scholarly journals Pyrodiversity promotes avian diversity over the decade following forest fire

2016 ◽  
Vol 283 (1840) ◽  
pp. 20161703 ◽  
Author(s):  
Morgan W. Tingley ◽  
Viviana Ruiz-Gutiérrez ◽  
Robert L. Wilkerson ◽  
Christine A. Howell ◽  
Rodney B. Siegel

An emerging hypothesis in fire ecology is that pyrodiversity increases species diversity. We test whether pyrodiversity—defined as the standard deviation of fire severity—increases avian biodiversity at two spatial scales, and whether and how this relationship may change in the decade following fire. We use a dynamic Bayesian community model applied to a multi-year dataset of bird surveys at 1106 points sampled across 97 fires in montane California. Our results provide strong support for a positive relationship between pyrodiversity and bird diversity. This relationship interacts with time since fire, with pyrodiversity having a greater effect on biodiversity at 10 years post-fire than at 1 year post-fire. Immediately after fires, patches of differing burn severities hold similar bird communities, but over the ensuing decade, bird assemblages within patches of contrasting severities differentiate. When evaluated at the scale of individual fires, fires with a greater heterogeneity of burn severities hold substantially more species. High spatial heterogeneity in severity, sometimes called ‘mixed-severity fire', is a natural part of wildfire regimes in western North America, but may be jeopardized by climate change and a legacy of fire suppression. Forest management that encourages mixed-severity fire may be critical for sustaining biodiversity across fire-prone landscapes.

Author(s):  
Sandy P Harrison ◽  
Iain Colin Prentice ◽  
Keith J Bloomfield ◽  
Ning Dong ◽  
Matthias Forkel ◽  
...  

Abstract Recent extreme wildfire seasons in several regions have been associated with exceptionally hot, dry conditions, made more probable by climate change. Much research has focused on extreme fire weather and its drivers, but natural wildfire regimes – and their interactions with human activities – are far from being comprehensively understood. There is a lack of clarity about the ‘causes’ of wildfire, and about how ecosystems could be managed for the co-existence of wildfire and people. We present evidence supporting an ecosystem-centred framework for improved understanding and modelling of wildfire. Wildfire has a long geological history and is a pervasive natural process in contemporary plant communities. In some biomes, wildfire would be more frequent without human settlement; in others they would be unchanged or less frequent. A world without fire would have greater forest cover, especially in present-day savannas. Many species would be missing, because fire regimes have co-evolved with plant traits that resist, adapt to or promote wildfire. Certain plant traits are favoured by different fire frequencies, and may be missing in ecosystems that are normally fire-free. For example, post-fire resprouting is more common among woody plants in high-frequency fire regimes than where fire is infrequent. The impact of habitat fragmentation on wildfire crucially depends on whether the ecosystem is fire-adapted. In normally fire-free ecosystems, fragmentation facilitates wildfire starts and is detrimental to biodiversity. In fire-adapted ecosystems, fragmentation inhibits fires from spreading and fire suppression is detrimental to biodiversity. This interpretation explains observed, counterintuitive patterns of spatial correlation between wildfire and potential ignition sources. Lightning correlates positively with burnt area only in open ecosystems with frequent fire. Human population correlates positively with burnt area only in densely forested regions. Models for vegetation-fire interactions must be informed by insights from fire ecology to make credible future projections in a changing climate.


2020 ◽  
Vol 40 (3) ◽  
pp. 468-476
Author(s):  
Corey T. Callaghan ◽  
John H. Wilshire ◽  
John M. Martin ◽  
Richard E. Major ◽  
Mitchell B. Lyons ◽  
...  

Urbanisation is altering local flora and fauna, but urban greenspaces can provide refugia for a variety of taxa. However, we often lack basic biodiversity information (e.g., species richness) for these urban greenspaces. Citizen science projects are continuously improving our understanding of ecology at broad temporal and spatial scales. But, many conservation-relevant decisions are idiosyncratic and made at small management scales (e.g., local government). Given a general bias of citizen science data towards areas with large human populations, citizen scientists are best placed to contribute to improving our understanding of the biodiversity within cities and urban greenspaces. We introduce the Greenspace Bird Calculator: a web-app aimed at enhancing our collective knowledge of bird diversity in urban greenspaces. Users of the web-app could be land managers seeking to understand the bird diversity in the greenspaces they manage. It is built in a reproducible workflow, allowing anyone to delineate a greenspace and submit it to the web-app administrator, receiving an output comprising the greenspace’s total bird diversity. The Greenspace Bird Calculator web-app provides an automated tool to utilise existing eBird citizen science data to calculate species richness for urban greenspaces globally. Critically, the GBC web-app statistically assesses available data that otherwise would be unlikely to be considered by decision-makers. This web-app is an example of the evolution of citizen science, whereby the data collected has been analysed to allow accessible interpretation and inclusion into urban greenspace management and planning.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Z. L. Steel ◽  
B. Campos ◽  
W. F. Frick ◽  
R. Burnett ◽  
H. D. Safford

AbstractWildfire is an important ecological process that influences species’ occurrence and biodiversity generally. Its effect on bats is understudied, creating challenges for habitat management and species conservation as threats to the taxa worsen globally and within fire-prone ecosystems. We conducted acoustic surveys of wildfire areas during 2014–2017 in conifer forests of California’s Sierra Nevada Mountains. We tested effects of burn severity and its variation, or pyrodiversity, on occupancy and diversity for the 17-species bat community while accounting for imperfect detection. Occupancy rates increased with severity for at least 6 species and with pyrodiversity for at least 3. Two other species responded negatively to pyrodiversity. Individual species models predicted maximum occupancy rates across burn severity levels but only one species occurred most often in undisturbed areas. Species richness increased from approximately 8 species in unburned forests to 11 in pyrodiverse areas with moderate- to high-severity. Greater accessibility of foraging habitats, as well as increased habitat heterogeneity may explain positive responses to wildfire. Many bat species appear well adapted to wildfire, while a century of fire suppression and forest densification likely reduced habitat quality for the community generally. Relative to other taxa, bats may be somewhat resilient to increases in fire severity and size; trends which are expected to continue with accelerating climate change.


2014 ◽  
Vol 23 (1) ◽  
pp. 1 ◽  
Author(s):  
Chad T. Hanson ◽  
Dennis C. Odion

Research in the Sierra Nevada range of California, USA, has provided conflicting results about current trends of high-severity fire. Previous studies have used only a portion of available fire severity data, or considered only a portion of the Sierra Nevada. Our goal was to investigate whether a trend in fire severity is occurring in Sierra Nevada conifer forests currently, using satellite imagery. We analysed all available fire severity data, 1984–2010, over the whole ecoregion and found no trend in proportion, area or patch size of high-severity fire. The rate of high-severity fire has been lower since 1984 than the estimated historical rate. Responses of fire behaviour to climate change and fire suppression may be more complex than assumed. A better understanding of spatiotemporal patterns in fire regimes is needed to predict future fire regimes and their biological effects. Mechanisms underlying the lack of an expected climate- and time since fire-related trend in high-severity fire need to be identified to help calibrate projections of future fire. The effects of climate change on high-severity fire extent may remain small compared with fire suppression. Management could shift from a focus on reducing extent or severity of fire in wildlands to protecting human communities from fire.


2018 ◽  
Vol 5 (1) ◽  
pp. 53-59
Author(s):  
Nurud S. S. ◽  
Abdullah I. ◽  
Saari M ◽  
NorMariah A. ◽  
Rafee B

A combustible material is one of fire hazard where the amount of combustible materials or fire load could affect the heat release and fire severity in enclosure. The fire severity in the context of fire load is related to intensity and duration of fire in enclosure. Fire load survey is conducted in this study to estimate the amount of combustible materials in wholesale premise since it become threat to life safety and property loss. The determinations of fire load in 3-storey wholesale premise in Kuantan city is conducted by using combination fire load survey method; weighing and inventory method. Result from fire load survey can help to determine the sufficient requirements of fire suppression in premise as well as fire fighters intervention strategy. An extension of this study, the data could be used as an important input to design fire for deterministic analysis in fire risk assessment to quantify the level of fire risk towards life, property and environment.


Author(s):  
Kathleen Doyle ◽  
Dennis Knight

In the early 1970's, the growing awareness of the potential ecological impacts of fire suppression and the threat of more intensive fires due to fuel accumulation in fire-suppressed forests prompted the National Park Service to allow some fires to burn (Grand Teton National Park 1974). One of the first "prescribed natural fires" in a western National Park was the Waterfalls Canyon Fire (WCF) in Grand Teton National Park (GTNP). It was ignited by lightning in July 1974. Amid much public controversy (Anonymous 1974), the fire burned 1414 ha before it was extinguished by snow in December. In the following year, GTNP biologists established permanent plots within and adjacent to the WCF in forests dominated by subalpine fir, Engelmann spruce, and lodgepole pine, and which varied in fire severity and time since fire. The goal of the study was to document the effect of the 1974 fire by monitoring long-term changes in vegetation, breeding birds, and small mammals (Barmore et al. 1976). Data were collected from four study areas in 1975, 1976, 1977, and 1983 under the direction of William Barmore. In 1991 and 1992 we resampled the permanently-marked vegetation plots and breeding bird transects. Our objectives were to compile, analyze and interpret all of the data collected from the four study areas since 1975.


Drones ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 17
Author(s):  
Elena Ausonio ◽  
Patrizia Bagnerini ◽  
Marco Ghio

The recent huge technological development of unmanned aerial Vehicles (UAVs) can provide breakthrough means of fighting wildland fires. We propose an innovative forest firefighting system based on the use of a swarm of hundreds of UAVs able to generate a continuous flow of extinguishing liquid on the fire front, simulating the effect of rain. Automatic battery replacement and extinguishing liquid refill ensure the continuity of the action. We illustrate the validity of the approach in Mediterranean scrub first computing the critical water flow rate according to the main factors involved in the evolution of a fire, then estimating the number of linear meters of active fire front that can be extinguished depending on the number of drones available and the amount of extinguishing fluid carried. A fire propagation cellular automata model is also employed to study the evolution of the fire. Simulation results suggest that the proposed system can provide the flow of water required to fight low-intensity and limited extent fires or to support current forest firefighting techniques.


2021 ◽  
Author(s):  
Dante Föllmi ◽  
Jantiene Baartman ◽  
João Pedro Nunes ◽  
Akli Benali

<p><strong>Abstract</strong></p><p>Wildfires have become an increasing threat for Mediterranean ecosystems, due to increasing climate change induced wildfire activity and changing land management practices. Apart from the initial risk, fire can alter the soil in various ways depending on different fire severities and thus post-fire erosion processes are an important component in assessing wildfires’ negative effects. Recent post-fire erosion (modelling) studies often focus on a short time window and lack the attention for sediment dynamics at larger spatial scales. Yet, these large spatial and temporal scales are fundamental for a better understanding of catchment sediment dynamics and long-term destructive effects of multiple fires on post-fire erosion processes. In this study the landscape evolution model LAPSUS was used to simulate erosion and deposition in the 404 km<sup>2</sup> Águeda catchment in northern-central Portugal over a 41 year (1979-2020) timespan. To include variation in fire severity and its impact on the soil four burnt severity classes, represented by the difference Normalized Burn Ratio (dNBR), were parameterized. Although model calibration was difficult due to lack of spatial and temporal measured data, the results show that average post-fire net erosion rates were significantly higher in the wildfire scenarios (5.95 ton ha<sup>-1</sup> yr<sup>-1</sup>) compared to those of a non-wildfire scenario (0.58 ton ha<sup>-1</sup> yr<sup>-1</sup>). Furthermore, erosion values increased with a higher level of burnt severity and multiple fires increased the overall sediment build-up in the catchment, fostering an increase in background sediment yield. Simulated erosion patterns showed great spatial variability with large deposition and erosion rates inside streams. Due to this variability, it was difficult to identify land uses that were most sensitive for post-fire erosion, because some land-uses were located in more erosion-sensitive areas (e.g. streams, gullies) or were more affected by high burnt severity levels than others. Despite these limitations, LAPSUS performed well on addressing spatial sediment processes and has the ability to contribute to pre-fire management strategies. For instance, the percentage soil loss map (i.e. comparison of erosion and soil depth maps) could identify locations at risk.</p>


Author(s):  
Julien Ruffault ◽  
Thomas Curt ◽  
Nicolas K. Martin St-Paul ◽  
Vincent Moron ◽  
Ricardo M. Trigo

Abstract. Increasing drought conditions under global warming are expected to alter the frequency and distribution of large, high intensity wildfires. Yet, little is known regarding how it will affect fire weather and translate into wildfire behaviour. Here, we analysed the climatology of extreme wildfires that occurred during the exceptionally dry summers of 2003 and 2016 in Mediterranean France. We identified two distinct shifts in fire climatology towards fire weather spaces that had not been explored before, and which result from specific interactions between the types of drought and the types of fire. In 2016, a long-lasting press drought intensified wind-driven fires. In 2003, a hot drought combining a heatwave with a press drought intensified heat-driven fires. Our findings highlight that increasing drought conditions projected by climate change scenarios might affect the dryness of fuel compartments and create several new generations of wildfire overwhelming fire suppression capacities.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2039 ◽  
Author(s):  
Marcela Suarez-Rubio ◽  
Todd R. Lookingbill

Housing development beyond the urban fringe (i.e., exurban development) is one of the fastest growing forms of land-use change in the United States. Exurban development’s attraction to natural and recreational amenities has raised concerns for conservation and represents a potential threat to wildlife. Although forest-dependent species have been found particularly sensitive to low housing densities, it is unclear how the spatial distribution of houses affects forest birds. The aim of this study was to assess forest bird responses to changes in the spatial pattern of exurban development and also to examine species responses when forest loss and forest fragmentation were considered. We evaluated landscape composition around North American Breeding Bird Survey stops between 1986 and 2009 by developing a compactness index to assess changes in the spatial pattern of exurban development over time. Compactness was defined as a measure of how clustered exurban development was in the area surrounding each survey stop at each time period considered. We used Threshold Indicator Taxa Analysis to detect the response of forest and forest-edge species in terms of occurrence and relative abundance along the compactness gradient at two spatial scales (400-m and 1-km radius buffer). Our results showed that most forest birds and some forest-edge species were positively associated with high levels of compactness at the larger spatial scale; the proportion of forest in the surrounding landscape also had a significant effect when forest loss and forest fragmentation were accounted for. In contrast, the spatial configuration of exurban development was an important predictor of occurrence and abundance for only a few species at the smaller spatial scale. The positive response of forest birds to compactness at the larger scale could represent a systematic trajectory of decline and could be highly detrimental to bird diversity if exurban growth continues and creates more compacted development.


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