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Jayne Belnap - One of the best experts on this subject based on the ideXlab platform.
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grazing induced changes to Biological Soil Crust cover mediate hillslope erosion in long term exclosure experiment
Rangeland Ecology & Management, 2020Co-Authors: Jayne Belnap, Stephen E Fick, Michael C DuniwayAbstract:Abstract Dryland ecosystems are particularly vulnerable to erosion generated by livestock grazing. Quantifying this risk across a variety of landscape settings is essential for successful adaptive management, particularly in light of a changing climate. In the Upper Colorado River Basin, there are nearly 25 000 km2 of rangelands with underlying Soils derived from Mancos Shale, an erodible and saline geologic parent material. Salinity is a major concern within the Colorado River watershed, much of which is attributed to runoff and leaching from Mancos Shale deposits. In a 60-yr paired-watershed experiment in western Colorado, we used silt fences to measure differences in saline hillslope erosion, including both total sediment yield and concentrations of primary saline constituents (Na and Se), in watersheds that were either exposed to grazing or where livestock was excluded. After accounting for the strong effects of Soil type, slope, and antecedent precipitation, we found that grazing increased sediment loss by ≈50% across our 8-yr time series (0.1–1.5 tn ha−1), consistent with levels reported at the watershed scale in early published work from studies at the same location. Eroded sediment Se levels were low and unaffected by grazing history, but Na concentrations were significantly reduced on grazed hillslopes, likely due to depletion of surface Na in Soils exposed to chronic Soil disturbance by livestock. Variable selection and path analysis identified that Biological Soil Crust (BSC) cover, more than any other variable, explained the differences in sediment yields between grazed and ungrazed watersheds, partially through the enhancement of Soil aggregate stability. Our results suggest that BSC cover should be granted heightened consideration in rangeland decision support tools (e.g., state-and-transition models) and that measures to reduce surface disturbance from livestock such as altering the timing or intensity of grazing may be effective for reducing downstream impacts.
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Biological Soil Crust and disturbance controls on surface hydrology in a semi arid ecosystem
Ecosphere, 2017Co-Authors: Akasha M Faist, Jayne Belnap, Jeffrey E Herrick, Justin W Van Zee, Nichole N BargerAbstract:Biological Soil Crust communities (bioCrusts) play an important role in surface hydrologic processes in dryland ecosystems and can be dramatically altered with Soil surface disturbance. In this study, through a simulated rainfall experiment, we examined bioCrust hydrologic responses to disturbance (trampling and scraping) at different developmental stages on sandy Soils on the Colorado Plateau. Our results showed that all disturbance treatments of the early-successional light cyanobacterial bioCrusts reduced runoff after 10 min of cumulative rainfall. Scraped and scraped + trampled treatments also reduced runoff after 30 min in the light bioCrust when compared to the intact controls but runoff in the trampling treatments was not significantly reduced. Light bioCrust sediment loss trended toward a decrease in total amount of sediment lost in all disturbance treatments but not significantly so. In contrast, trampling well-developed dark cyano-lichen bioCrusts demonstrated an opposite response than the less-developed light bioCrusts and increased runoff after 30 min of cumulative rainfall and in total sediment loss relative to intact controls. Scraping in dark Crusts did not increase runoff, implying that Soil aggregate structure was important to the infiltration process. Well-developed, intact dark bioCrusts generally had lower runoff and sediment loss and highest aggregate stability, whereas the less-developed light bioCrusts were highest in runoff and sediment loss after disturbance when compared to the controls. These results suggest the importance of maintaining the well-developed dark bioCrusts, as they are beneficial for lowering runoff and reducing Soil loss and redistribution on the landscape. These data also suggest that upslope patches of light bioCrust may either support water transport to downslope vegetation patches or alternatively this runoff may place dark bioCrust patches at risk of disruption and loss, given that light patches increase runoff and thus Soil erosion potential.
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Synthesis on Biological Soil Crust Research
Biological Soil Crusts: An Organizing Principle in Drylands, 2016Co-Authors: Bettina Weber, Jayne Belnap, Burkhard BüdelAbstract:In this closing chapter, we summarize the advances in Biological Soil Crust (bioCrust) research made during the last 1.5 decades. In the first part of the chapter, we discuss how in some research fields, such as the microbial diversity of fungi, bacteria, and microfauna, the interaction between bioCrusts and vascular plants, and in the rehabilitation of bioCrusts, particularly large achievements have been made. We also review the corroboration and refinement of previously established knowledge in other research areas, e.g., in the fields of Soil stabilization and disturbance effects.
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climate change and physical disturbance manipulations result in distinct Biological Soil Crust communities
Applied and Environmental Microbiology, 2015Co-Authors: Blaire Steven, Sasha C Reed, Cheryl R Kuske, La Verne Gallegosgraves, Jayne BelnapAbstract:Biological Soil Crusts (bioCrusts) colonize plant interspaces in many drylands and are critical to Soil nutrient cycling. Multiple climate change and land use factors have been shown to detrimentally impact bioCrusts on a macroscopic (i.e., visual) scale. However, the impact of these perturbations on the bacterial components of the bioCrusts remains poorly understood. We employed multiple long-term field experiments to assess the impacts of chronic physical (foot trampling) and climatic changes (2°C Soil warming, altered summer precipitation [wetting], and combined warming and wetting) on bioCrust bacterial biomass, composition, and metabolic profile. The bioCrust bacterial communities adopted distinct states based on the mechanism of disturbance. Chronic trampling decreased biomass and caused small community compositional changes. Soil warming had little effect on bioCrust biomass or composition, while wetting resulted in an increase in the cyanobacterial biomass and altered bacterial composition. Warming combined with wetting dramatically altered bacterial composition and decreased Cyanobacteria abundance. Shotgun metagenomic sequencing identified four functional gene categories that differed in relative abundance among the manipulations, suggesting that climate and land use changes affected Soil bacterial functional potential. This study illustrates that different types of bioCrust disturbance damage bioCrusts in macroscopically similar ways, but they differentially impact the resident Soil bacterial communities, and the communities' functional profiles can differ depending on the disturbance type. Therefore, the nature of the perturbation and the microbial response are important considerations for management and restoration of drylands.
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dryland Biological Soil Crust cyanobacteria show unexpected decreases in abundance under long term elevated co2
Environmental Microbiology, 2012Co-Authors: Blaire Steven, Jayne Belnap, La Verne Gallegosgraves, Chris M Yeager, David R Evans, Cheryl R KuskeAbstract:Biological Soil Crusts (bioCrusts) cover Soil surfaces in many drylands globally. The impacts of 10 years of elevated atmospheric CO2 on the cyanobacteria in bioCrusts of an arid shrubland were examined at a large manipulated experiment in Nevada, USA. Cyanobacteria-specific quantitative PCR surveys of cyanobacteria small-subunit (SSU) rRNA genes suggested a reduction in bioCrust cyanobacterial biomass in the elevated CO2 treatment relative to the ambient controls. Additionally, SSU rRNA gene libraries and shotgun metagenomes showed reduced representation of cyanobacteria in the total microbial community. Taxonomic composition of the cyanobacteria was similar under ambient and elevated CO2 conditions, indicating the decline was manifest across multiple cyanobacterial lineages. Recruitment of cyanobacteria sequences from replicate shotgun metagenomes to cyanobacterial genomes representing major bioCrust orders also suggested decreased abundance of cyanobacteria sequences across the majority of genomes tested. Functional assignment of cyanobacteria-related shotgun metagenome sequences indicated that four subsystem categories, three related to oxidative stress, were differentially abundant in relation to the elevated CO2 treatment. Taken together, these results suggest that elevated CO2 affected a generalized decrease in cyanobacteria in the bioCrusts and may have favoured cyanobacteria with altered gene inventories for coping with oxidative stress.
Emma K Steggles - One of the best experts on this subject based on the ideXlab platform.
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Biological Soil Crust and vascular plant interactions in western myall acacia papyrocarpa open woodland in south australia
Journal of Vegetation Science, 2019Co-Authors: Emma K Steggles, Jose M Facelli, Phillip J Ainsley, L M PoundAbstract:AIM: Biological Soil Crust (BSC) is a key component of arid environments and plays a major role in determining ecological structure and function. Our research aim was to examine several mechanisms that contribute to BSC–plant interactions at species and community levels, to increase our understanding of plant community dynamics. LOCATION: Yellabinna Regional Reserve, South Australia (30°50′17.99″ S, 132°12′10.37″ E). METHODS: We used seed extraction techniques to examine Soil seed banks beneath patches with and without BSC, and field and glasshouse experiments to study the effects of Crust presence and disturbance on seedling emergence and survival. We also explored the influence of chemical leachates from BSC on seed germination. RESULTS: Biological Soil Crust plays a pivotal role in influencing spatial patterns in Soil seed bank composition. Our results showed less propagules accumulate in Soils beneath Crust when compared with patches without Crust, and that propagule size is a contributing factor to determining their distribution between patch types. We found that late‐stage BSC physically inhibited seedling emergence, which increased when the BSC was disturbed in field experiments. Low seedling survivorship in both patch types suggests that although BSC may suppress recruitment in favourable years, it is low precipitation levels that have the over‐riding impact on recruitment success. Finally, leachates from late‐stage BSC were found to inhibit germination in three annual plant species, whilst early‐stage BSC accelerated germination in one annual plant. This clearly shows that leachate effects on seed germination vary according to plant species and Crust successional stage. CONCLUSION: Overall, we identified several mechanisms through which BSC has complex effects on the annual and short‐lived perennial plant guilds of arid lands. These mechanisms contribute to species diversity through the creation of spatial heterogeneity in Soil seed bank structure and emergence opportunities.
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Original data supporting results in the paper: Steggles EK, Facelli JM, Ainsley PJ and Pound LM (2019 in print) Biological Soil Crust and vascular plant interactions in Western Myall (Acacia papyrocarpa) open woodland in South Australia" Journal of V
2019Co-Authors: Emma K Steggles, Jose M Facelli, Phillip J Ainsley, Leanne PoundAbstract:Original data supporting results in the paper:Emma K. Steggles, José M. Facelli, Phillip J. Ainsley and Leanne M. Pound (2019 in print) Biological Soil Crust and vascular plant interactions in Western Myall (Acacia papyrocarpa) open woodland in South Australia. Journal of Vegetation Science
Pablo Garciapalacios - One of the best experts on this subject based on the ideXlab platform.
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Biological Soil Crust microsites are the main contributor to Soil respiration in a semiarid ecosystem
Ecosystems, 2011Co-Authors: Andrea P Castillomonroy, Fernando T. Maestre, Santiago Soliveres, Pablo Garciapalacios, Ana ReyAbstract:Biological Soil Crusts (BSCs) are a key biotic component of dryland ecosystems worldwide. However, most studies carried out to date on carbon (C) fluxes in these ecosystems, such as Soil respiration, have neglected them. We conducted a 3.5-year field experiment to evaluate the spatio-temporal heterogeneity of Soil respiration in a semiarid Stipa tenacissima steppe and to assess the contribution of BSC-dominated areas to the annual Soil respiration of the whole ecosystem. We selected the six most frequent microsites in the study area: Stipa tussocks (ST), Retama sphaerocarpa shrubs (RS), and open areas with very low (<5% BSC cover, BS), low, medium and high cover of well-developed BSCs. Soil respiration rates did not differ among BSCdominated microsites but were significantly higher and lower than those found in BS and ST microsites, respectively. A model using Soil temperature and Soil moisture accounted for over 85% of the temporal variation in Soil respiration throughout the studied period. Using this model, we estimated a range of 240.4‐322.6 g C m -2 y -1 released by Soil respiration at our study area. Vegetated (ST and RS) and BSC-dominated microsites accounted for 37 and 42% of this amount, respectively. Our results indicate that accounting for the spatial heterogeneity in Soil respiration induced by BSCs is crucial to provide accurate estimations of this flux at the ecosystem level. They also highlight that BSC-dominated areas are the main contributor to the total C released by Soil respiration and, therefore, must be considered when estimating C budgets in drylands.
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do biotic interactions modulate ecosystem functioning along stress gradients insights from semi arid plant and Biological Soil Crust communities
Philosophical Transactions of the Royal Society B, 2010Co-Authors: Fernando T. Maestre, Matthew A Bowker, Cristina Escolar, Maria D Puche, Santiago Soliveres, Sara Maltezmouro, Pablo Garciapalacios, Andrea P Castillomonroy, Isabel MartinezAbstract:Climate change will exacerbate the degree of abiotic stress experienced by semi-arid ecosystems. While abiotic stress profoundly affects biotic interactions, their potential role as modulators of ecosystem responses to climate change is largely unknown. Using plants and Biological Soil Crusts, we tested the relative importance of facilitative–competitive interactions and other community attributes (cover, species richness and species evenness) as drivers of ecosystem functioning along stress gradients in semi-arid Mediterranean ecosystems. Biotic interactions shifted from facilitation to competition along stress gradients driven by water availability and temperature. These changes were, however, dependent on the spatial scale and the community considered. We found little evidence to suggest that biotic interactions are a major direct influence upon indicators of ecosystem functioning (Soil respiration, organic carbon, water-holding capacity, compaction and the activity of enzymes related to the carbon, nitrogen and phosphorus cycles) along stress gradients. However, attributes such as cover and species richness showed a direct effect on ecosystem functioning. Our results do not agree with predictions emphasizing that the importance of plant–plant interactions will be increased under climate change in dry environments, and indicate that reductions in the cover of plant and Biological Soil Crust communities will negatively impact ecosystems under future climatic conditions.
L M Pound - One of the best experts on this subject based on the ideXlab platform.
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Biological Soil Crust and vascular plant interactions in western myall acacia papyrocarpa open woodland in south australia
Journal of Vegetation Science, 2019Co-Authors: Emma K Steggles, Jose M Facelli, Phillip J Ainsley, L M PoundAbstract:AIM: Biological Soil Crust (BSC) is a key component of arid environments and plays a major role in determining ecological structure and function. Our research aim was to examine several mechanisms that contribute to BSC–plant interactions at species and community levels, to increase our understanding of plant community dynamics. LOCATION: Yellabinna Regional Reserve, South Australia (30°50′17.99″ S, 132°12′10.37″ E). METHODS: We used seed extraction techniques to examine Soil seed banks beneath patches with and without BSC, and field and glasshouse experiments to study the effects of Crust presence and disturbance on seedling emergence and survival. We also explored the influence of chemical leachates from BSC on seed germination. RESULTS: Biological Soil Crust plays a pivotal role in influencing spatial patterns in Soil seed bank composition. Our results showed less propagules accumulate in Soils beneath Crust when compared with patches without Crust, and that propagule size is a contributing factor to determining their distribution between patch types. We found that late‐stage BSC physically inhibited seedling emergence, which increased when the BSC was disturbed in field experiments. Low seedling survivorship in both patch types suggests that although BSC may suppress recruitment in favourable years, it is low precipitation levels that have the over‐riding impact on recruitment success. Finally, leachates from late‐stage BSC were found to inhibit germination in three annual plant species, whilst early‐stage BSC accelerated germination in one annual plant. This clearly shows that leachate effects on seed germination vary according to plant species and Crust successional stage. CONCLUSION: Overall, we identified several mechanisms through which BSC has complex effects on the annual and short‐lived perennial plant guilds of arid lands. These mechanisms contribute to species diversity through the creation of spatial heterogeneity in Soil seed bank structure and emergence opportunities.
Sam Drake - One of the best experts on this subject based on the ideXlab platform.
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the effects of plantation development on Biological Soil Crust and topSoil properties in a desert in northern china
Geoderma, 2011Co-Authors: Halin Zhao, Yirui Guo, Ruilian Zhou, Sam DrakeAbstract:Abstract Afforestation was one of most successful measures to rehabilitate desertified lands and to improve regional eco-environments in the Horqin Sand Land. A field experiment was conducted during 2005 and 2006 in the Horqin Sand Land to investigate the effects of Populus simonii plantation growth on Soil Crust formation and topSoil properties. The results showed that plantation establishment promoted the development of Biological Soil Crust and improved properties of topSoil 0–5 cm under the Crust in sand dunes. As the plantation aged, Soil Crust developed gradually from a physical Crust, to a lichen Crust and then to a moss Crust and Crust coverage, thickness, hardness, very fine sand content, clay, silt, organic carbon and nutrients increased significantly. Clay, silt, organic carbon and nutrients in topSoil 0–2.5 cm and 2.5–5.0 cm under the Soil Crust increased with plantation age and Crust development, but the magnitude of changes decreased with increasing Soil depth. Changes in Soil physical and chemical properties in the Crust had a significant positive correlation with plantation age, and changes in physical and chemical properties in the 0–5.0 cm layer of topSoil had a significant positive correlation with Soil Crust development and plantation age. Soil Crust development and changes in topSoil properties under the Soil Crust can be attributed primarily to the reestablishment of vegetation and the duration that the vegetation is in place.
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Biological Soil Crust and surface Soil properties in different vegetation types of horqin sand land china
Catena, 2010Co-Authors: Halin Zhao, Yirui Guo, Ruilian Zhou, Sam DrakeAbstract:Abstract Physical and chemical properties (including coverage, thickness, hardness, moisture, particle size distribution, organic matter and nutrient contents etc.) of Biological Soil Crust and 0–5.0 cm surface Soil under the Crust in three types of vegetation (semi-shrub Artemisia frigida, shrub Salix gordejevii and tree Populus simonii) were surveyed in 2005 and 2006 in Horqin Sand Land to understand the effects of different vegetation types on development of Soil Crust and surface Soil properties under Crust. The results showed that 1) no physical Soil Crust or Biological Soil Crust (BSC) formed on mobile dunes without vegetation, though most ground surface in originally mobile dunes had been covered by BSC fifteen years after planted vegetation was established; 2) BSC development was best in shrub S. gordejevii sites, second in semi-shrub A. frigida sites, and weakest in tree P. simonii sites; 3) development of BSC was better in moss Crust distributed mainly beneath or near plant canopies than in lichen Crust distributed mainly between plant canopies in all three vegetation types; 4) surface Soil properties 0–5.0 cm under BSC were improved significantly in all three vegetation types compared to those in mobile sand land. The magnitude of improvement was greater in S. gordejevii sites than in A. frigida and P. simonii sites, and greater in moss Crust sites than lichen Crust sites, but the magnitude of improvement decreased significantly with increasing surface Soil depth; 5) based on the above-mentioned results, we suggest that S. gordejevii should be favored in future planting in Horqin Sand Land.