Phenological Events and Their Environmental Triggers in Mojave Desert Ecosystems

Ecology ◽  
1974 ◽  
Vol 55 (4) ◽  
pp. 856-863 ◽  
Author(s):  
Janice C. Beatley
Keyword(s):  
Mojave Desert ◽  
Desert Ecosystems

Relationships of Native Desert Plants with Red Brome (Bromus rubens): Toward Identifying Invasion-Reducing Species

2011 ◽  
Vol 4 (1) ◽  
pp. 115-124 ◽  
Author(s):  
Scott R. Abella ◽  
Donovan J. Craig ◽  
Lindsay P. Chiquoine ◽  
Kathryn A. Prengaman ◽  
Sarah M. Schmid ◽  
...  
Keyword(s):  
Mojave Desert ◽  
Native Species ◽  
Strongly Correlated ◽  
Annual Grass ◽  
Desert Ecosystems ◽  
Red Brome ◽  
Bromus Rubens ◽  
Competitive Abilities ◽  
Practical Implications

AbstractThe interactions between native and exotic species occur on a continuum from facilitative to competitive. A growing thrust in invasive species science is differentiating where particular native species occur along this continuum, with practical implications for identifying species that might reduce the invasibility of ecosystems. We used a greenhouse experiment to develop a competitive hierarchy of 27 native species with red brome, an invasive annual grass in the arid lands of the southwestern United States, and a field study to assess in situ responses of brome to native perennial species in the Mojave Desert. Native species most competitive with brome in the competition experiment included the annuals Esteve's pincushion and western fiddleneck and the perennials eastern Mojave buckwheat, sweetbush, and brittlebush, which reduced brome biomass to 49 to 70% of its grown-alone amount. There was no clear difference in competitive abilities with brome between annual and perennial natives, and competiveness was not strongly correlated (r = 0.15) with the biomass of the native species. In the field, sweetbush and brittlebush supported among the least cover of brome, suggesting congruence of the strong early competitive abilities of these species with in situ patterns of brome distribution. At the other extreme, brome attained its highest average cover (19%) below littleleaf ratany, significantly greater than all but 3 of the 16 species evaluated. Cover by brome was only weakly related (r = 0.19) to the area of the perennial canopy, suggesting that factors other than the sizes of perennial plants were linked to differences in brome cover among species. Results suggest that (1) interactions with brome differ substantially among native species, (2) these interactions are not as closely linked to biomass production as in more temperate regions, and (3) there is potential for identifying native species that can reduce invasion of desert ecosystems.

scholarly journals Simulated Photovoltaic Solar Panels Alter the Seed Bank Survival of Two Desert Annual Plant Species

Plants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1125
Author(s):  
Rebecca R. Hernandez ◽  
Karen E. Tanner ◽  
Sophia Haji ◽  
Ingrid M. Parker ◽  
Bruce M. Pavlik ◽  
...  
Keyword(s):  
Solar Energy ◽  
Plant Species ◽  
Seed Bank ◽  
Mojave Desert ◽  
Life Stage ◽  
Early Life Stage ◽  
Energy Development ◽  
Desert Plant ◽  
Desert Ecosystems ◽  
Growing Seasons

Seed bank survival underpins plant population persistence but studies on seed bank trait-environment interactions are few. Changes in environmental conditions relevant to seed banks occur in desert ecosystems owing to solar energy development. We developed a conceptual model of seed bank survival to complement methodologies using in-situ seed bank packets. Using this framework, we quantified the seed bank survival of two closely related annual desert plant species, one rare (Eriophyllum mohavense) and one common (Eriophyllum wallacei), and the seed bank–environment interactions of these two species in the Mojave Desert within a system that emulates microhabitat variation associated with solar energy development. We tracked 4860 seeds buried across 540 seed packets and found, averaged across both species, that seed bank survival was 21% and 6% for the first and second growing seasons, respectively. After two growing seasons, the rare annual had a significantly greater seed bank survival (10%) than the common annual (2%). Seed bank survival across both species was significantly greater in shade (10%) microhabitats compared to runoff (5%) and control microhabitats (3%). Our study proffers insight into this early life-stage across rare and common congeners and their environmental interactions using a novel conceptual framework for seed bank survival.

Tenebrionid Beetles

2002 ◽  
Author(s):  
Francisco Sanchez Piñero ◽  
Rolf L. Aalbu
Keyword(s):  
Water Loss ◽  
Mojave Desert ◽  
Feeding Habits ◽  
High Surface ◽  
Arid Environments ◽  
Dominant Group ◽  
Desert Ecosystems ◽  
Defensive Glands ◽  
Physiological Adaptations ◽  
A Site

Desert islands in the Sea of Cortés are inhabited by a rich arthropod fauna. Although the seemingly barren landscape may appear devoid of arthropods at midday, at night one may often see members of one of the dominant groups of animals on the islands, the tenebrionid beetles. Highly variable in shape and size, the Tenebrionidae are one of the most highly evolved and diverse families of beetles. Tenebrionidae is perhaps the fifth largest beetle family (>2000 genera), and about half of these are uniquely adapted to arid environments and form a dominant group in desert ecosystems (Crawford 1991). For example, the adult biomass of one species (Asbolus verrucosus) at a site in the northern Mojave Desert was found to be greater (275 g/ha) than the combined biomass of all mammals, birds, and reptiles (a total of 263 g/ha) in the same area (Thomas 1979). The major problem that insects encounter in desert environments is water loss; their relatively high surface-volume ratios cause rapid desiccation in dry air (Crawford 1981). Water is lost mainly through transpiration (combined cuticular and respiratory water loss) but also through defecation, defensive secretions, and oviposition. Adaptations to desert conditions can thus be categorized as either ecological adaptations (finding or creating moist conditions) or morpho-physiological adaptations (protection and resistance against desiccation) (Ghilarov 1964). Adaptations which have made tenebrionids desert specialists all contribute to either reducing transpiratory or other water loss or allowing survival in harsh desert environments: body-shape diversity; the ability to seek refuge underground by either digging or using existing holes and crevices; omnivorous feeding habits; timing of both daily and seasonal activities to coincide with the most favorable environmental conditions; fused elytra composed of unique, straight-chain hydrocarbons (which allow tight molecular packing), creating a protective, sealed subelytral cavity; the ability to secrete protective wax layers on the cuticular surface; and loss of defensive glands (for review, see Aalbu in press). Tenebrionid species found in arid environments can be categorized into three groups according to their capacity to withstand harsh desert conditions. The tenebrionids most highly adapted to arid environments are characterized by flightlessness, fused elytra, subelytral cavities, and lack of defensive glands.

Effects of high fire frequency in creosote bush scrub vegetation of the Mojave Desert

2012 ◽  
Vol 21 (1) ◽  
pp. 61 ◽  
Author(s):  
Matthew L. Brooks
Keyword(s):  
Mojave Desert ◽  
Plant Invasions ◽  
Fire Frequency ◽  
Creosote Bush ◽  
Community Characteristics ◽  
Short Term ◽  
Desert Ecosystems ◽  
Perennial Plants ◽  
Bromus Rubens ◽  
Creosote Bush Scrub

Plant invasions can increase fire frequency in desert ecosystems where fires were historically infrequent. Although there are many resource management concerns associated with high frequency fire in deserts, fundamental effects on plant community characteristics remain largely unstudied. Here I describe the effects of fire frequency on creosote bush scrub vegetation in the Mojave Desert, USA. Biomass of the invasive annual grass Bromus rubens L. increased following fire, but did not increase further with additional fires. In contrast, density, cover and species richness of native perennial plants each decreased following fire and continued to decrease with subsequent fires, although not as dramatically as after the initial fire. Responses were similar 5 and 14 years post-fire, except that cover of Hymenoclea salsola Torr. & A. Gray and Achnatherum speciosa Trin. & Rupr. both increased in areas burnt once. These results suggest that control of B. rubens may be equally warranted after one, two or three fires, but revegetation of native perennial plants is most warranted following multiple fires. These results are valid within the scope of this study, which is defined as relatively short term vegetation responses (≤14 years) to short fire return intervals (6.3 and 7.3 years for the two and three fire frequency levels) within creosote bush scrub of the Mojave Desert.

scholarly journals Insights into dryland biocrust microbiome: geography, soil depth and crust type affect biocrust microbial communities and networks in Mojave Desert, USA

2020 ◽  
Vol 96 (9) ◽  
Author(s):  
Nuttapon Pombubpa ◽  
Nicole Pietrasiak ◽  
Paul De Ley ◽  
Jason E Stajich
Keyword(s):  
Microbial Communities ◽  
Mojave Desert ◽  
Plant Pathogens ◽  
Soil Depth ◽  
Ecosystem Functions ◽  
Node Degree ◽  
Desert Ecosystems ◽  
Indicator Taxa ◽  
Green Algal ◽  
Alternaria Sp

ABSTRACT Biocrusts are the living skin of drylands, comprising diverse microbial communities that are essential to desert ecosystems. Despite there being extensive knowledge on biocrust ecosystem functions and lichen and moss biodiversity, little is known about factors structuring diversity among their microbial communities. We used amplicon-based metabarcode sequencing to survey microbial communities from biocrust surface and subsurface soils at four sites located within the Mojave Desert. Five biocrust types were examined: Light-algal/Cyanobacteria, Cyanolichen, Green-algal lichen, Smooth-moss and Rough-moss crust types. Microbial diversity in biocrusts was structured by several characteristics: (i) central versus southern Mojave sites displayed different community signatures, (ii) indicator taxa of plant-associated fungi (plant pathogens and wood saprotrophs) were identified at each site, (iii) surface and subsurface microbial communities were distinct and (iv) crust types had distinct indicator taxa. Network analysis ranked bacteria–bacteria interactions as the most connected of all within-domain and cross-domain interaction networks in biocrust surface samples. Actinobacteria, Proteobacteria, Cyanobacteria and Ascomycota functioned as hubs among all phyla. The bacteria Pseudonocardia sp. (Pseudonocardiales, Actinobacteria) and fungus Alternaria sp. (Pleosporales, Ascomycota) were the most connected had the highest node degree. Our findings provide crucial insights for dryland microbial community ecology, conservation and sustainable management.

scholarly journals Simulated Photovoltaic Solar Panels Alters the Seed Bank Survival of Desert Annual Plant Species

2020 ◽  
Author(s):  
Rebecca R. Hernandez ◽  
Karen Tanner ◽  
Sophia Haji ◽  
Ingrid Parker ◽  
Bruce Pavlik ◽  
...  
Keyword(s):  
Solar Energy ◽  
Plant Species ◽  
Seed Bank ◽  
Mojave Desert ◽  
Life Stage ◽  
Early Life Stage ◽  
Energy Development ◽  
Desert Plant ◽  
Desert Ecosystems ◽  
Growing Seasons

Seed bank survival underpins plant population persistence but studies on seed bank trait-environment interactions are few. Changes in environmental conditions relevant to seed banks occur in desert ecosystems owing to solar energy development. We developed a conceptual model of seed bank survival to complement methodologies using in-situ seed bank packets. Using this framework, we quantified the seed bank survival of two closely related annual desert plant species, one rare (Eriophyllum mohavense) and one common (Eriophyllum wallacei) and the seed bank-environment interactions of these two species in the Mojave Desert within a system that emulates microhabitat variation associated with solar energy development. We tracked 4,860 seeds buried across 540 seed packets and found, averaged across both species, that seed bank survival was 21% and 6% for the first and second growing seasons, respectively. After two growing seasons, the rare annual had a significantly greater seed bank survival (10%) than the common annual (2%). Seed bank survival, across both species, was significantly greater in Shade (10%) microhabitats compared to Runoff (5%) microhabitats and Control microhabitats (3%). Our study confers insight into this early life-stage across rare and common congeners and their environmental interactions using a novel conceptual framework for seed bank survival.

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