scholarly journals Identifying Mechanisms for Successful Ecological Restoration with Salvaged Topsoil in Coastal Sage Scrub Communities

Diversity ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 150 ◽  
Author(s):  
Katharina T. Schmidt ◽  
Mia Maltz ◽  
Priscilla Ta ◽  
Banafshe Khalili ◽  
Claudia Weihe ◽  
...  

Although aboveground metrics remain the standard, restoring functional ecosystems should promote both aboveground and belowground biotic communities. Restoration using salvaged soil—removal and translocation of topsoil from areas planned for development, with subsequent deposition at degraded sites—is an alternative to traditional methods. Salvaged soil contains both seed and spore banks, which may holistically augment restoration. Salvaged soil methods may reduce non-native germination by burying non-native seeds, increase native diversity by adding native seeds, or transfer soil microbiomes, including arbuscular mycorrhizal fungi (AMF), to recipient sites. We transferred soil to three degraded recipient sites and monitored soil microbes, using flow cytometry and molecular analyses, and characterized the plant community composition. Our findings suggest that salvaged soil at depths ≥5 cm reduced non-native grass cover and increased native plant density and species richness. Bacterial abundance at recipient sites were statistically equivalent to donor sites in abundance. Overall, topsoil additions affected AMF alpha diversity and community composition and increased rhizophilic AMF richness. Because salvaged soil restoration combines multiple soil components, including native plant and microbial propagules, it may promote both aboveground and belowground qualities of the donor site, when applying this method for restoring invaded and degraded ecosystems.

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11792
Author(s):  
Mei Yang ◽  
Zhaoyong Shi ◽  
Bede S. Mickan ◽  
Mengge Zhang ◽  
Libing Cao

Background Global warming can alter plant productivity, and community composition which has consequences for soil-plant associated microorganisms. Arbuscular mycorrhizal fungi (AMF) are distributed widely and form symbiotic relationships with more than 80% of vascular plants and play a key role in nutrient cycling processes at the ecosystem scale. Methods A simulated warming experiment at multiple elevations (3,000, 3,500, 3,800, and 4,170 m) was conducted utilizing an in-situ open-top chamber (OTC) for exploring the effect of global warming on AMF community structure in the Qinghai-Tibet Plateau (QTP). This region has been identified as one of the most sensitive areas to climatic changes. Soil DNA was extracted and sequenced using next the Mi-Seq platform for diversity profiling. Results AMF richness was higher under the simulated warming chamber, however this only occurred in the elevation of 3,500 m. Warming did not alter other AMF alpha diversity indices (e.g. Shannon, Ace, and Simpson evenness index). Glomus and Acaulospora were the dominate AMF genera as assessed through their relative abundance and occurrence in control and warming treatments at the different elevations. Conclusion Warming changed significantly AMF community. The effects of warming on AMF community structure varied depend on elevations. Moreover, the occurrences of AMF in different genera were also presented the different responses to warming in four elevations.


Botany ◽  
2016 ◽  
Vol 94 (6) ◽  
pp. 425-433 ◽  
Author(s):  
Edith B. Allen ◽  
Louise M. Egerton-Warburton ◽  
Bridget E. Hilbig ◽  
Justin M. Valliere

Anthropogenic nitrogen (N) deposition and invasive species are causing declines in global biodiversity, and both factors impact the diversity and functioning of arbuscular mycorrhizal (AM) fungi. Shifts in arbuscular mycorrhizal fungal (AMF) communities can generate feedback to native plants and affect their success, as was observed in California’s coastal sage scrub, which is a Mediterranean-type shrubland threatened by invasive grasses. As vegetation-type conversion from native shrubland to exotic annual grassland increased along a gradient of increasing N deposition, the richness of native plant species and of spore morphotypes decreased. Rapid declines in all plant and fungal values occurred at the critical load (CL) of 10–11 kg N·ha−1·year−1, indicating that AM fungi respond to the same environmental signals as the plants, and can be used to assess CL. Shrub root colonization also decreased along the N gradient, but colonization of the invasive grass was dominated by a fine AMF endophyte that was unresponsive to elevated N. A greenhouse experiment to assess AMF functioning showed that the native shrub Artemisia californica Less. had a negative growth response to an inoculum from high-N but not low-N soils, whereas the invasive grass Bromus rubens L. had a positive response to both inocula. Differential functioning of AM fungi under N deposition may in part explain vegetation-type conversion and the decline of this native shrubland.


2019 ◽  
Author(s):  
Coline Deveautour ◽  
Sally Power ◽  
Kirk Barnett ◽  
Raul Ochoa-Hueso ◽  
Suzanne Donn ◽  
...  

Climate models project overall a reduction in rainfall amounts and shifts in the timing of rainfall events in mid-latitudes and sub-tropical dry regions, which threatens the productivity and diversity of grasslands. Arbuscular mycorrhizal fungi may help plants to cope with expected changes but may also be impacted by changing rainfall, either via the direct effects of low soil moisture on survival and function or indirectly via changes in the plant community. In an Australian mesic grassland (former pasture) system, we characterised plant and arbuscular mycorrhizal (AM) fungal communities every six months for nearly four years to two altered rainfall regimes: i) ambient, ii) rainfall reduced by 50% relative to ambient over the entire year and iii) total summer rainfall exclusion. Using Illumina sequencing, we assessed the response of AM fungal communities sampled from contrasting rainfall treatments and evaluated whether variation in AM fungal communities was associated with variation in plant community richness and composition. We found that rainfall reduction influenced the fungal communities, with the nature of the response depending on the type of manipulation, but that consistent results were only observed after more than two years of rainfall manipulation. We observed significant co-associations between plant and AM fungal communities on multiple dates. Predictive co-correspondence analyses indicated more support for the hypothesis that fungal community composition influenced plant community composition than vice versa. However, we found no evidence that altered rainfall regimes were leading to distinct co-associations between plants and AM fungi. Overall, our results provide evidence that grassland plant communities are intricately tied to variation in AM fungal communities. However, in this system, plant responses to climate change may not be directly related to impacts of altered rainfall regimes on AM fungal communities. Our study shows that AM fungal communities respond to changes in rainfall but that this effect was not immediate. The AM fungal community may influence the composition of the plant community. However, our results suggest that plant responses to altered rainfall regimes at our site may not be resulting via changes in the AM fungal communities.


2021 ◽  
Author(s):  
Maede Faghihinia ◽  
Yi Zou ◽  
Yongfei Bai ◽  
Martin Dudáš ◽  
Rob Marrs ◽  
...  

Abstract Arbuscular mycorrhizal fungi (AMF) are the predominant type of mycorrhizal fungi in roots and rhizosphere soil of grass species worldwide. Grasslands are currently experiencing increasing grazing pressure, but it is not yet clear how grazing intensity and host plant grazing preference by large herbivores interact with soil- and root-associated AMF communities. Here, we tested whether the diversity and community composition of AMF in the roots and rhizosphere soil of two dominant perennial grasses grazed differently by livestock change in response to grazing intensity. We conducted a study in a long-term field experiment in which seven levels of field-manipulated grazing intensities were maintained for 13 years in a typical steppe grassland in northern China. We extracted DNA from the roots and rhizosphere soil of two dominant grasses, Leymus chinense (Trin.) Tzvel. and Stipa grandis P. Smirn, with contrasting grazing preference by sheep. AMF DNA from root and soil samples were then subjected to molecular analysis. Our results showed that AMF α-diversity (richness) at the virtual taxa (VT) level varied as a function of grazing intensity. Different VTs showed completely different responses along the gradient, one increasing, one decreasing and others showing no response. Glomeraceae was the most abundant AMF family along the grazing gradient, which fits well with the theory of disturbance tolerance of this group. In addition, sheep grazing preference for host plants did not explain a considerable variation in AMF α-diversity. However, the two grass species exhibited different community composition in their roots and rhizosphere soils. Roots exhibited a lower α-diversity and higher β-diversity within the AMF community than soils. Overall, our results suggest that long-term grazing intensity might have changed the abundance of functionally-diverse AMF taxa in favor of those with disturbance-tolerant traits. We suggest our results would be useful in informing the choice of mycorrhizal fungi indicator variables when assessing the impacts of grassland management choices on grassland ecosystem functioning.


2003 ◽  
Vol 16 (1) ◽  
pp. 131 ◽  
Author(s):  
J. Bell ◽  
S. Wells ◽  
D. A. Jasper ◽  
L. K. Abbott

Field experiments were conducted at rehabilitation sites at two contrasting mines in Western Australia. At both mines, Acacia spp. are important components of the rehabilitation ecosystem. At a mineral sands mine near Eneabba, dry-root inoculum of the arbuscular mycorrhizal (AM) fungus Glomus invermaium (WUM 10) was introduced into riplines with three rates of phosphate fertiliser application. Plants were assessed for mycorrhizal colonisation and phosphorus status. There was no plant growth benefit from inoculation. A considerable number of infective propagules of indigenous AM fungi was already present in the topsoil. The inoculant fungus as well as the indigenous AM fungi formed mycorrhizas, but only in a small number of Acacia and other native plant species. In a study of AM fungal inoculation at a gold mine rehabilitation site at Boddington, dry-root inoculum of G.�invermaium was applied to riplines prior to seeding. Despite apparently ideal environmental conditions, colonisation of native seedlings was limited. Possible reasons for this were investigated in further experiments that addressed environmental factors such as soil temperature and moisture and factors such as the age of the plant and presence of a colonised cover crop. Inoculum remained infective even under moist conditions in field soil for at least 4 months. Its infectivity decreased in parallel with falling temperatures. However, the level of infectivity present did not ensure extensive colonisation of native plants such as Acacia seedlings in the field. Susceptibility of Acacia seedlings to colonisation by AM fungi appeared to be seasonal, as colonisation increased with increasing daytime temperatures and daylight hours.


Botany ◽  
2016 ◽  
Vol 94 (6) ◽  
pp. 481-491 ◽  
Author(s):  
Catherine A. Gehring ◽  
Michaela Hayer ◽  
Lluvia Flores-Rentería ◽  
Andrew F. Krohn ◽  
Egbert Schwartz ◽  
...  

Invasive, non-native plant species can alter soil microbial communities in ways that contribute to their persistence. While most studies emphasize mycorrhizal fungi, invasive plants also may influence communities of dark septate fungi (DSF), which are common root endophytes that can function like mycorrhizas. We tested the hypothesis that a widespread invasive plant in the western United States, cheatgrass (Bromus tectorum L.), influenced the abundance and community composition of DSF by examining the roots and rhizosphere soils of cheatgrass and two native plant species in cheatgrass-invaded and noninvaded areas of sagebrush steppe. We focused on cheatgrass because it is negatively affected by mycorrhizal fungi and colonized by DSF. We found that DSF root colonization and operational taxonomic unit (OTU) richness were significantly higher in sagebrush (Artemisia tridentata Nutt.) and rice grass (Achnatherum hymenoides (Roem. & Schult.) Barkworth) from invaded areas than noninvaded areas. Cheatgrass roots had similar levels of DSF colonization and OTU richness as native plants. The community composition of DSF varied with invasion in the roots and soils of native species and among the roots of the three plant species in the invaded areas. The substantial changes in DSF we observed following cheatgrass invasion argue for comparative studies of DSF function in native and non-native plant species.


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