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Remote sensing analysis of vegetation recovery following short-interval fires in Southern California shrublands.

Meng R, Dennison PE, D'Antonio CM, Moritz MA - PLoS ONE (2014)

Bottom Line: Increased fire frequency has been shown to promote alien plant invasions in the western United States, resulting in persistent vegetation type change.However, extensive type conversion of chaparral to grassland was not evident in this study.Most variables, with the exception of elevation, were moderately or poorly correlated with differences in vegetation recovery.

View Article: PubMed Central - PubMed

Affiliation: Department of Geography, University of Utah, Salt Lake City, Utah, United States of America.

ABSTRACT
Increased fire frequency has been shown to promote alien plant invasions in the western United States, resulting in persistent vegetation type change. Short interval fires are widely considered to be detrimental to reestablishment of shrub species in southern California chaparral, facilitating the invasion of exotic annuals and producing "type conversion". However, supporting evidence for type conversion has largely been at local, site scales and over short post-fire time scales. Type conversion has not been shown to be persistent or widespread in chaparral, and past range improvement studies present evidence that chaparral type conversion may be difficult and a relatively rare phenomenon across the landscape. With the aid of remote sensing data covering coastal southern California and a historical wildfire dataset, the effects of short interval fires (<8 years) on chaparral recovery were evaluated by comparing areas that burned twice to adjacent areas burned only once. Twelve pairs of once- and twice-burned areas were compared using normalized burn ratio (NBR) distributions. Correlations between measures of recovery and explanatory factors (fire history, climate and elevation) were analyzed by linear regression. Reduced vegetation cover was found in some lower elevation areas that were burned twice in short interval fires, where non-sprouting species are more common. However, extensive type conversion of chaparral to grassland was not evident in this study. Most variables, with the exception of elevation, were moderately or poorly correlated with differences in vegetation recovery.

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Related in: MedlinePlus

Time interval and time since second fire versus change in DMN.a. Time interval between two fires versus change in DMN from 1985 to 2010. b. Time since second fire to 2010 versus change in DMN from 1985 to 2010.
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pone-0110637-g006: Time interval and time since second fire versus change in DMN.a. Time interval between two fires versus change in DMN from 1985 to 2010. b. Time since second fire to 2010 versus change in DMN from 1985 to 2010.

Mentions: Time interval between two fires and time since second fire to 2010 were plotted against change in DMN (Figure 6a; Figure 6b). There was no apparent trend between time interval between fires or recovery time and change in DMN (Table 5). Shorter fire return intervals did not produce higher DMN values, which would be consistent with type conversion due to elimination of obligate seeding species.


Remote sensing analysis of vegetation recovery following short-interval fires in Southern California shrublands.

Meng R, Dennison PE, D'Antonio CM, Moritz MA - PLoS ONE (2014)

Time interval and time since second fire versus change in DMN.a. Time interval between two fires versus change in DMN from 1985 to 2010. b. Time since second fire to 2010 versus change in DMN from 1985 to 2010.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4206446&req=5

pone-0110637-g006: Time interval and time since second fire versus change in DMN.a. Time interval between two fires versus change in DMN from 1985 to 2010. b. Time since second fire to 2010 versus change in DMN from 1985 to 2010.
Mentions: Time interval between two fires and time since second fire to 2010 were plotted against change in DMN (Figure 6a; Figure 6b). There was no apparent trend between time interval between fires or recovery time and change in DMN (Table 5). Shorter fire return intervals did not produce higher DMN values, which would be consistent with type conversion due to elimination of obligate seeding species.

Bottom Line: Increased fire frequency has been shown to promote alien plant invasions in the western United States, resulting in persistent vegetation type change.However, extensive type conversion of chaparral to grassland was not evident in this study.Most variables, with the exception of elevation, were moderately or poorly correlated with differences in vegetation recovery.

View Article: PubMed Central - PubMed

Affiliation: Department of Geography, University of Utah, Salt Lake City, Utah, United States of America.

ABSTRACT
Increased fire frequency has been shown to promote alien plant invasions in the western United States, resulting in persistent vegetation type change. Short interval fires are widely considered to be detrimental to reestablishment of shrub species in southern California chaparral, facilitating the invasion of exotic annuals and producing "type conversion". However, supporting evidence for type conversion has largely been at local, site scales and over short post-fire time scales. Type conversion has not been shown to be persistent or widespread in chaparral, and past range improvement studies present evidence that chaparral type conversion may be difficult and a relatively rare phenomenon across the landscape. With the aid of remote sensing data covering coastal southern California and a historical wildfire dataset, the effects of short interval fires (<8 years) on chaparral recovery were evaluated by comparing areas that burned twice to adjacent areas burned only once. Twelve pairs of once- and twice-burned areas were compared using normalized burn ratio (NBR) distributions. Correlations between measures of recovery and explanatory factors (fire history, climate and elevation) were analyzed by linear regression. Reduced vegetation cover was found in some lower elevation areas that were burned twice in short interval fires, where non-sprouting species are more common. However, extensive type conversion of chaparral to grassland was not evident in this study. Most variables, with the exception of elevation, were moderately or poorly correlated with differences in vegetation recovery.

Show MeSH
Related in: MedlinePlus