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Ecosystem-based management advocates that forestry disturbances should aim to emulate natural disturbances to mitigate the landscape-level impact of forest management. This study compares the impact of clear-cuts followed by a prescribed burn (CCPB) with clear-cuts alone (CC) and current careful logging practices (CLAAG: “careful logging around advanced growth”) on understory composition within black spruce (Picea mariana Miller (BSP)) paludified forest stands at the plot, site, and treatment levels using a functional-type approach. Vascular and nonvascular taxa showed significant differences in composition at the plot level among treatments. We found that pioneer taxa occurred mainly in CCPB sites, while late-successional taxa characterized CC sites. CLAAG sites had higher taxa richness than CCPB and CC sites, and we found that CCPB treatments were most likely to promote vascular taxa compositions that are more similar to those observed after natural disturbances. Additionally, the relative abundance of Sphagnum spp., responsible for paludification, was significantly reduced in sites treated by prescribed burning. This study therefore presents results suggesting that prescribed burning might represent a sustainable alternative to current harvesting techniques in the Clay Belt of eastern Canada that could help in preserving biodiversity (in terms of understory species assemblage) while maintaining or even enhancing forest productivity.

Wildland fires in Southern California can be divided into two categories: fall fires, which are typically driven by strong offshore Santa Ana winds, and summer fires, which occur with comparatively weak onshore winds and hot and dry weather. Both types of fire contribute significantly to annual burned area and economic loss. An improved understanding of the relationship between Southern California's meteorology and fire is needed to improve predictions of how fire will change in the future and to anticipate management needs. We used output from a regional climate model constrained by reanalysis observations to identify Santa Ana events and partition fires into those occurring during periods with and without Santa Ana conditions during 1959–2009. We then developed separate empirical regression models for Santa Ana and non-Santa Ana fires to quantify the effects of meteorology on fire number and size. These models explained approximately 58% of the seasonal and interannual variation in the number of Santa Ana fires and 36% of the variation in non-Santa Ana fires. The number of Santa Ana fires increased during years when relative humidity during Santa Ana events and fall precipitation were below average, indicating that fuel moisture is a key controller of ignition. Relative humidity strongly affected Santa Ana fire size. Cumulative precipitation during the previous three winters was significantly correlated with the number of non-Santa Ana fires, presumably through increased fine fuel density and connectivity between infrastructure and nearby vegetation. Both relative humidity and the preceding wet season precipitation influenced non-Santa Ana fire size. Regression models driven by meteorology explained 57% of the temporal variation in Santa Ana burned area and 22% of the variation in non-Santa Ana burned area. The area burned by non-Santa Ana fires has increased steadily by 1.7% year−1 since 1959 (p < 0.006); the occurrence of extremely large Santa Ana fires has increased abruptly since 2003. Our results underscore the need to separately consider the fuel and meteorological controls on Santa Ana and non-Santa Ana fires when projecting climate change impacts on regional fire.

AGAP : GE2pop - Génomique évolutive et gestion des populations; International audience; Whether species can respond evolutionarily to current climate change is crucial for the persistence of many species. Yet, very few studies have examined genetic responses to climate change in manipulated experiments carried out in natural field conditions. We examined the evolutionary response to climate change in a common annelid worm using a controlled replicated experiment where climatic conditions were manipulated in a natural setting. Analyzing the transcribed genome of 15 local populations, we found that about 12% of the genetic polymorphisms exhibit differences in allele frequencies associated to changes in soil temperature and soil moisture. This shows an evolutionary response to realistic climate change happening over short-time scale, and calls for incorporating evolution into models predicting future response of species to climate change. It also shows that designed climate change experiments coupled with genome sequencing offer great potential to test for the occurrence (or lack) of an evolutionary response.

Spatial patterns and controls on burned area for two contrasting fire regimes in Southern California N. R. Faivre, 1, † Y. Jin, 2 M. L. Goulden, 1 and J. T. Randerson 1 1 Department 2 Department of Earth System Science, University of California, Irvine, California 92697-3100 USA of Land, Air and Water Resources, University of California, Davis, California 95616-8627 USA Citation: Faivre, N. R., Y. Jin, M. L. Goulden, and J. T. Randerson. 2016. Spatial patterns and controls on burned area for two contrasting fire regimes in Southern California. Ecosphere 7(5):e01210. 10.1002/ecs2.1210 Abstract. An improved understanding of the mechanisms that regulate wildfire risk at local to regional scales is needed for the design of effective fire and ecosystem management. We investigated the spatial distribution of burned area in Southern California during 1960–2009 using five different data-­driven meth- ods: multiple linear regression, generalized additive models (GAMs), GAMs with spatial autocorrelation, non-­linear multiplicative models, and random forest models. We used each method to separately develop burned area risk maps for Southern California’s two distinct wildfire regimes: Santa Ana (SA fires), which occur during high wind events mostly in autumn, and non-­Santa Ana fires (non-­SA fires), which occur mostly during the hot and dry Mediterranean-­climate summer. The different methods explained 38–63% of the spatial variance in burned area for SA fires and 21–48% for non-­SA fires. The two fire regimes had contrasting drivers, with Fosberg fire weather index, relative humidity, minimum temperature, and dis- tance to housing most important for SA fires, and shrub cover, road density, and distance to minor and major roads most important for non-­SA fires. Our modeling framework carries implications for the strate- gic placement of fire suppression resources, and for prevention planning in areas facing increasing human and climate pressures. Key words: biophysical drivers; fire frequency; geospatial regression models; human influence; Mediterranean ­ecosystems; Santa Ana fires; wildfire risk; wildland–urban interface. Received 22 July 2015; accepted 29 July 2015. Corresponding Editor: D. P. C. Peters. Copyright: © 2016 Faivre et al. This is an open access article under the terms of the Creative Commons Attribution ­License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. † E-mail: belotte.faivre@gmail.com I ntroduction loss and multiple fatalities (Brillinger et al. 2009, Keeley et al. 2009). Spatial and temporal variabil- ity in burned area within the region depends on ignition, meteorology, vegetation characteristics, topography, and fire suppression (Davis and Mi- chaelsen 1995, Zedler and Seiger 2000, Moritz et al. 2004). Large areas of wildland–urban inter- face further contribute to variability in burned area as a consequence of ignition probability, landscape fragmentation, and access points for suppression. Interactions between the envi- ronmental and human controls on wildfire are Southern California is prone to recurrent wild- land fire that strongly influences ecosystem pro- cesses and vegetation dynamics. Over the past 50 yr, an average of 40 large fires (>40 ha each) occurred each year, resulting in a mean burned area of 53 300 ha per yr (Jin et al. 2014). Despite considerable investment in fire suppression, fire perimeter data sets show an increasing trend in burned area since 1980 (Westerling 2006, Jin et al. 2014). These fires have caused extensive property v www.esajournals.org May 2016 v Volume 7(5) v Article e01210

Landscape pyrodiversity encapsulates the range of spatiotemporal variability in disturbance by fire. There is a widely-held view that diversity in fire regimes promotes biological diversity (i.e., the Pyrodiversity–Biodiversity paradigm). However, this relationship needs to be examined more carefully as pyrodiversity at the landscape scale remains poorly defined and difficult to quantify. Here, we used a novel approach to analyze landscape pyrodiversity by selecting and quantifying appropriate descriptors of fire variability at the landscape level. We characterized and classified observed fire mosaics at the 1 km scale using temporal attributes (fire frequency, time-since-fire and mean fire interval) and a variety of spatial attributes derived from landscape metrics. We trialed our approach on a 50-year record of fire patterns in two Mediterranean environments; (1) in southern France where fire regimes are dominated by unplanned (‘wild’-)fires and (2) in south-west Australia, where fire regimes are dominated by planned fires. We found that the landscape pyrodiversity of both regions was expressed by distinct gradients of both fire frequency and spatial diversity of fire patterns. As expected, the two environments were significantly different in landscape pyrodiversity, with contrasting mean fire frequency and mean time-since-fire patterns. However, we also found similarities between southern France and south-west Australia in the composition and configuration of their spatial fire patterns. Our results show that these two Mediterranean environments form a pyrodiversity continuum despite the disparate management regimes. Our findings also demonstrate that a quantitative characterization of pyrodiversity is central to developing new perspectives and practical tools for biodiversity conservation in fire-prone landscapes.

International audience; Genetic diversity is the amount of variation observed between DNA sequences from distinct individuals of a given species. This pivotal concept of population genetics has implications for species health, domest-ication, management and conservation. Levels of genetic diversity seem to vary greatly in natural populations and species, but the determinants of this variation, and particularly the relative influences of species biology and ecology versus population history, are still largely mysterious 1,2. Here we show that the diversity of a species is predictable , and is determined in the first place by its ecological strategy. We investigated the genome-wide diversity of 76 non-model animal species by sequencing the transcriptome of two to ten individuals in each species. The distribution of genetic diversity between species revealed no detectable influence of geographic range or invasive status but was accurately predicted by key species traits related to parental investment: long-lived or low-fecundity species with brooding ability were genetically less diverse than short-lived or highly fecund ones. Our analysis demonstrates the influence of long-term life-history strategies on species response to short-term environmental perturbations, a result with immediate implications for conservation policies. Since the early studies of evolutionary genetics, there has been no understanding of how and why genetic diversity levels vary between species. This old puzzle, considered four decades ago as 'the central problem in population genetics'

Wildfireignitionrequiresacombinationofanopenspark,andsuitableweatherandfuelconditions.Modelsof fire occurrence and burned area provide a good understanding of the physical and climatic factors that constrain and promote fire spread and recurrence, but information on how humans influence ignition patterns is still lacking at a scale compatible with integrated fire management.We investigated the relative importance of the physical, climatic andhuman factors regulating ignition probability across Southern California's National Forests. A 30-year exploratory analysis of one-way relationships indicated that distance to a road, distance to housing and topographic slope were the major determinants of ignition frequency. We used logistic and Poisson regression analyses to model ignition occurrence and frequency as a function of the dominant covariates. The resulting models explained ,70% of the spatial variability in ignition likelihood and 45% of the variability in ignition frequency. In turn, predicted ignition probability contributed to some of the spatial variability in burned area, particularly for summer fires. These models may enable estimates of fire ignition risk for the broader domain of Southern California and how this risk may change with future population and housing development. Our spatially explicit predictions may also be useful for strategic fire management in the region. Additional keywords: biophysical drivers, fire frequency, fire ignition, human influence, Mediterranean ecosystems, spatial regression model, wildland fire risk.

The effect of salinity was studied in natural populations of the black-chinned tilapia (Sarotherodon melanotheron) from West Africa. This euryhaline species colonizes nearly all coastal environments from bays to lagoons characterized by salinities ranging from fresh water to hypersaline water over 100 aEuro degrees. Individuals were sampled during the dry season at several locations characterized by different levels of salinity (3-102 aEuro degrees). Their osmotic status and their gills were analyzed. The branchial mitochondria-rich cells (MRC), localized at the basis of the filaments and along the lamellae in fish taken from the saline stations, showed a wide plasticity with significant differences in their number and size. The most striking results were a significant larger area (a parts per thousand 3x) and a higher number (a parts per thousand 55x) of MRC at high salinity (102 aEuro degrees) compared to low salinity (3 aEuro degrees). The major ion transporters and channels were localized by immunocytochemistry and different expression patterns have been recorded between stations. Despite an increased Na+/K+-ATPase (NKA) alpha-subunit expression and NKA activity, pointing to an increased monovalent ion excretion, a severe osmotic imbalance was recorded in animals living in hypersaline environments.