How do vegetation bands form in dry lands? Insights from numerical modeling and field studies in southern Nevada, USA

Pelletier, Jon D.; DeLong, Stephen B.; Orem, Caitlin A.; Becerra, P.; Compton, Kathleen; Gressett, Katrina; Lyons-Baral, John; McGuire, Luke A.; Molaro, J. L.; Spinler, J. C.

doi:10.1029/2012jf002465

Cited by 18 publications

(32 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5D). This predicted wavelength-slope relationship is consistent with empirical data (5,(8)(9)(10)(11).…”

Section: Pattern Generation From Uniform Vegetationsupporting

confidence: 88%

“…Moreover it is expected, because of the increased run-off on steeper gradients. However, this positive correlation is the opposite of the wavelength-slope relationship found empirically (5,(8)(9)(10)(11).…”

Section: Mathematical Modeling Of Semiarid Vegetationmentioning

confidence: 55%

“…The inferred relationship was not very strong because the data came from a variety of locations and involved a range of vegetation types, with relatively few data points from any one study. However, an inverse relationship between slope and wavelength has also been found in three recent detailed studies, of the African Sahel (10) and southwest United States (5,11).…”

mentioning

confidence: 54%

“…Those studies that have done this report the opposite trend: Wavelength increases with slope (11,12). This apparent contradiction has led to questioning of the mechanistic basis for vegetation patterns (5,11). However, previous studies have made the conventional assumption that patterns arise from preexisting unstable uniformly vegetated states.…”

mentioning

confidence: 94%

“…They are important as potential indicators of climate change and imminent regime shifts (2,3). Although other mechanisms have been suggested (4,5), the patterns are widely thought to arise from positive feedback between vegetation and infiltration of rainwater (3,6). Local increases in vegetation density cause greater infiltration, which promotes further growth, whereas rain falling on sparsely vegetated areas tends to run off to adjacent vegetated patches.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Using wavelength and slope to infer the historical origin of semiarid vegetation bands

Sherratt

2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Landscape-scale patterns of vegetation occur worldwide at interfaces between semiarid and arid climates. They are important as potential indicators of climate change and imminent regime shifts and are widely thought to arise from positive feedback between vegetation and infiltration of rainwater. On gentle slopes the typical pattern form is bands (stripes), oriented parallel to the contours, and their wavelength is probably the most accessible statistic for vegetation patterns. Recent field studies have found an inverse correlation between pattern wavelength and slope, in apparent contradiction with the predictions of mathematical models. Here I show that this “contradiction” is based on a flawed approach to calculating the wavelength in models. When pattern generation is considered in detail, the theory is fully consistent with empirical results. For realistic parameters, degradation of uniform vegetation generates patterns whose wavelength increases with slope, whereas colonization of bare ground gives the opposite trend. Therefore, the empirical finding of an inverse relationship can be used, in conjunction with climate records, to infer the historical origin of the patterns. Specifically, for the African Sahel my results suggest that banded vegetation originated by the colonization of bare ground during circa 1760–1790 or since circa 1850.

show abstract

“…5D). This predicted wavelength-slope relationship is consistent with empirical data (5,(8)(9)(10)(11).…”

Section: Pattern Generation From Uniform Vegetationsupporting

confidence: 88%

Section: Mathematical Modeling Of Semiarid Vegetationmentioning

confidence: 55%

mentioning

confidence: 54%

mentioning

confidence: 94%

mentioning

confidence: 99%

See 3 more Smart Citations

Using wavelength and slope to infer the historical origin of semiarid vegetation bands

Sherratt

2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

Forecasting the response of Earth's surface to future climatic and land use changes: A review of methods and research needs

et al. 2015

Self Cite

View full text Add to dashboard Cite

In the future, Earth will be warmer, precipitation events will be more extreme, global mean sea level will rise, and many arid and semiarid regions will be drier. Human modifications of landscapes will also occur at an accelerated rate as developed areas increase in size and population density. We now have gridded global forecasts, being continually improved, of the climatic and land use changes (C&LUC) that are likely to occur in the coming decades. However, besides a few exceptions, consensus forecasts do not exist for how these C&LUC will likely impact Earth-surface processes and hazards. In some cases, we have the tools to forecast the geomorphic responses to likely future C&LUC. Fully exploiting these models and utilizing these tools will require close collaboration among Earth-surface scientists and Earth-system modelers. This paper assesses the state-of-the-art tools and data that are being used or could be used to forecast changes in the state of Earth's surface as a result of likely future C&LUC. We also propose strategies for filling key knowledge gaps, emphasizing where additional basic research and/or collaboration across disciplines are necessary. The main body of the paper addresses cross-cutting issues, including the importance of nonlinear/threshold-dominated interactions among topography, vegetation, and sediment transport, as well as the importance of alternate stable states and extreme, rare events for understanding and forecasting Earth-surface response to C&LUC. Five supplements delve into different scales or process zones (global-scale assessments and fluvial, aeolian, glacial/periglacial, and coastal process zones) in detail.

show abstract

Effects of heterogeneous soil‐water diffusivity on vegetation pattern formation

Yizhaq

Sela

Svoray

et al. 2014

Water Resources Research

View full text Add to dashboard Cite

Many mathematical models have been proposed to explain the emergence of vegetation patterns in arid and semiarid environments, but only a few of them take into account the heterogeneity in the system properties. Here we present a rigorous study of the effects of heterogeneous soil-water diffusivity on vegetation patterns, using two mathematical models. The two models differ in the pattern-forming feedback that they capture; one model captures the infiltration contrast between vegetated and bare-soil domains, whereas the other model captures the increased growth rate of denser vegetation due to an enhanced ability to extract water from the soil. In both models, the most significant effect of the heterogeneity on the soil-water diffusivity is the increased durability of patterned vegetation to a reduced precipitation rate. An additional effect is that the heterogeneity makes the desertification process, namely, the transition from a spotted vegetation pattern to a bare-soil state, more gradual than in the homogeneous system. Our findings suggest that the heterogeneity cannot be neglected in the study of critical transitions in heterogeneous ecosystems and, particularly, in the study of the desertification process due to climate changes or anthropogenic disturbances.

show abstract

How do vegetation bands form in dry lands? Insights from numerical modeling and field studies in southern Nevada, USA

Cited by 18 publications

References 58 publications

Using wavelength and slope to infer the historical origin of semiarid vegetation bands

Using wavelength and slope to infer the historical origin of semiarid vegetation bands

Forecasting the response of Earth's surface to future climatic and land use changes: A review of methods and research needs

Effects of heterogeneous soil‐water diffusivity on vegetation pattern formation

Contact Info

Product

Resources

About