Climate change effects on southern California deserts

Abstract

Climate change has already affected southern California where regional increases in temperature and vegetation shifts have been observed. While all the CMIP5 temperature projections agree on a substantial level of warming throughout the year, there is fair bit of divergence in the magnitude and seasonality of projected changes in rainfall. While desert plants and animals are generally adapted to extreme conditions, some species may be approaching their physiological threshold. We calculated the climate velocity of both temperature and aridity (PPT/PET) in SE California to illustrate the spatial variability of climate projections and reported on the probable expansion of barren lands reducing current species survivorship. We used a vegetation model to illustrate both temporal and spatial shifts in land cover in response to changes in environmental conditions. Such information is useful to plan land use for renewable energy siting in the region.

A range‐wide model of contemporary, omnidirectional connectivity for the threatened Mojave desert tortoise

“…Similar to our results, Sadoti et al (2017) reported higher probability of movement with increasing NDVI and lower probability of tortoise movement during the highest monthly maximum temperatures. Maximum temperatures of the warmest months in the Mojave Desert are projected to increase approximately 2-3°C in the 21st century (Bachelet et al 2016). Although hotter temperatures during these months will likely restrict desert tortoise movements in the future, projected but variable increases in summer precipitation could mitigate the influence of hotter temperatures on such movements, and associated uncertainty in vegetation productivity will also make it difficult to predict how changes in NDVI will restrict or promote movement (Bachelet et al 2016).…”

“…Maximum temperatures of the warmest months in the Mojave Desert are projected to increase approximately 2-3°C in the 21st century (Bachelet et al 2016). Although hotter temperatures during these months will likely restrict desert tortoise movements in the future, projected but variable increases in summer precipitation could mitigate the influence of hotter temperatures on such movements, and associated uncertainty in vegetation productivity will also make it difficult to predict how changes in NDVI will restrict or promote movement (Bachelet et al 2016). Thus, future research should aim to model Mojave desert tortoise connectivity under a range of projected climate and vegetation scenarios.…”

Discriminating patterns and drivers of multiscale movement in herpetofauna: The dynamic and changing environment of the Mojave desert tortoise

“…Daily mean temperatures of the Mojave Desert are projected to increase approximately 2–3°C in the 21st century (Bachelet, Ferschweiler, Sheehan, & Strittholt, ). Climate models show poorer agreement in projecting precipitation, but tend to project either wetter winters (January–February) or summers (July–August; Rupp, Abatzoglou, Hegewisch, & Mote, ).…”

A test of desert shrub facilitation via radiotelemetric monitoring of a diurnal lizard

“…Deserts are highly distinct ecosystems that contribute significantly to global biodiversity and global ecosystem function. The conversion and loss of desert habitat is therefore a global biodiversity crisis requiring immediate intervention, including conservation of remaining undisturbed habitat and restoration of degraded desert (Bachelet, Ferschweiler, Sheehan, & Strittholt, ; Cook, ; Hannah, Carr, & Lankerani, ; Hoekstra, Boucher, Ricketts, & Roberts, ; Kéfi et al, ; Mouat & Lancaster, ; Westphal, Stewart, Tennant, Butterfield, & Sinervo, ). Identifying the drivers of ecological health in desert communities will be a crucial component of such interventions.…”