Tree-ring records provide global high-resolution information on tree-species responses to global change, forest carbon and water dynamics, and past climate variability and extremes. The underlying assumption is a stationary (time-stable), quasilinear relationship between tree growth and environment, which however conflicts with basic ecological and evolutionary theory. Indeed, our global assessment of the relevant tree-ring literature demonstrates non-stationarity in the majority of tested cases, not limited to specific proxies, environmental parameters, regions or species.Non-stationarity likely represents the general nature of the relationship between tree-growth proxies and environment. Studies assuming stationarity however score two times more citations influencing other fields of science and the science-policy interface. To reconcile ecological reality with the application of tree-ring proxies for climate or environmental estimates, we provide a clarification of the stationarity concept, propose a simple confidence framework for the re-evaluation of existing studies and recommend the use of a new statistical tool to detect non-stationarity in tree-ring proxies. Our contribution is meant to stimulate and facilitate discussion in light of our results to help increase confidence in tree-ring-based climate and environmental estimates for science, the public and policymakers. K E Y W O R D Sclimate reconstruction, dendroclimatology, model calibration, non-stationarity, proxy calibration, tree-rings

Abstract. Climate warming is expected to induce treelines to advance to higher elevations. Empirical studies in diverse mountain ranges, however, give evidence of both advancing alpine treelines and rather insignificant responses. The inconsistency of findings suggests distinct differences in the sensitivity of global treelines to recent climate change. It is still unclear where Himalayan treeline ecotones are located along the response gradient from rapid dynamics to apparently complete inertia. This paper reviews the current state of knowledge regarding sensitivity and response of Himalayan treelines to climate warming, based on extensive field observations, published results in the widely scattered literature, and novel data from ongoing research of the present authors.Several sensitivity indicators such as treeline type, treeline form, seed-based regeneration, and growth patterns are evaluated. Since most Himalayan treelines are anthropogenically depressed, observed advances are largely the result of land use change. Near-natural treelines are usually krummholz treelines, which are relatively unresponsive to climate change. Nevertheless, intense recruitment of treeline trees suggests a great potential for future treeline advance. Competitive abilities of seedlings within krummholz thickets and dwarf scrub heaths will be a major source of variation in treeline dynamics. Tree growth-climate relationships show mature treeline trees to be responsive to temperature change, in particular in winter and pre-monsoon seasons. High pre-monsoon temperature trends will most likely drive tree growth performance in the western and central Himalaya. Ecological niche modelling suggests that bioclimatic conditions for a range expansion of treeline trees will be created during coming decades.

invertebrate herbivory on dwarf birch (Betula glandulosa-nana 1 complex) increases with temperature and precipitation across the tundra biome ' Polar biology, vol. 40, no. 11, pp. 2265-2278. DOI: 10.1007%2Fs00300-017-2139 Digital Object Identifier (DOI): 10.1007%2Fs00300-017-2139-7 Link: Link to publication record in Edinburgh Research Explorer Document Version: Peer reviewed version Published In: Polar biology General rightsCopyright for the publications made accessible via the Edinburgh Research Explorer is retained by the author(s) and / or other copyright owners and it is a condition of accessing these publications that users recognise and abide by the legal requirements associated with these rights. Take down policyThe University of Edinburgh has made every reasonable effort to ensure that Edinburgh Research Explorer content complies with UK legislation. If you believe that the public display of this file breaches copyright please contact openaccess@ed.ac.uk providing details, and we will remove access to the work immediately and investigate your claim. Chronic, low intensity herbivory by invertebrates, termed background herbivory, has been understudied in tundra, 78 yet its impacts are likely to increase in a warmer Arctic. The magnitude of these changes is however hard to 79 predict as we know little about the drivers of current levels of invertebrate herbivory in tundra. We assessed the 80 intensity of invertebrate herbivory on a common tundra plant, the dwarf birch (Betula glandulosa-nana complex), 81 and investigated its relationship to latitude and climate across the tundra biome. Leaf damage by defoliating, 82 mining and gall-forming invertebrates was measured in samples collected from 192 sites at 56 locations. Our 83 results indicate that invertebrate herbivory is nearly ubiquitous across the tundra biome but occurs at low 84 intensity. On average, invertebrates damaged 11.2% of the leaves and removed 1.4% of total leaf area. The 85 damage was mainly caused by external leaf feeders, and most damaged leaves were only slightly affected (12% 86 leaf area lost). Foliar damage was consistently positively correlated with mid-summer (July) temperature and, to a 87 lesser extent, precipitation in the year of data collection, irrespective of latitude. Our models predict that, on 88 average, foliar losses to invertebrates on dwarf birch are likely to increase by 6-7% over the current levels with a 1 89 °C increase in summer temperatures. Our results show that invertebrate herbivory on dwarf birch is small in 90 magnitude but given its prevalence and dependence on climatic variables, background invertebrate herbivory 91 should be included in predictions of climate change impacts on tundra ecosystems. 92 3

A positive sedimentation sign exclusively and reliably occurs in patients with LSS, suggesting its usefulness in clinical practice. Future accuracy studies will address its sensitivity and specificity. If they confirm the sign's high specificity, a positive sedimentation sign can rule in LSS, and, with a high sensitivity, a negative sedimentation sign can rule out LSS.

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