An official website of the United States government
The goods and services provided by riverine systems are critical to humanity, and our reliance increases with our growing population and demands. As our activities expand, these systems continue to degrade throughout the world even as we try to restore them, and many efforts have not met expectations. One way to increase restoration effectiveness could be to explicitly design restorations to promote microbial communities, which are responsible for much of the organic matter breakdown, nutrient removal or transformation, pollutant removal, and biomass production in river ecosystems. In this paper, we discuss several design concepts that purposefully create conditions for these various microbial goods and services, and allow microbes to act as ecological restoration engineers. Focusing on microbial diversity and function could improve restoration effectiveness and overall ecosystem resilience to the stressors that caused the need for the restoration. Advances in next-generation sequencing now allow the use of microbial ‘omics techniques (e.g., metagenomics, metatranscriptomics) to assess stream ecological conditions in similar fashion to fish and benthic macroinvertebrates. Using representative microbial communities from stream sediments, biofilms, and the water column may greatly advance assessment capabilities. Microbes can assess restorations and ecosystem function where animals may not currently be present, and thus may serve as diagnostics for the suitability of animal reintroductions. Emerging applications such as ecological metatranscriptomics may further advance our understanding of the roles of specific restoration designs towards ecological services as well as assess restoration effectiveness.
more »
« less
Plant-Microbial Symbioses in Coastal Systems: Their Ecological Importance and Role in Coastal Restoration
Abstract Coastal systems are immensely valuable to humans. They contain unique ecosystems that are biodiversity reservoirs and provide key ecosystem services as well as a wealth of cultural heritage. Despite their importance to humans, many coastal systems are experiencing degradation that threatens their integrity and provisioning of services. While much is known about the plant communities and associated wildlife in coastal areas, the importance of microorganisms represents a large knowledge gap. Here we review the ecology of plant-microbial symbioses in coastal systems, including mycorrhizae, nitrogen fixers, endophytes, rhizosphere microbes, and pathogens. We focus on four common coastal communities: sand dunes, marshes, mangroves, and forests/shrublands. We also assess recent research and the potential for using microbes in coastal restoration efforts to mitigate anthropogenic impacts. We find that microbial symbionts are largely responsible for the health of plants constituting the foundation of coastal communities by affecting plant establishment, growth, competitive ability, and stress tolerance, as well as modulating biogeochemical cycling in these stressful coastal systems. Current use of microbial symbionts to augment restoration of stressful and degraded coastal systems is still very much in its infancy; however, it holds great promise for increasing restoration success on the coast. Much research is still needed to test and develop microbial inocula for facilitating restoration of different coastal systems. This is an excellent opportunity for collaboration between restoration practitioners and microbial ecologists to work toward a common goal of enhancing resilience of our coastal ecosystems at a time when these systems are vulnerable to an increasing number of threats.
more »
« less
- Award ID(s):
- 2027920
- PAR ID:
- 10372562
- Publisher / Repository:
- Springer Science + Business Media
- Date Published:
- Journal Name:
- Estuaries and Coasts
- Volume:
- 45
- Issue:
- 7
- ISSN:
- 1559-2723
- Format(s):
- Medium: X Size: p. 1805-1822
- Size(s):
- p. 1805-1822
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Restoration of coastal dunes following tropical storm events often requires renourishment of sand substrate dredged from offshore sources, although dredging has well‐described negative ecological impacts and high economic costs. As a potential solution, recycled glass sand (cullet) made from crushed glass bottles has been proposed as a potential replacement for dredging. However, glass sand substrates may have limited ability to provide support to coastal plant communities due to the absence of native soil microbial communities. To explore the potential use of glass sand as a substrate for dune plants in the Northern Gulf of Mexico, we compared the growth of Sea oats (Uniola paniculata), Beach morning‐glory (Ipomoea imperati), and Railroad vine (I. pes‐caprae) in glass sand to growth in live beach sand. To determine if inoculation of glass sand with native soil microbial communities improved survival, growth, and biomass production, we also tested plant growth in glass sand with native microbial amendments. Overall, we found no difference in the survival of the three dune species across three soil treatments and weak differences in plant growth and biomass production across our soil substrates. Our results suggest that glass sand substrates may be a viable option for coastal dune restoration, with limited differences between live beach sand, glass sand, and glass sand inoculated with native soil microbes. Restoration and replenishment of coastal dunes using glass sand as a substrate following tropical storms or sea‐level rise may allow coastal managers to reduce the economic and ecological damage associated with offshore sediment dredging.more » « less
-
Stams, Alfons J. (Ed.)ABSTRACT Biological soil crusts (biocrusts) are communities of microbes that inhabit the surface of arid soils and provide essential services to dryland ecosystems. While resistant to extreme environmental conditions, biocrusts are susceptible to anthropogenic disturbances that can deprive ecosystems of these valuable services for decades. Until recently, culture-based efforts to produce inoculum for cyanobacterial biocrust restoration in the southwestern United States focused on producing and inoculating the most abundant primary producers and biocrust pioneers, Microcoleus vaginatus and members of the family Coleofasciculaceae (also called Microcoleus steenstrupii complex). The discovery that a unique microbial community characterized by diazotrophs, known as the cyanosphere, is intimately associated with M. vaginatus suggests a symbiotic division of labor in which nutrients are traded between phototrophs and heterotrophs. To probe the potential use of such cyanosphere members in the restoration of biocrusts, we performed coinoculations of soil substrates with cyanosphere constituents. This resulted in cyanobacterial growth that was more rapid than that seen for inoculations with the cyanobacterium alone. Additionally, we found that the mere addition of beneficial heterotrophs enhanced the formation of a cohesive biocrust without the need for additional phototrophic biomass within native soils that contain trace amounts of biocrust cyanobacteria. Our findings support the hitherto-unknown role of beneficial heterotrophic bacteria in the establishment and growth of biocrusts and allow us to make recommendations concerning biocrust restoration efforts based on the presence of remnant biocrust communities in disturbed areas. Future biocrust restoration efforts should consider cyanobacteria and their beneficial heterotrophic community as inoculants. IMPORTANCE The advancement of biocrust restoration methods for cyanobacterial biocrusts has been largely achieved through trial and error. Successes and failures could not always be traced back to particular factors. The investigation and application of foundational microbial interactions existing within biocrust communities constitute a crucial step toward informed and repeatable biocrust restoration methods.more » « less
-
Summary Microbial communities can rapidly respond to stress, meaning plants may encounter altered soil microbial communities in stressful environments. These altered microbial communities may then affect natural selection on plants. Because stress can cause lasting changes to microbial communities, microbes may also cause legacy effects on plant selection that persist even after the stress ceases.To explore how microbial responses to stress and persistent microbial legacy effects of stress affect natural selection, we grewChamaecrista fasciculataplants in stressful (salt, herbicide, or herbivory) or nonstressful conditions with microbes that had experienced each of these environments in the previous generation.Microbial community responses to stress generally counteracted the effects of stress itself on plant selection, thereby weakening the strength of stress as a selective agent. Microbial legacy effects of stress altered plant selection in nonstressful environments, suggesting that stress‐induced changes to microbes may continue to affect selection after stress is lifted.These results suggest that soil microbes may play a cryptic role in plant adaptation to stress, potentially reducing the strength of stress as a selective agent and altering the evolutionary trajectory of plant populations.more » « less
-
Abstract Microbes play critical roles in dryland ecosystems, driving nutrient cycling, soil stability, and plant interactions. Despite their ecological importance, few studies have examined how microbial communities respond to vegetation changes in arid landscapes. In the northern extent of the Chihuahuan Desert, the encroachment of woody shrubs into grasslands has been occurring since the 1800s, largely driven by extensive livestock grazing and increased drought levels. In this study, we investigated how microbial communities respond to both biotic (i.e., vegetation) and abiotic (i.e., seasonality) factors, how they assemble in a changing landscape, and which taxa may be particularly responsive to shrub encroachment or even facilitating this transformation. We assessed microbial communities using soil surface samples across five distinct seasonal periods in a grassland-to-shrubland gradient in the Jornada Experimental Range in the Chihuahuan Desert through the use of phospholipid fatty-acid analysis and DNA metabarcoding techniques. Our findings reveal that bacterial and fungal biomass are significantly influenced by seasonal changes, with strong correlations to humidity and temperature fluctuations. We also found that fungal community assembly and diversity were highly impacted by vegetation whereas seasons were more impactful on bacteria. Our results support the idea that microbes may be playing a crucial role in facilitating the grassland-to-shrubland transition. Overall, our study highlights the complex interactions between microbial communities and biotic and abiotic factors in dryland systems. These findings are essential for understanding the future of dryland ecosystems undergoing shrub encroachment and provide a critical foundation for guiding restoration efforts, particularly those looking to incorporate microbial-mediated solutions.more » « less
