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Joshi KP, Adhikari G, Bhattarai D, Adhikari A, Lamichanne S. Forest fire vulnerability in Nepal's chure region: Investigating the influencing factors using generalized linear model. Heliyon 2024; 10:e28525. [PMID: 38596031 PMCID: PMC11002069 DOI: 10.1016/j.heliyon.2024.e28525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 03/20/2024] [Accepted: 03/20/2024] [Indexed: 04/11/2024] Open
Abstract
The Chure region, among the world's youngest mountains, stands out as highly susceptible to natural calamities, particularly forest fires. The region has consistently experienced forest fire incidents, resulting in the degradation of valuable natural and anthropogenic resources. Despite its vulnerability, there have been limited studies to understand the relationship of various causative factors for the recurring fire problem. Hence, to comprehend the influencing factors for the recurring forest fire problem and its extent, we utilized generalized linear modeling under binary logistic regression to combine the dependent variable of satellite detected fire points and various independent variables. We conducted a variance inflation factor (VIF) test and correlation matrix to identify the 14 suitable variables for the study. The analysis revealed that forest fires occurred mostly during the three pre-monsoon periods and had a significant positive relation with the area under forest, rangeland, bare-grounds, and Normalized Difference Vegetation Index (NDVI) (P < 0.05). Consequently, our model showed that the probability of fire incidents decreases with elevation, precipitation, and population density (P < 0.05). Among the significant variables, the forest areas emerges as the most influencing factor, followed by precipitation, elevation, area of rangeland, population density, NDVI, and the area of bare ground. The validation of the model was done through the area under the curve (AUC = 0.92) and accuracy (ACC = 0.89) assessments, which showed the model performed excellently in terms of predictive capabilities. The modeling result and the forest fire susceptible map provide valuable insights into the forest fire vulnerability in the region, offering baseline information about forest fires that will be helpful for line agencies to prepare management strategies to further prevent the deterioration of the region.
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Affiliation(s)
| | - Gunjan Adhikari
- Institute of Forestry, Pokhara Campus, Tribhuvan University, Pokhara, Nepal
| | - Divya Bhattarai
- Faculty of Forestry, Agriculture and Forestry University, Hetauda, 44100, Nepal
- Nepal Conservation and Research Center, Ratnanagar-6, Sauraha, Chitwan, Nepal
| | | | - Saurav Lamichanne
- Faculty of Forestry, Agriculture and Forestry University, Hetauda, 44100, Nepal
- Nepal Conservation and Research Center, Ratnanagar-6, Sauraha, Chitwan, Nepal
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2
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Goodwin MJ, Hurteau MD. The effect of shrub cover on conifer water-use patterns, growth and response to precipitation variability in the southern Sierra Nevada. TREE PHYSIOLOGY 2024; 44:tpae004. [PMID: 38198740 DOI: 10.1093/treephys/tpae004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 12/26/2023] [Accepted: 01/04/2024] [Indexed: 01/12/2024]
Abstract
As wildfires increase in size and severity, large areas of forest are undergoing substantial increases in shrub cover. In forests where water is the limiting resource, the partitioning of soil water between shrubs and young trees may determine how shrubs affect tree growth and water-stress. Here we evaluated juvenile trees (average age = 32 years) of two dominant conifer species in the southern Sierra Nevada of California (Abies concolor (white fir) and Pinus jeffreyi (Jeffrey pine)) growing in the presence or absence of shrubs. The two shrub species included Arctostaphylos patula and Ceanothus cordulatus, a nitrogen-fixing species. We analyzed the δ2H and δ18O values of xylem water for both tree and shrub species to assess how shrub cover affects the water-uptake patterns of conifers and whether there is niche partitioning between trees and shrubs. We found that growing near shrubs did not have a significant effect on the water source dynamics of either tree species, with similar source water contributions calculated for conifers growing in both the presence and absence of shrubs. Using a tree-ring analysis of growth and δ13C from 2016 to 2021, a period of high precipitation variability, we found that shrub cover had a positive effect on tree growth while decreasing carbon discrimination, which may be due to increased nitrogen availability from Ceanothus cordulatus. Overall, our results suggest that growing in the presence of shrubs does not alter the water uptake patterns of white fir and Jeffrey pine and instead may have a positive effect on the growth rates of these species during both wet and dry years.
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Affiliation(s)
- Marissa J Goodwin
- Department of Biology, University of New Mexico, 219 Yale Blvd NE, Albuquerque, NM 87131, USA
| | - Matthew D Hurteau
- Department of Biology, University of New Mexico, 219 Yale Blvd NE, Albuquerque, NM 87131, USA
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3
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Gorta SBZ, Callaghan CT, Samonte F, Ooi MKJ, Mesaglio T, Laffan SW, Cornwell WK. Multi-taxon biodiversity responses to the 2019-2020 Australian megafires. GLOBAL CHANGE BIOLOGY 2023; 29:6727-6740. [PMID: 37823682 DOI: 10.1111/gcb.16955] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Revised: 08/29/2023] [Accepted: 09/05/2023] [Indexed: 10/13/2023]
Abstract
Conditions conducive to fires are becoming increasingly common and widespread under climate change. Recent fire events across the globe have occurred over unprecedented scales, affecting a diverse array of species and habitats. Understanding biodiversity responses to such fires is critical for conservation. Quantifying post-fire recovery is problematic across taxa, from insects to plants to vertebrates, especially at large geographic scales. Novel datasets can address this challenge. We use presence-only citizen science data from iNaturalist, collected before and after the 2019-2020 megafires in burnt and unburnt regions of eastern Australia, to quantify the effect of post-fire diversity responses, up to 18 months post-fire. The geographic, temporal, and taxonomic sampling of this dataset was large, but sampling effort and species discoverability were unevenly spread. We used rarefaction and prediction (iNEXT) with which we controlled sampling completeness among treatments, to estimate diversity indices (Hill numbers: q = 0-2) among nine broad taxon groupings and seven habitats, including 3885 species. We estimated an increase in species diversity up to 18 months after the 2019-2020 Australian megafires in regions which were burnt, compared to before the fires in burnt and unburnt regions. Diversity estimates in dry sclerophyll forest matched and likely drove this overall increase post-fire, while no taxon groupings showed clear increases inconsistent with both control treatments post-fire. Compared to unburnt regions, overall diversity across all taxon groupings and habitats greatly decreased in areas exposed to extreme fire severity. Post-fire life histories are complex and species detectability is an important consideration in all post-fire sampling. We demonstrate how fire characteristics, distinct taxa, and habitat influence biodiversity, as seen in local-scale datasets. Further integration of large-scale datasets with small-scale studies will lead to a more robust understanding of fire recovery.
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Affiliation(s)
- Simon B Z Gorta
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, New South Wales, Australia
| | - Corey T Callaghan
- Department of Wildlife Ecology and Conservation, Fort Lauderdale Research and Education Center, University of Florida, Davie, Florida, USA
| | - Fabrice Samonte
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, New South Wales, Australia
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, New South Wales, Australia
| | - Mark K J Ooi
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, New South Wales, Australia
| | - Thomas Mesaglio
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, New South Wales, Australia
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, New South Wales, Australia
| | - Shawn W Laffan
- Earth and Sustainability Science Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, New South Wales, Australia
| | - Will K Cornwell
- Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, New South Wales, Australia
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, UNSW Sydney, Sydney, New South Wales, Australia
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4
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Shearman TM, Varner JM, Hood SM, van Mantgem PJ, Cansler CA, Wright M. Predictive accuracy of post-fire conifer death declines over time in models based on crown and bole injury. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2023; 33:e2760. [PMID: 36218008 DOI: 10.1002/eap.2760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 08/08/2022] [Accepted: 09/07/2022] [Indexed: 06/16/2023]
Abstract
A key uncertainty of empirical models of post-fire tree mortality is understanding the drivers of elevated post-fire mortality several years following fire, known as delayed mortality. Delayed mortality can represent a substantial fraction of mortality, particularly for large trees that are a conservation focus in western US coniferous forests. Current post-fire tree mortality models have undergone limited evaluation of how injury level and time since fire interact to influence model accuracy and predictor variable importance. Less severe injuries potentially serve as an indicator for vulnerability to additional stressors such as bark beetle attack or moisture stress. We used a collection of 164,293 individual tree records to examine post-fire tree mortality in eight western USA conifers: Abies concolor, Abies grandis, Calocedrus decurrens, Larix occidentalis, Pinus contorta, Pinus lambertiana, Pinus ponderosa, and Pseudotsuga menziesii. We evaluated the importance of fire injury predictors on discriminating between surviving trees versus immediate and delayed post-fire mortality. We fit balanced random forest models for each species using cumulative tree mortality from 1 to 5-years post-fire. We compared these results to multi-class random forest models using first-year mortality, 2-5-year mortality, and survival 5-years post-fire as a response variable. Crown volume scorched, diameter at breast height, and relative bark char height, were used as predictor variables. The cumulative mortality models all predicted trees that died within 1-year of fire with high accuracy but failed to predict 2-5-year mortality. The multi-class models were an improvement but had lower accuracy for predicting 2-5-year mortality. Multi-class model accuracies ranged from 85% to 95% across all species for predicting 1-year post-fire mortality, 42%-71% for predicting 2-5-year mortality, and 64%-85% for predicting trees that lived past 5-years. Our study highlights the differences in tree species tolerance to fire injury and suggests that including second-order predictors such as beetle attack or climatic water stress before and after fire will be critical to improve accuracy and better understand the mechanisms and patterns of fire-caused tree death. Random forest models have potential for management applications such as post-fire harvesting and simulating future stand dynamics.
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Affiliation(s)
| | | | - Sharon M Hood
- USDA Forest Service Rocky Mountain Research Station, Missoula, Montana, USA
| | | | - C Alina Cansler
- School of Environmental and Forest Sciences, University of Washington, Seattle, Washington, USA
| | - Micah Wright
- U.S. Geological Survey, Western Ecological Research Center, Arcata, California, USA
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5
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Gong XW, Hao GY. The synergistic effect of hydraulic and thermal impairments accounts for the severe crown damage in Fraxinus mandshurica seedlings following the combined drought-heatwave stress. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 856:159017. [PMID: 36167124 DOI: 10.1016/j.scitotenv.2022.159017] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 09/20/2022] [Accepted: 09/20/2022] [Indexed: 06/16/2023]
Abstract
Drought combined with extreme heatwaves has been increasingly identified as the important trigger of worldwide tree mortality in the context of climate change; nonetheless, our understanding of the potential hydraulic and thermal impairments of hot droughts to trees and the subsequent post-recovery process remains limited. To investigate the response of tree water and carbon relations to drought, heatwave, and combined drought-heatwave stresses, three-year-old potted seedlings of Fraxinus mandshurica Rupr., a dominant tree species in temperate forests of northeast China, were grown under well-watered and drought-stressed conditions and exposed to a rapid, acute heatwave treatment. During the heatwave treatment with a maximum temperature exceeding 40 °C for two days, the leaf temperature of drought-stressed seedlings was, on average, 5 °C higher than that of well-watered counterparts due to less effective evaporative cooling, indicating that soil water availability influenced leaf thermoregulatory capacity during hot extremes. Consistently, more pronounced crown damage, as shown by 13 % irreversible leaf scorch, was found in seedlings under the drought-heatwave treatment relative to sole heatwave treatment, alongside the more severe stem xylem embolism and leaf electrolyte leakage. While the heatwave treatment accelerated the depletion of non-structural carbohydrates in drought-stressed seedlings, the increase of branch soluble sugar concentration in response to heatwave might be related to the requirement for maintaining hydraulic functioning via osmoregulation under high dehydration risk. The coordination between leaf stomatal conductance and total non-structural carbohydrate content during the post-heatwave recovery phase implied that plant-water relations and carbon physiology were closely coupled in coping with hot droughts. This study highlights that, under scenarios of aggravating drought co-occurring with heatwaves, tree seedlings could face a high risk of crown decline in relation to the synergistically increased hydraulic and thermal impairments.
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Affiliation(s)
- Xue-Wei Gong
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Key Laboratory of Terrestrial Ecosystem Carbon Neutrality, Liaoning Province, Shenyang 110016, China; Qingyuan Forest CERN, National Observation and Research Station, Liaoning Province, Shenyang 110016, China
| | - Guang-You Hao
- CAS Key Laboratory of Forest Ecology and Management, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China; Key Laboratory of Terrestrial Ecosystem Carbon Neutrality, Liaoning Province, Shenyang 110016, China; Qingyuan Forest CERN, National Observation and Research Station, Liaoning Province, Shenyang 110016, China.
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6
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Williams JN, Safford HD, Enstice N, Steel ZL, Paulson AK. High‐severity burned area and proportion exceed historic conditions in Sierra Nevada, California, and adjacent ranges. Ecosphere 2023. [DOI: 10.1002/ecs2.4397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- J. N. Williams
- Department of Environmental Science and Policy University of California Davis California USA
| | - H. D. Safford
- Department of Environmental Science and Policy University of California Davis California USA
- Vibrant Planet Incline Village Nevada USA
| | - N. Enstice
- California Department of Conservation Sacramento California USA
- California Sierra Nevada Conservancy Auburn California USA
| | - Z. L. Steel
- USDA Forest Service Rocky Mountain Research Station Fort Collins Colorado USA
| | - A. K. Paulson
- USDA Forest Service, Humboldt‐Toiyabe National Forest Sparks Nevada USA
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7
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Coop JD. Postfire futures in southwestern forests: Climate and landscape influences on trajectories of recovery and conversion. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2023; 33:e2725. [PMID: 36054332 PMCID: PMC10078526 DOI: 10.1002/eap.2725] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 04/29/2022] [Accepted: 06/24/2022] [Indexed: 06/15/2023]
Abstract
Southwestern ponderosa pine forests are vulnerable to fire-driven conversion in a warming and drying climate, yet little is known about what kinds of ecological communities may replace them. To characterize postfire vegetation trajectories and their environmental determinants, plant assemblages (361 sample plots including 229 vascular plant species, surveyed in 2017) were sampled within eight burns that occurred between 2000 and 2003. I used nonmetric multidimensional scaling, k-means clustering, principal component analysis, and random forest models to assess relationships between vegetation pattern, topographic and landscape factors, and gridded climate data. I describe seven postfire community types, including regenerating forests of ponderosa pine, aspen, and mixed conifers, shrub-dominated communities of Gambel oak and mixed species, and herb-dominated communities of native bunchgrasses and mixtures of ruderal, native, and nonnative species. Forest recovery was generally associated with cooler, mesic sites in proximity to forested refugia; shifts toward scrub and grassland types were most common in warmer, dryer locations distant from forested refugia. Under future climate scenarios, models project decreases in postfire forest recovery and increases in nonforest vegetation. However, forest to nonforest conversion was partially offset under a scenario of reduced burn severity and increased retention of forested refugia, highlighting important management opportunities. Burning trends in the southwestern United States suggest that postfire vegetation will occupy a growing landscape fraction, compelling renewed management focus on these areas and paradigm shifts that accommodate ecological change. I illustrate how management decisions around resisting, accepting, or directing change could be informed by an understanding of processes and patterns of postfire community variation and likely future trajectories.
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Affiliation(s)
- Jonathan D. Coop
- Clark School of Environment and SustainabilityWestern Colorado UniversityGunnisonColoradoUSA
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Ward M, Carwardine J, Watson JEM, Pintor A, Stuart S, Possingham HP, Rhodes JR, Carey AR, Auerbach N, Reside A, Yong CJ, Tulloch AIT. How to prioritize species recovery after a megafire. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2022; 36:e13936. [PMID: 35561069 PMCID: PMC9804514 DOI: 10.1111/cobi.13936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 04/09/2022] [Accepted: 04/26/2022] [Indexed: 06/15/2023]
Abstract
Due to climate change, megafires are increasingly common and have sudden, extensive impacts on many species over vast areas, leaving decision makers uncertain about how best to prioritize recovery. We devised a decision-support framework to prioritize conservation actions to improve species outcomes immediately after a megafire. Complementary locations are selected to extend recovery actions across all fire-affected species' habitats. We applied our method to areas burned in the 2019-2020 Australian megafires and assessed its conservation advantages by comparing our results with outcomes of a site-richness approach (i.e., identifying areas that cost-effectively recover the most species in any one location). We found that 290 threatened species were likely severely affected and will require immediate conservation action to prevent population declines and possible extirpation. We identified 179 subregions, mostly in southeastern Australia, that are key locations to extend actions that benefit multiple species. Cost savings were over AU$300 million to reduce 95% of threats across all species. Our complementarity-based prioritization also spread postfire management actions across a wider proportion of the study area compared with the site-richness method (43% vs. 37% of the landscape managed, respectively) and put more of each species' range under management (average 90% vs. 79% of every species' habitat managed). In addition to wildfire response, our framework can be used to prioritize conservation actions that will best mitigate threats affecting species following other extreme environmental events (e.g., floods and drought).
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Affiliation(s)
- Michelle Ward
- Centre for Biodiversity and Conservation ScienceThe University of QueenslandSt LuciaQueenslandAustralia
- School of Earth and Environmental SciencesThe University of QueenslandBrisbaneQueenslandAustralia
- World Wide Fund for Nature–AustraliaBrisbaneQueenslandAustralia
| | | | - James E. M. Watson
- Centre for Biodiversity and Conservation ScienceThe University of QueenslandSt LuciaQueenslandAustralia
- School of Earth and Environmental SciencesThe University of QueenslandBrisbaneQueenslandAustralia
| | - Anna Pintor
- School of Marine and Tropical BiologyJames Cook UniversityCairnsQueenslandAustralia
| | - Stephanie Stuart
- Saving our Species Program, Department of Planning, Industry and EnvironmentParramattaNew South WalesAustralia
| | - Hugh P. Possingham
- Centre for Biodiversity and Conservation ScienceThe University of QueenslandSt LuciaQueenslandAustralia
| | - Jonathan R. Rhodes
- Centre for Biodiversity and Conservation ScienceThe University of QueenslandSt LuciaQueenslandAustralia
- School of Earth and Environmental SciencesThe University of QueenslandBrisbaneQueenslandAustralia
| | - Alexander R. Carey
- Saving our Species Program, Department of Planning, Industry and EnvironmentParramattaNew South WalesAustralia
- Charles Darwin UniversityCasuarinaNorthern TerritoryAustralia
| | - Nancy Auerbach
- Saving our Species Program, Department of Planning, Industry and EnvironmentParramattaNew South WalesAustralia
| | - April Reside
- Centre for Biodiversity and Conservation ScienceThe University of QueenslandSt LuciaQueenslandAustralia
- School of Earth and Environmental SciencesThe University of QueenslandBrisbaneQueenslandAustralia
| | - Chuan Ji Yong
- Centre for Biodiversity and Conservation ScienceThe University of QueenslandSt LuciaQueenslandAustralia
| | - Ayesha I. T. Tulloch
- School of Life and Environmental SciencesUniversity of SydneyCamperdownNew South WalesAustralia
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9
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Dynamic Evaluation of Early Silvicultural Treatments for Wildfire Prevention. FORESTS 2022. [DOI: 10.3390/f13060858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Thinning young forest stands is a common practice to improve the future development of the remaining trees and enhance their resistance to abiotic and biotic disturbances. The objective of this study was to consider the effectiveness of precommercial thinning, over time, implemented on Pinus halepensis (Aleppo pine) thickets, regarding fuel evolution and potential fire behavior. For this purpose, we established 44 plots on untreated and thinned Aleppo pine stands, measured all of the relevant fuel characteristics and simulated fire behavior under average and extreme fire weather scenarios. The plots were at different stages of fuel evolution (0.5 to 10 years since treatment, plus untreated stands), so that the evolution of the variables defining forest structure and the amount and distribution of surface fuels could be captured. The results show that precommercial thinning, when accompanied with pruning and surface fuel management, had a clear impact on fire behavior and on the potential of fire crowning during the first two to four years after the treatment. After that initial period, the buildup of understory vegetation minimized treatment effectiveness in mitigating potential fire behavior. In general, it can be stated that precommercial thinning has a positive impact on fire mitigation, but the impact that opening the tree canopy has on ground vegetation development must be considered in order to plan more efficient management strategies.
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Abstract
As the effects of climate change accumulate and intensify, resource managers juggle existing goals and new mandates to operationalize adaptation. Fire managers contend with the direct effects of climate change on resources in addition to climate-induced disruptions to fire regimes and subsequent ecosystem effects. In systems stressed by warming and drying, increased fire activity amplifies the pace of change and scale of severe disturbance events, heightening the urgency for management action. Fire managers are asked to integrate information on climate impacts with their professional expertise to determine how to achieve management objectives in a changing climate with altered fire regimes. This is a difficult task, and managers need support as they incorporate climate adaptation into planning and operations. We present a list of adaptation strategies and approaches specific to fire and climate based on co-produced knowledge from a science–management partnership and pilot-tested in a two-day workshop with natural resource managers and regional stakeholders. This “menu” is a flexible and useful tool for fire managers who need to connect the dots between fire ecology, climate science, adaptation intent, and management implementation. It was created and tested as part of an adaptation framework used widely across the United States and should be applicable and useful in many fire-prone forest ecosystems.
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11
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Forest Fire Assessment Using Remote Sensing to Support the Development of an Action Plan Proposal in Ecuador. REMOTE SENSING 2022. [DOI: 10.3390/rs14081783] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Worldwide, forest fires exert effects on natural ecosystems, contributing to economic/human losses, health effects, and climate change. Spectral indices are an essential tool for monitoring and analyzing forest fires. These indices make it possible to evaluate the affected areas and help mitigate possible future events and reduce damage. The case study addressed in this work corresponds to the Cerro of the Guadual community of La Carolina parish (Ibarra, Ecuador). This work aims to evaluate the degree of severity and the recovery of post-fire vegetation, employing the multitemporal analysis of spectral indices and correlating these with the climatological aspects of the region. The methodological process was based on (i) background information collection, (ii) remote sensing data, (iii) spectral index analysis, (iv) multivariate analysis, and (v) a forest fire action plan proposal. Landsat-8 OLI satellite images were used for multitemporal analysis (2014–2020). Using the dNDVI index, the fire’s severity was classified as unburned and very low severity in regard to the areas that did not regenerate post-fire, which represented 10,484.64 ha. In contrast, the areas classified as high and very high severity represented 5859.06 ha and 2966.98 ha, respectively. In addition, the dNBR was used to map the burned areas. The high enhanced regrowth zones represented an area of 8017.67 ha, whereas the moderate/high-severity to high-severity zones represented 3083.72 ha and 1233.49 ha, respectively. The areas with a high severity level corresponded to native forests, which are challenging to recover after fires. These fire severity models were validated with 31 in situ data from fire-starting points and they presented an accuracy of 99.1% in the high severity category. In addition, through the application of principal component analysis (PCA) with data from four meteorological stations in the region, a bimodal behavior was identified corresponding to the climatology of the area (dry season and rainy season), which is related to the presence of fires (in the dry season). It is essential to note that after the 2014 fire, locally, rainfall decreased and temperatures increased. Finally, the proposed action plan for forest fires made it possible to define a safe and effective evacuation route to reduce the number of victims during future events.
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12
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Furniss TJ, Das AJ, van Mantgem PJ, Stephenson NL, Lutz JA. Crowding, climate, and the case for social distancing among trees. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2022; 32:e2507. [PMID: 34870871 DOI: 10.1002/eap.2507] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Revised: 06/25/2021] [Accepted: 07/30/2021] [Indexed: 06/13/2023]
Abstract
In an emerging era of megadisturbance, bolstering forest resilience to wildfire, insects, and drought has become a central objective in many western forests. Climate has received considerable attention as a driver of these disturbances, but few studies have examined the complexities of climate-vegetation-disturbance interactions. Current strategies for creating resilient forests often rely on retrospective approaches, seeking to impart resilience by restoring historical conditions to contemporary landscapes, but historical conditions are becoming increasingly unattainable amidst modern bioclimatic conditions. What becomes an appropriate benchmark for resilience when we have novel forests, rapidly changing climate, and unprecedented disturbance regimes? We combined two longitudinal datasets-each representing some of the most comprehensive spatially explicit, annual tree mortality data in existence-in a post-hoc factorial design to examine the nonlinear relationships between fire, climate, forest spatial structure, and bark beetles. We found that while prefire drought elevated mortality risk, advantageous local neighborhoods could offset these effects. Surprisingly, mortality risk (Pm ) was higher in crowded local neighborhoods that burned in wet years (Pm = 42%) compared with sparse neighborhoods that burned during drought (Pm = 30%). Risk of beetle attack was also increased by drought, but lower conspecific crowding impeded the otherwise positive interaction between fire and beetle attack. Antecedent fire increased drought-related mortality over short timespans (<7 years) but reduced mortality over longer intervals. These results clarify interacting disturbance dynamics and provide a mechanistic underpinning for forest restoration strategies. Importantly, they demonstrate the potential for managed fire and silvicultural strategies to offset climate effects and bolster resilience to fire, beetles, and drought.
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Affiliation(s)
- Tucker J Furniss
- Wildland Resources Department and Ecology Center, Utah State University, Logan, Utah, USA
- USDA Forest Service, Pacific Northwest Research Station, Wenatchee, Washington, USA
| | - Adrian J Das
- U.S. Geological Survey, Western Ecological Research Center, Three Rivers, California, USA
| | | | - Nathan L Stephenson
- U.S. Geological Survey, Western Ecological Research Center, Three Rivers, California, USA
| | - James A Lutz
- Wildland Resources Department and Ecology Center, Utah State University, Logan, Utah, USA
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Dorey JB, Rebola CM, Davies OK, Prendergast KS, Parslow BA, Hogendoorn K, Leijs R, Hearn LR, Leitch EJ, O'Reilly RL, Marsh J, Woinarski JCZ, Caddy-Retalic S. Continental risk assessment for understudied taxa post-catastrophic wildfire indicates severe impacts on the Australian bee fauna. GLOBAL CHANGE BIOLOGY 2021; 27:6551-6567. [PMID: 34592040 DOI: 10.1111/gcb.15879] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Accepted: 08/23/2021] [Indexed: 06/13/2023]
Abstract
The 2019-2020 Australian Black Summer wildfires demonstrated that single events can have widespread and catastrophic impacts on biodiversity, causing a sudden and marked reduction in population size for many species. In such circumstances, there is a need for conservation managers to respond rapidly to implement priority remedial management actions for the most-affected species to help prevent extinctions. To date, priority responses have been biased towards high-profile taxa with substantial information bases. Here, we demonstrate that sufficient data are available to model the extinction risk for many less well-known species, which could inform much broader and more effective ecological disaster responses. Using publicly available collection and GIS datasets, combined with life-history data, we modelled the extinction risk from the 2019-2020 catastrophic Australian wildfires for 553 Australian native bee species (33% of all described Australian bee taxa). We suggest that two species are now eligible for listing as Endangered and nine are eligible for listing as Vulnerable under IUCN criteria, on the basis of fire overlap, intensity, frequency, and life-history traits: this tally far exceeds the three Australian bee species listed as threatened prior to the wildfire. We demonstrate how to undertake a wide-scale assessment of wildfire impact on a poorly understood group to help to focus surveys and recovery efforts. We also provide the methods and the script required to make similar assessments for other taxa or in other regions.
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Affiliation(s)
- James B Dorey
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia
- Earth and Biological Sciences, South Australian Museum, Adelaide, SA, Australia
| | - Celina M Rebola
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia
| | - Olivia K Davies
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia
| | - Kit S Prendergast
- School of Molecular and Life Sciences, Curtin University, Perth, WA, Australia
| | - Ben A Parslow
- Earth and Biological Sciences, South Australian Museum, Adelaide, SA, Australia
| | - Katja Hogendoorn
- School of Agriculture, Food and Wine, The University of Adelaide, Adelaide, SA, Australia
| | - Remko Leijs
- Earth and Biological Sciences, South Australian Museum, Adelaide, SA, Australia
| | - Lucas R Hearn
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia
| | - Emrys J Leitch
- School of Biological Sciences and Environment Institute, University of Adelaide, North Terrace, SA, Australia
| | - Robert L O'Reilly
- College of Science and Engineering, Flinders University, Adelaide, SA, Australia
| | - Jessica Marsh
- Earth and Biological Sciences, South Australian Museum, Adelaide, SA, Australia
- Harry Butler Research Institute, Murdoch University, Murdoch, WA, Australia
| | - John C Z Woinarski
- National Environmental Science Program Threatened Species Recovery Hub, Research Institute for the Environment and Livelihoods, Charles Darwin University, Casuarina, NT, Australia
- School of Ecosystem and Forest Sciences, University of Melbourne, Parkville, Vic., Australia
| | - Stefan Caddy-Retalic
- School of Biological Sciences and Environment Institute, University of Adelaide, North Terrace, SA, Australia
- School of Life and Environmental Sciences, University of Sydney, Sydney, NSW, Australia
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14
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Balantic C, Adams A, Gross S, Mazur R, Sawyer S, Tucker J, Vernon M, Mengelt C, Morales J, Thorne JH, Brown TM, Athearn N, Morelli TL. Toward climate change refugia conservation at an ecoregion scale. CONSERVATION SCIENCE AND PRACTICE 2021. [DOI: 10.1111/csp2.497] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Affiliation(s)
- Cathleen Balantic
- Northeast Climate Adaptation Science Center, Department of Environmental Conservation University of Massachusetts Amherst Amherst Massachusetts USA
| | - Andrea Adams
- Earth Research Institute University of California Santa Barbara Santa Barbara California USA
| | - Shana Gross
- Ecology Program USDA Forest Service, Region 5 South Lake Tahoe California USA
| | - Rachel Mazur
- Division of Resources Management and Science Yosemite National Park El Portal California USA
| | - Sarah Sawyer
- USDA Forest Service, Pacific Southwest Region Vallejo California USA
| | - Jody Tucker
- USDA Forest Service, Pacific Southwest Region Vallejo California USA
| | - Marian Vernon
- Point Blue Conservation Science Petaluma California USA
| | - Claudia Mengelt
- U.S. Fish and Wildlife Service Science Applications Sacramento California USA
| | - Jennifer Morales
- Climate Change Program California Department of Water Resources Fresno California USA
| | - James H. Thorne
- Department of Environmental Science and Policy University of California Davis California USA
| | - Timothy M. Brown
- Department of Ecology and Evolutionary Biology University of California Santa Cruz California USA
| | - Nicole Athearn
- Division of Resources Management and Science National Park Service El Portal California USA
| | - Toni Lyn Morelli
- U.S. Geological Survey, Northeast Climate Adaptation Science Center, Department of Environmental Conservation University of Massachusetts Amherst Amherst Massachusetts USA
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15
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Wayman RB, Safford HD. Recent bark beetle outbreaks influence wildfire severity in mixed-conifer forests of the Sierra Nevada, California, USA. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02287. [PMID: 33426715 DOI: 10.1002/eap.2287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 09/11/2020] [Accepted: 10/06/2020] [Indexed: 06/12/2023]
Abstract
In temperate forests, elevated frequency of drought related disturbances will likely increase the incidence of interactions between disturbances such as bark beetle epidemics and wildfires. Our understanding of the influence of recent drought and insect-induced tree mortality on wildfire severity has largely lacked information from forests adapted to frequent fire. A recent unprecedented tree mortality event in California's Sierra Nevada provides an opportunity to examine this disturbance interaction in historically frequent-fire forests. Using field data collected within areas of recent tree mortality that subsequently burned in wildfire, we examined whether and under what conditions wildfire severity relates to severity of prefire tree mortality in Sierra Nevada mixed-conifer forests. We collected data on 180 plots within the 2015 Rough Fire and 2016 Cedar Fire footprints (California, USA). Our analyses identified prefire tree mortality as influential on all measures of wildfire severity (basal area killed by fire, RdNBR, and canopy torch) on the Cedar Fire, although it was less influential than fire weather (relative humidity). Prefire tree mortality was influential on two of three fire-severity measures on the Rough Fire, and was the most important predictor of basal area killed by fire; topographic position was influential on two metrics. On the Cedar Fire, the influence of prefire mortality on basal area killed by fire was greater under milder weather conditions. All measures of fire severity increased as prefire mortality increased up to prefire mortality levels of approximately 30-40%; further increases did not result in greater fire severity. The interacting disturbances shifted a pine-dominated system (Rough Fire) to a cedar-pine-fir system, while the pre-disturbance fir-cedar system (Cedar Fire) saw its dominant species unchanged. Managers of historically frequent-fire forests will benefit from utilizing this information when prioritizing fuels reduction treatments in areas of recent tree mortality, as it is the first empirical study to document a relationship between prefire mortality and subsequent wildfire severity in these systems. This study contributes to a growing body of evidence that the influence of prefire tree mortality on wildfire severity in temperate coniferous forests may depend on other conditions capable of driving extreme wildfire behavior, such as weather.
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Affiliation(s)
- Rebecca B Wayman
- Department of Environmental Science and Policy, University of California, Davis, 95616, USA
| | - Hugh D Safford
- Department of Environmental Science and Policy, University of California, Davis, 95616, USA
- Pacific Southwest Region, USDA Forest Service, Vallejo, California, 94592, USA
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16
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Hood SM. Physiological responses to fire that drive tree mortality. PLANT, CELL & ENVIRONMENT 2021; 44:692-695. [PMID: 33410515 DOI: 10.1111/pce.13994] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 11/16/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
This article comments on: Short- and long-term effects of fire on stem hydraulics in Pinus ponderosa saplings.
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Affiliation(s)
- Sharon M Hood
- US Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, Missoula, Montana, USA
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17
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Galbraith SM, Cane JH, Rivers JW. Wildfire severity influences offspring sex ratio in a native solitary bee. Oecologia 2021; 195:65-75. [PMID: 33392790 DOI: 10.1007/s00442-020-04809-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 11/19/2020] [Indexed: 10/22/2022]
Abstract
Although ecological disturbances can have a strong influence on pollinators through changes in habitat, virtually no studies have quantified how characteristics of wildfire influence the demography of essential pollinators. Nevertheless, evaluating this topic is critical for understanding how wildfire is linked to pollinator population dynamics, particularly given recent changes in wildfire frequency and severity in many regions of the world. In this study, we measured the demographic response of the blue orchard bee (Osmia lignaria) across a natural gradient of wildfire severity to assess how variation in wildfire characteristics influenced reproductive output, offspring sex ratio, and offspring mass. We placed nest blocks with a standardized number and sex ratio of pre-emergent adult bees across the wildfire gradient, finding some evidence for a positive but highly variable relationship between reproductive output and fire severity surrounding the nest site at both local (100 m) and landscape (750 m) scales. In addition, the production of female offspring was > 10% greater at nest sites experiencing the greatest landscape-scale fire severity relative to the lowest-severity areas. The finding that blue orchard bees biased offspring production towards the more expensive offspring sex with increasing fire severity shows a functional response to changes in habitat quality through increased density of flowering plants. Our findings indicate that burned mixed-conifer forest provides forage for the blue orchard bee across a severity gradient, and that the increase in floral resources that follows high-severity fire leads females to shift resource allocation to the more costly sex when nesting.
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Affiliation(s)
- Sara M Galbraith
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, USA.
- Department of Forest Resources, Engineering, and Management, Oregon State University, Corvallis, OR, USA.
| | - James H Cane
- USDA-ARS Pollinating Insects Research Unit, Logan, UT, USA
| | - James W Rivers
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, USA
- Department of Forest Resources, Engineering, and Management, Oregon State University, Corvallis, OR, USA
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18
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Chi X, Yang G, Sun K, Li X, Wang T, Zhang A, Li Y, Cheng M, Wang Q. Old ginkgo trees in China:Distribution, determinants and implications for conservation. Glob Ecol Conserv 2020. [DOI: 10.1016/j.gecco.2020.e01304] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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19
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García-Llamas P, Suárez-Seoane S, Fernández-Manso A, Quintano C, Calvo L. Evaluation of fire severity in fire prone-ecosystems of Spain under two different environmental conditions. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2020; 271:110706. [PMID: 32778251 DOI: 10.1016/j.jenvman.2020.110706] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 04/11/2020] [Accepted: 05/04/2020] [Indexed: 06/11/2023]
Abstract
Severe fires associated to climate change and land cover changes are becoming more frequent in Mediterranean Europe. The influence of environmental drivers on fire severity, especially under different environmental conditions is still not fully understood. In this study we aim to determine the main environmental variables that control fire severity in large fires (>500 ha) occurring in fire-prone ecosystems under two different environmental conditions following a transition (Mediterranean-Oceanic)-Mediterranean climatic gradient within the Iberian Peninsula, and to provide management recommendations to mitigate fire damage. We estimated fire severity as the differenced Normalized Burn Ratio, through images obtained from Landsat 8 OLI. We also examined the relative influence of pre-fire vegetation structure (vegetation composition and configuration), pre-fire weather conditions, fire history and topography on fire severity using Random Forest machine learning algorithms. The results indicated that the severity of fires occurring along the transition (Mediterranean-Oceanic)-Mediterranean climatic gradient was primarily controlled by pre-fire vegetation composition. Nevertheless, the effect of vegetation composition was strongly dependent on interactions with fire recurrence and pre-fire vegetation structural configuration. The relationship between fire severity, weather and topographic predictors was not consistent among fires occurring in the Mediterranean-Oceanic transition and Mediterranean sites. In the Mediterranean-Oceanic transition site, fire severity was determined by weather conditions (i.e., summer cumulative rainfall), rather than being associated to topography, suggesting that the control exerted by topography may be overwhelmed by weather controls. Conversely, results showed that topography only had a major effect on fire severity in the Mediterranean site. The results of this study highlight the need to prioritise fuel treatments aiming at breaking fuel continuity and reducing fuel loads as an effective management strategy to mitigate fire damage in areas of high fire recurrence.
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Affiliation(s)
- Paula García-Llamas
- Biodiversity and Environmental Management Dpt., Faculty of Biological and Environmental Sciences, University of León, Campus de Vegazana s/n, 24071, León, Spain; Institute of Environmental Research (IMA), University of Léon, 24071, León, Spain.
| | - Susana Suárez-Seoane
- University of Oviedo. Department of Organisms and Systems Biology (Ecology Unit) and Research Unit of Biodiversity (UO-CSIC-PA), Oviedo, Mieres, Spain
| | - Alfonso Fernández-Manso
- Agrarian Science and Engineering Department, University of León, Av. Astorga s/n, 24400, Ponferrada, Spain
| | - Carmen Quintano
- Electronic Technology Department, Sustainable Forest Management Research Institute, University of Valladolid, Spanish National Institute for Agriculture and Food Research and Technology (INIA), C/Francisco Mendizábal s/n, 47014, Valladolid, Spain
| | - Leonor Calvo
- Biodiversity and Environmental Management Dpt., Faculty of Biological and Environmental Sciences, University of León, Campus de Vegazana s/n, 24071, León, Spain; Institute of Environmental Research (IMA), University of Léon, 24071, León, Spain
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20
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Drought Increases Vulnerability of Pinus ponderosa Saplings to Fire-Induced Mortality. FIRE-SWITZERLAND 2020. [DOI: 10.3390/fire3040056] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The combination of drought and fire can cause drastic changes in forest composition and structure. Given the predictions of more frequent and severe droughts and forecasted increases in fire size and intensity in the western United States, we assessed the impact of drought and different fire intensities on Pinus ponderosa saplings. In a controlled combustion laboratory, we exposed saplings to surface fires at two different fire intensity levels (quantified via fire radiative energy; units: MJ m−2). The recovery (photosynthesis and bud development) and mortality of saplings were monitored during the first month, and at 200- and 370-days post-fire. All the saplings subjected to high intensity surface fires (1.4 MJ m−2), regardless of the pre-fire water status, died. Seventy percent of pre-fire well-watered saplings recovered after exposure to low intensity surface fire (0.7 MJ m−2). All of the pre-fire drought-stressed saplings died, even at the lower fire intensity. Regardless of the fire intensity and water status, photosynthesis was significantly reduced in all saplings exposed to fire. At 370 days post-fire, burned well-watered saplings that recovered had similar photosynthesis rates as unburned plants. In addition, all plants that recovered or attempted to recover produced new foliage within 35 days following the fire treatments. Our results demonstrate that the pre-fire water status of saplings is an important driver of Pinus ponderosa sapling recovery and mortality after fire.
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21
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Rahmani S, Price O. Effects of 38 years of wildfires on tree density in the Blue Mountains, Australia. AUSTRAL ECOL 2020. [DOI: 10.1111/aec.12952] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Simin Rahmani
- Centre for Environmental Risk Management of Bushfires School of Earth, Atmosphere and Life Sciences University of Wollongong Wollongong New South Wales2522Australia
| | - Owen Price
- Centre for Environmental Risk Management of Bushfires School of Earth, Atmosphere and Life Sciences University of Wollongong Wollongong New South Wales2522Australia
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22
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Changes in Multi-Level Biodiversity and Soil Features in a Burned Beech Forest in the Southern Italian Coastal Mountain. FORESTS 2020. [DOI: 10.3390/f11090983] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In the context of global warming and increasing wildfire occurrence, this study aims to examine, for the first time, the changes in multi-level biodiversity and key soil features related to soil functioning in a burned Mediterranean beech forest. Two years after the 2017 wildfire, changes between burned and unburned plots of beech forest were analyzed for plant communities (vascular plant and cover, bryophytes diversity, structural, chorological, and ecological variables) and soil features (main chemical properties, microbial biomass and activity, bacterial community composition, and diversity), through a synchronic study. Fire-induced changes in the micro-environmental conditions triggered a secondary succession process with colonization by many native pioneer plant species. Indeed, higher frequency (e.g., Scrophularia vernalis L., Rubus hirtus Waldst. and Kit. group, and Funaria hygrometrica Hedw.) or coverage (e.g., Verbascum thapsus L. subsp. thapsus and Digitalis micrantha Roth ex Schweigg.) of the species was observed in the burned plots, whereas the typical forest species showed a reduction in frequency, but not in cover, except for Fagus sylvatica subsp. sylvatica. Overall, an increase in plant species and family richness was found in the burned plots, mainly in the herbaceous and bryophyte layers, compared to the unburned plots. Burned plots showed an increase in therophytes, chamaephytes, cosmopolites, steno-Mediterranean and Atlantic species, and a decrease in geophytes and Eurasiatic plants. Significant differences were found in burned vs. control soils for 10 phyla, 40 classes, 79 orders, 145 families, 342 genera, and 499 species of bacteria, with about 50% of each taxon over-represented and 50% under-represented in burned than in control. Changes in bacterial richness within several families (reduction in Acidobacteriaceae, Solibacteraceae, Rhodospirillaceae, and Sinobacteraceae; increase in Micrococcaceae, Comamonadaceae, Oxalobacteraceae, Pseudomonadaceae, Hymenobacteraceae, Sphingomonadaceae, Cytophagaceae, Nocardioidaceae, Opitutaceae, Solirubrobacteraceae, and Bacillaceae) in burned soil were related to fire-induced chemical changes of soil (pH, electrical conductivity, and cation exchange capacity). No evident effect of the wildfire was found on organic C content, microbial biomass (total microbial carbon and fungal mycelium) and activity, and microbial indexes (fungal percentage of microbial C, metabolic quotient, and quotient of mineralization), suggesting that soil functions remained unchanged in the burned area. Therefore, we hypothesize that, without an additional disturbance event, a re-establishment of beech forest can be expected but with an unpredictable time of post-fire succession.
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23
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Furniss TJ, Larson AJ, Kane VR, Lutz JA. Wildfire and drought moderate the spatial elements of tree mortality. Ecosphere 2020. [DOI: 10.1002/ecs2.3214] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Affiliation(s)
- Tucker J. Furniss
- Wildland Resources Department and Ecology Center Utah State University Logan Utah84322USA
| | - Andrew J. Larson
- Wilderness Institute and Department of Forest Management University of Montana Missoula Montana59812USA
| | - Van R. Kane
- School of Environmental and Forest Sciences University of Washington Seattle Washington98195USA
| | - James A. Lutz
- Wildland Resources Department and Ecology Center Utah State University Logan Utah84322USA
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24
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Coop JD, Parks SA, Stevens-Rumann CS, Crausbay SD, Higuera PE, Hurteau MD, Tepley A, Whitman E, Assal T, Collins BM, Davis KT, Dobrowski S, Falk DA, Fornwalt PJ, Fulé PZ, Harvey BJ, Kane VR, Littlefield CE, Margolis EQ, North M, Parisien MA, Prichard S, Rodman KC. Wildfire-Driven Forest Conversion in Western North American Landscapes. Bioscience 2020; 70:659-673. [PMID: 32821066 PMCID: PMC7429175 DOI: 10.1093/biosci/biaa061] [Citation(s) in RCA: 107] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Changing disturbance regimes and climate can overcome forest ecosystem resilience. Following high-severity fire, forest recovery may be compromised by lack of tree seed sources, warmer and drier postfire climate, or short-interval reburning. A potential outcome of the loss of resilience is the conversion of the prefire forest to a different forest type or nonforest vegetation. Conversion implies major, extensive, and enduring changes in dominant species, life forms, or functions, with impacts on ecosystem services. In the present article, we synthesize a growing body of evidence of fire-driven conversion and our understanding of its causes across western North America. We assess our capacity to predict conversion and highlight important uncertainties. Increasing forest vulnerability to changing fire activity and climate compels shifts in management approaches, and we propose key themes for applied research coproduced by scientists and managers to support decision-making in an era when the prefire forest may not return.
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Affiliation(s)
- Jonathan D Coop
- School of Environment and Sustainability, Western Colorado University, Gunnison
| | - Sean A Parks
- Research ecologist with the Aldo Leopold Wilderness Research Institute, Rocky Mountain Research Station, US Forest Service, Missoula, Montana
| | | | - Shelley D Crausbay
- Senior scientist with Conservation Science Partners, Fort Collins, Colorado
| | - Philip E Higuera
- Department of Ecosystem and Conservation Sciences, University of Montana, Missoula, Montana
| | | | - Alan Tepley
- Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, Alberta, Canada
| | - Ellen Whitman
- Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, Alberta, Canada
| | - Timothy Assal
- Department of Geography, Kent State University, Kent, Ohio
| | - Brandon M Collins
- Fire Research and Outreach, University of California, Berkeley, Berkeley, California, and with the Pacific Southwest Research Station, US Forest Service, in Davis, California
| | - Kimberley T Davis
- Department of Ecosystem and Conservation Sciences, University of Montana, Missoula
| | | | - Donald A Falk
- Natural Resources and the Environment, University of Arizona, Tucson
| | - Paula J Fornwalt
- Rocky Mountain Research Station, US Forest Service, Fort Collins, Colorado
| | - Peter Z Fulé
- School of Forestry, Northern Arizona University, Flagstaff
| | - Brian J Harvey
- School of Environmental and Forest Sciences, University of Washington, Seattle
| | - Van R Kane
- School of Environmental and Forest Sciences, University of Washington, Seattle
| | - Caitlin E Littlefield
- Caitlin Littlefield is a postdoctoral research associate, Rubenstein School of Environment and Natural Resources, University of Vermont, Burlington
| | - Ellis Q Margolis
- US Geological Survey, New Mexico Landscapes Field Station, Santa Fe
| | - Malcolm North
- US Forest Service, Pacific Southwest Research Station, Mammoth Lakes, California
| | - Marc-André Parisien
- Natural Resources Canada, Canadian Forest Service, Northern Forestry Centre, Edmonton, Alberta, Canada
| | - Susan Prichard
- School of Environmental and Forest Sciences, University of Washington, Seattle
| | - Kyle C Rodman
- Department of Forest and Wildlife Ecology, University of Wisconsin, Madison
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25
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Ward M, Tulloch AIT, Radford JQ, Williams BA, Reside AE, Macdonald SL, Mayfield HJ, Maron M, Possingham HP, Vine SJ, O’Connor JL, Massingham EJ, Greenville AC, Woinarski JCZ, Garnett ST, Lintermans M, Scheele BC, Carwardine J, Nimmo DG, Lindenmayer DB, Kooyman RM, Simmonds JS, Sonter LJ, Watson JEM. Impact of 2019–2020 mega-fires on Australian fauna habitat. Nat Ecol Evol 2020; 4:1321-1326. [DOI: 10.1038/s41559-020-1251-1] [Citation(s) in RCA: 129] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Accepted: 06/18/2020] [Indexed: 11/09/2022]
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26
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The Fire and Tree Mortality Database, for empirical modeling of individual tree mortality after fire. Sci Data 2020; 7:194. [PMID: 32572035 PMCID: PMC7308274 DOI: 10.1038/s41597-020-0522-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 05/14/2020] [Indexed: 11/18/2022] Open
Abstract
Wildland fires have a multitude of ecological effects in forests, woodlands, and savannas across the globe. A major focus of past research has been on tree mortality from fire, as trees provide a vast range of biological services. We assembled a database of individual-tree records from prescribed fires and wildfires in the United States. The Fire and Tree Mortality (FTM) database includes records from 164,293 individual trees with records of fire injury (crown scorch, bole char, etc.), tree diameter, and either mortality or top-kill up to ten years post-fire. Data span 142 species and 62 genera, from 409 fires occurring from 1981-2016. Additional variables such as insect attack are included when available. The FTM database can be used to evaluate individual fire-caused mortality models for pre-fire planning and post-fire decision support, to develop improved models, and to explore general patterns of individual fire-induced tree death. The database can also be used to identify knowledge gaps that could be addressed in future research. Measurement(s) | plant morphology trait • tree mortality • fire • tree fire injury • wildfire | Technology Type(s) | digital curation | Factor Type(s) | year of data collection • geographic location of fire • tree fire injury | Sample Characteristic - Organism | trees | Sample Characteristic - Environment | forest ecosystem | Sample Characteristic - Location | Cascades Region • Blue Mountains • Far Northern Rockies • Sierra Nevada • Piedmont Province • Region of Piedmont • Atlantic and Gulf Coastal Plain Floristic Province • Northern Rocky Mountains Provincial Park |
Machine-accessible metadata file describing the reported data: 10.6084/m9.figshare.12369293
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27
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Multivariate climate departures have outpaced univariate changes across global lands. Sci Rep 2020; 10:3891. [PMID: 32127547 PMCID: PMC7054431 DOI: 10.1038/s41598-020-60270-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 02/05/2020] [Indexed: 11/08/2022] Open
Abstract
Changes in individual climate variables have been widely documented over the past century. However, assessments that consider changes in the collective interaction amongst multiple climate variables are relevant for understanding climate impacts on ecological and human systems yet are less well documented than univariate changes. We calculate annual multivariate climate departures during 1958-2017 relative to a baseline 1958-1987 period that account for covariance among four variables important to Earth's biota and associated systems: annual climatic water deficit, annual evapotranspiration, average minimum temperature of the coldest month, and average maximum temperature of the warmest month. Results show positive trends in multivariate climate departures that were nearly three times that of univariate climate departures across global lands. Annual multivariate climate departures exceeded two standard deviations over the past decade for approximately 30% of global lands. Positive trends in climate departures over the last six decades were found to be primarily the result of changes in mean climate conditions consistent with the modeled effects of anthropogenic climate change rather than changes in variability. These results highlight the increasing novelty of annual climatic conditions viewed through a multivariate lens and suggest that changes in multivariate climate departures have generally outpaced univariate departures in recent decades.
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28
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Richter C, Rejmánek M, Miller JED, Welch KR, Weeks J, Safford H. The species diversity × fire severity relationship is hump‐shaped in semiarid yellow pine and mixed conifer forests. Ecosphere 2019. [DOI: 10.1002/ecs2.2882] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Clark Richter
- Department of Evolution and Ecology University of California – Davis Davis California USA
| | - Marcel Rejmánek
- Department of Evolution and Ecology University of California – Davis Davis California USA
| | | | - Kevin R. Welch
- Department of Plant Sciences University of California – Davis Davis California USA
| | - JonahMaria Weeks
- Department of Environmental Science and Policy University of California – Davis Davis California USA
| | - Hugh Safford
- Department of Environmental Science and Policy University of California – Davis Davis California USA
- USDA Forest Service Pacific Southwest Region Vallejo California USA
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Urza AK, Weisberg PJ, Chambers JC, Sullivan BW. Shrub facilitation of tree establishment varies with ontogenetic stage across environmental gradients. THE NEW PHYTOLOGIST 2019; 223:1795-1808. [PMID: 31125432 DOI: 10.1111/nph.15957] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 05/19/2019] [Indexed: 06/09/2023]
Abstract
Plant-plant interactions are important drivers of ecosystem structure and function, yet predicting interaction outcomes across environmental gradients remains challenging. Understanding how interactions are affected by ontogenetic shifts in plant characteristics can provide insight into the drivers of interactions and improve our ability to anticipate ecosystem responses to environmental change. We developed a conceptual framework of nurse shrub facilitation of tree establishment. We used a combination of field experiments and environmental measurements to test the framework with a shrub (Artemisia tridentata) and a tree (Pinus monophylla), two foundation species in a semiarid environment. Shrub microsites allowed trees to overcome an early population bottleneck and successfully establish in areas without tree cover. Shrubs facilitated trees at multiple ontogenetic stages, but the net outcome of the interaction shifted from strongly positive to neutral after the transition of P. monophylla from juvenile to adult foliage. Microhabitat conditions varied across a broad elevational gradient, but interaction outcomes were not strongly related to elevation. Favorable microsites provided by A. tridentata cover are crucial for P. monophylla recovery after stand-replacing disturbance. Models of vegetation response to rapid global environmental change should incorporate the critically important role of nurse shrub interactions for ameliorating population bottlenecks in tree establishment.
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Affiliation(s)
- Alexandra K Urza
- USDA Forest Service, Rocky Mountain Research Station, 920 Valley Rd, Reno, NV, 89512, USA
- Program in Ecology, Evolution and Conservation Biology, University of Nevada-Reno, 1664 N. Virginia St., Reno, NV, 89557, USA
| | - Peter J Weisberg
- Program in Ecology, Evolution and Conservation Biology, University of Nevada-Reno, 1664 N. Virginia St., Reno, NV, 89557, USA
- Department of Natural Resources and Environmental Science, University of Nevada-Reno, 1664 N. Virginia St., Reno, NV, 89557, USA
| | - Jeanne C Chambers
- USDA Forest Service, Rocky Mountain Research Station, 920 Valley Rd, Reno, NV, 89512, USA
- Program in Ecology, Evolution and Conservation Biology, University of Nevada-Reno, 1664 N. Virginia St., Reno, NV, 89557, USA
| | - Benjamin W Sullivan
- Program in Ecology, Evolution and Conservation Biology, University of Nevada-Reno, 1664 N. Virginia St., Reno, NV, 89557, USA
- Department of Natural Resources and Environmental Science, University of Nevada-Reno, 1664 N. Virginia St., Reno, NV, 89557, USA
- Global Water Center, University of Nevada-Reno, 1664 N. Virginia St, Reno, NV, 89557, USA
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30
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Newman EA, Kennedy MC, Falk DA, McKenzie D. Scaling and Complexity in Landscape Ecology. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00293] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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31
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Voelker SL, Merschel AG, Meinzer FC, Ulrich DEM, Spies TA, Still CJ. Fire deficits have increased drought sensitivity in dry conifer forests: Fire frequency and tree-ring carbon isotope evidence from Central Oregon. GLOBAL CHANGE BIOLOGY 2019; 25:1247-1262. [PMID: 30536531 DOI: 10.1111/gcb.14543] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Accepted: 10/04/2018] [Indexed: 06/09/2023]
Abstract
A century of fire suppression across the Western United States has led to more crowded forests and increased competition for resources. Studies of forest thinning or stand conditions after mortality events have provided indirect evidence for how competition can promote drought stress and predispose forests to severe fire and/or bark beetle outbreaks. Here, we demonstrate linkages between fire deficits and increasing drought stress through analyses of annually resolved tree-ring growth, fire scars, and carbon isotope discrimination (Δ13 C) across a dry mixed-conifer forest landscape. Fire deficits across the study area have increased the sensitivity of leaf gas exchange to drought stress over the past >100 years. Since 1910, stand basal area in these forests has more than doubled and fire-return intervals have increased from 25 to 140 years. Meanwhile, the portion of interannual variation in tree-ring Δ13 C explained by the Palmer Drought Severity Index has more than doubled in ca. 300-500-year-old Pinus ponderosa as well as in fire-intolerant, ca. 90-190-year-old Abies grandis. Drought stress has increased in stands with a basal area of ≥25 m2 /ha in 1910, as indicated by negative temporal Δ13 C trends, whereas stands with basal area ≤25 m2 /ha in 1910, due to frequent or intense wildfire activity in decades beforehand, were initially buffered from increased drought stress and have benefited more from rising ambient carbon dioxide concentrations, [CO2 ], as demonstrated by positive temporal Δ13 C trends. Furthermore, the average Δ13 C response across all P. ponderosa since 1830 indicates that photosynthetic assimilation rates and stomatal conductance have been reduced by ~10% and ~20%, respectively, compared to expected trends due to increasing [CO2 ]. Although disturbance legacies contribute to local-scale intensity of drought stress, fire deficits have reduced drought resistance of mixed-conifer forests and made them more susceptible to challenges by pests and pathogens and other disturbances.
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Affiliation(s)
- Steven L Voelker
- Plants, Soils and Climate Department, Utah State University, Logan, Utah
| | - Andrew G Merschel
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, Oregon
| | | | | | - Thomas A Spies
- USDA Forest Service Pacific Northwest Research Station, Portland, Oregon
| | - Christopher J Still
- Department of Forest Ecosystems and Society, Oregon State University, Corvallis, Oregon
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32
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Duffy PB, Field CB, Diffenbaugh NS, Doney SC, Dutton Z, Goodman S, Heinzerling L, Hsiang S, Lobell DB, Mickley LJ, Myers S, Natali SM, Parmesan C, Tierney S, Williams AP. Strengthened scientific support for the Endangerment Finding for atmospheric greenhouse gases. Science 2018; 363:science.aat5982. [DOI: 10.1126/science.aat5982] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 11/30/2018] [Indexed: 01/04/2023]
Abstract
We assess scientific evidence that has emerged since the U.S. Environmental Protection Agency’s 2009 Endangerment Finding for six well-mixed greenhouse gases and find that this new evidence lends increased support to the conclusion that these gases pose a danger to public health and welfare. Newly available evidence about a wide range of observed and projected impacts strengthens the association between the risk of some of these impacts and anthropogenic climate change, indicates that some impacts or combinations of impacts have the potential to be more severe than previously understood, and identifies substantial risk of additional impacts through processes and pathways not considered in the Endangerment Finding.
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van Mantgem PJ, Falk DA, Williams EC, Das AJ, Stephenson NL. Pre-fire drought and competition mediate post-fire conifer mortality in western U.S. National Parks. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2018; 28:1730-1739. [PMID: 30151923 DOI: 10.1002/eap.1778] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 04/05/2018] [Accepted: 05/10/2018] [Indexed: 06/08/2023]
Abstract
Tree mortality is an important outcome of many forest fires. Extensive tree injuries from fire may lead directly to mortality, but environmental and biological stressors may also contribute to tree death. However, there is little evidence showing how the combined effects of two common stressors, drought and competition, influence post-fire mortality. Geographically broad observations of three common western coniferous trees subjected to prescribed fire showed the likelihood of post-fire mortality was related to intermediate-term (10 yr) pre-fire average radial growth, an important component of tree vigor. Path analysis showed that indices of competition and drought stress prior to fire can be described in terms of joint effects on growth, indirectly affecting post-fire mortality. Our results suggest that the conditions that govern the relationship between growth and mortality in unburned stands may also apply to post-fire environments. Thus, biotic and abiotic changes that affect growth negatively (e.g., drought stress) or positively (e.g., growth releases following thinning treatments) prior to fire may influence expressed fire severity, independent of fire intensity (e.g., heat flux, residence time). These relationships suggest that tree mortality may increase under stressful climatic or stand conditions even if fire behavior remains constant.
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Affiliation(s)
- Phillip J van Mantgem
- Western Ecological Research Center, U.S. Geological Survey, Arcata, California, 95521, USA
| | - Donald A Falk
- School of Natural Resources and the Environment, University of Arizona, Tucson, Arizona, 85721, USA
| | - Emma C Williams
- School of Natural Resources and the Environment, University of Arizona, Tucson, Arizona, 85721, USA
| | - Adrian J Das
- Western Ecological Research Center, U.S. Geological Survey, Three Rivers, California, 93271, USA
| | - Nathan L Stephenson
- Western Ecological Research Center, U.S. Geological Survey, Three Rivers, California, 93271, USA
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34
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Madeira L, Gartner T. Forest Resilience Bond Sparks Innovative Collaborations Between Water Utilities and Wide-Ranging Stakeholders. ACTA ACUST UNITED AC 2018. [DOI: 10.1002/awwa.1097] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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35
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Davis KT, Higuera PE, Sala A. Anticipating fire‐mediated impacts of climate change using a demographic framework. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13132] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kimberley T. Davis
- Department of Ecosystem and Conservation Sciences University of Montana Missoula Montana
| | - Philip E. Higuera
- Department of Ecosystem and Conservation Sciences University of Montana Missoula Montana
| | - Anna Sala
- Division of Biological Sciences University of Montana Missoula Montana
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36
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Disequilibrium of fire-prone forests sets the stage for a rapid decline in conifer dominance during the 21 st century. Sci Rep 2018; 8:6749. [PMID: 29712940 PMCID: PMC5928035 DOI: 10.1038/s41598-018-24642-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 04/09/2018] [Indexed: 11/18/2022] Open
Abstract
The impacts of climatic changes on forests may appear gradually on time scales of years to centuries due to the long generation times of trees. Consequently, current forest extent may not reflect current climatic patterns. In contrast with these lagged responses, abrupt transitions in forests under climate change may occur in environments where alternative vegetation states are influenced by disturbances, such as fire. The Klamath forest landscape (northern California and southwest Oregon, USA) is currently dominated by high biomass, biodiverse temperate coniferous forests, but climate change could disrupt the mechanisms promoting forest stability (e.g. growth, regeneration and fire tolerance). Using a landscape simulation model, we estimate that about one-third of the Klamath forest landscape (500,000 ha) could transition from conifer-dominated forest to shrub/hardwood chaparral, triggered by increased fire activity coupled with lower post-fire conifer establishment. Such shifts were widespread under the warmer climate change scenarios (RCP 8.5) but were surprisingly prevalent under the climate of 1949–2010, reflecting the joint influences of recent warming trends and the legacy of fire suppression that may have enhanced conifer dominance. Our results demonstrate that major forest ecosystem shifts should be expected when climate change disrupts key stabilizing feedbacks that maintain the dominance of long-lived, slowly regenerating trees.
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37
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Predicting Potential Fire Severity Using Vegetation, Topography and Surface Moisture Availability in a Eurasian Boreal Forest Landscape. FORESTS 2018. [DOI: 10.3390/f9030130] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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38
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Michaletz ST. Xylem dysfunction in fires: towards a hydraulic theory of plant responses to multiple disturbance stressors. THE NEW PHYTOLOGIST 2018; 217:1391-1393. [PMID: 29405361 DOI: 10.1111/nph.15013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Affiliation(s)
- Sean T Michaletz
- Biosphere 2, University of Arizona, Tucson, AZ, 85721, USA
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721, USA
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39
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Historic Frequency and Severity of Fire in Whitebark Pine Forests of the Cascade Mountain Range, USA. FORESTS 2018. [DOI: 10.3390/f9020078] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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40
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Cansler CA, McKenzie D, Halpern CB. Fire enhances the complexity of forest structure in alpine treeline ecotones. Ecosphere 2018. [DOI: 10.1002/ecs2.2091] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- C. Alina Cansler
- Fire, Fuel, and Smoke Science Program USDA Forest Service Missoula Montana 59808 USA
| | - Donald McKenzie
- Pacific Wildland Fire Sciences Lab USDA Forest Service Seattle Washington 98103 USA
| | - Charles B. Halpern
- School of Environmental and Forest Sciences University of Washington Seattle Washington 98195 USA
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41
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Karavani A, Boer MM, Baudena M, Colinas C, Díaz-Sierra R, Pemán J, de Luis M, Enríquez-de-Salamanca Á, Resco de Dios V. Fire-induced deforestation in drought-prone Mediterranean forests: drivers and unknowns from leaves to communities. ECOL MONOGR 2018. [DOI: 10.1002/ecm.1285] [Citation(s) in RCA: 71] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Asaf Karavani
- Master Course Mediterranean Forestry and Natural Resources Management; Universitat de Lleida; E25198 Lleida Spain
| | - Matthias M. Boer
- Hawkesbury Institute for the Environment; Western Sydney University; Richmond New South Wales 2753 Australia
| | - Mara Baudena
- Copernicus Institute of Sustainable Development, Environmental Science Group; Utrecht University; P.O. Box 80115 3508 TC Utrecht The Netherlands
| | - Carlos Colinas
- Department of Crop and Forest Sciences-AGROTECNIO Center; Universitat de Lleida; E 25198 Lleida Spain
| | - Rubén Díaz-Sierra
- Mathematical and Fluid Physics Department; Faculty of Sciences; Universidad Nacional de Educación a Distancia; Madrid 28040 Spain
| | - Jesús Pemán
- Department of Crop and Forest Sciences-AGROTECNIO Center; Universitat de Lleida; E 25198 Lleida Spain
| | - Martín de Luis
- Department of Geography and Regional Planning; University of Zaragoza; 50009 Zaragoza Spain
| | - Álvaro Enríquez-de-Salamanca
- Mathematical and Fluid Physics Department; Faculty of Sciences; Universidad Nacional de Educación a Distancia; Madrid 28040 Spain
| | - Víctor Resco de Dios
- Department of Crop and Forest Sciences-AGROTECNIO Center; Universitat de Lleida; E 25198 Lleida Spain
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42
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Kitzberger T, Falk DA, Westerling AL, Swetnam TW. Direct and indirect climate controls predict heterogeneous early-mid 21st century wildfire burned area across western and boreal North America. PLoS One 2017; 12:e0188486. [PMID: 29244839 PMCID: PMC5731736 DOI: 10.1371/journal.pone.0188486] [Citation(s) in RCA: 98] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 11/08/2017] [Indexed: 11/23/2022] Open
Abstract
Predicting wildfire under future conditions is complicated by complex interrelated drivers operating across large spatial scales. Annual area burned (AAB) is a useful index of global wildfire activity. Current and antecedent seasonal climatic conditions, and the timing of snowpack melt, have been suggested as important drivers of AAB. As climate warms, seasonal climate and snowpack co-vary in intricate ways, influencing fire at continental and sub-continental scales. We used independent records of seasonal climate and snow cover duration (last date of permanent snowpack, LDPS) and cell-based Structural Equation Models (SEM) to separate direct (climatic) and indirect (snow cover) effects on relative changes in AAB under future climatic scenarios across western and boreal North America. To isolate seasonal climate variables with the greatest effect on AAB, we ran multiple regression models of log-transformed AAB on seasonal climate variables and LDPS. We used the results of multiple regressions to project future AAB using GCM ensemble climate variables and LDPS, and validated model predictions with recent AAB trends. Direct influences of spring and winter temperatures on AAB are larger and more widespread than the indirect effect mediated by changes in LDPS in most areas. Despite significant warming trends and reductions in snow cover duration, projected responses of AAB to early-mid 21st century are heterogeneous across the continent. Changes in AAB range from strongly increasing (one order of magnitude increases in AAB) to moderately decreasing (more than halving of baseline AAB). Annual wildfire area burned in coming decades is likely to be highly geographically heterogeneous, reflecting interacting regional and seasonal climate drivers of fire occurrence and spread.
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Affiliation(s)
- Thomas Kitzberger
- Laboratorio Ecotono, CONICET–INIBIOMA, Universidad Nacional del Comahue, Quintral, Bariloche, Argentina
- * E-mail:
| | - Donald A. Falk
- University of Arizona, Laboratory of Tree-Ring Research, Tucson, AZ, United States of America
- University of Arizona, School of Natural Resources and the Environment, Environment and Natural Resources Building, Tucson, AZ, United States of America
| | - Anthony L. Westerling
- Sierra Nevada Research Institute, University of California, Merced, California, United States of America
| | - Thomas W. Swetnam
- University of Arizona, Laboratory of Tree-Ring Research, Tucson, AZ, United States of America
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43
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Tepley AJ, Thompson JR, Epstein HE, Anderson-Teixeira KJ. Vulnerability to forest loss through altered postfire recovery dynamics in a warming climate in the Klamath Mountains. GLOBAL CHANGE BIOLOGY 2017; 23:4117-4132. [PMID: 28447370 DOI: 10.1111/gcb.13704] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Revised: 02/27/2017] [Accepted: 03/12/2017] [Indexed: 05/26/2023]
Abstract
In the context of ongoing climatic warming, certain landscapes could be near a tipping point where relatively small changes to their fire regimes or their postfire forest recovery dynamics could bring about extensive forest loss, with associated effects on biodiversity and carbon-cycle feedbacks to climate change. Such concerns are particularly valid in the Klamath Region of northern California and southwestern Oregon, where severe fire initially converts montane conifer forests to systems dominated by broadleaf trees and shrubs. Conifers eventually overtop the competing vegetation, but until they do, these systems could be perpetuated by a cycle of reburning. To assess the vulnerability of conifer forests to increased fire activity and altered forest recovery dynamics in a warmer, drier climate, we characterized vegetation dynamics following severe fire in nine fire years over the last three decades across the climatic aridity gradient of montane conifer forests. Postfire conifer recruitment was limited to a narrow window, with 89% of recruitment in the first 4 years, and height growth tended to decrease as the lag between the fire year and the recruitment year increased. Growth reductions at longer lags were more pronounced at drier sites, where conifers comprised a smaller portion of live woody biomass. An interaction between seed-source availability and climatic aridity drove substantial variation in the density of regenerating conifers. With increasing climatic water deficit, higher propagule pressure (i.e., smaller patch sizes for high-severity fire) was needed to support a given conifer seedling density, which implies that projected future increases in aridity could limit postfire regeneration across a growing portion of the landscape. Under a more severe prospective warming scenario, by the end of the century more than half of the area currently capable of supporting montane conifer forest could become subject to minimal conifer regeneration in even moderate-sized (10s of ha) high-severity patches.
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Affiliation(s)
- Alan J Tepley
- Smithsonian Conservation Biology Institute, Front Royal, VA, USA
| | | | - Howard E Epstein
- Department of Environmental Sciences, University of Virginia, Charlottesville, VA, USA
| | - Kristina J Anderson-Teixeira
- Smithsonian Conservation Biology Institute, Front Royal, VA, USA
- Center for Tropical Forest Science - Forest Global Earth Observatory, Smithsonian Tropical Research Institute, Panama, Republic of Panama
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44
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Jones KW, Cannon JB, Saavedra FA, Kampf SK, Addington RN, Cheng AS, MacDonald LH, Wilson C, Wolk B. Return on investment from fuel treatments to reduce severe wildfire and erosion in a watershed investment program in Colorado. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2017; 198:66-77. [PMID: 28501609 DOI: 10.1016/j.jenvman.2017.05.023] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Revised: 05/03/2017] [Accepted: 05/06/2017] [Indexed: 06/07/2023]
Abstract
A small but growing number of watershed investment programs in the western United States focus on wildfire risk reduction to municipal water supplies. This paper used return on investment (ROI) analysis to quantify how the amounts and placement of fuel treatment interventions would reduce sediment loading to the Strontia Springs Reservoir in the Upper South Platte River watershed southwest of Denver, Colorado following an extreme fire event. We simulated various extents of fuel mitigation activities under two placement strategies: (a) a strategic treatment prioritization map and (b) accessibility. Potential fire behavior was modeled under each extent and scenario to determine the impact on fire severity, and this was used to estimate expected change in post-fire erosion due to treatments. We found a positive ROI after large storm events when fire mitigation treatments were placed in priority areas with diminishing marginal returns after treating >50-80% of the forested area. While our ROI results should not be used prescriptively they do show that, conditional on severe fire occurrence and precipitation, investments in the Upper South Platte could feasibly lead to positive financial returns based on the reduced costs of dredging sediment from the reservoir. While our analysis showed positive ROI focusing only on post-fire erosion mitigation, it is important to consider multiple benefits in future ROI calculations and increase monitoring and evaluation of these benefits of wildfire fuel reduction investments for different site conditions and climates.
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Affiliation(s)
- Kelly W Jones
- Department of Human Dimensions of Natural Resources, Colorado State University, Fort Collins, CO, USA.
| | - Jeffery B Cannon
- Colorado Forest Restoration Institute, Colorado State University, Fort Collins, CO, USA
| | - Freddy A Saavedra
- Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, CO, USA
| | - Stephanie K Kampf
- Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, CO, USA
| | | | - Antony S Cheng
- Colorado Forest Restoration Institute, Colorado State University, Fort Collins, CO, USA; Department of Forest and Rangeland Stewardship, Colorado State University, Fort Collins, CO, USA
| | - Lee H MacDonald
- Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, CO, USA
| | - Codie Wilson
- Department of Geosciences, Colorado State University, Fort Collins, CO, USA
| | - Brett Wolk
- Colorado Forest Restoration Institute, Colorado State University, Fort Collins, CO, USA
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45
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Liang S, Hurteau MD, Westerling AL. Response of Sierra Nevada forests to projected climate-wildfire interactions. GLOBAL CHANGE BIOLOGY 2017; 23:2016-2030. [PMID: 27801532 DOI: 10.1111/gcb.13544] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Revised: 10/21/2016] [Accepted: 10/25/2016] [Indexed: 06/06/2023]
Abstract
Climate influences forests directly and indirectly through disturbance. The interaction of climate change and increasing area burned has the potential to alter forest composition and community assembly. However, the overall forest response is likely to be influenced by species-specific responses to environmental change and the scale of change in overstory species cover. In this study, we sought to quantify how projected changes in climate and large wildfire size would alter forest communities and carbon (C) dynamics, irrespective of competition from nontree species and potential changes in other fire regimes, across the Sierra Nevada, USA. We used a species-specific, spatially explicit forest landscape model (LANDIS-II) to evaluate forest response to climate-wildfire interactions under historical (baseline) climate and climate projections from three climate models (GFDL, CCSM3, and CNRM) forced by a medium-high emission scenario (A2) in combination with corresponding climate-specific large wildfire projections. By late century, we found modest changes in the spatial distribution of dominant species by biomass relative to baseline, but extensive changes in recruitment distribution. Although forest recruitment declined across much of the Sierra, we found that projected climate and wildfire favored the recruitment of more drought-tolerant species over less drought-tolerant species relative to baseline, and this change was greatest at mid-elevations. We also found that projected climate and wildfire decreased tree species richness across a large proportion of the study area and transitioned more area to a C source, which reduced landscape-level C sequestration potential. Our study, although a conservative estimate, suggests that by late century, forest community distributions may not change as intact units as predicted by biome-based modeling, but are likely to trend toward simplified community composition as communities gradually disaggregate and the least tolerant species are no longer able to establish. The potential exists for substantial community composition change and forest simplification beyond this century.
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Affiliation(s)
- Shuang Liang
- Intercollege Graduate Degree Program in Ecology and Department of Ecosystem Science and Management, The Pennsylvania State University, 228 Forest Resources Building, University Park, PA, 16802, USA
| | - Matthew D Hurteau
- Department of Biology, University of New Mexico, MSC03 2020, Albuquerque, NM, 87131, USA
| | - Anthony LeRoy Westerling
- Sierra Nevada Research Institute, University of California, 5200 N. Lake Road, Merced, CA, 95343, USA
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Shanahan E, Irvine KM, Thoma D, Wilmoth S, Ray A, Legg K, Shovic H. Whitebark pine mortality related to white pine blister rust, mountain pine beetle outbreak, and water availability. Ecosphere 2016. [DOI: 10.1002/ecs2.1610] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Erin Shanahan
- Greater Yellowstone Inventory and Monitoring Network National Park Service Bozeman Montana 59715 USA
| | - Kathryn M. Irvine
- U.S. Geological Survey Northern Rocky Mountain Science Center Bozeman Montana 59715 USA
| | - David Thoma
- Greater Yellowstone Inventory and Monitoring Network National Park Service Bozeman Montana 59715 USA
| | - Siri Wilmoth
- U.S. Geological Survey Northern Rocky Mountain Science Center Bozeman Montana 59715 USA
| | - Andrew Ray
- Greater Yellowstone Inventory and Monitoring Network National Park Service Bozeman Montana 59715 USA
| | - Kristin Legg
- Greater Yellowstone Inventory and Monitoring Network National Park Service Bozeman Montana 59715 USA
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47
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Developing and Implementing Climate Change Adaptation Options in Forest Ecosystems: A Case Study in Southwestern Oregon, USA. FORESTS 2016. [DOI: 10.3390/f7110268] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
Global increases in fire frequency driven by anthropogenic greenhouse emissions and land use change could threaten unique and ancient species by creeping into long-term fire refugia. The perhumid and mountainous western half of Tasmania is a globally important refugium for palaeo-endemic, fire intolerant lineages, especially conifers. Reproductive strategy will be crucial to the resilience of these organisms under warmer, dryer and more fire prone climates. This study analysed clonal versus sexual reproduction in old growth plots dominated by the palaeo-endemic conifer Athrotaxis cupressoides (Cupressaceae), a species that lacks any traits to tolerate frequent landscape fire. Across most of the seven plots the amount of sexually derived individuals was lower than clonally derived with, on average, 60% of all stems belonging to the same multi-locus lineage (MLL) (i.e. were clonal). Some MLLs were large spanning over 10 s of metres and consisted of up to 62 stems. The high mortality after fire and the rarity of sexual regeneration means that the range of this fire-intolerant species is likely to contract under enhanced fire regimes and has a limited capacity to disperse via seed to available fire refugia in the landscape.
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Wang JJ, Dahlgren RA, Erşan MS, Karanfil T, Chow AT. Temporal variations of disinfection byproduct precursors in wildfire detritus. WATER RESEARCH 2016; 99:66-73. [PMID: 27135374 DOI: 10.1016/j.watres.2016.04.030] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 04/08/2016] [Accepted: 04/13/2016] [Indexed: 06/05/2023]
Abstract
The Rim Fire ignited on August 17, 2013 and became the third largest wildfire in California history. The fire consumed 104,131 ha of forested watersheds that were the drinking water source for 2.6 million residents in the San Francisco Bay area. To understand temporal variations in dissolved organic matter (DOM) after the wildfire and its potential impacts on disinfection byproduct (DBP) formation in source water supply, we collected the 0-5 cm ash/soil layer with surface deposits of white ash (high burn severity) and black ash (moderate burn severity) within the Rim Fire perimeter in Oct 2013 (pre-rainfall) for five sequential extractions, and in Dec 2013 (∼87 mm cumulative precipitation) and Aug 2014 (∼617 mm cumulative precipitation) for a single water extraction. Water-extractable DOM was characterized by absorption and fluorescence spectroscopy and DBP formation tests. Both increasing cumulative precipitation in the field or number of extractions in the lab resulted in a significant decrease in specific conductivity, dissolved organic carbon, and DBP formation potential, but an increase in DOM aromaticity (reflected by specific UV absorbance). However, the lab sequential leaching failed to capture the increase of the NOx(-)-N/NH4(+)-N ratio and the decrease in pH and dissolved organic carbon/nitrogen ratio of ash/soil extracts from Oct 2013 to Aug 2014. Increasing cumulative precipitation, inferring an increase in leaching after fire, led to an increase in DOM reactivity to form trihalomethanes, haloacetic acids, and chloral hydrate, but not for haloketones, haloacetonitrile, or N-nitrosodimethylamine, which were more related to the original burn severity. This study highlights that fire-affected DBP precursors for different DBP species have distinct temporal variation possibly due to their various sensitivity to biogeochemical alterations.
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Affiliation(s)
- Jun-Jian Wang
- Baruch Institute of Coastal Ecology & Forest Science, Clemson University, Georgetown, SC, 29442, USA
| | - Randy A Dahlgren
- Department of Land, Air and Water Resources, University of California - Davis, CA, 95616, USA
| | - Mahmut S Erşan
- Department of Environmental Engineering and Earth Sciences, Clemson University, Anderson, SC, 29625, USA
| | - Tanju Karanfil
- Department of Environmental Engineering and Earth Sciences, Clemson University, Anderson, SC, 29625, USA
| | - Alex T Chow
- Baruch Institute of Coastal Ecology & Forest Science, Clemson University, Georgetown, SC, 29442, USA; Department of Environmental Engineering and Earth Sciences, Clemson University, Anderson, SC, 29625, USA.
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