Rainfall interception by mountain big sagebrush (Artemisia tridentataspp.vaseyana): Dryland shrub canopy cover affects net precipitation

Abstract

Canopy interception loss is an important component of the water budget for many ecosystems, and may be particularly influential in semi-arid shrublands where water is limiting. In this experiment, we quantified interception loss by mountain big sagebrush (Artemisia tridentata spp. vaseyana) using simulated rainfall events in the field.Various levels of canopy cover and rainfall intensities were tested to measure their effects on net precipitation and interception loss. Additionally, the comparisons were made between three methods of measuring shrub cover to enhance the scalability of results. Stands of sagebrush from 20% to 50% canopy cover intercepted 18.5 ± 12.5% of incoming precipitation. Percent interception loss differed by 13.7% between the high and low cover classes, indicating that net precipitation may be significantly reduced under mature, dense stands of sagebrush. Hemispherical photography was a viable method for estimating canopy cover in this vegetation type.Interception loss by sagebrush was 14% lower on average than pinyon and juniper measured in the same watershed. Results from this study quantified the effects of sagebrush canopy on rainfall interception and improved understanding of vegetation dynamics in the sagebrush steppe.

Assessing canopy rainfall partitioning by Mediterranean dryland shrubs under extreme rainfall

“…Although this study provides important insights into the role of shrub morphological parameters in predicting canopy interception capacity, there are three limitations that should be addressed in future research. First, in all simulations, the study used a constant amount and intensity of rainfall, but the temporal dynamics of these two storm characteristics can affect interception process and associated water flow (e.g., Carlyle‐Moses & Gash, 2011; Snyder et al, 2022; Zhang et al, 2017). Therefore, although the study gives indications about the magnitude of this hydrological process under the water input of one extremely intense rainfall condition, the effect of time‐varying depth and intensity on the interception process needs to be further explored and incorporated into the proposed prediction model (Yang et al, 2019).…”

“…Climate change is altering rain events and their partitioning by plant canopies in ways relevant to ecosystem functioning (Di Nuzzo et al, 2022; Lian et al, 2022), thus, much research has explored rainfall interception. However, interception research has been overwhelmingly focused on forest environments (Carlyle‐Moses & Gash, 2011; Levia et al, 2019), while croplands, shrublands, and grasslands have received less attention (Belmonte Serrato & Romero, 1998; Dunkerley, 2000; Snyder et al, 2022). This is surprising as shrublands account for a meaningful fraction of land cover, ~11% (Ritchie & Roser, 2013), shrubs can compose a substantial fraction of understory communities in many forests (Sun et al, 2022), shrub encroachment is a global area of research interest and conservation concern (Maestre et al, 2016), and the interception by shrubs can be even greater compared to forest stands within a given area.…”