Short-term effects of experimental fires on a Mojave Desert seed bank

Todd C. Esque; James A. Young; C. Richard Tracy

Home/Archive/USGS

USGS · 70003340

Short-term effects of experimental fires on a Mojave Desert seed bank

Todd C. Esque·James A. Young·C. Richard Tracy

View original source ↗Read source document ↗Export metadata ↓

Abstract

A Mojave Desert shrub community was experimentally burned to understand changes in seed bank of desert annual plant species in response to wildfire. Seed mortality ranged from 55 to 80%, and fire caused significant losses of native and alien annual seeds. Schismus arabicus , Schismus barbatus , Bromus madritensis , Bromus tectorum , Erodium cicutarium and Plantago spp. made up >95% of the seed bank. Bromus spp. and Plantago spp. had proportionately greater mortality of seeds than did Schismus spp. and E. cicutarium . Schismus spp. can be lodged into soil cracks thus avoiding lethal temperatures. E. cicutarium has a self-drilling mechanism that places the seeds at greater depth in the soil. Greater seed mortality occurred beneath shrub canopies than interspaces for most species ( Plantago , spp., Bromus spp., and E. cicutarium ), but microsite had little effect on Schismus spp. Fire reduced the perennial Ambrosia dumosa densities under canopies. Fire reduced the mean number of species found in samples by about one species per plot and no species was extirpated on experimental plots. The relative abundances of common species did not change dramatically as a result of fire or microsite, however; seed densities varied by treatment and affected interpretations of species compositions.

Explore related subjects

Journal of Arid Environments Article

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Todd C. Esque, James A. Young, C. Richard Tracy. 2010. Short-term effects of experimental fires on a Mojave Desert seed bank. https://pubs.usgs.gov/publication/70003340

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

USGS2026

Bird guilds exhibit varied responses to floodplain forest restoration in the Colorado River delta, Mexico

Grouping species into guilds can be useful to inform management decisions locally and at broader scales because guilds lack species-specificity. We investigated the response of five breeding bird guilds to riparian habitat restoration in the arid Colorado River delta, based on two decades of bird detections (2002–2021) at 230 bird count stations across 7 routes in actively revegetated (“restored”) sites, and 20 routes in non-actively revegetated (“control”) sites. We used guilds based on habitat associations. We also described changes in vegetation and explored their influence on bird species detections and guild dynamics. Riparian forest bird specialists responded positively to active revegetation, but this positive response was delayed and weaker in a river reach where restoration began later and featured less typical riparian vegetation. Birds associated with wetland habitat showed a positive response to restoration in the wettest reach, which had a baseline of high abundance of wetland birds in control sites and relatively abundant macrophyte cover. Conversely, the abundance of desert scrub bird specialists was highest in the driest and least vegetated restored reach. Generalists only exhibited decreased detections in the wettest restored reach. All this occurred while declines of riparian forest, wetland, desert scrub, and generalist bird species observed over a decade prior to restoration had stabilized in control sites. Detections of birds associated with agricultural fields increased in the study area, irrespective of restoration efforts. Our study demonstrates that the choice of bird guilds as ecological indicators can significantly influence the interpretation of restoration outcomes.

Arizona↗

USGS2024

Coyotes in the Great Basin desert do not exhibit a spatial response following the removal of anthropogenic water sources

Coyote ( Canis latrans ) range expansion into desert ecosystems has highlighted the role of anthropogenic water sources in arid ecosystems. Despite hypotheses that additional water facilitated this expansion, previous studies reported that coyotes did not exhibit a spatial or dietary response to removal of anthropogenic water. We used GPS data to examine if coyotes responded to water removal at a finer spatial scale than previously investigated. Our integrated step selection analysis did not find evidence that coyotes adjusted their distance to water following water removal. Vegetation was an important factor in habitat selection of coyotes, with riparian and agricultural areas being the most selected among vegetation types. Coyotes selected for locations where hunting and trapping was prohibited. Possibly the cause of increased coyote abundance in our study area was not due to the introduction of anthropogenic water sources but rather due to the cessation of regional lethal predator control programs. These two management decisions both occurred in the 1970s, therefore, their influences on the subsequent increase of coyote abundance may have been conflated. Our results, in combination with previous studies, provide evidence that coyotes are desert-adapted carnivores that do not rely on anthropogenic water sources.

Journal of Arid Environments↗

USGS2024

Mixed responses of tenebrionid beetles to solar energy development in the Mojave Desert

Solar energy development causes land-use change and habitat alteration that may affect desert ecosystems. Tenebrionid beetles have evolved to exploit desert environments and heavily contribute to ecosystem functionality in aridlands, yet their species-specific, ecological responses to solar energy development are unknown. Our objective was to elucidate effects of solar energy development decisions at a solar power facility (392 MW) on a tenebrionid beetle community in the Mojave Desert. Seven years post-construction, we used pitfall traps to collect tenebrionid beetles for one month in treatments representing variably intense site preparation practices and conservation measures, including blading (i.e., bulldozing), mowing, and establishment of undeveloped patches in solar fields, replicated across three power blocks comprising the facility and in undeveloped control sites surrounding the facility. Blading caused significant, deleterious effects on tenebrionid beetle abundance, species richness, and diversity. Ordination revealed apparent overlap of non-bladed treatments and controls, suggesting that intermediate levels of disturbance from less intensive solar energy development decisions may serve to minimize negative effects of solar energy development on tenebrionid communities. Anepsius delicatulus and Triorophus laevis , the two most commonly collected tenebrionids, were significantly more abundant in non-bladed treatments in the solar facility than in undeveloped controls; thus, solar facilities with minimized disturbance to vegetation may provide preferred habitat for certain tenebrionid species. Our results demonstrate the value of understanding variable responses of insects to solar energy development decisions in deserts to inform real-world adaptive management of natural resources during the renewable energy transition.

California↗