) made it possible to conduct this field course at Svalbard with 21 students from 12 nationalities and 4 continents as participants and co-authors to this data paper. The ITEX experiment and field site was funded by UNIS and the University of Iceland Research Funds (grants to ISJ) and the Research Council of Norway (grant 246080/E10). We thank Pernille Bronken Eidesen for introducing us to the local study systems and invaluable assistance with taxonomic identifications, Geir Wing Gabrielsen for background information on the seabird nutrient input gradient below the little auk colony in Bjørndalen, and Christine Schirmer and her team of internship students at the University of Arizona for assistance with stoichiometric and isotope analysis.The Arctic is warming at a rate four times the global average, while also being exposed to other global environmental changes, resulting in widespread vegetation and ecosystem change. Integrating functional trait-based approaches with multi-level vegetation, ecosystem, and landscape data enables a holistic understanding of the drivers and consequences of these changes. In two High Arctic study systems near Longyearbyen, Svalbard, a 20-year ITEX warming experiment and elevational gradients with and without nutrient input from nesting seabirds, we collected data on vegetation composition and structure, plant functional traits, ecosystem fluxes, multispectral remote sensing, and microclimate. The dataset contains 1,962 plant records and 16,160 trait measurements from 34 vascular plant taxa, for 9 of which these are the first published trait data. By integrating these comprehensive data, we bridge knowledge gaps and expand trait data coverage, including on intraspecific trait variation. These data can offer insights into ecosystem functioning and provide baselines to assess climate and environmental change impacts. Such knowledge is crucial for effective conservation and management in these vulnerable regions

Plant traits and associated data from a warming experiment, a seabird colony, and along elevation in Svalbard

Abstract The Arctic is warming at a rate four times the global average, while also being exposed to other global environmental changes, resulting in widespread vegetation and ecosystem change. Integrating functional trait-based approaches with multi-level vegetation, ecosystem, and landscape data enables a holistic understanding of the drivers and consequences of these changes. In two High Arctic study systems near Longyearbyen, Svalbard, a 20-year ITEX warming experiment and elevational gradients with and without nutrient input from nesting seabirds, we collected data on vegetation composition and structure, plant functional traits, ecosystem fluxes, multispectral remote sensing, and microclimate. The dataset contains 1,962 plant records and 16,160 trait measurements from 34 vascular plant taxa, for 9 of which these are the first published trait data. By integrating these comprehensive data, we bridge knowledge gaps and expand trait data coverage, including on intraspecific trait variation. These data can offer insights into ecosystem functioning and provide baselines to assess climate and environmental change impacts. Such knowledge is crucial for effective conservation and management in these vulnerable regions

Plant traits and associated data from a warming experiment, a seabird colony, and along elevation in Svalbard

Acknowledgements: This research was conducted at the University Centre in Svalbard (UNIS), which provided background knowledge of the study sites and systems, accommodation, lab space, and logistical support for lab and field work during the PFTC4 course. Funding provided by the Norwegian Center for International Cooperation in Education (SIU) and the Research Council of Norway (grants 2013/10074, HNP2015/10037, INTPART 274831) made it possible to conduct this field course at Svalbard with 21 students from 12 nationalities and 4 continents as participants and co-authors to this data paper. The ITEX experiment and field site was funded by UNIS and the University of Iceland Research Funds (grants to ISJ) and the Research Council of Norway (grant 246080/E10). We thank Pernille Bronken Eidesen for introducing us to the local study systems and invaluable assistance with taxonomic identifications, Geir Wing Gabrielsen for background information on the seabird nutrient input gradient below the little auk colony in Bjørndalen, and Christine Schirmer and her team of internship students at the University of Arizona for assistance with stoichiometric and isotope analysis.The Arctic is warming at a rate four times the global average, while also being exposed to other global environmental changes, resulting in widespread vegetation and ecosystem change. Integrating functional trait-based approaches with multi-level vegetation, ecosystem, and landscape data enables a holistic understanding of the drivers and consequences of these changes. In two High Arctic study systems near Longyearbyen, Svalbard, a 20-year ITEX warming experiment and elevational gradients with and without nutrient input from nesting seabirds, we collected data on vegetation composition and structure, plant functional traits, ecosystem fluxes, multispectral remote sensing, and microclimate. The dataset contains 1,962 plant records and 16,160 trait measurements from 34 vascular plant taxa, for 9 of which these are the first published trait data. By integrating these comprehensive data, we bridge knowledge gaps and expand trait data coverage, including on intraspecific trait variation. These data can offer insights into ecosystem functioning and provide baselines to assess climate and environmental change impacts. Such knowledge is crucial for effective conservation and management in these vulnerable regions