Fire Seasonality Mechanisms Are Fundamental for Understanding Broader Fire Regime Effects

2020 ◽  
Vol 35 (10) ◽  
pp. 869-871
Author(s):  
Russell G. Miller ◽  
Ryan Tangney ◽  
Neal J. Enright ◽  
Joseph B. Fontaine ◽  
David J. Merritt ◽  
...  
Keyword(s):  
Fire Regime ◽  
Fire Seasonality

scholarly journals Easy-To-Interpret Procedure to Analyze Fire Seasonality and the Influence of Land Use in Fire Occurrence: A Case Study in Central Italy

Fire ◽  
2020 ◽  
Vol 3 (3) ◽  
pp. 46
Author(s):  
Sofia Bajocco ◽  
Carlotta Ferrara ◽  
Daniela Guglietta ◽  
Carlo Ricotta
Keyword(s):  
Land Use ◽  
Fire Regime ◽  
Anthropogenic Activities ◽  
Central Italy ◽  
Fire Risk ◽  
Management Tool ◽  
Fire Occurrence ◽  
Fire Seasonality ◽  
Graphical Tool ◽  
In Fire

Fire frequency and fire seasonality are among the main components of the fire regime. In the Mediterranean Basin, climate directly drives fire occurrence, controlling fuel flammability and determining the fire-prone conditions, so that intense fires prevail during the dry and warm season of the year. However, humans also play a direct role in wildfire regimes, severely altering fuel features, fire policies and land-use management, as well as the timing and location of fire ignitions, to such an extent that anthropogenic activities have overcome the role of climate in shaping fire regimes. The main purpose of this work is to propose a graphical tool capable of identifying the most fire-prone portions of the territory and to explore the differences between the summer and winter fire risk; to this end, we analyzed the seasonal fire risk in the Latium region (central Italy) and its drivers in terms of land-use types, by using a fuel phenology framework. The results demonstrated that climate is not the main cause of bimodal seasonality in fire occurrence and that the existence of two annual fire seasons in Latium is strongly correlated with how humans use fire as a land management tool. The proposed approach may represent an easy-to-interpret pyrogeographical framework applicable in any environment and updatable over time, useful for identifying spatial gradients, and for recognizing fire regime temporal patterns.

Analysis of natural regeneration of Scots pine forest in the high Campine after a fire

1988 ◽  
Vol 53 ◽  
Author(s):  
N. Lust
Keyword(s):  
Scots Pine ◽  
Natural Regeneration ◽  
Fire Regime ◽  
Pine Forest ◽  
Seed Supply ◽  
Regeneration Period ◽  
The Social ◽  
Short Period ◽  
Fire Area ◽  
Scots Pine Forest

The  study deals with the spontaneous resettlement of a fire area, after  destruction of 600 ha Scots pine forest. The following items have been  examined in particular: the composition of the tree species, the duration of  the regeneration period, the influence of the parent stand, the exposition,  the slope, the treatment, the fire regime and the social differentiation.      The resettlement took place very quickly and over a very short period.  Birch and Scots pine take up 95 % of the stem number. The regeneration result  is precarious, yet mostly good. The parent stand is favourable both to seed  supply and to microclimate, but only over a short distance. The Scots pine  prefers more open and dry areas, whereas birch needs more humidity.     Practice has shown that natural regeneration of Scots pine stands is  possible. The forest treatment, however, is very important. It determines not  only the immediate result of the regeneration, but also the composition and  the structure of the future stand.

scholarly journals Prescribed burning in a mediterranean-climate region mitigates the disturbance by bushfire to a critical food resource for an endangered bird, the Carnaby’s cockatoo

Fire Ecology ◽  
2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Valerie S. Densmore ◽  
Emma S. Clingan
Keyword(s):  
Seed Production ◽  
Prescribed Burning ◽  
Fire Regime ◽  
Fire Hazard ◽  
Food Resource ◽  
Management Tool ◽  
Fire Intensity ◽  
Prescribed Burns ◽  
Low Intensity ◽  
Percentage Survival

Abstract Background Prescribed burning is used to reduce fire hazard in highly flammable vegetation types, including Banksia L.f. woodland that occurs on the Swan Coastal Plain (SCP), Western Australia, Australia. The 2016 census recorded well over 1.9 million people living on the SCP, which also encompasses Perth, the fourth largest city in Australia. Banksia woodland is prone to frequent ignitions that can cause extensive bushfires that consume canopy-stored banksia seeds, a critical food resource for an endangered bird, the Carnaby’s cockatoo (Calyptorynchus latirostris, Carnaby 1948). The time needed for banksias to reach maturity and maximum seed production is several years longer than the typical interval between prescribed burns. We compared prescribed burns to bushfires and unburned sites at three locations in banksia woodland to determine whether low-intensity prescribed burns affect the number of adult banksias and their seed production. Study sites were matched to the same vegetation complex, fire regime, and time-since-fire to isolate fire intensity as a variable. Results Headfire rates of spread and differenced normalized burn ratios indicated that prescribed burning was generally of a much lower intensity than bushfire. The percentage survival of adult banksias and their production of cones and follicles (seeds) did not decrease during the first three years following a prescribed burn. However, survival and seed production were significantly diminished followed high-intensity bushfire. Thus, carrying capacity for Carnaby’s cockatoo was unchanged by prescribed burning but decreased markedly following bushfire in banksia woodland. Conclusions These results suggest that prescribed burning is markedly different from bushfire when considering appropriate fire intervals to conserve canopy habitats in fire-resilient vegetation communities. Therefore, low-intensity prescribed burning represents a viable management tool to reduce the frequency and extent of bushfire impacts on banksia woodland and Carnaby’s cockatoo.

scholarly journals The distribution of woody species in relation to climate and fire in Yosemite National Park, California, USA

Fire Ecology ◽  
2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Jan W. van Wagtendonk ◽  
Peggy E. Moore ◽  
Julie L. Yee ◽  
James A. Lutz
Keyword(s):  
Plant Species ◽  
Sierra Nevada ◽  
Species Distribution ◽  
National Park ◽  
Woody Plant ◽  
Fire Regime ◽  
Yosemite National Park ◽  
Distribution Models ◽  
Ecological Zones ◽  
Woody Plant Species

Abstract Background The effects of climate on plant species ranges are well appreciated, but the effects of other processes, such as fire, on plant species distribution are less well understood. We used a dataset of 561 plots 0.1 ha in size located throughout Yosemite National Park, in the Sierra Nevada of California, USA, to determine the joint effects of fire and climate on woody plant species. We analyzed the effect of climate (annual actual evapotranspiration [AET], climatic water deficit [Deficit]) and fire characteristics (occurrence [BURN] for all plots, fire return interval departure [FRID] for unburned plots, and severity of the most severe fire [dNBR]) on the distribution of woody plant species. Results Of 43 species that were present on at least two plots, 38 species occurred on five or more plots. Of those 38 species, models for the distribution of 13 species (34%) were significantly improved by including the variable for fire occurrence (BURN). Models for the distribution of 10 species (26%) were significantly improved by including FRID, and two species (5%) were improved by including dNBR. Species for which distribution models were improved by inclusion of fire variables included some of the most areally extensive woody plants. Species and ecological zones were aligned along an AET-Deficit gradient from cool and moist to hot and dry conditions. Conclusions In fire-frequent ecosystems, such as those in most of western North America, species distribution models were improved by including variables related to fire. Models for changing species distributions would also be improved by considering potential changes to the fire regime.

scholarly journals A reconstruction of the recent fire regimes of Majete Wildlife Reserve, Malawi, using remote sensing

Fire Ecology ◽  
2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Willem A. Nieman ◽  
Brian W. van Wilgen ◽  
Alison J. Leslie
Keyword(s):  
Remote Sensing ◽  
Fire Management ◽  
Fire Regime ◽  
Fire Regimes ◽  
Dry Season ◽  
Annual Rainfall ◽  
Vegetation Types ◽  
Local Evidence ◽  
Hot Dry Season ◽  
Wildlife Reserve

Abstract Background Fire is an important process that shapes the structure and functioning of African savanna ecosystems, and managers of savanna protected areas use fire to achieve ecosystem goals. Developing appropriate fire management policies should be based on an understanding of the determinants, features, and effects of prevailing fire regimes, but this information is rarely available. In this study, we report on the use of remote sensing to develop a spatially explicit dataset on past fire regimes in Majete Wildlife Reserve, Malawi, between 2001 and 2019. Moderate Resolution Imaging Spectroradiometer (MODIS) images were used to evaluate the recent fire regime for two distinct vegetation types in Majete Wildlife Reserve, namely savanna and miombo. Additionally, a comparison was made between MODIS and Visible Infrared Imager Radiometer Suite (VIIRS) images by separately evaluating selected aspects of the fire regime between 2012 and 2019. Results Mean fire return intervals were four and six years for miombo and savanna vegetation, respectively, but the distribution of fire return intervals was skewed, with a large proportion of the area burning annually or biennially, and a smaller proportion experiencing much longer fire return intervals. Variation in inter-annual rainfall also resulted in longer fire return intervals during cycles of below-average rainfall. Fires were concentrated in the hot-dry season despite a management intent to restrict burning to the cool-dry season. Mean fire intensities were generally low, but many individual fires had intensities of 14 to 18 times higher than the mean, especially in the hot-dry season. The VIIRS sensors detected many fires that were overlooked by the MODIS sensors, as images were collected at a finer scale. Conclusions Remote sensing has provided a useful basis for reconstructing the recent fire regime of Majete Wildlife Reserve, and has highlighted a current mismatch between intended fire management goals and actual trends. Managers should re-evaluate fire policies based on our findings, setting clearly defined targets for the different vegetation types and introducing flexibility to accommodate natural variation in rainfall cycles. Local evidence of the links between fires and ecological outcomes will require further research to improve fire planning.

Bark in Woody Plants: Understanding the Diversity of a Multifunctional Structure

2019 ◽  
Vol 59 (3) ◽  
pp. 535-547 ◽  
Author(s):  
Julieta A Rosell
Keyword(s):  
Woody Plants ◽  
Fire Regime ◽  
Soluble Sugars ◽  
Plant Performance ◽  
Functional Ecology ◽  
Bark Thickness ◽  
Outer Bark ◽  
Plant Parts ◽  
Selective Forces ◽  
Plant Ecological

Abstract Most biological structures carry out multiple functions. Focusing on only one function to make adaptive inferences overlooks that manifold selection pressures and tradeoffs shape the characteristics of a multifunctional structure. Focusing on single functions can only lead to a partial picture of the causes underlying diversity and the evolutionary origin of the structure in question. I illustrate this discussion using bark as a study case. Bark comprises all the tissues surrounding the xylem in woody plants. Broadly, bark includes an inner and mostly living region and an outer, dead one. Of all plant structures, bark has the most complex anatomical structure and ontogenetic origin involving two (and often three) different meristems. Traditionally, the wide diversity in bark traits, mainly bark thickness, has been interpreted as the result of the selective pressures imposed by fire regime. However, recent research has shown that explanations based on fire regime cannot account for salient patterns of bark variation globally including the very strong inner bark thickness–stem diameter scaling, which is likely due to metabolic needs, and the very high intracommunity variation in total, inner, and outer bark thickness, and in inner:outer proportions. Moreover, explanations based on fire disregard that in addition to fire protection, bark carries out several other crucial functions for plants including translocation of photosynthates; storage of starch, soluble sugars, water, and other compounds; protection from herbivores, pathogens, and high temperatures; wound closure, as well as mechanical support, photosynthesis, and likely being involved in xylem embolism repair. All these functions are crucial for plant performance and are involved in synergistic (e.g., storage of water and insulation) and trade-off relationships (e.g., protection from fire vs photosynthetic activity). Focusing on only one of these functions, protection from fire has provided an incomplete picture of the selective forces shaping bark diversity and has severely hindered our incipient understanding of the functional ecology of this crucial region of woody stems. Applying a multifunctional perspective to the study of bark will allow us to address why we observe such high intracommunity variation in bark traits, why some bark trait combinations are ontogenetically impossible or penalized by selection, how bark is coordinated functionally with other plant parts, and as a result, to understand how bark contributes to the vast diversity of plant ecological strategies across the globe.

Eighty years of change: vegetation in the montane ecoregion of Jasper National Park, Alberta, Canada

2002 ◽  
Vol 32 (11) ◽  
pp. 2010-2021 ◽  
Author(s):  
Jeanine M Rhemtulla ◽  
Ronald J Hall ◽  
Eric S Higgs ◽  
S Ellen Macdonald
Keyword(s):  
National Park ◽  
Vegetation Change ◽  
Fire Regime ◽  
Reference Conditions ◽  
Habitat Diversity ◽  
Climatic Conditions ◽  
Aerial Photographs ◽  
Contributing Factors ◽  
Jasper National Park ◽  
Closed Canopy

Repeat ground photographs (taken in 1915 and 1997) from a series of topographical survey stations and repeat aerial photographs (flown in 1949 and 1991) were analysed to assess changes in vegetation composition and distribution in the montane ecoregion of Jasper National Park, in the Rocky Mountains of Alberta, Canada. A quantitative approach for assessing relative vegetation change in repeat ground photographs was developed and tested. The results indicated a shift towards late-successional vegetation types and an increase in crown closure in coniferous stands. Grasslands, shrub, juvenile forest, and open forests decreased in extent, and closed-canopy forests became more prevalent. The majority of forest stands succeeded to dominance by coniferous species. Changes in vegetation patterns were likely largely attributable to shifts in the fire regime over the last century, although climatic conditions and human activity may also have been contributing factors. Implications of observed changes include decreased habitat diversity, increased possibility of insect outbreaks, and potential for future high-intensity fire events. Results of the study increase knowledge of historical reference conditions and may help to establish restoration goals for the montane ecoregion of the park.

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