Long-term relations among fire, fuel, and climate in the north-western US based on lake-sediment studies

2008 ◽  
Vol 17 (1) ◽  
pp. 72 ◽  
Author(s):  
Cathy Whitlock ◽  
Jennifer Marlon ◽  
Christy Briles ◽  
Andrea Brunelle ◽  
Colin Long ◽  
...  

Pollen and high-resolution charcoal records from the north-western USA provide an opportunity to examine the linkages among fire, climate, and fuels on multiple temporal and spatial scales. The data suggest that general charcoal levels were low in the late-glacial period and increased steadily through the last 11 000 years with increasing fuel biomass. At local scales, fire occurrence is governed by the interaction of site controls, including vegetation, local climate and fire weather, and topography. At subregional scales, patterns in the long term fire-episode frequency data are apparent: The Coast Range had relatively few fires in the Holocene, whereas the Klamath–Siskiyou region experienced frequent fire episodes. Fire regimes in the northern Rocky Mountains have been strongly governed by millennial- and centennial-scale climate variability and regional differences in summer moisture. At regional scales, sites in present-day summer-dry areas show a period of protracted high fire activity within the early Holocene that is attributed to intensified summer drought in the summer-dry region. Sites in summer-wet areas show the opposite pattern, that fire was lower in frequency than present in the early Holocene as result of strengthened monsoonal circulation then. Higher fire-episode frequency at many sites in the last 2000 years is attributed to greater drought during the Medieval Climate Anomaly and possibly anthropogenic burning. The association between drought, increased fire occurrence, and available fuels evident on several time scales suggests that long-term fire history patterns should be considered in current assessments of historical fire regimes and fuel conditions.

2017 ◽  
Vol 78 ◽  
pp. 270-281 ◽  
Author(s):  
Swanni T. Alvarado ◽  
Tamires Fornazari ◽  
Andresa Cóstola ◽  
Leonor Patricia Cerdeira Morellato ◽  
Thiago Sanna Freire Silva

Author(s):  
Paul Huddie

The year 2014 marked the 160th anniversary of the beginning of the Crimean War, 1854–6. It was during that anniversary year that the names of Crimea, Sevastopol, Simferopol and the Black Sea re-entered the lexicon of Ireland, and so did the terms ‘Russian aggression’, ‘territorial violation’ and ‘weak neighbour’. Coincidentally, those same places and terms, and the sheer extent to which they perpetuated within Irish and even world media as well as popular parlance, had not been seen nor heard since 1854. It was in that year that the British and French Empires committed themselves to war in the wider Black Sea region and beyond against the Russian Empire. The latter had demonstrated clear aggression, initially diplomatic and later military, against its perceived-to-be-weak neighbour and long-term adversary in the region, the Ottoman Empire, or Turkey. As part of that aggression Russia invaded the latter’s vassal principalities in the north-western Balkans, namely Wallachia and Moldavia (part of modern-day Romania), collectively known as the Danubian Principalities. Russia had previously taken Crimea from the Ottomans in 1783....


2014 ◽  
Vol 23 (7) ◽  
pp. 959 ◽  
Author(s):  
Larissa L. Yocom ◽  
Peter Z. Fulé ◽  
Donald A. Falk ◽  
Celia García-Domínguez ◽  
Eladio Cornejo-Oviedo ◽  
...  

We investigated the influence of broad- v. fine-scale factors on fire in an unusual landscape suitable for distinguishing the drivers of fire synchrony. Our study was conducted in the Sierra Madre Oriental mountain range, in north-eastern Mexico. We worked in nine sites on three parallel mountains that receive nearly identical broad-scale climatic influence, but between which fires are unlikely to spread. We collected and cross dated samples from 357 fire-scarred trees in nine sites in high-elevation mixed-conifer forests and identified fire dates. We used Jaccard similarity analysis to evaluate synchrony among sites and quantified relationships between climate and fire occurrence. Fires were historically frequent (mean fire interval ranged from 8 to 16 years in all sites) and dates of fire exclusion ranged from 1887 to 1962. We found low fire synchrony among the three mountains, indicating a strong influence of fine-scale factors on fire occurrence. Fire regime attributes were similar across mountains despite the independence of fire dates. La Niña events were associated with fire over time, although not significantly since the 1830s. Our results highlight the importance of scale in describing fire regimes and suggest that we can use fire history to understand controls on complex ecosystem processes and patterns.


Ecology ◽  
2012 ◽  
Author(s):  
John Parminter

Abiotic natural disturbance agents include wildfire, wind, landslides, snow avalanches, volcanoes, flooding, and other weather-related phenomena. Fire is of particular interest because of its antiquity, its natural role in many terrestrial ecosystems, its long-term use by humans to modify vegetation, and its potentially serious threat to life and property. Fire ecology is the art and science of understanding natural and human fire history and fire effects on the environment, species, ecosystems, and landscapes. This knowledge aids the development of fire and ecosystem management plans and activities. Fire history is determined by a number of techniques that use available physical or cultural evidence to examine particular temporal and spatial scales. Fire effects on the environment and organisms are determined by observation and experimentation, but the findings are variable and often contradictory. Fire regimes are used to characterize the role of fire in specific ecosystems and can help guide ecosystem restoration activities. Attitudes toward fire have evolved over time, as good and bad experiences combined with improved scientific understanding to influence our perspectives. Natural disturbances came to be viewed as integral parts of ecosystems rather than external perturbations. We now strive to allow fire to maintain its natural role in wilderness areas and parks and also to emulate natural disturbances, such as fire, when designing forest harvesting operations. This article focuses on how and what we know about fire’s history, its effects on different components of the environment, its role in specific vegetation types, and its relationship with human culture.


2020 ◽  
Author(s):  
Carlo Brandini ◽  
Stefano Taddei ◽  
Valentina Vannucchi ◽  
Michele Bendoni ◽  
Bartolomeo Doronzo ◽  
...  

<p>In this work we present the results obtained through a dynamic downscaling of the ERA5 reanalysis dataset (hindcast) of ECMWF, using high-resolution meteorological and wave models defined on unstructured computation grids along the Mediterranean coasts, with a particular focus on the North-Western Mediterranean area. Downscaling of the ERA5 meteorological data is obtained through the BOLAM and MOLOCH models (up to a resolution of 2.5 km) which force an unstructured WW3 model with a resolution of up to 500 m along the coast. Models were validated through available meteorological stations, wave buoy data and X-band wave radars, the latter for the purposes of wave spectra validation.</p><p>On the one hand, this allowed, by extracting the time series of some attack parameters of the waves along the coast, and according to the type of coast (rocky coasts, sandy coasts, coastal structures etc.), to compute the return periods and to characterize the impact of any individual storm. On the other hand, it is possible to highlight some trends observed in the last 30 years, during which recent research is showing an increasing evidence  of some changes in global circulation at regional to local scales. These changes also include effects of wind rotation, wave regimes, storm surges, wave-induced coastal currents and coastal morphodynamics. For example, in the North-Western Mediterranean extreme events belonging to cyclonic weather-types circulation with stronger S-SE components (like the storm of October 28-30th 2018 and many others), rather than events associated with perturbations of Atlantic origin and zonal circulation, are becoming more frequent. These long-term wind/wave climate trends can have consequences not only in the assessment of long-term risk due to main morphodynamic variations (ie. coastal erosion), but also in the short-term risk assessment.</p><p>This work was funded by the EU MAREGOT project (2017-2020) and ECMWF Special Project spitbran  “Evaluation of coastal climate trends in the Mediterranean area by means of high-resolution and multi-model downscaling of ERA5 reanalysis” (2018-2020).</p>


2020 ◽  
Vol 29 (7) ◽  
pp. 602
Author(s):  
Grant L. Harley ◽  
Emily K. Heyerdahl ◽  
James D. Johnston ◽  
Diana L. Olson

Riparian forests link terrestrial and freshwater communities and therefore understanding the landscape context of fire regimes in these forests is critical to fully understanding the landscape ecology. However, few direct studies of fire regimes exist for riparian forests, especially in the landscape context of adjacent upland forests or studies of long-term climate drivers of riparian forest fires. We reconstructed a low-severity fire history from tree rings in 38 1-ha riparian plots and combined them with existing fire histories from 104 adjacent upland plots to yield 2633 fire scars sampled on 454 trees. Historically (1650–1900), low-severity fires burned more frequently in upland than in riparian plots, but this difference was not significant (P=0.15). During more than half of the fire years at both sites, fires were extensive and burned synchronously in riparian and upland plots, and climate was significantly dry during these years. However, climate was not significantly dry when fires burned in only one plot type. Historically, entire riparian zones likely burned in these two study sites of the Blue Mountains during dry years. This study suggests that riparian and upland forests could be managed similarly, especially given the projected increases to fire frequency and intensity from impending climate change.


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