Fire and biodiversity in the Anthropocene

The workshop leading to this paper was funded by the Centre Tecnològic Forestal de Catalunya and the ARC Centre of Excellence for Environmental Decisions. L.T.K. was supported by a Victorian Postdoctoral Research Fellowship (Victorian Government), a Centenary Fellowship (University of Melbourne), and an Australian Research Council Linkage Project Grant (LP150100765). A.R. was supported by the Xunta de Galicia (Postdoctoral Fellowship ED481B2016/084-0) and the Foundation for Science and Technology under the FirESmart project (PCIF/MOG/0083/2017). A.L.S. was supported by a Marie Skłodowska-Curie Individual Fellowship (746191) under the European Union Horizon 2020 Programme for Research and Innovation. L.R. was supported by the Australian Government’s National Environmental Science Program through the Threatened Species Recovery Hub. L.B. was partially supported by the Spanish Government through the INMODES (CGL2014-59742-C2-2-R) and the ERANET-SUMFORESTS project FutureBioEcon (PCIN-2017-052). This research was supported in part by the U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station.BACKGROUND Fire has shaped the diversity of life on Earth for millions of years. Variation in fire regimes continues to be a source of biodiversity across the globe, and many plants, animals, and ecosystems depend on particular temporal and spatial patterns of fire. Although people have been using fire to modify environments for millennia, the combined effects of human activities are now changing patterns of fire at a global scale—to the detriment of human society, biodiversity, and ecosystems. These changes pose a global challenge for understanding how to sustain biodiversity in a new era of fire. We synthesize how changes in fire activity are threatening species with extinction across the globe, highlight forward-looking methods for predicting the combined effects of human drivers and fire on biodiversity, and foreshadow emerging actions and strategies that could revolutionize how society manages fire for biodiversity in the Anthropocene. ADVANCES Our synthesis shows that interactions with anthropogenic drivers such as global climate change, land use, and biotic invasions are transforming fire activity and its impacts on biodiversity. More than 4400 terrestrial and freshwater species from a wide range of taxa and habitats face threats associated with modified fire regimes. Many species are threatened by an increase in fire frequency or intensity, but exclusion of fire in ecosystems that need it can also be harmful. The prominent role of human activity in shaping global ecosystems is the hallmark of the Anthropocene and sets the context in which models and actions must be developed. Advances in predictive modeling deliver new opportunities to couple fire and biodiversity data and to link them with forecasts of multiple drivers including drought, invasive plants, and urban growth. Making these connections also provides an opportunity for new actions that could revolutionize how society manages fire. Emerging actions include reintroduction of mammals that reduce fuels, green fire breaks comprising low-flammability plants, strategically letting wildfires burn under the right conditions, managed evolution of populations aided by new genomics tools, and deployment of rapid response teams to protect biodiversity assets. Indigenous fire stewardship and reinstatement of cultural burning in a modern context will enhance biodiversity and human well-being in many regions of the world. At the same time, international efforts to reduce greenhouse gas emissions are crucial to reduce the risk of extreme fire events that contribute to declines in biodiversity. OUTLOOK Conservation of Earth’s biological diversity will be achieved only by recognition of and response to the critical role of fire in shaping ecosystems. Global changes in fire regimes will continue to amplify interactions between anthropogenic drivers and create difficult trade-offs between environmental and social objectives. Scientific input will be crucial for navigating major decisions about novel and changing ecosystems. Strategic collection of data on fire, biodiversity, and socioeconomic variables will be essential for developing models to capture the feedbacks, tipping points, and regime shifts characteristic of the Anthropocene. New partnerships are also needed to meet the challenges ahead. At the local and regional scale, getting more of the “right” type of fire in landscapes that need it requires new alliances and networks to build and apply knowledge. At the national and global scale, biodiversity conservation will benefit from greater integration of fire into national biodiversity strategies and action plans and in the implementation of international agreements and initiatives such as the UN Convention on Biological Diversity. Placing the increasingly important role of people at the forefront of efforts to understand and adapt to changes in fire regimes is central to these endeavors.PostprintPeer reviewe

Bridging the divide: Integrating animal and plant paradigms to secure the future of biodiversity in fire-prone ecosystems

© 2018 by the authors.Conserving animals and plants in fire-prone landscapes requires evidence of how fires affect modified ecosystems. Despite progress on this front, fire ecology is restricted by a dissonance between two dominant paradigms: ‘fire mosaics’ and ‘functional types’. The fire mosaic paradigm focuses on animal responses to fire events and spatial variation, whereas the functional type paradigm focuses on plant responses to recurrent fires and temporal variation. Fire management for biodiversity conservation requires input from each paradigm because animals and plants are interdependent and influenced by spatial and temporal dimensions of fire regimes. We propose that better integration of animal-based and plant-based approaches can be achieved by identifying common metrics that describe changes in multiple taxa; linking multiple components of the fire regime with animal and plant data; understanding plant-animal interactions; and incorporating spatial and temporal characteristics of fires into conservation management. Our vision for a more integrated fire ecology could be implemented via a collaborative and global network of research and monitoring sites, where measures of animals and plants are linked to real-time data on fire regimes.Kelly was funded by the Australian Research Council Centre of Excellence for Environmental Decisions and a Victorian Postdoctoral Research Fellowship delivered by veski on behalf of the Victorian Government. Brotons and Pausas were funded by the Government of Spain on Project CGL2017-89999-C2 and CGL2015-64086-P, respectively. Smith was supported by Marie Skłodowska-Curie Individual Fellowship FIRESCAPE-746191 under the EU H2020 Programme for Research and Innovation

Data from: Interactions between rainfall, fire and herbivory drive resprouter vital rates in a semi-arid ecosystem

1. Global change is threatening ecosystems and biodiversity worldwide, creating a pressing need to understand how climate and disturbance regimes interact and influence the persistence of species. We quantify how three ecosystem drivers– rainfall, fire and herbivory – influence vital rates in the perennial resprouting graminoid, Triodia scariosa, a foundation species of semi-arid Australia. 2. We used an 11 year data set from a fire and herbivore exclosure experiment, to model flowering, post-fire recruitment and the post-fire survival of seedlings and resprouting plants. Regression modelling quantified the effect of rainfall, inter-fire interval, fire type (wildfire or prescribed fire), grazing by herbivores (native and feral) and an interaction between fire type and herbivory on T. scariosa populations. 3. Rainfall, fire and herbivory had significant effects on post-fire recruitment and the survival of seedlings and resprouting plants, including strong interactions between these drivers. Herbivory following wildfire had a minor effect, but in years of below-average rainfall herbivory following prescribed fire had a large effect, reducing the survival of seedlings and resprouting plants by 20% and over 50% respectively, relative to post-fire survival under average rainfall conditions. 4. Variation in rainfall underpinned significant variation in post-fire resprouting and seedling survival, thus we postulate rainfall primarily drives the dynamics of T. scariosa populations. 5. Synthesis. This study highlights the importance of modelling interactions between key ecosystem drivers when predicting how changes in global climate and disturbance regimes influence plant vital rates. Relatively small changes to disturbance regimes can substantially alter population processes, even in perennial resprouting species. This work suggests that conservation of foundation species, such as T. scariosa, will benefit if fire management decisions are better integrated with inter-annual weather forecasts and herbivore management

Triodia scariosa vital rate data

Four data files for modelling Triodia scariosa vital rates: the proportion of seedlings surviving and established plants resprouting in the first and second years after fire; the proportion of the population flowering, and the post-fire germination rate. Rainfall data is not included as it is already publicly available

Data from: Assessing the sensitivity of biodiversity indices used to inform fire management

Biodiversity indices are widely used to summarise changes in the distribution and abundance of multiple species and measure progress towards management targets. However, the sensitivity of biodiversity indices to the data, landscape classification and conservation values underpinning them are rarely interrogated. There are limited studies to help scientists and land managers use biodiversity indices in the presence of fire and vegetation succession. The geometric mean of species’ relative abundance or occurrence (G) is a biodiversity index that can be used to determine the mix of post-fire vegetation that maximizes biodiversity. We explored the sensitivity of G to i) type of biodiversity data, ii) representation of ecosystem states, iii) expression of conservation values and iv) uncertainty in species’ response to landscape structure. Our case study is an area of fire-prone woodland in southern Australia where G is used in fire management planning. We analysed three data sets to determine the fire responses of 170 bird, mammal and reptile species. G and fire management targets were sensitive to the species included in the analysis. The optimal mix of vegetation successional states for threatened birds was more narrowly defined than the optimal mix for all species combined. G was less sensitive to successional classification (i.e. number of states); although classifications of increasing complexity provided additional insights into desirable levels of heterogeneity. Weighting species by conservation status or endemism influenced the mix of vegetation states that maximized biodiversity. When a higher value was placed on threatened species the importance of late successional vegetation was emphasized. Representing variation in individual species’ response to vegetation structure made it clearer when a decrease in G was likely to reflect a significant reduction in species occurrences. Synthesis and applications. Data, models and conservation values can be combined using biodiversity indices to make robust environmental decisions. Combining different types of biodiversity data using composite indices, such as the geometric mean, can improve the coverage and relevance of biodiversity indices. We recommend that evaluation of biodiversity indices for fire management verify how index assumptions align with management objectives, consider the relative merits of different types of biodiversity data, test sensitivity of ecosystem state definitions and incorporate conservation values through species weightings

Species_data_Triodia&ChenopodMallee

Two data files, one for species recorded in Triodia Mallee and the other for species recorded in Chenopod Mallee. The data is the relative occurrence or abundance of each species by vegetation stage for the three alternate models of vegetation succession (3-stage, 4-stage and 6/7-stage). Species are listed by data type; presence-absence (PA), presence-only (PO) or expert estimates (EE). Some species are present in more than one data type

Leaf and flower colour difference.

<p>Pairwise Euclidean distance in CIE 1976 (L*a*b*) space was calculated and an nMDS generated for a) yellow-orange flowers and b) leaves (the leaf nMDS used data from the two highest quality cameras only: the Nikon D300 and Sony NEX-5n).</p

Variation in leaf colour measured by different cameras.

<p>Leaf colour is shown in <i>a*</i>-<i>b*</i> space for five species calculated from images taken with five different digital cameras.</p

Flower colour difference between species in the field and two invasive species.

<p>Pairwise mean flower colour difference (measured as the Earth Mover’s Distance) was calculated between individual yellow-orange flowers of different species and mean colour of individuals of <i>H</i>. <i>aurantiacum</i> (light bars) and <i>H</i>. <i>praealtum</i> (dark bars). 95% confidence intervals are shown.</p