What are the effects of herbivore diversity on tundra ecosystems? : A systematic review protocol

Funding Information: The project was funded by the Icelandic Research Fund (Grant Nr. 217754) and the European Union’s Horizon 2020 programme (CHARTER project, Grant Agreement Nr. 869471). Funding for open access publication was provided by the Agricultural University of Iceland. The funding bodies had no influence in the design of the study and collection, analysis and interpretation of data. Funding Information: This study is a contribution of the Herbivory Network (http://herbivory.lbhi.is), a UArctic Thematic Network. Publisher Copyright: © 2022, The Author(s).Background: Changes in the diversity of herbivore communities can strongly influence the functioning of northern ecosystems. Different herbivores have different impacts on ecosystems because of differences in their diets, behaviour and energy requirements. The combined effects of different herbivores can in some cases compensate each other but lead to stronger directional changes elsewhere. However, the diversity of herbivore assemblages has until recently been a largely overlooked dimension of plant–herbivore interactions. Given the ongoing environmental changes in tundra ecosystems, with increased influx of boreal species and changes in the distribution and abundance of arctic herbivores, a better understanding of the consequences of changes in the diversity of herbivore assemblages is needed. This protocol presents the methodology that will be used in a systematic review on the effects of herbivore diversity on different processes, functions and properties of tundra ecosystems. Methods: This systematic review builds on an earlier systematic map on herbivory studies in the Arctic that identified a relatively large number of studies assessing the effects of multiple herbivores. The systematic review will include primary field studies retrieved from databases, search engines and specialist websites, that compare responses of tundra ecosystems to different levels of herbivore diversity, including both vertebrate and invertebrate herbivores. We will use species richness of herbivores or the richness of functional groups of herbivores as a measure of the diversity of the herbivore assemblages. Studies will be screened in three stages: title, abstract and full text, and inclusion will follow clearly identified eligibility criteria, based on their target population, exposure, comparator and study design. The review will cover terrestrial Arctic ecosystems including the forest-tundra ecotone. Potential outcomes will include multiple processes, functions and properties of tundra ecosystems related to primary productivity, nutrient cycling, accumulation and dynamics of nutrient pools, as well as the impacts of herbivores on other organisms. Studies will be critically appraised for validity, and where studies report similar outcomes, meta-analysis will be performed.Peer reviewe

Cryptogamic cover determines soil attributes and functioning in polar terrestrial ecosystems

Congreso organizado por la Sociedade Portuguesa de Ecologia (SPECO) en Portugal, del 9 al 12 de Diciembre de 2020We still lack studies that provide evidence for direct links between the development ofs oils urface cryptogamic communities and soil attributes and functioning. This is particularly truein areas free of potentially confounding factors suchas different soil types, landuses,oranthropogenic disturbances. Despite the ecológical importance of polar ecosystems and their sensitivity to climate change, we are far from understanding how their soils function and will respond to climate change-driven alteration sin above and below groundfeatures. We used two complementary approaches (i.e. cover gradients in the fore front of retreating glaciers as well as long-time deglaciated areas with well developed cryptogamic cover types) to evaluate the role of cryptogams driving multiples oil bioticanda bioticat tributes and function ingratesin polar terrestrial ecosystems. Increases in cryptogamic cover were consistently related to increases inorganic matter accumulation, soilfertility, and bacterial diversity, butal soin enhanced soil function ingrates in both sampling areas. However, we alsos how that theability to influence soil attributes varies among different polar cryptogamic covers, indicating that their differential ability to thrive under climate-change scenarios will largely determine the fate of polar soils in coming decades

Sharing of photobionts in sympatric populations of Thamnolia and Cetraria lichens : evidence from high-throughput sequencing

In this study, we explored the diversity of green algal symbionts (photobionts) in sympatric populations of the cosmopolitan lichen-forming fungi Thamnolia and Cetraria. We sequenced with both Sanger and Ion Torrent High-Throughput Sequencing technologies the photobiont ITS-region of 30 lichen thalli from two islands: Iceland and Öland. While Sanger recovered just one photobiont genotype from each thallus, the Ion Torrent data recovered 10–18 OTUs for each pool of 5 lichen thalli, suggesting that individual lichens can contain heterogeneous photobiont populations. Both methods showed evidence for photobiont sharing between Thamnolia and Cetraria on Iceland. In contrast, our data suggest that on Öland the two mycobionts associate with distinct photobiont communities, with few shared OTUs revealed by Ion Torrent sequencing. Furthermore, by comparing our sequences with public data, we identified closely related photobionts from geographically distant localities. Taken together, we suggest that the photobiont composition in Thamnolia and Cetraria results from both photobiont-mycobiont codispersal and local acquisition during mycobiont establishment and/or lichen growth. We hypothesize that this is a successful strategy for lichens to be flexible in the use of the most adapted photobiont for the environment.Title in thesis list of papers: Differential sharing of photobionts in sympatric populations of Thamnolia and Cetraria lichens: evidence from next generation sequencing</p

What are the effects of herbivore diversity on tundra ecosystems? : A systematic review protocol

Funding Information: The project was funded by the Icelandic Research Fund (Grant Nr. 217754) and the European Union’s Horizon 2020 programme (CHARTER project, Grant Agreement Nr. 869471). Funding for open access publication was provided by the Agricultural University of Iceland. The funding bodies had no influence in the design of the study and collection, analysis and interpretation of data. Funding Information: This study is a contribution of the Herbivory Network (http://herbivory.lbhi.is), a UArctic Thematic Network. Publisher Copyright: © 2022, The Author(s).Background: Changes in the diversity of herbivore communities can strongly influence the functioning of northern ecosystems. Different herbivores have different impacts on ecosystems because of differences in their diets, behaviour and energy requirements. The combined effects of different herbivores can in some cases compensate each other but lead to stronger directional changes elsewhere. However, the diversity of herbivore assemblages has until recently been a largely overlooked dimension of plant–herbivore interactions. Given the ongoing environmental changes in tundra ecosystems, with increased influx of boreal species and changes in the distribution and abundance of arctic herbivores, a better understanding of the consequences of changes in the diversity of herbivore assemblages is needed. This protocol presents the methodology that will be used in a systematic review on the effects of herbivore diversity on different processes, functions and properties of tundra ecosystems. Methods: This systematic review builds on an earlier systematic map on herbivory studies in the Arctic that identified a relatively large number of studies assessing the effects of multiple herbivores. The systematic review will include primary field studies retrieved from databases, search engines and specialist websites, that compare responses of tundra ecosystems to different levels of herbivore diversity, including both vertebrate and invertebrate herbivores. We will use species richness of herbivores or the richness of functional groups of herbivores as a measure of the diversity of the herbivore assemblages. Studies will be screened in three stages: title, abstract and full text, and inclusion will follow clearly identified eligibility criteria, based on their target population, exposure, comparator and study design. The review will cover terrestrial Arctic ecosystems including the forest-tundra ecotone. Potential outcomes will include multiple processes, functions and properties of tundra ecosystems related to primary productivity, nutrient cycling, accumulation and dynamics of nutrient pools, as well as the impacts of herbivores on other organisms. Studies will be critically appraised for validity, and where studies report similar outcomes, meta-analysis will be performed.Peer reviewe