It is well known that climate change is occurring rapidly at regional scales, yet microclimate variation might serve to buffer its immediate impacts on the biosphere. In tundra systems, terricolous lichens are often the dominant groundcover organisms, and represent an important source of microclimatic heterogeneity at ground level. However, with increasingly mild winter conditions, dwarf shrubs are encroaching into previously lichen-dominated ridgetops, which is likely to cause a major shift in the microclimatic landscape experienced by soil organisms, seeds and plants growing close to the soil surface. To date, tundra lichen mats have been studied as a whole community rather than a heterogeneous mixture of species with varied functional traits. Here, we measured soil temperature and moisture buffering, relative to a cleared paired control, and four relevant functional traits (albedo, water holding capacity, shading, and height) in seven lichen and one encroaching shrub species in south-central Norway. Our results show that all lichen species reduce the diurnal temperature range under their canopies, with substantial variation among species that can partially be explained by differences in shading. Contrary to expectations, several lichens species had a negative effect on soil moisture, which related to their capacity to absorb, and therefore intercept, rainfall. The encroaching shrub, Betula nana, exhibited a far weaker ability to affect the soil microclimate. Our results suggest that there is considerable fine-scale variation in microclimates among lichen species and that a transition to a shrub-dominated system will markedly alter the ground-level microclimate mosaic.

Alpine ecosystems around the world are threatened due to climate change. The presence of pollinators is critical for the reproduction of many alpine plant species, however the shrinking of alpine ecosystems and changes in species phenologies might drive a rapid decline of plant-pollinators interactions that we are unaware. In this study, we aim to investigate the effects of climate change in alpine plant-pollinator communities. We have analysed changes of a plant-pollinator community in the Australian Alps (Kosciuszko National Park) using as a baseline plant-pollinator community data collected 30 years ago and comparing it to recent data. We have used traditional methods (flower-visitor observations) and novel approaches (pollen DNA metabarcoding) to quantify plant-pollinator network structure. We found significant changes related to network structure (e.g. modularity), community composition and relative abundances. Furthermore, we found an increase of shrub species in the alpine area and a decrease of herbaceous alpine plants. Interestingly, we also found an increase of introduced species and changes in insect and plant phenology. Overall the results suggest that climate change is altering alpine plant-pollinator communities and producing a shrinking of Australian alpine ecosystems.

The mountain pygmy possum’s (Burramys parvus) ability to hibernate is a key adaption to the alpine areas of Australia. However, current hibernation patterns are likely to be disrupted by climate change, as they are generally temperature-induced. To quantify this change we used mechanistic species distribution models, consisting of a metabolic animal model and a microclimatic model, which were validated against data from previously published physiological and microhabitat studies. Our results indicate that at Mount Kosciuszko National Park, the location of the second largest population of this critically endangered mammal, the total number of hours in which it can undergo hibernation in 2050 will decrease by 32%, equivalent to almost 6 weeks, when compared to 2010. However, this does not encapsulate the expected fluctuation of future temperatures with the number of consecutive hours suitable for hibernation shrinking by 59%. This increase in the likelihood of arousal may be compounded by the recently observed drastic decline in Bogong moths (Agrotis infusa). The moths are a key food source in winter and their decline is likely caused by climate change and recent drought. In addition, an increase in foraging time (due to sporadic moth numbers) and a decrease in snow cover (the number of hours in which the snow depth exceeds 0mm is modelled to decrease by 79%), may escalate predation by cats and foxes. These threats, in concert do not bode well for Australia’s only alpine marsupial.

Arid Australia experienced a period of dramatic high rainfall in 2010 and 2011 that broke long-standing rainfall records. This rainfall resulted in a dramatic pulse in primary productivity that led to outbreaks of many species with irruptive population dynamics including native rodents (Muridae). Notable among these species was the long-haired rat (Rattus villosissimus), the largest extant rodent in arid Australia (body mass: 150 g) that had not irrupted in the western Simpson Desert for over 25 years. The presence of the long-haired rat resulted in several novel ecological interactions, specifically: 1) long-haired rat predation on smaller mammals (body mass <100 g); 2) invasion by the rats in to refuge habitat of the nationally vulnerable plains mouse (Pseudomys australis), and 3) feeding and associated damage to the nationally vulnerable keystone tree species (Acacia peuce). Here, we examine the impacts of the long-haired rat outbreak on native rodents and on Acacia peuce based on long-term monitoring of the system. We show that although the native rodents have been unaffected in the long-term, Acacia peuce stands impacted by the rats show increased mortality and reduced growth. We discuss these results in light of projected changes in the climate of arid Australia.

The function of tropical coral reefs uniquely hinges upon the maintenance of a symbiosis existing at the microscopic level. If we are to ensure the persistence of reefs under a warming climate of particular importance is identification of drivers that may increase the resistance of this relationship, ultimately mitigating against coral bleaching and mortality. Underpinning this resistance is an interplay between biological and physical factors. One such physical factor identified as affecting coral responses under thermal anomalies is water velocity. Here we show that increased water flow velocities under a simulated bleaching event result in differences in symbiont photophysiology compared to a lower water flow treatment. We show that with the onset of stress at ecologically pivotal temperatures, high water flow velocities increase the recovery capacity of endosymbiont photosystems. The apparent mitigating effect of high flow is reduced after further accumulation of thermal stress, with equal reductions in endosymbiont populations being measured in both high and low flow treatments at the end of the heating period. Further understanding the physiological and hydrodynamic drivers of coral responses to thermal stress can improve our predictive capabilities and inform targeted management responses, thereby increasing the resilience of reefs into the future.

Climate change is prompting increasing calls to ensure that ecological restoration and nature conservation actions are robust to changing environments. We propose the term ‘ecological renovation’ to distinguish such climate change-ready actions from historically-focused approaches. To evaluate and progress the development of ecological renovation options, we reviewed the global literature and established a typology recognising a matrix of 23 intervention option types. The typology is arranged on the basis of the mechanisms targeted by the intervention (those that aim to evade or ameliorate changing conditions or ecological functions, versus those that aim to build adaptive capacity) and the nature of the tools used to manipulate them (‘low-regrets’ or ‘climate-targeted’). Despite a burgeoning literature since 2008, we found that the majority of effort has focused on ‘low-regrets’ adaptation approaches that aim to build adaptive capacity. This is in many ways desirable, but more attention to ‘climate-targeted’ approaches may be needed as climate change accelerates. Importantly, much of the inference in the 473 reviewed studies was drawn from ecological reasoning and modelling, with only 16% providing new empirical evidence. To help shift the paradigm towards humans as ‘renovators’ rather than ‘restorers’ of a prior world, we propose that priorities for future ecological research include: (1) informing societal discussion and decision-making about nature conservation goals under climate change, (2) adapting and upscaling conservation planning to accommodate climate-adapted goals, and (3) reconceptualizing experimental approaches to build more empirical evidence and expedite discovery of new climate adaptation options.