Effects of reindeer grazing and recovery after cessation of grazing on the ground-dwelling spider assemblage in Finnish Lapland

The effect of reindeer Rangifer tarandus L. grazing on the ground-dwelling spider assemblage in Northern Finland was studied. Changes in species richness, abundance and evenness of spider assemblages were analyzed in relation to changes in vegetation and environmental factors in long term grazed and ungrazed sites as well as sites that had recently switched from grazed to ungrazed and vice versa. Grazing was found to have a significant impact on height and biomass of lichens and other ground vegetation. However, it seemed not to have an impact on the total abundance of spiders. This is likely caused by opposing family and species level responses of spiders to the grazing regime. Lycosid numbers were highest in grazed and linyphiid numbers in ungrazed areas. Lycosidae species richness was highest in ungrazed areas whereas Linyphiidae richness showed no response to grazing. Four Linyphiidae, one Thomisidae and one Lycosidae species showed strong preference for specific treatments. Sites that had recovered from grazing for nine years and the sites that were grazed for the last nine years but were previously ungrazed resembled the long term grazed sites. The results emphasize the importance of reindeer as a modifier of boreal forest ecosystems but the impact of reindeer grazing on spiders seems to be family and species specific. The sites with reversed grazing treatment demonstrate that recovery from strong grazing pressure at these high latitudes is a slow process whereas reindeer can rapidly change the conditions in previously ungrazed sites similar to long term heavily grazed conditions.</p

Living, dead, and absent trees-How do moth outbreaks shape small-scale patterns of soil organic matter stocks and dynamics at the Subarctic mountain birch treeline?

Mountain birch forests (Betula pubescens Ehrh. ssp. czerepanovii) at the subarctic treeline not only benefit from global warming, but are also increasingly affected by caterpillar outbreaks from foliage-feeding geometrid moths. Both of these factors have unknown consequences on soil organic carbon (SOC) stocks and biogeochemical cycles. We measured SOC stocks down to the bedrock under living trees and under two stages of dead trees (12 and 55 years since moth outbreak) and treeless tundra in northern Finland. We also measured in-situ soil respiration, potential SOC decomposability, biological (enzyme activities and microbial biomass), and chemical (N, mineral N, and pH) soil properties. SOC stocks were significantly higher under living trees (4.1 +/- 2.1 kg m(2)) than in the treeless tundra (2.4 +/- 0.6 kg m(2)), and remained at an elevated level even 12 (3.7 +/- 1.7 kg m(2)) and 55 years (4.9 +/- 3.0 kg m(2)) after tree death. Effects of tree status on SOC stocks decreased with increasing distance from the tree and with increasing depth, that is, a significant effect of tree status was found in the organic layer, but not in mineral soil. Soil under living trees was characterized by higher mineral N contents, microbial biomass, microbial activity, and soil respiration compared with the treeless tundra; soils under dead trees were intermediate between these two. The results suggest accelerated organic matter turnover under living trees but a positive net effect on SOC stocks. Slowed organic matter turnover and continuous supply of deadwood may explain why SOC stocks remained elevated under dead trees, despite the heavy decrease in aboveground C stocks. We conclude that the increased occurrence of moth damage with climate change would have minor effects on SOC stocks, but ultimately decrease ecosystem C stocks (49% within 55 years in this area), if the mountain birch forests will not be able to recover from the outbreaks.Peer reviewe

White paper on Terrestrial Ecological and Environmental Research Infrastructures in Finland: Analysis of the current landscape and proposal for future steps

This White Paper presents a vision of globally leading, scientifically important and socially relevant environmental research infrastructures (RIs) in Finland, and identifies what we consider as the key issues to be developed to improve the impact and to support the Finnish national infrastructures in their international visibility. The focus is on: 1. The scientific questions driving the terrestrial ecosystem and environmental research globally and in Finland; 2. Specific requirements by different user groups in Finland for ecological and environmental RIs; and 3. Roadmap for the sustainable ecological and environmental RI in Finland. We also present the strategies of organizations regarding their RI development, and the existing infrastructures and networks which form the basis for future development. The final goal of this document is to encourage the development of a coherent vision at national level, and to increase the scientific significance, national synergies and benefits towards a stronger research community. The need for developing a national RI strategy for environmental field arises from the global challenges, which threaten the ecosystems’ functioning. Human activities are imposing many identified, but also previously unknown pressures to ecosystem properties and functions, which are also feeding back to the societies via the quality and quantity of ecosystem services. However, the ecosystem responses to changes in environment are in many cases poorly quantified and the studies only cover short time scales. In order to succeed in providing answers to the grand challenges (ICSU 2010), integrated research infrastructures and efficient analysis tools are crucially needed. The request to improve our knowledge of the state of the environment and the complex biosphere-hydrosphere-atmosphere interactions, and to detect and analyze the impact of global change on these systems has been recognized as a general priority in developing environmental research infrastructures in EU and globally. Currently, Finland is one of the world leaders in atmospheric and environmental sciences, both in terms of research and in coordinating the European and global observation station networks and infrastructures. With this existing experience from close-by research fields and the high research outputs from ecology and ecophysiology in our research organizations, Finland has also the potential to actively promote the ecosystem RI concept, and to act as an example of integrated RIs for other countries. The vision is to develop the capacity of the Finnish ecosystem research community to integrate, upscale and synthesize the observations with relevant holistic process understanding as well as open and reliable data management practices. This can be implemented by creating functional and cost-efficient in-situ platforms and by providing quality-checked data in findable, accessible, interoperable and reusable (FAIR) manner for high-level environmental research. This White paper was made in connection with the INAR Ecosystems initiative funded by Academy of Finland and updated with proceeding of European processes, and it provides a starting point for national cooperation in environmental research infrastructures. Keywords: Terrestrial ecosystems, research infrastructures, ESFRI</p

White paper on Terrestrial Ecological and Environmental Research Infrastructures in Finland

This White Paper presents a vision of globally leading, scientifically important and socially relevant environmental research infrastructures (RIs) in Finland, and identifies what we consider as the key issues to be developed to improve the impact and to support the Finnish national infrastructures in their international visibility. The focus is on: 1. The scientific questions driving the terrestrial ecosystem and environmental research globally and in Finland; 2. Specific requirements by different user groups in Finland for ecological and environmental RIs; and 3. Roadmap for the sustainable ecological and environmental RI in Finland. We also present the strategies of organizations regarding their RI development, and the existing infrastructures and networks which form the basis for future development. The final goal of this document is to encourage the development of a coherent vision at national level, and to increase the scientific significance, national synergies and benefits towards a stronger research community. The need for developing a national RI strategy for environmental field arises from the global challenges, which threaten the ecosystems’ functioning. Human activities are imposing many identified, but also previously unknown pressures to ecosystem properties and functions, which are also feeding back to the societies via the quality and quantity of ecosystem services. However, the ecosystem responses to changes in environment are in many cases poorly quantified and the studies only cover short time scales. In order to succeed in providing answers to the grand challenges (ICSU 2010), integrated research infrastructures and efficient analysis tools are crucially needed. The request to improve our knowledge of the state of the environment and the complex biosphere-hydrosphere-atmosphere interactions, and to detect and analyze the impact of global change on these systems has been recognized as a general priority in developing environmental research infrastructures in EU and globally. Currently, Finland is one of the world leaders in atmospheric and environmental sciences, both in terms of research and in coordinating the European and global observation station networks and infrastructures. With this existing experience from close-by research fields and the high research outputs from ecology and ecophysiology in our research organizations, Finland has also the potential to actively promote the ecosystem RI concept, and to act as an example of integrated RIs for other countries. The vision is to develop the capacity of the Finnish ecosystem research community to integrate, upscale and synthesize the observations with relevant holistic process understanding as well as open and reliable data management practices. This can be implemented by creating functional and cost-efficient in-situ platforms and by providing quality-checked data in findable, accessible, interoperable and reusable (FAIR) manner for high-level environmental research. This White paper was made in connection with the INAR Ecosystems initiative funded by Academy of Finland and updated with proceeding of European processes, and it provides a starting point for national cooperation in environmental research infrastructures

Hiding in the background: community-level patterns in invertebrate herbivory across the tundra biome

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 group of species, so predicting future change remains challenging. We investigated large-scale patterns of invertebrate herbivory across the tundra biome at the community level and explored how these patterns are related to long-term climatic conditions and year-of-sampling weather, habitat characteristics, and aboveground biomass production. Utilizing a standardized protocol, we collected samples from 92 plots nested within 20 tundra sites during summer 2015. We estimated the community-weighted biomass lost based on the total leaf area consumed by invertebrates for the most common plant species within each plot. Overall, invertebrate herbivory was prevalent at low intensities across the tundra, with estimates averaging 0.94% and ranging between 0.02 and 5.69% of plant biomass. Our results suggest that mid-summer temperature influences the intensity of invertebrate herbivory at the community level, consistent with the hypothesis that climate warming should increase plant losses to invertebrates in the tundra. However, most of the observed variation in herbivory was associated with other site level characteristics, indicating that other local ecological factors also play an important role. More details about the local drivers of invertebrate herbivory are necessary to predict the consequences for rapidly changing tundra ecosystems.KeywordsBackground herbivory Biomass loss Climate change Community-weighted average Invertebrate Insects Tundra </div

Hydroclimatic Controls on the Isotopic (δ18 O, δ2 H, d-excess) Traits of Pan-Arctic Summer Rainfall Events

Arctic sea-ice loss is emblematic of an amplified Arctic water cycle and has critical feedback implications for global climate. Stable isotopes (delta O-18, delta H-2, d-excess) are valuable tracers for constraining water cycle and climate processes through space and time. Yet, the paucity of well-resolved Arctic isotope data preclude an empirically derived understanding of the hydrologic changes occurring today, in the deep (geologic) past, and in the future. To address this knowledge gap, the Pan-Arctic Precipitation Isotope Network (PAPIN) was established in 2018 to coordinate precipitation sampling at 19 stations across key tundra, subarctic, maritime, and continental climate zones. Here, we present a first assessment of rainfall samples collected in summer 2018 (n = 281) and combine new isotope and meteorological data with sea ice observations, reanalysis data, and model simulations. Data collectively establish a summer Arctic Meteoric Water Line where delta H-2 = 7.6.delta O-18-1.8 (r(2) = 0.96, p 0.75 parts per thousand/degrees C) were observed at continental sites, while statistically significant temperature relations were generally absent at coastal stations. Model outputs indicate that 68% of the summer precipitating air masses were transported into the Arctic from mid-latitudes and were characterized by relatively high delta O-18 values. Yet 32% of precipitation events, characterized by lower delta O-18 and high d-excess values, derived from northerly air masses transported from the Arctic Ocean and/or its marginal seas, highlighting key emergent oceanic moisture sources as sea ice cover declines. Resolving these processes across broader spatial-temporal scales is an ongoing research priority, and will be key to quantifying the past, present, and future feedbacks of an amplified Arctic water cycle on the global climate system

Genes Involved in Systemic and Arterial Bed Dependent Atherosclerosis - Tampere Vascular Study

BACKGROUND: Atherosclerosis is a complex disease with hundreds of genes influencing its progression. In addition, the phenotype of the disease varies significantly depending on the arterial bed. METHODOLOGY/PRINCIPAL FINDINGS: We characterized the genes generally involved in human advanced atherosclerotic (AHA type V-VI) plaques in carotid and femoral arteries as well as aortas from 24 subjects of Tampere Vascular study and compared the results to non-atherosclerotic internal thoracic arteries (n=6) using genome-wide expression array and QRT-PCR. In addition we determined genes that were typical for each arterial plaque studied. To gain a comprehensive insight into the pathologic processes in the plaques we also analyzed pathways and gene sets dysregulated in this disease using gene set enrichment analysis (GSEA). According to the selection criteria used (>3.0 fold change and p-value <0.05), 235 genes were up-regulated and 68 genes down-regulated in the carotid plaques, 242 genes up-regulated and 116 down-regulated in the femoral plaques and 256 genes up-regulated and 49 genes down-regulated in the aortic plaques. Nine genes were found to be specifically induced predominantly in aortic plaques, e.g., lactoferrin, and three genes in femoral plaques, e.g., chondroadherin, whereas no gene was found to be specific for carotid plaques. In pathway analysis, a total of 28 pathways or gene sets were found to be significantly dysregulated in atherosclerotic plaques (false discovery rate [FDR] <0.25). CONCLUSIONS: This study describes comprehensively the gene expression changes that generally prevail in human atherosclerotic plaques. In addition, site specific genes induced only in femoral or aortic plaques were found, reflecting that atherosclerotic process has unique features in different vascular beds