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Data from: Postglacial climate and fire-mediated vegetation change on the western Olympic Peninsula, Washington
The mode and tempo of forest compositional change during periods of rapid climate change, including the potential for the fire regime to produce non-linear relationships between climate and vegetation, is a long-standing theme of forest ecological research. In the old conifer forests of the coastal Pacific Northwest, fire disturbances are sufficiently rare that their relation to climate and their ecological effects are poorly understood. We used a 14,700-year high-resolution sediment record from Yahoo Lake on the Olympic Peninsula to examine vegetation (landscape vegetation from pollen and local vegetation from macrofossils) and fire (landscape fire from total charcoal and local fire from charcoal peaks) in conjunction with independent records of climate. We hypothesized that the successional stage of the local forest will exhibit alternate stable states over a range of fire activity, that species turnover will increase abruptly above a certain level of fire activity and that both responses would be more gradual at the landscape scale than the local scale. Supporting these hypotheses, at the local scale we found strong evidence for alternate stable states of late vs. early successional communities and inertia of species turnover to changing fire activity. At the landscape scale, vegetation responded more gradually to changing fire activity. From 14,700 to 7000 years ago, high landscape vegetation turnover occurred along with high landscape fire activity, especially during the warm summers of the early Holocene. In several instances local species turned over completely following fire events but several centuries after climate change. In contrast, during the last 7000 years the local forest composition was dominated by late-successional species with little species turnover despite periods of moderate fire activity. We suggest that the relatively minor climate fluctuations of the past 7000 years were not sufficient to cause large-scale species turnover after fire. The Yahoo Lake fire and vegetation record of the early Holocene provides a model for dramatic ecosystem change following an anticipated shift to warmer summer temperatures.
Data from: Impacts of growing-season climate on tree growth and post-fire regeneration in ponderosa pine and Douglas-fir forests
We studied the impacts of climate variability on low-elevation forests in the U.S. northern Rocky Mountains by quantifying how post-fire tree regeneration and radial growth varied with growing-season climate. We reconstructed post-fire regeneration and radial growth rates of Pinus ponderosa and Pseudotsuga menziesii at 33 sites that burned between 1992 and 2007, by aging seedlings at the root-shoot boundary. We also measured radial growth in adult trees from 12 additional sites that burned between 1900 and 1990. To quantify the relationship between climate and regeneration, we characterized seasonal climate before, during, and after recruitment pulses using superposed epoch analysis. To quantify growth sensitivity to climate, we performed moving regression analysis for each species and for juvenile and adult life stages. Climatic conditions favoring regeneration and tree growth differed between species. Water deficit and temperature were significantly lower than average during recruitment pulses of ponderosa pine, suggesting that germination-year climate limits regeneration. Growing degree days were significantly higher than average during years with Douglas-fir recruitment pulses, but water deficit was significantly lower one year following pulses, suggesting moisture sensitivity in two-year-old seedlings. Growth was also sensitive to water deficit, but effects varied between life stages, species, and through time, with juvenile ponderosa pine growth more sensitive to climate than adult growth and juvenile Douglas-fir growth. Increasing water deficit corresponded with reduced adult growth of both species. Increases in maximum temperature and water deficit corresponded with increases in juvenile growth of both species in the early 20th century but strong reductions in growth for juvenile ponderosa pine in recent decades. Changing sensitivity of growth to climate suggests that increased temperature and water deficit may be pushing these species towards the edge of their climatic tolerances. Our study demonstrates increased vulnerability of dry mixed-conifer forests to post-fire regeneration failures and decreased growth as temperatures and drought increase. Shifts towards unfavorable conditions for regeneration and juvenile growth may alter the composition and resilience of low-elevation forests to future climate and fire activity.
Data from: Twenty-four years after the Yellowstone fires: are postfire lodgepole pine stands converging in structure and function?
Disturbance and succession have long been of interest in ecology, but how landscape patterns of ecosystem structure and function evolve following large disturbances is poorly understood. After nearly 25 years, lodgepole pine (Pinus contorta var. latifolia) forests that regenerated after the 1988 Yellowstone Fires (Wyoming, USA) offer a prime opportunity to track the fate of disturbance-created heterogeneity in stand structure and function in a wilderness setting. In 2012, we resampled 72 permanent plots to ask (1) How have postfire stand structure and function changed between 11 and 24 yr postfire, and what variables explain these patterns and changes? (2) How has landscape-level (among-stand) variability in postfire stand structure and function changed between 11 and 24 yr postfire? We expected to see evidence of convergence beginning to emerge, but also that initial postfire stem density would still determine trajectories of biomass accumulation. After 24 yr, postfire lodgepole pine density remained very high (mean = 21,738 stems ha−1, range = 0 to 344,067 stems ha−1). Stem density increased in most plots between 11 and 24 yr postfire, but declined sharply where 11-yr-postfire stem density was > 72,000 stems ha−1. Stems were small in high-density stands, but stand-level lodgepole pine leaf area, foliage biomass, and live aboveground biomass increased over time and with increasing stem density. After 24 yr, mean annual lodgepole pine aboveground net primary production (ANPP) was high (mean = 5 Mg ha−1 yr−1, range = 0 to 16.5 Mg ha−1 yr−1). Among stands, lodgepole pine ANPP increased with stem density, which explained 69% of the variation; another 8% of the variation was explained by environmental covariates. Early patterns of postfire lodgepole pine regeneration, which were contingent on prefire serotiny and fire severity, remained the dominant driver of stand structure and function. We observed mechanisms that would lead to convergence in stem density (structure) over time, but it was landscape variation in functional variables that declined substantially. Stand structure and function have not converged across the burned landscape, but our evidence suggests function will converge sooner than structure.
Data from: Developmental changes in hippocampal CA1 single neuron firing and theta activity during associative learning
Hippocampal development is thought to play a crucial role in the emergence of many forms of learning and memory, but ontogenetic changes in hippocampal activity during learning have not been examined thoroughly. We examined the ontogeny of hippocampal function by recording theta and single neuron activity from the dorsal hippocampal CA1 area while rat pups were trained in associative learning. Three different age groups [postnatal days (P)17-19, P21-23, and P24-26] were trained over six sessions using a tone conditioned stimulus (CS) and a periorbital stimulation unconditioned stimulus (US). Learning increased as a function of age, with the P21-23 and P24-26 groups learning faster than the P17-19 group. Age- and learning-related changes in both theta and single neuron activity were observed. CA1 pyramidal cells in the older age groups showed greater task-related activity than the P17-19 group during CS-US paired sessions. The proportion of trials with a significant theta (4–10 Hz) power change, the theta/delta ratio, and theta peak frequency also increased in an age-dependent manner. Finally, spike/theta phase-locking during the CS showed an age-related increase. The findings indicate substantial developmental changes in dorsal hippocampal function that may play a role in the ontogeny of learning and memory.
Predator responses to fire: a global systematic review and meta-analysis
1. Knowledge of how disturbances such as fire shape habitat structure and composition, and affect animal interactions, is fundamental to ecology and ecosystem management. Predators also exert strong effects on ecological communities, through top-down regulation of prey and competitors, which can result in trophic cascades. Despite their ubiquity, ecological importance and potential to interact with fire, our general understanding of how predators respond to fire remains poor, hampering ecosystem management. 2. To address this important knowledge gap, we conducted a systematic review and meta-analysis of the effects of fire on terrestrial, vertebrate predators worldwide. We found 160 studies spanning 1978–2018. There were 36 studies with sufficient information for meta-analysis, from which we extracted 96 effect sizes (Hedge's g) for 67 predator species relating to changes in abundance indices, occupancy or resource selection in burned and unburned areas, or before and after fire. 3. Studies spanned geographic locations, taxonomic families, and study designs, but most were located in North America and Oceania (59% and 24%, respectively), and largely focussed on felids (24%) and canids (25%). Half (50%) of the studies reported responses to wildfire, and nearly one third concerned prescribed fires. 4. There were no clear, general responses of predators to fire, nor relationships with geographic area, biome or life history traits (e.g. body mass and diet). Responses varied considerably between species. Analysis of species for which at least three effect sizes had been reported in the literature revealed that red foxes (Vulpes vulpes) mostly responded positively to fire (e.g. higher abundance in burned compared to unburned areas) and eastern racers (Coluber constrictor) negatively, with variances overlapping zero only slightly for both species. 5. Our systematic review and meta-analysis revealed strong variation in predator responses to fire, and geographic and taxonomic knowledge gaps. Varied responses of predator species to fire likely depend on ecosystem context. Consistent reporting of ongoing monitoring and management experiments is required to improve understanding of the mechanisms driving predator responses to fire, and any broader effects (e.g. trophic interactions). The divergent responses of species in our study suggest that adaptive, context-specific management of predator-fire relationships is required. 23-Oct-2019
Data from: Woody cover in wet and dry African savannas after six decades of experimental fires
1. Fire is an integral process in savannas because it plays a crucial role in altering woody cover of this globally important biome. 2. In this study we examine the long term effects of varying fire frequencies over a 60 year time period in South Africa. We analyse the effects of fire exclusion and of experimental burns every 1, 2 and 3 years on woody cover, tree abundance and stem structure on a wet and dry savanna. 3. Increased fire frequency did not display a consistent effect on woody cover. The presence of fire, irrespective of frequency, was much more influential in lowering tree abundance in the wet savanna than the dry savanna. In the dry savanna, fire was more effective in greatly increasing coppicing in trees, when compared to the wet savannas. 4. Synthesis: The effects of fire on three measures of savanna woody vegetation differed between wet and dry experimental sites. We suggest that vegetation responses to fire are dependent on local conditions, which are likely influenced by rainfall. Therefore we suggest that management strategies should take account of whether a savanna is a wet or dry system when implementing fire management regimes.
Data from: Belowground community responses to fire: meta-analysis reveals contrasting responses of soil microorganisms and mesofauna
Global fire regimes are shifting due to climate and land use changes. Understanding the responses of belowground communities to fire is key to predicting changes in the ecosystem processes they regulate. We conducted a comprehensive meta-analysis of 1634 observations from 131 empirical studies to investigate the effect of fire on soil microorganisms and mesofauna. Fire had a strong negative effect on soil biota biomass, abundance, richness, evenness, and diversity. Fire reduced microorganism biomass and abundance by up to 96%. Bacteria were more resistant to fire than fungi. Fire reduced nematode abundance by 88% but had no significant effect on soil arthropods. Fire reduced richness, evenness and diversity of soil microorganisms and mesofauna by up to 99%. We found little evidence of temporal trends towards recovery within 10 years post-disturbance suggesting little resilience of the soil community to fire. Interactions between biome, fire type, and depth explained few of these negative trends. Future research at the intersection of fire ecology and soil biology should aim to integrate soil community structure with the ecosystem processes they mediate under changing global fire regimes.
Data from: Longleaf pine proximity effects on air temperatures and hardwood top-kill from prescribed fire
Background Regulation of the dominance of sprouting understory hardwoods is a common objective for prescribed fire in open-canopy longleaf pine woodland of the southeastern USA. Nevertheless, little is known about the influence of individual pines on fire and hardwood mortality. We studied growing-season fires in stem-mapped stands in southwest Georgia USA which displayed large variation in structure due to cutting treatments applied 7 yr earlier. We measured air temperature and heating duration, and measured post-fire sprouting behavior of four guilds of understory hardwoods: mesic oaks, upland oaks, xeric oaks, and fleshy-fruited hardwoods. Mean air temperature (i.e., of flames, buoyant plume and smoldering combustion) and heating duration (time over 60°C) were analyzed with respect to fuel-bed conditions and neighboring tree density. Hardwood top-kill was analyzed with respect to neighboring tree density and hardwood height. Results Size of and distance to longleaf pines strongly affected time over 60°C, which increased linearly from a mean of 87 s to a mean of 234 s across a gradient of pine basal area from 0 to 30 m2 ha-1. Mean air temperature during prescribed fire was unaffected by pine density but increased linearly from a mean of 114°C to a mean of 148°C across a gradient of wiregrass cover from 0 to 100%. Neighborhood models showed that time over 60°C during the burns was longest at the base of pines and decreased by two-thirds at 3.3 m distance. Pines affected hardwood top-kill probability at a similar scale, the effect at 4.4 m decreasing by two-thirds compared to at the base of the pine. The four hardwood guilds were readily top-killed when ≤ 1 m tall, but at 2 m height upland and xeric oaks had become more resistant to top-kill than mesic oaks or fleshy fruited broadleaved trees. Conclusions The influence of individual pine trees on heating duration and top-kill power of prescribed fire drops by ⅔ of maximum within 3 to 4 m of a tree, compared to a maximum at the base of the tree. Neighborhood models provide a method to estimate tree effects on prescribed fire heating duration and top-kill probability, and thus a way of predicting stand structures that provide ecological benefits of openings while remaining below thresholds that trigger vigorous hardwood response.
Data from: Fire-regime complacency and sensitivity to centennial- through millennial-scale climate change in Rocky Mountain subalpine forests, Colorado, U.S.A.
1. Key uncertainties in anticipating future fire regimes are their sensitivity to climate change, and the degree to which climate will impact fire regimes directly, through increasing the probability of fire, versus indirectly, through changes in vegetation and landscape flammability. 2. We studied the sensitivity of subalpine forest fire regimes (i.e., fire frequency, fire severity) to previously documented climate variability over the past 6000 years, utilizing pollen and macroscopic charcoal from high-resolution lake-sediment records in Rocky Mountain National Park, Colorado. We combined data from the four lakes to provide composite records of vegetation and fire history within a 200 km2 study area. 3. Rates of forest burning were relatively complacent to millennial-scale summer cooling and decreased effective moisture. Mean return intervals between fire episodes, defined over 500-year periods, generally varied between 150-250 years, consistent with tree-ring-based estimates spanning recent centuries. Variability around these long-term means, however, was significantly correlated with variability in summer moisture (i.e., more burning with drier summers), inferred from existing lake-level and supporting paleoenvironmental records. 4. The most pronounced change in fire regimes was in response to decreased subalpine forest density ca. 2400 cal. year BP, itself a response to regional cooling. This indirect impact of climate was followed by a decrease in charcoal production per fire, a proxy for crown-fire severity, while the long-term rate of burning remained unchanged. Over the last 1500 years, increased summer evaporation and drought frequency were associated with increased fire severity, highlighting a direct link between fire and climate. 5. Synthesis: Subalpine forest fire history reveals complacency and sensitivity of fire regimes to changing vegetation and hydroclimate over the past 6000 years. Complacency is highlighted by non-varying fire frequency over millennia. Sensitivity is evident through changes in biomass burned per fire (and inferred fire severity), in response to climate-induced changes in forest density and, more recently, increased summer drought. Overall, the paleo record suggests that (i) fire severity may be more responsive to climate change than fire frequency in Rocky Mountain subalpine forests, and (ii) the indirect impacts of climate on vegetation and fuels are important mechanisms determining fire-regime response to climate change.
Data from: Synergistic effects of fire and elephants on arboreal animals in an African savannah
1. Disturbance is a crucial determinant of animal abundance, distribution and community structure in many ecosystems, but the ways in which multiple disturbance types interact remain poorly understood. The effects of multiple-disturbance interactions can be additive, subadditive or super-additive (synergistic). Synergistic effects in particular can accelerate ecological change; thus, characterizing such synergies, the conditions under which they arise, and how long they persist has been identified as a major goal of ecology. 2. We factorially manipulated two principal sources of disturbance in African savannas, fire and elephants, and measured their independent and interactive effects on the numerically dominant vertebrate (the arboreal gekkonid lizard Lygodactylus keniensis) and invertebrate (a guild of symbiotic Acacia ants) animal species in a semi-arid Kenyan savanna. 3. Elephant exclusion alone (minus fire) had negligible effects on gecko density. Fire alone (minus elephants) had negligible effects on gecko density after 4 months, but increased gecko density twofold after 16 months, likely because the decay of fire-damaged woody biomass created refuges and nest sites for geckos. In the presence of elephants, fire increased gecko density nearly threefold within 4 months of the experimental burn; this occurred because fire increased the incidence of elephant damage to trees, which in turn improved microhabitat quality for geckos. However, this synergistic positive effect of fire and elephants attenuated over the ensuing year, such that only the main effect of fire was evident after 16 months. 4. Fire also altered the structure of symbiotic plant-ant assemblages occupying the dominant tree species (Acacia drepanolobium); this influenced gecko habitat selection but did not explain the synergistic effect of fire and elephants. However, fire-driven shifts in plant-ant occupancy may have indirectly mediated this effect by increasing trees' susceptibility to elephant damage. 5. Our findings confirm the importance of fire × elephant interactions in structuring arboreal wildlife populations. Where habitat modification by megaherbivores facilitates co-occurring species, fire may amplify these effects in the short term by increasing the frequency or intensity of herbivory, leading to synergy. In the longer term, tree mortality due to both top kill by fire and toppling by large herbivores may reduce overall microhabitat availability, eliminating the synergy.
Data from: Fire-induced population reduction and landscape opening increases gene flow via pollen dispersal in Pinus halepensis
Population reduction and disturbances may alter dispersal, mating patterns and gene flow. Rather than taking the common approach of comparing different populations or sites, here we studied gene flow via wind-mediated effective pollen dispersal on the same plant individuals before and after a fire-induced population drop, in a natural stand of Pinus halepensis. The fire killed 96% of the pine trees in the stand and cleared the vegetation in the area. Thirteen trees survived in two groups separated by ~80 m, and seven of these trees had serotinous (closed) pre-fire cones that did not open despite the fire. We analyzed pollen from closed pre- and post-fire cones using microsatellites. The two groups of surviving trees were highly genetically differentiated, and the pollen they produced also showed strong among-group differentiation and very high kinship both before and after the fire, indicating limited and very local pollen dispersal. The pollen not produced by the survivors also showed significant pre-fire spatial genetic structure and high kinship, indicating mainly within-population origin and limited gene flow from outside, but became spatially homogeneous with random kinship after the fire. We suggest that post-fire gene flow via wind-mediated pollen dispersal increased by two putative mechanisms: 1) a drastic reduction in local pollen production due to population thinning, effectively increasing pollen immigration; 2) an increase in wind speeds in the vegetation-free post-fire landscape. This research shows that dispersal can alleviate negative genetic effects of population size reduction, and that disturbances might enhance gene flow, rather than reduce it.
Data from: The influence of fire frequency on the structure and botanical composition of savanna ecosystems
Savannas cover 60% of the land surface in Southern Africa, with fires and herbivory playing a key role in their ecology. The Limpopo National Park (LNP) is a 10,000 km2 conservation area in southern Mozambique and key to protecting savannas in the region. Fire is an important factor in LNP's landscapes, but little is known about its role in the park's ecology. In this study, we explored the interaction between fire frequency (FF), landscape and vegetation. To assess the FF, we analysed ten years of the MODerate resolution Imaging Spectroradiometer (MODIS) burned area product (2003-2013). A stratified-random sampling approach was used to assess biodiversity across three dominant landscapes (Nwambia Sandveld-NS, Lebombo North-LN and Shrubveld Mopane on Calcrete-C) and two FF levels (low - twice or less; and high - 3 times or more, during 10 years). Six ha were sampled in each stratum, except for the LN vs High FF in which low accessibility allowed only 3 ha sampling. FF was higher in NS and LN landscapes, where 25% and 34% of the area, respectively burned more than three times in 10 years. The landscape type was the main determinant of grass composition and biomass. However, in the sandy NS biomass was higher under high FF. The three landscapes supported three different tree/shrub communities, but FF resulted in compositional variations in NS and LN. Fire frequency had no marked influence on woody structural parameters (height, density and phytomass). We concluded that the savannas in LNP are mainly driven by landscape (geology), but FF may impose specific modifications. We recommend a fire laissez-faire management system for most of the park and a long-term monitoring system of vegetation to address vegetation changes related to fire. Fire management should be coordinated with the neighboring Kruger National Park, given its long history of fire management.
Data from: Metapopulation dynamics of the mistletoe and its host in savanna areas with different fire occurrence
Mistletoes are aerial hemiparasitic plants which occupy patches of favorable habitat (host trees) surrounded by unfavorable habitat and may be possibly modeled as a metapopulation. A metapopulation is defined as a subdivided population that persists due to the balance between colonization and extinction in discrete habitat patches. Our aim was to evaluate the dynamics of the mistletoe Psittacanthus robustus and its host Vochysia thyrsoidea in three Brazilian savanna areas using a metapopulation approach. We also evaluated how the differences in terms of fire occurrence affected the dynamic of those populations (two areas burned during the study and one was fire protected). We monitored the populations at six-month intervals. P. robustus population structure and dynamics met the expected criteria for a metapopulation: i) the suitable habitats for the mistletoe occur in discrete patches; (ii) local populations went extinct during the study and (iii) colonization of previously non-occupied patches occurred. The ratio of occupied patches decreased in all areas with time. Local mistletoe populations went extinct due to two different causes: patch extinction in area with no fire and fire killing in the burned areas. In a burned area, the largest decrease of occupied patch ratios occurred due to a fire event that killed the parasites without, however, killing the host trees. The greatest mortality of V. thyrsoidea occurred in the area without fire. In this area, all the dead trees supported mistletoe individuals and no mortality was observed for parasite-free trees. Because P. robustus is a fire sensitive species and V. thyrsoidea is fire tolerant, P. robustus seems to increase host mortality, but its effect is lessened by periodic burning that reduces the parasite loads.
Data from: Demographic legacies of fire history in an African savanna
Fire is a key determinant of woody vegetation structure in savanna ecosystems, acting both independently and synergistically through interactions with herbivores. Fire influences biodiversity and ecological functioning, but quantifying its effects on woody structure is challenging at both species and community scales. Deeper insight into fire effects, and fire-herbivore interactions, can be gained through the examination of species-specific demographic and dynamic changes occurring across areas with different fire regimes in the presence of large herbivores. We used the Carnegie Airborne Observatory (an integrated LiDAR and imaging spectroscopy system) to map woody tree structure, species and dynamics over a four-year interval across two adjacent savanna landscapes with contrasting fire histories in Kruger National Park, South Africa. A history of higher fire frequency was associated with reduced woody canopy cover (17% vs. 23%) and an increased overall rate of treefall (27% vs. 18%). The landscape with a history of higher fire frequency displayed a shift in woody canopy height distribution from a unimodal curve to a bimodal pattern at the community scale, with large reductions in height classes < 7 m. Differences in tree height distributions and treefall rates across sites were underpinned by species-specific responses to fire frequency. Acacia nigrescens displayed the highest rates of treefall, most likely related to elephant activity, with losses exceeding 40% in the 6-9 m height classes. Synthesis. Our findings indicate that fire history imparts demographic legacies not only on vegetation structure, but also on current vegetation dynamics. Current treefall rates of certain tree species are exacerbated by a history of higher fire frequency. Species-specific and context-conscious investigations are critical for elucidating the driving mechanisms underlying broader community patterns.
Data from: Survival analysis and classification methods for forest fire size
Factors affecting wildland-fire size distribution include weather, fuels, and fire suppression activities. We present a novel application of survival analysis to quantify the effects of these factors on a sample of sizes of lightning-caused fires from Alberta, Canada. Two events were observed for each fire: the size at initial assessment (by the first fire fighters to arrive at the scene) and the size at "being held" (a state when no further increase in size is expected). We developed a statistical classifier to try to predict cases where there will be a growth in fire size (i.e., the size at "being held" exceeds the size at initial assessment). Logistic regression was preferred over two alternative classifiers, with covariates consistent with similar past analyses. We conducted survival analysis on the group of fires exhibiting a size increase. A screening process selected three covariates: an index of fire weather at the day the fire started, the fuel type burning at initial assessment, and a factor for the type and capabilities of the method of initial attack. The Cox proportional hazards model performed better than three accelerated failure time alternatives. Both fire weather and fuel type were highly significant, with effects consistent with known fire behaviour. The effects of initial attack method were not statistically significant, but did suggest a reverse causality that could arise if fire management agencies were to dispatch resources based on a-priori assessment of fire growth potentials. We discuss how a more sophisticated analysis of larger data sets could produce unbiased estimates of fire suppression effect under such circumstances.
Data from: Spatio-temporal effects of logging and fire on tall, wet temperate eucalypt forest birds
Forests globally are subject to multiple disturbances such as logging and fire that create complex temporal variation in spatial patterns of forest cover and stand age. However, investigations that quantify temporal changes in biodiversity in response to multiple forms of disturbance in space and time are relatively uncommon. Over a 10-year period, we investigated the response of bird species to spatio-temporal changes in cover associated with logging and wildfire in the Mountain Ash (Eucalyptus regnans) forests of south-eastern Australia. Specifically, we examined how bird occurrence changed with shifts in the proportion of area burnt or logged in a 4.5km radius surrounding each of 87 field survey sites. Overall species richness was greatest in older forest patches. Bird species richness declined as the amount of fire around each site increased. At the individual species level, most species were more likely to be found in old growth than younger forest. Twenty-five of 36 bird species we modeled, exhibited a negative response to the amount of fire in the surrounding landscape (while two species responded positively to fire). Only nine species exhibited signs of post-fire recovery. Ten species were more likely to be recorded as the proportion of logged forest surrounding a site increased, suggesting a possible "concentration effect" with displaced birds moving into unlogged areas following harvesting of adjacent areas. In contrast to predictions from the disturbance-congruence hypothesis, no bird species exhibited similar responses to fire and logging in the landscape surrounding our sites. Similarly, no bird life history traits were associated with burned or logged forest, although insectivorous birds were more likely to be found in old growth forests and increased over time. Birds in Mountain Ash forests are strongly associated with old growth stands and exhibit complex, time-dependent and species-specific responses to landscape disturbance. Despite logging and fire both being high-severity perturbations, species responses to one kind of landscape-scale disturbance are not readily predictable based on an understanding of the responses to another kind of (albeit superficially similar) disturbance.
Mesophication in temperate Europe: a dendrochronological reconstruction of tree succession and fires in a mixed deciduous stand in Białowieża Forest / supporting data
<p>The attached data was gathered to investigate the successional changes in Bialowieza Forest mixed-deciduous stands by reconstructing the long-term tree population dynamics (tree-ring data). Traces of fires were documented from a 43ha area to explore whether fire was involved in shaping the succession of this habitat.</p>
Data from: Fire may mediate effects of landscape connectivity on plant community richness in prairie remnants
Following the predictions of island biogeography and metapopulation theory, efforts to understand and maintain plant communities have focused on spatial attributes such as patch size and connectivity. However, despite a large body of literature, the effects of these spatial attributes remain uncertain, and accumulating evidence suggests that they may interact with local patch characteristics. Here, we assess the role of spatial attributes (patch size and connectivity at two time periods) and of patch quality (indicated by number of years since last fire, as this is a fire-dependent system) in determining plant species richness at 63 remnant prairie sites in Wisconsin, USA. Our results demonstrate significant main effects of patch size, with larger patches being richer than small patches, and of fire, with recent-fire sites being richer than fire-excluded sites. We also report a novel interaction between number of years since fire and patch connectivity. Historical (1950) connectivity was negatively related to species richness at recent-fire sites, but positively related to species richness at fire-excluded sites, while current (2000) connectivity and species richness were positively correlated at recent-fire sites, but unrelated at fire-excluded sites. Our findings indicate that measures of patch quality such as time since last fire can alter the association between spatial attributes such as patch size or connectivity and species richness.
Data from: Fire does not strongly affect genetic diversity or structure of a common treefrog in the endangered Florida scrub
Fire regimes influence natural populations of organisms in diverse ways, via direct effects on population dynamics as well as indirect effects on habitat and ecosystem processes. Although many amphibian species have evolved to persist in fire-dependent ecosystems, the effects of fire on the genetic diversity of amphibian populations remain relatively unexplored. We examined how different aspects of fire history relate to population genetic diversity and structure of an abundant anuran, Hyla femoralis, in a large, intact area of Florida scrub containing hundreds of seasonally inundated ponds. Specifically, we assessed the overall population genetic structure and examined whether variation in time since fire, fire intensity, or historical fire frequency at breeding sites explained spatial variation in genetic diversity. Based on our sampling of 17 breeding aggregations within the 2,100-ha study area, neither recent nor frequent fire reduce genetic diversity or restrict connectivity among ponds for H. femoralis. Overall, mean effective population sizes were large (average range = 68–572). We detected a positive trend between effective population size (Ne) and average intensity of the most-recent fire, with this factor explaining 42% of the variation in Ne. Our results contrast with previous studies that consistently demonstrate strong relationships between fire history and population genetic structure of scrub-associated lizard species, suggesting that H. femoralis is resilient to a wide range of fire regimes. More generally, our study contributes to understanding the roles of life-history characteristics and environmental unpredictability in shaping organisms' responses to fire.
Fire refugia facilitate forest and savanna co‐existence as alternative stable states
<p>Aim: Does complex topography facilitate the establishment and persistence of fire‐ sensitive (forest) vegetation in a fire‐prone landscape? We test the prediction that fire‐sensitive vegetation will establish and persist in areas where the fire return interval is lower due to a topographic hindrance on fire spread. Location: Hluhluwe–iMfolozi Park, KwaZulu Natal, South Africa.</p> <p>Methods: Using aerial photographs from six time periods between 1937 and 2013, we mapped vegetation changes in Hluhluwe–iMfolozi Park (HiP). Using a general‐ ized additive model (GAM), we built a habitat suitability index (HSI) map for forest vegetation based on topographic variables related to fire behaviour and the vegeta‐ tion distribution maps from each time period. We investigated transitions between vegetation types between time periods based on the HSI map, as well as the effects of neighbourhood vegetation on transition probabilities.</p> <p>Results: Forest cover has increased overall from 1937 to 2013, however, this has not been a linear increase with a peak in extent in the early 1990s. The HSI, using topo‐ graphic predictors associated with fire behaviour, correlates with areas of expansion and contraction of forest vegetation. The patterns of expansion and contraction are, however, more nuanced, with the in situ vegetation neighbourhood playing a large role.</p> <p>Main Conclusions: Forest distributions in HiP have not remained static over time and have expanded into areas that were once savannas. This is a dynamic system where both forest and savanna boundaries can change considerably. Fire refugia are impor‐ tant for the long‐term persistence of forests in fire‐prone landscapes.</p>
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Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.