Micro-Climatic Amelioration in a California Desert: Artificial Shelter Versus Shrub Canopy

Abstract

Anthropogenic factors such as climate change, land use, urbanization, alongside the spread of invasive species are some of the challenges impacting the arid and semi-arid regions globally. The canopy of many native plants including shrubs and trees not only provides refuge from predators for some animals but also offers a shelter from climatic stressors for other plants. The canopy of native vegetation can thus be a microhabitat critical to the persistence of many species locally, and it is vital to better understand its importance for the conservation and recovery of species in these landscapes. In this study, we tested the hypothesis that triangular and rectangular artificial canopies function similarly to the canopy of resident native shrubs when ameliorating the understory micro-climate. Three light permeabilities including 15%, 50%, and 90% were tested by measuring soil and air temperature with light relative to paired open gap (non-canopied) microsites and shrubs. Shelters offered more stable temperatures and reduction in light compared to the open gap and were not significantly different from established native shrubs. This suggests that this simple, affordable intervention can provide a stopgap solution that approximates natural heterogeneity in climate at fine scales and offers a refuge whilst managers and stakeholders restore native vegetation such as slow-growing and difficult to establish shrubs within this ecosystem.

Foundation plant species provide resilience and microclimatic heterogeneity in drylands

“…distinct refuges) 23 . (2) Shrubs buffer the microclimate but changes between shrub-open contrasts move in tandem (reduced magnitude in stressors but similar trends seasonally) 24 . (3) Shrubs indirectly influence microclimate through facilitation of ground-covering plants (indirect vegetation buffering) 22 .…”

Homogeneous microenvironmental conditions under nurses promote facilitation

“…Less variable environments may provide stable biotic refuge for species evading the harsh effects of growing on bare soil. For instance, plants protected by neighbouring vegetation experience fewer abiotic fluctuations in arid regions than species growing directly on the exposed bare ground (Ghazian et al., 2020; Sotomayor & Drezner, 2019). These effects have also been observed in other systems, such as alpine environments, where cushion species provide a more stable environment than tussock species, resulting in more significant nursing effects for the former (Anthelme et al., 2014).…”

Habitat heterogeneity affects the thermal ecology of an endangered lizard

“…There also appears to be a trade‐off between more accurate thermoregulation and activity spent aboveground, as implied by the fact that lizards at Shrubless had higher thermoregulatory accuracy and spent more time in burrows. In addition to deploying artificial shade structures (Ghazian et al., 2020), ensuring the continued presence of D. ingens may be essential in securing G. sila persistence. Burrows excavated by ecosystem engineers such as D. ingens are often critical to the survival of other community members (Pike & Mitchell, 2013; Prugh & Brashares, 2012).…”