Altered Fire Regimes Affect Landscape Patterns of Plant Succession in the Foothills and Mountains of Southern California

Humans influence the frequency and spatial pattern of fire and contribute to altered fire regimes, but fuel loading is often the only factor considered when planning management activities to reduce fire hazard. Understanding both the human and biophysical landscape characteristics that explain how fire patterns vary should help to identify where fire is most likely to threaten values at risk. We used human and biophysical explanatory variables to model and map the spatial patterns of both fire ignitions and fire frequency in the Santa Monica Mountains, a human-dominated southern California landscape. Most fires in the study area are caused by humans, and our results showed that fire ignition patterns were strongly influenced by human variables. In particular, ignitions were most likely to occur close to roads, trails, and housing development but were also related to vegetation type. In contrast, biophysical variables related to climate and terrain (January temperature, transformed aspect, elevation, and slope) explained most of the variation in fire frequency. Although most ignitions occur close to human infrastructure, fires were more likely to spread when located farther from urban development. How far fires spread was ultimately related to biophysical variables, and the largest fires in southern California occurred as a function of wind speed, topography, and vegetation type. Overlaying predictive maps of fire ignitions and fire frequency may be useful for identifying high-risk areas that can be targeted for fire management actions.

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Using knowledge of natural disturbances to support sustainable forest management in the northern Clay Belt

The Forestry Chronicle ◽

10.5558/tfc83326-3 ◽

2007 ◽

Vol 83 (3) ◽

pp. 326-337 ◽

Cited By ~ 44

Author(s):

Yves Bergeron ◽

Pierre Drapeau ◽

Sylvie Gauthier ◽

Nicolas Lecomte

Keyword(s):

Forest Management ◽

Sustainable Forest Management ◽

Black Spruce ◽

Natural Disturbance ◽

Fire Regimes ◽

Landscape Patterns ◽

Management Approach ◽

Natural Disturbances ◽

Natural Fire ◽

Coarse Filter

Several concepts are at the basis of forest ecosystem management, but a relative consensus exists around the idea of a forest management approach that is based on natural disturbances and forest dynamics. This type of approach aims to reproduce the main attributes of natural landscapes in order to maintain ecosystems within their natural range of variability and avoid creating an environment to which species are not adapted. By comparing attributes associated with natural fire regimes and current forest management, we were able to identify four major differences for the black spruce forest of the Clay Belt. The maintenance of older forests, the spatial extent of cutover areas, the maintenance of residuals within cutovers and disturbance severity on soils are major issues that should be addressed. Silvicultural strategies that mitigate differences between natural and managed forests are briefly discussed. Key words: natural disturbance, landscape patterns, coarse filter, harvest pattern, volume retention, historic variability, even-aged management

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Spatial patterns and controls on burned area for two contrasting fire regimes in Southern California

Ecosphere ◽

10.1002/ecs2.1210 ◽

2016 ◽

Vol 7 (5) ◽

Cited By ~ 16

Author(s):

N. R. Faivre ◽

Y. Jin ◽

M. L. Goulden ◽

J. T. Randerson

Keyword(s):

Spatial Patterns ◽

Southern California ◽

Fire Regimes ◽

Burned Area

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Fire Management in Coastal Sage-scrub, Southern California, USA

Environmental Conservation ◽

10.1017/s0376892900015551 ◽

1985 ◽

Vol 12 (2) ◽

pp. 141-146 ◽

Cited By ~ 7

Author(s):

George P. Malanson

Keyword(s):

Computer Simulation ◽

Southern California ◽

Prescribed Burning ◽

Fire Regime ◽

Wildland Fire ◽

Fire Regimes ◽

Coastal Sage Scrub ◽

Fire Intensity ◽

Sage Scrub ◽

Fire Intervals

Wildland fire management directly affects the forces of natural selection to which plant taxa become adapted. Changes in a fire regime will often result in changes in the relative abundance of particular species, and may cause the extinction of some of them. Life-history characteristics are important indicators of adaptation to recurrent disturbance, such as may be produced by fire. The incorporation of these characteristics in a computer simulation allows of the projection of species abundance under different fire regimes.Through prescribed burning and fire suppression, fire interval and fire intensity can be controlled to some extent. The fire intensity for given sets of fuel, site, and meteoro-logical conditions, representing given fire-intervals, is calculated with the use of a fire behaviour computer simulation. These results are incorporated in computer simulation of the demographic competition of the five dominant shrub species of coastal sage-scrub in the Santa Monica Mountains of southern California: Artemisia californica, Encelia californica, Eriogonum cinereum, Salvia leucophylla, and S. mellifera. The model incorporates resprouting proportions, seedling establishment, and growth, and assumes survivorship rates in simulating scramble competition for space. Foliar cover-values of the five species are projected for nine different fire regimes. Short fire-intervals of the order of 10–20 years, such as might occur under a regime of prescribed burning, may eliminate or greatly reduce some species, whereas longer intervals allow the maintenance of a more diverse community especially of shrubs. Fixed and variable interval-lengths do not produce appreciably different results.This study suggests that prescribed burning at 10–20 years' intervals should not be used indiscriminately to reduce wildland fire hazard in southern California. The fire intervals that will reduce the hazard, may eliminate some dominant native shrub species. A ‘natural’ fire regime which would maintain the natural vegetation while constituting only a minimum hazard to homesites may, unfortunately, be mutually exclusive goals in the coastal sage-scrub of southern California.

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Modelling long-term fire regimes of southern California shrublands

International Journal of Wildland Fire ◽

10.1071/wf09102 ◽

2011 ◽

Vol 20 (1) ◽

pp. 1 ◽

Cited By ~ 14

Author(s):

Seth H. Peterson ◽

Max A. Moritz ◽

Marco E. Morais ◽

Philip E. Dennison ◽

Jean M. Carlson

Keyword(s):

Southern California ◽

Fire Regime ◽

Fire Regimes ◽

Fire Spread ◽

Computationally Efficient ◽

Interval Maps ◽

Spread Model ◽

Wind Events ◽

In Fire

This paper explores the environmental factors that drive the southern California chaparral fire regime. Specifically, we examined the response of three fire regime metrics (fire size distributions, fire return interval maps, cumulative total area burned) to variations in the number of ignitions, the spatial pattern of ignitions, the number of Santa Ana wind events, and live fuel moisture, using the HFire fire spread model. HFire is computationally efficient and capable of simulating the spatiotemporal progression of individual fires on a landscape and aggregating results for fully resolved individual fires over hundreds or thousands of years to predict long-term fire regimes. A quantitative understanding of the long-term drivers of a fire regime is of use in fire management and policy.

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Development of soil in heterogeneous landscapes of a high alpine catchment in the Central European Alps

10.5194/egusphere-egu2020-18826 ◽

2020 ◽

Author(s):

Svenja Müller ◽

Katharina Ramskogler ◽

Bettina Knoflach ◽

Johann Stötter ◽

Brigitta Erschbamer ◽

...

Keyword(s):

Soil Properties ◽

Soil Formation ◽

Soil Development ◽

Snow Accumulation ◽

Landscape Patterns ◽

Plant Succession ◽

European Alps ◽

South Tyrol ◽

Initial Soil ◽

Geological Substrate

In high mountain environments with harsh weather conditions, soil development and its limitations strongly depend on topography and morphodynamics, both leading to heterogeneous landscape patterns of different geological substrate, vegetation, (micro)relief, and (micro)climate. In addition, as glaciers currently are retreating disproportionately strong, a large area is exposed to initial soil development, enabling to study time related issues of soil formation.These mosaic-like patterns are particularly intensified within the high-alpine and nival zone, due to the dominating influence of cryospheric elements, such as ice (e.g. retreating glaciers), snow (e.g. snowbeds; shallow self-deepening sinks with snow accumulation at altitudes above 2500 m a.s.l.), and frost (e.g. causing solifluction, controlling physical weathering, changing permafrost dynamics, increasing the probability mass movements and sediment transport). The high-alpine environment with its site diversity therefore represents a perfect study area to analyze soil-vegetation-interactions at various microsites within a single catchment.To study the influence of time, the glacier foreland of Zufall- and F&#252;rkeleferner (Martelltal, South Tyrol) was found to be excellent for an interdisciplinary chronosequence study. Large amounts of historical maps, aerial orthophotos, and remote sensing data are available, enabling reconstructed glacier retreat with a high spatial and temporal accuracy. Study sites of different soil age were chosen for the analysis of various soil and vegetation parameters. The influence of temperature and soil water availability were determined by installing temperature and soil matric potential data loggers.Furthermore, to study soil development as a function of geological substrate, microrelief, altitude, slope, and microclimate, an additional transect along an altitudinal gradient (Martelltal, South Tyrol, within the maximum extent of Egesen) was sampled and analyzed regarding central soil properties, vegetation, and microclimate. Directly bordering to those sites, heterogeneous and morphodynamically active microsites were investigated. These special sites were characterized by different morphological features, in particularly: soil sinks of different genesis, hilltops, and scree-dominated sites with initial soil development after primary plant succession.As expected, we found clear trends of soil development with changing altitude and/or time. However, the small-scaled special sites differed distinctly from the reference sites regarding basic soil properties such as soil pH or soil organic matter content, and also remarkably in plant-available NH4-N, microbial activity, and microbial biomass. This was especially true where the water regime was strongly affected by the microrelief.The observed distinct changes in soil properties within small scales of sometimes only several meters help to better understand and predict soil formation and diversity as well as soil-plant-interactions in high alpine environments of the European Alps.

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Asynchronous lightning and Santa Ana winds highlight human role in southern California fire regimes

Environmental Research Letters ◽

10.1088/1748-9326/aace39 ◽

2018 ◽

Vol 13 (7) ◽

pp. 074024

Author(s):

Jacob Bendix ◽

Justin J Hartnett

Keyword(s):

Southern California ◽

Fire Regimes ◽

Santa Ana ◽

Santa Ana Winds

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Evaluating a century of fire patterns in two Rocky Mountain wilderness areas using digital fire atlases

Canadian Journal of Forest Research ◽

10.1139/x01-141 ◽

2001 ◽

Vol 31 (12) ◽

pp. 2107-2123 ◽

Cited By ~ 50

Author(s):

Matthew G Rollins ◽

Thomas W Swetnam ◽

Penelope Morgan

Keyword(s):

Management Strategies ◽

Rocky Mountain ◽

Fire Regimes ◽

Landscape Patterns ◽

Fuels Management ◽

Rotation Periods ◽

Period 1880 ◽

Wilderness Areas ◽

Baseline Information ◽

Fire Intervals

Changes in fire size, shape, and frequency under different fire-management strategies were evaluated using time series of fire perimeter data (fire atlases) and mapped potential vegetation types (PVTs) in the Gila Aldo Leopold Wilderness Complex (GALWC) in New Mexico and the SelwayBitterroot Wilderness Complex (SBWC) in Idaho and Montana. Relative to pre-Euro-American estimates, fire rotations in the GALWC were short during the recent wildfire-use period (19751993) and long during the pre-modern suppression period (19091946). In contrast, fire rotations in the SBWC were short during the pre-modern suppression period (18801934) and long during the modern suppression period (19351975). In general, fire-rotation periods were shorter in mid-elevation, shade-intolerant PVTs. Fire intervals in the GALWC and SBWC are currently longer than fire intervals prior to Euro-American settlement. Proactive fire and fuels management are needed to restore fire regimes in each wilderness complex to within natural ranges of variability and to reduce the risk of catastrophic wildfire in upper elevations of the GALWC and nearly the entire SBWC. Analyses of fire atlases provide baseline information for evaluating landscape patterns across broad landscapes.

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