Evaluating Drought Impact on Postfire Recovery of Chaparral Across Southern California

Storey, Emanuel A.; Stow, Douglas A.; Roberts, Dar A.; O’Leary, John F.; Davis, Frank W.

doi:10.1007/s10021-020-00551-2

Cited by 9 publications

(13 citation statements)

References 76 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The five-year average rainfall following the latter fire was also found to not be a significant driver of vegetation type change, which is in line with other studies (Storey et al, 2020, Meng et al, 2014), although see Storey et al (2021). Storey et al (2020) found climactic water deficit to be a stronger predictor of chaparral recovery compared to total precipitation and water conditions preceding fire were generally more predictive of recovery than conditions following fire. Finer temporal scale patterns of rainfall (e.g., light rainfall over a month vs. a one-day downpour, early winter vs. late winter) will also likely be important to consider in the seasons leading up to fire and the first year following fire.…”

Section: Discussionsupporting

confidence: 89%

“…The five-year average rainfall following the latter fire was also found to not be a significant driver of vegetation type change, which is in line with other studies (Storey et al, 2020, Meng et al, 2014, although see Storey et al (2021). Storey et al (2020) found climactic water deficit to be a stronger predictor of chaparral recovery compared to total precipitation and . CC-BY-NC-ND 4.0 International license available under a was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.…”

Section: Discussionsupporting

confidence: 89%

“…Indeed, Meng et al (2014) and Syphard et al (2019b) found elevation to be a strong driver of vegetation change with more chaparral conversion occurring at lower elevations. Analysis by Storey et al (2019) included a more extensive range of chaparral stands in southern California and found vegetation change was greatest in the eastern portion of their study region and at higher elevations and was a result of drought and fire interactions.…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Short-interval fires and vegetation change in southern California

Sm¹,

Cm³

2021

Preprint

View full text Add to dashboard Cite

Questions: In southern California, shortened fire return intervals may contribute to a decrease in native chaparral shrub presence and an increase in non-native annual grass presence. To test the hypothesis that short-fire return intervals promote a loss in shrub cover, we examined the contribution of single short-interval fires and abiotic conditions on the change of shrub cover within Ventura and Los Angeles counties. Through evaluating pre- and post-fire historical aerial images, we answered the following questions, 1) How has vegetation type cover changed after repeat fires? and 2) What landscape variables contribute the most to the observed change? Location: Ventura County and Los Angeles County, California, USA. Methods: We assessed the impact of a single short-interval fire by comparing vegetation recovery in adjacent once- and twice-burned fire burn polygons (long- and short-interval respectively). Pixel plots were examined within each polygon and vegetation cover was classified to vegetation type. We determined the best predictor of vegetation type cover with a linear mixed effects model comparison using Akaike Information Criterion. Results: Pre-fire and post-fire community type cover was highly correlated. Burn interval was the best predictor of tree cover change (lower cover in twice-burned pixel plots). Aspect was the best predictor of sage scrub cover change (greater cover on north-facing aspects). Years since fire was the best predictor of chaparral cover change (positive correlation) and sage scrub cover change (negative correlation). Conversion of chaparral to sage scrub cover was more likely to occur than conversion of chaparral to annual grass cover. Conclusions: Our study did not find extensive evidence of a decrease in chaparral shrub cover due to a single short-interval fire. Instead, post-fire cover was highly correlated with pre-fire cover. Chaparral recovery, however, was dynamic suggesting that stand recovery may be strongly influenced by local scale conditions and processes.

show abstract

Section: Discussionsupporting

confidence: 89%

“…The five-year average rainfall following the latter fire was also found to not be a significant driver of vegetation type change, which is in line with other studies (Storey et al, 2020, Meng et al, 2014, although see Storey et al (2021). Storey et al (2020) found climactic water deficit to be a stronger predictor of chaparral recovery compared to total precipitation and . CC-BY-NC-ND 4.0 International license available under a was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity.…”

Section: Discussionsupporting

confidence: 89%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Short-interval fires and vegetation change in southern California

Sm¹,

Cm³

2021

Preprint

View full text Add to dashboard Cite

show abstract

“…Drought following fire can lead to increased shrub mortality during post‐fire recovery (Figure 3B; Pratt et al, 2014; Pausas et al, 2016). Drought before a fire reduces reproductive output and seed banks, and plant carbohydrate stores that are needed to fuel post‐fire resprouting (Pausas et al, 2016), thus limiting recovery (Figure 3B; Enright et al, 2015; Storey et al, 2020).…”

Section: Causes Of Chaparral Vegetation‐type Conversionmentioning

confidence: 99%

“…Once herbs are established, feedbacks may promote their expansion and prevent shrubs from re‐establishing (Park and Jenerette, 2019). The speed and inevitability of VTC at this stage is important to understand, and abundant partially type‐converted stands (shrub cover 51–99% with exotic herbs present) appear to be stable for decades (Park et al, 2018; Storey et al, 2020). Without a sufficient seed bank, these sites will likely become type‐converted over time without active restoration.…”

Section: Causes Of Chaparral Vegetation‐type Conversionmentioning

confidence: 99%

Vegetation‐type conversion of evergreen chaparral shrublands to savannahs dominated by exotic annual herbs: causes and consequences for ecosystem function

Pratt

2021

American J of Botany

View full text Add to dashboard Cite

Woody, evergreen shrublands are the archetypal community in mediterranean‐type ecosystems, and these communities are profoundly changed when they undergo vegetation‐type conversion (VTC) to become annual, herb‐dominated communities. Recently, VTC has occurred throughout southern California chaparral shrublands, likely with changes in important ecosystem functions. The mechanisms that lead to VTC and subsequent changes to ecosystem processes are important to understand as they have regional and global implications for ecosystem services, climate change, land management, and policy. The main drivers of VTC are altered fire regimes, aridity, and anthropogenic disturbance. Some changes to ecosystem function are certain to occur with VTC, but their magnitudes are unclear, whereas other changes are unpredictable. I present two hypotheses: (1) VTC leads to warming that creates a positive feedback promoting additional VTC, and (2) altered nitrogen dynamics create negative feedbacks and promote an alternative stable state in which communities are dominated by herbs. The patterns described for California are mostly relevant to the other mediterranean‐type shrublands of the globe, which are biodiversity hotspots and threatened by VTC. This review examines the extent and causes of VTC, ecosystem effects, and future research priorities.

show abstract

Extreme pre‐fire drought decreases shrub regeneration on fertile soils

Werner

Harrison

Safford

et al. 2021

Ecological Applications

View full text Add to dashboard Cite

Extreme drought and increasing temperatures can decrease the resilience of plant communities to fires. Not only may extremely dry conditions during or after fires lead to higher plant mortality and poorer recruitment, but severe pre‐fire droughts may reduce the seed production and belowground vigor that are essential to post‐fire plant recovery, and may indirectly facilitate invasion. We studied survival, recruitment, and growth of shrubs and herbs in chaparral (shrubland) communities in Northern California after a 2015 fire that immediately followed California’s extreme 3‐yr drought. We followed the same protocols used to study similar, adjacent communities after a 1999 fire that did not follow a drought, and we compared the two recovery trajectories. Overall, the 2015 fire was not more severe than the 1999 fire, yet it caused higher mortality and lower growth of resprouting shrubs on fertile (sandstone) soils. In contrast, the 2015 fire did not affect the mortality or growth of resprouting shrubs on infertile (serpentine) soils, the density of shrub seedlings, or the richness or cover of native herbs differently than the 1999 fire. However, the 2015 fire facilitated a massive increase in exotic herbaceous cover, especially on fertile soils, possibly portending the early stages of a type conversion to exotic‐dominated grassland. Our findings indicate that the consequences of climate change on fire‐dependent communities will include effects of pre‐fire as well as post‐fire climate, and that resprouting shrubs are particularly likely to be sensitive to pre‐fire drought.

show abstract

Evaluating Drought Impact on Postfire Recovery of Chaparral Across Southern California

Cited by 9 publications

References 76 publications

Short-interval fires and vegetation change in southern California

Short-interval fires and vegetation change in southern California

Vegetation‐type conversion of evergreen chaparral shrublands to savannahs dominated by exotic annual herbs: causes and consequences for ecosystem function

Extreme pre‐fire drought decreases shrub regeneration on fertile soils

Contact Info

Product

Resources

About