Abstract
Changes in plant assemblages can influence biotic and abiotic soil conditions. These changes can cause plant–soil feedbacks that can inhibit or facilitate plant germination and growth. Here, we contribute to a growing literature examining plant–soil feedbacks in the endangered sage scrub ecosystem by examining the germination and growth of Artemisia californica, the dominant native shrub species in the ecosystem, in soil conditioned by two widespread plant invaders (Brassica nigra, Bromus madritensis ssp. rubens), and the germination and growth of these invasive species in conspecific and heterospecific soils. Our findings suggest that: (i) A. californica soils can limit establishment of some species (B. nigra) but not others (B. madritensis), (ii) A. californica soil conditions reduce growth of all plant species, and (iii) non-natives are negatively impacted by soil microbes, but in some contexts can do better in heterospecific soil. As our findings were often incongruent with other studies that examined interactions among similar species at other sites, we suggest that we are at our infancy of understanding these complex interactions, and that developing a predictive framework for understanding plant soil feedbacks in the sage scrub ecosystem involves understanding how various plant species respond in different soil contexts within the ecosystem.
Highlights
Changes in plant assemblages can influence multiple aspects of a soil environment, including both soil abiotic and biotic conditions [1,2,3,4]
We examined germination and growth of A. californica in soil conditioned by widespread plant invaders not previously examined, and by examining germination and growth of these invasive species in conspecific and heterospecific soils
Our results contribute to a small but growing body of literature examining plant–soil feedbacks in the endangered California sage scrub ecosystem [3,7,26,27], and demonstrate that plant–soil feedbacks depend on both the plant species identity and soil context
Summary
Changes in plant assemblages can influence multiple aspects of a soil environment, including both soil abiotic (e.g., nutrient concentrations, pH) and biotic (e.g., composition and abundance of microbial assemblages) conditions [1,2,3,4]. When trying to understand how plant–soil feedbacks influence invasion processes, we are often interested in examining whether: (i) native species modify soils in ways that can restrict establishment and spread of invasive species—e.g., biotic resistance [8,9,10]; (ii) successful plant invaders are released from soil pathogens in their invasive range (enemy release hypothesis) [11,12]; and (iii) non-native species alter soil conditions to reinforce their dominance [13,14]. Invasive grasses and forbs reduce fire return intervals as they increase ignition probabilities in the hot summer months when they are dead, facilitating further loss of sage scrub and type-conversion to invasive habitats throughout the region, as non-native species are often the first to colonize an area after a disturbance [24,25]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
