This study presents a unique data set from a laboratory experiment where we explored changes in the chemical composition of deionized water samples exposed to smoke. Inside a laboratory hood, water ...samples placed into a chamber were exposed to smoke for up to 60 min. The pattern of variations in hydrochemistry observed over time with increasing smoke exposure was similar in response to two different smoke treatments generated from burning tree litter. To estimate the smoke dosage and assess the consistency of replicate smoke treatments, we conducted additional experiments to evaluate changes in light transmission. Smoke inputs to the deionized water samples drove changes in hydrochemistry, with increases in acidity (with decreasing pH values), the content of organic matter (with increasing concentrations of dissolved organic carbon and dissolved organic nitrogen), and the content of inorganic N species (with increasing concentrations of ammonium, nitrate, and nitrite). The study was conducted on deionized water samples, and the results may not be directly transferrable to natural waters. Stream or lake waters that are low in ionic strength, poorly buffered, or low in acid‐neutralizing capacity might respond the most similar to the results of this study. In contrast, well‐buffered surface waters having higher acid‐neutralizing capacity would be more likely to neutralize acidic inputs from the smoke without significant effects on water quality. The publicly available dataset associated with this study will contribute to further consideration of the relative importance of short‐term changes in hydrochemistry driven by in‐stream inputs (e.g., changes in water chemistry from direct smoke deposition to the water surface) in contrast to terrestrial inputs (e.g., changes in water chemistry stemming from altered flow paths and source areas of the burned watershed landscape).
This study explored the direct effects of smoke penetrating the water surface in altering water quality.
A data set is presented from a lab experiment exploring changes in the hydrochemical composition of deionized water samples exposed to smoke.
The data generate hypotheses about short‐term changes in hydrochemistry that could result from smoke exposures to surface waters having low acid‐neutralizing capacity.
Ongoing climate change may undermine the effectiveness of protected area networks in preserving the set of biotic components and ecological processes they harbor, thereby jeopardizing their ...conservation capacity into the future. Metrics of climate change, particularly rates and spatial patterns of climatic alteration, can help assess potential threats. Here, we perform a continent‐wide climate change vulnerability assessment whereby we compare the baseline climate of the protected area network in North America (Canada, United States, México—NAM) to the projected end‐of‐century climate (2071–2100). We estimated the projected pace at which climatic conditions may redistribute across NAM (i.e., climate velocity), and identified future nearest climate analogs to quantify patterns of climate relocation within, among, and outside protected areas. Also, we interpret climatic relocation patterns in terms of associated land‐cover types. Our analysis suggests that the conservation capacity of the NAM protection network is likely to be severely compromised by a changing climate. The majority of protected areas (~80%) might be exposed to high rates of climate displacement that could promote important shifts in species abundance or distribution. A small fraction of protected areas (<10%) could be critical for future conservation plans, as they will host climates that represent analogs of conditions currently characterizing almost a fifth of the protected areas across NAM. However, the majority of nearest climatic analogs for protected areas are in nonprotected locations. Therefore, unprotected landscapes could pose additional threats, beyond climate forcing itself, as sensitive biota may have to migrate farther than what is prescribed by the climate velocity to reach a protected area destination. To mitigate future threats to the conservation capacity of the NAM protected area network, conservation plans will need to capitalize on opportunities provided by the existing availability of natural land‐cover types outside the current network of NAM protected areas.
We perform a North America continent‐wide (México, United States, Canada) climate change vulnerability assessment to quantify potential patterns of climate relocation within, among, and outside protected areas. Our analysis suggests that the conservation capacity of the North American protection network is likely to be severely compromised by a changing climate as the majority of protected areas might be exposed to high rates of climate displacement. The majority of nearest climatic analogs for protected areas are in nonprotected locations, and therefore, unprotected landscapes could pose additional threats (beyond climate forcing itself) as sensitive biota may have to migrate farther than what is prescribed by the climate velocity to reach a protected area destination.
1. The earliest examples of alternative community states in the literature appear to be descriptions of natural vegetation said to both depend on and promote fire. Nonetheless, alternative community ...states determined by fire have rarely been documented at landscape scales and in natural vegetation. This is because spatial autocorrelation may confound analyses, experimental manipulations are difficult and a long-term perspective is needed to demonstrate that alternative community states can persist for multiple generations. 2. We hypothesized that alternative community states occur in a largely forested landscape in the Klamath Mountains, north-western California, USA, where shrub-dominated sclerophyllous vegetation establishes after fire that is lethal to forests. Forests redevelop if succession is not arrested by fire. Our hypothesis would require that sclerophyll and forest vegetation states each be maintained by different self-reinforcing relationships with fire. 3. To test this hypothesis, we examined pyrogenicity of forest and sclerophyll vegetation as a function of time since the previous fire, accounting for spatial autocorrelation. Fire exclusion served as a de facto experimental treatment. Areas where fire had proceeded to occur served as controls. 4. Our findings are consistent with the occurrence of alternative community states established and maintained by different self-reinforcing feedbacks with fire. Sclerophyll vegetation was more pyrogenic, especially where time-since-fire (TSF) was relatively short, a favourable relationship for this fire-dependent vegetation. Forests were much less pyrogenic, especially where TSF was long, favouring their maintenance. Fire exclusion therefore has led to afforestation and rapid retreat of fire-dependent vegetation. 5. Synthesis: We have documented how different self-reinforcing combustion properties of forest and sclerophyll vegetation can naturally produce alternative states coexisting side-by-side in the same environment. Such fire-mediated alternative states may be underappreciated, in part, because they are difficult to demonstrate definitively. In addition, the dynamics they exhibit contrast with common perceptions that fire hazard increases deterministically with TSF in forests and shrublands. Addressing the impacts of fire exclusion will probably require a management shift to better allow fire to perform its ecological role in shaping landscape diversity and maintaining fire-dependent biota.
Human activities threaten the effectiveness of protected areas (PAs) in achieving their conservation goals across the globe. In this study, we contrast the influence of human and macro-environmental ...factors driving fire activity inside and outside PAs. Using area burned between 1984 and 2014 for 11 ecoregions in Canada and the United States, we built and compared statistical models of fire likelihood using the MaxEnt software and a set of 11 key anthropogenic, climatic, and physical variables. Overall, the full model (i.e. including all variables) performed better (adjusted area under the curve ranging from 0.71 to 0.95 for individual ecoregions) than the model that excluded anthropogenic variables. Both model types (with and without anthropogenic variables) generally performed better inside than outside the PAs. Climatic variables were usually of foremost importance in explaining fire activity inside and outside PAs, with anthropogenic variables being the second most important predictors, even inside PAs. While the individual contributions of anthropogenic variables indicate that fire activity decreased as of function of increasing human footprint, the anthropogenic effects were often substantially greater than those of physical features and were comparable to or even greater than climatic effects in some densely developed ecoregions, both outside and within PAs (e.g. Mediterranean California, Eastern Temperate Forest, and Tropical Wet Forests). Together, these results show the pervasive impact of humans on fire regimes inside PAs, as well as outside PAs. Given the increasing attractiveness of PAs, the implications for adaptive fire management beyond the concept of naturalness in the PAs are discussed. Our assessment of human-altered fire activity could serve as an indicator of human pressure in PAs; however, we suggest that further analysis is needed to understand specific interactions among fire, human pressures, and the environmental conditions at the scale of PAs.
Climate change and disruptions to global fire activity Moritz, Max A; Parisien, Marc-André; Batllori, Enric ...
Ecosphere (Washington, D.C),
2012-June, June 2012, 2012-06-00, 20120601, Letnik:
3, Številka:
6
Journal Article
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Future disruptions to fire activity will threaten ecosystems and human well-being throughout the world, yet there are few fire projections at global scales and almost none from a broad range of ...global climate models (GCMs). Here we integrate global fire datasets and environmental covariates to build spatial statistical models of fire probability at a 0.5° resolution and examine environmental controls on fire activity. Fire models are driven by climate norms from 16 GCMs (A2 emissions scenario) to assess the magnitude and direction of change over two time periods, 2010-2039 and 2070-2099. From the ensemble results, we identify areas of consensus for increases or decreases in fire activity, as well as areas where GCMs disagree. Although certain biomes are sensitive to constraints on biomass productivity and others to atmospheric conditions promoting combustion, substantial and rapid shifts are projected for future fire activity across vast portions of the globe. In the near term, the most consistent increases in fire activity occur in biomes with already somewhat warm climates; decreases are less pronounced and concentrated primarily in a few tropical and subtropical biomes. However, models do not agree on the direction of near-term changes across more than 50% of terrestrial lands, highlighting major uncertainties in the next few decades. By the end of the century, the magnitude and the agreement in direction of change are projected to increase substantially. Most far-term model agreement on increasing fire probabilities (∼62%) occurs at mid- to high-latitudes, while agreement on decreasing probabilities (∼20%) is mainly in the tropics. Although our global models demonstrate that long-term environmental norms are very successful at capturing chronic fire probability patterns, future work is necessary to assess how much more explanatory power would be added through interannual variation in climate variables. This study provides a first examination of global disruptions to fire activity using an empirically based statistical framework and a multi-model ensemble of GCM projections, an important step toward assessing fire-related vulnerabilities to humans and the ecosystems upon which they depend.
Foundations of translational ecology Enquist, Carolyn AF; Jackson, Stephen T; Garfin, Gregg M ...
Frontiers in ecology and the environment,
12/2017, Letnik:
15, Številka:
10
Journal Article
Recenzirano
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Ecologists who specialize in translational ecology (TE) seek to link ecological knowledge to decision making by integrating ecological science with the full complement of social dimensions that ...underlie today's complex environmental issues. TE is motivated by a search for outcomes that directly serve the needs of natural resource managers and decision makers. This objective distinguishes it from both basic and applied ecological research and, as a practice, it deliberately extends research beyond theory or opportunistic applications. TE is uniquely positioned to address complex issues through interdisciplinary team approaches and integrated scientist-practitioner partnerships. The creativity and context-specific knowledge of resource managers, practitioners, and decision makers inform and enrich the scientific process and help shape use-driven, actionable science. Moreover, addressing research questions that arise from on-the-ground management issues - as opposed to the top-down or expert-oriented perspectives of traditional science - can foster the high levels of trust and commitment that are critical for long-term, sustained engagement between partners.
Fire plays a crucial role in many ecosystems, and a better understanding of different controls on fire activity is needed. Here we analyze spatial variation in fire danger during episodic wind events ...in coastal southern California, a densely populated Mediterranean‐climate region. By reconstructing almost a decade of fire weather patterns through detailed simulations of Santa Ana winds, we produced the first high‐resolution map of where these hot, dry winds are consistently most severe and which areas are relatively sheltered. We also analyzed over half a century of mapped fire history in chaparral ecosystems of the region, finding that our models successfully predict where the largest wildfires are most likely to occur. There is a surprising lack of information about extreme wind patterns worldwide, and more quantitative analyses of their spatial variation will be important for effective fire management and sustainable long‐term urban development on fire‐prone landscapes.
Vegetation tolerance to drought depends on an array of site-specific environmental and plant physiological factors. This tolerance is poorly understood for many forest types despite its importance ...for predicting and managing vegetation stress. We analyzed the relationships between precipitation variability and forest die-off in California's Sierra Nevada and introduce a new measure of drought tolerance that emphasizes plant access to subsurface moisture buffers. We applied this metric to California's severe 2012-2015 drought, and show that it predicted the patterns of tree mortality. We then examined future climate scenarios, and found that the probability of droughts that lead to widespread die-off increases threefold by the end of the 21st century. Our analysis shows that tree mortality in the Sierra Nevada will likely accelerate in the coming decades and that forests in the Central and Northern Sierra Nevada that largely escaped mortality in 2012-2015 are vulnerable to die-off.
Recent, large fires in the western United States have rekindled debates about fire management and the role of natural fire regimes in the resilience of terrestrial ecosystems. This real-world ...experience parallels debates involving abstract models of forest fires, a central metaphor in complex systems theory. Both real and modeled fire-prone landscapes exhibit roughly power law statistics in fire size versus frequency. Here, we examine historical fire catalogs and a detailed fire simulation model; both are in agreement with a highly optimized tolerance model. Highly optimized tolerance suggests robustness tradeoffs underlie resilience in different fire-prone ecosystems. Understanding these mechanisms may provide new insights into the structure of ecological systems and be key in evaluating fire management strategies and sensitivities to climate change.
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