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Germino MJ, Kluender CR, Anthony CR. Plant community trajectories following livestock exclusion for conservation vary and hinge on initial invasion and soil‐biocrust conditions in shrub steppe. CONSERVATION SCIENCE AND PRACTICE 2022. [DOI: 10.1111/csp2.12838] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Matthew J. Germino
- U.S. Geological Survey Forest and Rangeland Ecosystem Science Center Boise Idaho USA
| | - Chad R. Kluender
- U.S. Geological Survey Forest and Rangeland Ecosystem Science Center Boise Idaho USA
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Kidron GJ, Xiao B, Benenson I. Data variability or paradigm shift? Slow versus fast recovery of biological soil crusts-a review. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 721:137683. [PMID: 32197290 DOI: 10.1016/j.scitotenv.2020.137683] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 02/27/2020] [Accepted: 03/01/2020] [Indexed: 06/10/2023]
Abstract
Biological soil crusts, known also as biocrusts, provide valuable ecosystem services, especially in arid and semiarid regions. They may affect geomorphological (stability), hydrological (infiltration, evaporation), biochemical (carbon and nitrogen fixation) and ecological (germination and growth of vascular plants) processes, and their disturbance may have important ecological consequences. The common view, as reflected in hundreds of papers, regards biocrusts as having extremely slow recovery with characteristic time of up to hundreds and even thousands of years. Long recovery time implies that disturbance or climate change may have severe long-lasting consequences even once the conditions return to their initial state, triggering ample efforts to hasten biocrust recovery by inoculation. We critically analyze available estimates of the crust recovery time and present systematic measurements and theoretical considerations that attest to relatively rapid recovery of the crusts. We conclude that the likely recovery time of cyanobacterial crusts is 5-10 years, while that of lichen- and moss-dominated crusts is 10-20 years. Subsequently, costly and potentially negative effects to the ecosystem during inoculation should be weighed against the fast natural recovery of the biocrusts.
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Affiliation(s)
- Giora J Kidron
- Institute of Earth Sciences, The Hebrew University, Givat Ram Campus, Jerusalem 91904, Israel.
| | - Bo Xiao
- College of Land Science and Technology, China Agricultural University, Beijing 100193, China.
| | - Itzhak Benenson
- Department of Geography and Human Environment, Tel Aviv University, Tel Aviv 69978, Israel.
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Condon LA, Pyke DA. Components and Predictors of Biological Soil Crusts Vary at the Regional vs. Plant Community Scales. Front Ecol Evol 2020. [DOI: 10.3389/fevo.2019.00449] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Bates ST, Nash TH, Garcia-Pichel F. Patterns of diversity for fungal assemblages of biological soil crusts from the southwestern United States. Mycologia 2017; 104:353-61. [PMID: 22123652 DOI: 10.3852/11-232] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Scott T. Bates
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado 80309
| | - Thomas H. Nash
- School of Life Sciences, Arizona State University, P.O. Box 874501, Tempe, Arizona 85287-4501
| | - Ferran Garcia-Pichel
- School of Life Sciences, Arizona State University, P.O. Box 874501, Tempe, Arizona 85287-4501
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Description of Deinococcus oregonensis sp. nov., from biological soil crusts in the Southwestern arid lands of the United States of America. Arch Microbiol 2016; 199:69-76. [PMID: 27515516 DOI: 10.1007/s00203-016-1273-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/21/2016] [Accepted: 07/19/2016] [Indexed: 10/21/2022]
Abstract
Biological soil crusts are distinct habitats, harbor unique prokaryotic diversity and gave an impetus to isolate novel species. In the present study, a pink-pigmented bacterium, (OR316-6T), was isolated from biological soil crusts using oligotrophic BG11-PGY medium. Strain OR316-6T was Gram-positive, short rods, non-motile and non-spore forming. Cells were positive for catalase, oxidase and β-galactosidase and negative for most of the enzymatic activities. The major fatty acids present were C16:0, C17:0, and C16:1ω7c and contained MK-8 and MK-10 as the predominant menaquinones. The cell wall peptidoglycan was of A3β variant with L-ornithine as the diamino acid. Based on the above characteristics, strain OR316-6T was assigned to the genus Deinococcus. The phylogenetic analysis indicated that strain OR316-6T was closely related to D. aquatilis DSM 23025T with a 16S rRNA gene similarity of 99.3 % and clustered with a bootstrap value of 100 %. DNA-DNA similarity between strain OR316-6T and D. aquatilis DSM 23025T was 37.0 % indicating that strain OR316-6T was a novel species. Further, DNA fingerprinting of stains OR316-6T and D. aquatilis DSM 23035T demonstrated that both strains were related to each other with a similarity coefficient of only 0.32 and supported the species status to strain OR316-6T. In addition, phenotypic characteristics distinguished strain OR316-6T from D. aquatilis DSM 23025T. Based on the cumulative differences, strain OR316-16T exhibited with its closely related species, it was identified as a novel species and proposed the name Deinococcus oregonensis sp. nov. The type strain is D. oregonensis sp. nov. (OR316-6T = JCM 13503T = DSM 17762T).
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Chiquoine LP, Abella SR, Bowker MA. Rapidly restoring biological soil crusts and ecosystem functions in a severely disturbed desert ecosystem. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2016; 26:1260-1272. [PMID: 27509763 DOI: 10.1002/15-0973] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Restoring biological soil crusts (biocrusts) in degraded drylands can contribute to recovery of ecosystem functions that have global implications, including erosion resistance and nutrient cycling. To examine techniques for restoring biocrusts, we conducted a replicated, factorial experiment on recently abandoned road surfaces by applying biocrust inoculation (salvaged and stored dry for two years), salvaged topsoil, an abiotic soil amendment (wood shavings), and planting of a dominant perennial shrub (Ambrosia dumosa). Eighteen months after treatments, we measured biocrust abundance and species composition, soil chlorophyll a content and fertility, and soil resistance to erosion. Biocrust addition significantly accelerated biocrust recovery on disturbed soils, including increasing lichen and moss cover and cyanobacteria colonization. Compared to undisturbed controls, inoculated plots had similar lichen and moss composition, recovered 43% of total cyanobacteria density, had similar soil chlorophyll content, and exhibited recovery of soil fertility and soil stability. Inoculation was the only treatment that generated lichen and moss cover. Topsoil application resulted in partial recovery of the cyanobacteria community and soil properties. Compared to untreated disturbed plots, topsoil application without inoculum increased cyanobacteria density by 186% and moderately improved soil chlorophyll and ammonium content and soil stability. Topsoil application produced 22% and 51% of the cyanobacteria density g⁻¹ soil compared to undisturbed and inoculated plots, respectively. Plots not treated with either topsoil or inoculum had significantly lower cyanobacteria density, soil chlorophyll and ammonium concentrations, and significantly higher soil nitrate concentration. Wood shavings and Ambrosia had no influence on biocrust lichen and moss species recovery but did affect cyanobacteria composition and soil fertility. Inoculation of severely disturbed soil with native biocrusts rapidly restored biocrust communities and soil stability such that restored areas were similar to undisturbed desert within three years. Using salvaged biocrust as inoculum can be an effective tool in ecological restoration because of its efficacy and simple implementation. Although salvaging biocrust material can be technically difficult and potentially costly, utilizing opportunities to salvage material in planned future disturbance can provide additional land management tools.
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Structure, Composition, and Function of Biocrust Lichen Communities. BIOLOGICAL SOIL CRUSTS: AN ORGANIZING PRINCIPLE IN DRYLANDS 2016. [DOI: 10.1007/978-3-319-30214-0_7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Natural Recovery of Biological Soil Crusts After Disturbance. BIOLOGICAL SOIL CRUSTS: AN ORGANIZING PRINCIPLE IN DRYLANDS 2016. [DOI: 10.1007/978-3-319-30214-0_23] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Garcia V, Aranibar J, Pietrasiak N. Multiscale effects on biological soil crusts cover and spatial distribution in the Monte Desert. ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY 2015. [DOI: 10.1016/j.actao.2015.08.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Concostrina-Zubiri L, Huber-Sannwald E, Martínez I, Flores Flores JL, Reyes-Agüero JA, Escude A, Belnap J. Biological soil crusts across disturbance–recovery scenarios: effect of grazing regime on community dynamics. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2014; 24:1863-1877. [PMID: 29210244 DOI: 10.1890/13-1416.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Grazing represents one of the most common disturbances in drylands worldwide, affecting both ecosystem structure and functioning. Despite the efforts to understand the nature and magnitude of grazing effects on ecosystem components and processes, contrasting results continue to arise. This is particularly remarkable for the biological soil crust (BSC) communities (i.e., cyanobacteria, lichens, and bryophytes), which play an important role in soil dynamics. Here we evaluated simultaneously the effect of grazing impact on BSC communities (resistance) and recovery after livestock exclusion (resilience) in a semiarid grassland of Central Mexico. In particular, we examined BSC species distribution, species richness, taxonomical group cover (i.e., cyanobacteria, lichen, bryophyte), and composition along a disturbance gradient with different grazing regimes (low, medium, high impact) and along a recovery gradient with differently aged livestock exclosures (short-, medium-, long-term exclusion). Differences in grazing impact and time of recovery from grazing both resulted in slight changes in species richness; however, there were pronounced shifts in species composition and group cover. We found we could distinguish four highly diverse and dynamic BSC species groups: (1) species with high resistance and resilience to grazing, (2) species with high resistance but low resilience, (3) species with low resistance but high resilience, and (4) species with low resistance and resilience. While disturbance resulted in a novel diversity configuration, which may profoundly affect ecosystem functioning, we observed that 10 years of disturbance removal did not lead to the ecosystem structure found after 27 years of recovery. These findings are an important contribution to our understanding of BCS dynamics from a species and community perspective placed in a land use change context.
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Van Buren R, Allphin L, Philbrik M. Obituary: Kimball Taylor Harper, 1931–2011. WEST N AM NATURALIST 2012. [DOI: 10.3398/064.072.0116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Maestre FT, Bowker MA, Cantón Y, Castillo-Monroy AP, Cortina J, Escolar C, Escudero A, Lázaro R, Martínez I. Ecology and functional roles of biological soil crusts in semi-arid ecosystems of Spain. JOURNAL OF ARID ENVIRONMENTS 2011; 75:1282-1291. [PMID: 25908884 PMCID: PMC4404999 DOI: 10.1016/j.jaridenv.2010.12.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Biological soil crusts (BSCs), composed of lichens, cyanobacteria, mosses, liverworts and microorganisms, are key biotic components of arid and semi-arid ecosystems worldwide. Despite they are widespread in Spain, these organisms have been historically understudied in this country. This trend is beginning to change as a recent wave of research has been identifying BSCs as a model ecological system. Many studies and research projects carried out in Spain have explored the role of BSCs on water, carbon and nitrogen fluxes, the interactions between BSCs and vascular plants, their dynamics after disturbances, and their response to global change, among other topics. In this article we review the growing body of research on BSCs available from semi-arid areas of Spain, highlighting its importance for increasing our knowledge on this group of organisms. We also discuss how it is breaking new ground in emerging research areas on the ecology of BSCs, and how it can be use to guide management and restoration efforts. Finally, we provide directions for future research on the ecology of BSCs in Spain and abroad.
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Affiliation(s)
- Fernando T. Maestre
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, 28933 Móstoles, Spain
- Corresponding author: Phone: +34914888511; Fax: +34916647490;
| | - Matthew A. Bowker
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, 28933 Móstoles, Spain
| | - Yolanda Cantón
- Departamento de Edafología y Química Agrícola, Escuela Politécnica Superior, Universidad de Almería, La Cañada de San Urbano S/N, 04120, Almería, Spain
| | - Andrea P. Castillo-Monroy
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, 28933 Móstoles, Spain
| | - Jordi Cortina
- Departamento de Ecología and IMEM, Universidad de Alicante, Apartado de correos 99, 03080 Alicante, Spain
| | - Cristina Escolar
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, 28933 Móstoles, Spain
| | - Adrián Escudero
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, 28933 Móstoles, Spain
| | - Roberto Lázaro
- Estación Experimental de Zonas Áridas, CSIC, Carretera de sacramento, S/N; La Cañada de San Urbano, 04120, Almería, Spain
| | - Isabel Martínez
- Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Escuela Superior de Ciencias Experimentales y Tecnología, Universidad Rey Juan Carlos, 28933 Móstoles, Spain
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Pietrasiak N, Johansen JR, LaDoux T, Graham RC. Comparison of Disturbance Impacts to and Spatial Distribution of Biological Soil Crusts in the Little San Bernardino Mountains of Joshua Tree National Park, California. WEST N AM NATURALIST 2011. [DOI: 10.3398/064.071.0412] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Daryanto S, Eldridge DJ. Plant and soil surface responses to a combination of shrub removal and grazing in a shrub-encroached woodland. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2010; 91:2639-2648. [PMID: 20696514 DOI: 10.1016/j.jenvman.2010.07.038] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2009] [Revised: 06/24/2010] [Accepted: 07/19/2010] [Indexed: 05/29/2023]
Abstract
Shrub encroachment into open woodland is a widespread phenomenon in semi-arid woodlands worldwide. Encroachment or woody thickening, is thought to result from overgrazing, changes in fire regimes and increased atmospheric carbon dioxide concentrations. Eighteen years after one-off shrub removal by ploughing we assessed the effects of four different land management systems resulting from two levels each of grazing (grazed, ungrazed) with and without ploughing, on the cover of landscape units, soil surface condition, diversity of understorey plants and density of shrubs. We recorded 2-7 times more patches under conventional conservation (unploughed-ungrazed) than the others treatments, and plant cover and diversity were greater on the two conservation (ungrazed) plots, irrespective of ploughing. Soils under shrubs and log mounds had greater indices of infiltration, stability and nutrients. Shrub density under the active pastoral (ploughed-grazed) treatment was two and a half times greater than that in other treatments, but results were not significant. The effects of different treatments on shrubs were largely species-specific. Overall, our results suggest that ploughing does not provide long-term control of encroaching shrubs.
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Affiliation(s)
- Stefani Daryanto
- Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia.
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Bates ST, Garcia-Pichel F. A culture-independent study of free-living fungi in biological soil crusts of the Colorado Plateau: their diversity and relative contribution to microbial biomass. Environ Microbiol 2008; 11:56-67. [PMID: 18764875 DOI: 10.1111/j.1462-2920.2008.01738.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecular methodologies were used to investigate free-living fungal communities associated with biological soil crusts (BSCs), along km-scale transects on the Colorado Plateau (USA). Two cyanobacteria-dominated crust types that did not contain significant lichen cover were examined. Fungal community diversity and composition were assessed with PCR-denaturing gradient gel electrophoresis (DGGE) fingerprinting and sequencing, and fungi-specific quantitative PCR was used to measure fungal population densities as compared with those of bacteria. Our results clearly indicate that free-living fungi, while ubiquitous in BSCs, are less diverse and contribute far less biomass than their bacterial counterparts. Biological soil crust fungal community structure differed from that of uncrusted soils in their surroundings. Phylogenetic analyses placed the majority of BSC fungi within the Ascomycota, confirmed the importance of dematiaceous fungi, and pointed to members of the genera Alternaria and Acremonium as the most common free-living fungi in these crusts. Phylotypes potentially representing novel taxa were recovered, as were several belonging to the Basidiomycota that would not have been readily recognized by culture-dependant means.
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Affiliation(s)
- Scott T Bates
- School of Life Sciences, Arizona State University, Main Campus, Tempe, AZ 85287, USA.
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Differential regulation of pathogens: the role of habitat disturbance in predicting prevalence of Sin Nombre virus. Oecologia 2007; 155:429-39. [PMID: 18064494 DOI: 10.1007/s00442-007-0922-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2006] [Accepted: 11/09/2007] [Indexed: 10/22/2022]
Abstract
Deer mice (Peromyscus maniculatus) are the primary reservoir for Sin Nombre virus (SNV), a North American hantavirus that causes disease with high mortality in humans. Recent studies have proposed that habitat disturbance affects prevalence of SNV in deer mice; however, the outcomes proposed in these studies are in opposition to each other. Our objectives were to test these divergent hypotheses by: (1) measuring SNV infection in deer mice within a patchwork of disturbance; and (2) evaluating the relationships between SNV prevalence, population density and demography as possible mechanisms. In 2003 and 2004, we sampled 1,297 deer mice from 17 sites with varying levels of disturbance in the Great Basin Desert. Across sites and years, SNV prevalence varied from 0.0 to 38.9%. We found a negative relationship between SNV prevalence and disturbance. Although we found no direct relationship between SNV prevalence and deer mouse density, we found that density was highest on sites with the lowest levels of disturbance. The number of deer mice that survived across seasons (e.g., trans-seasonal survivors) differed across levels of disturbance and was greatest on our least disturbed study sites [Formula: see text] moderate on sites with intermediate levels of disturbance (x = 5.61%) and zero on highly disturbed sites. On low-disturbance sites, a greater proportion of trans-seasonal survivors were SNV seropositive (28.80%) compared to the intermediate-disturbance sites (16.67). Collectively, our results indicate that habitat disturbance plays a predictive role in SNV prevalence, with highly disturbed sites having reduced long-term survival of deer mice, including survival of infected individuals.
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Bowker MA. Biological Soil Crust Rehabilitation in Theory and Practice: An Underexploited Opportunity. Restor Ecol 2007. [DOI: 10.1111/j.1526-100x.2006.00185.x] [Citation(s) in RCA: 262] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Clements DR, Krannitz PG, Gillespie SM. Seed Bank Responses to Grazing History by Invasive and Native Plant Species in a Semi-desert Shrub-steppe Environment. NORTHWEST SCIENCE 2007. [DOI: 10.3955/0029-344x-81.1.37] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Bryophyte Mats Inhibit Germination of Non-native Species in Burnt Temperate Native Grassland Remnants. Biol Invasions 2006. [DOI: 10.1007/s10530-004-2881-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Belnap J, Eldridge D. Disturbance and Recovery of Biological Soil Crusts. ECOLOGICAL STUDIES 2001. [DOI: 10.1007/978-3-642-56475-8_27] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Belnap J. Surface disturbances: Their role in accelerating desertification. ENVIRONMENTAL MONITORING AND ASSESSMENT 1995; 37:39-57. [PMID: 24197839 DOI: 10.1007/bf00546879] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Maintaining soil stability and normal water and nutrient cycles in desert systems is critical to avoiding desertification. These particular ecosystem processes are threatened by trampling of livestock and people, and by off-road vehicle use. Soil compaction and disruption of cryptobiotic soil surfaces (composed of cyanobacteria, lichens, and mosses) can result in decreased water availability to vascular plants through decreased water infiltration and increased albedo with possible decreased precipitation. Surface disturbance may also cause accelerated soil loss through wind and water erosion and decreased diversity and abundance of soil biota. In addition, nutrient cycles can be altered through lowered nitrogen and carbon inputs and slowed decomposition of soil organic matter, resulting in lower nutrient levels in associated vascular plants. Some cold desert systems may be especially susceptible to these disruptions due to the paucity of surface-rooting vascular plants for soil stabilization, fewer nitrogen-fixing higher plants, and lower soil temperatures, which slow nutrient cycles. Desert soils may recover slowly from surface disturbances, resulting in increased vulnerability to desertification. Recovery from compaction and decreased soil stability is estimated to take several hundred years. Re-establishment rates for soil bacterial and fungal populations are not known. The nitrogen fixation capability of soil requires at least 50 years to recover. Recovery of crusts can be hampered by large amounts of moving sediment, and re-establishment can be extremely difficult in some areas. Given the sensitivity of these resources and slow recovery times, desertification threatens million of hectares of semiarid lands in the United States.
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Affiliation(s)
- J Belnap
- National Biological Service, 2282 S. West Resource Blvd., 84532, Moab, Utah, USA
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West NE. Structure and Function of Microphytic Soil Crusts in Wildland Ecosystems of Arid to Semi-arid Regions. ADV ECOL RES 1990. [DOI: 10.1016/s0065-2504(08)60055-0] [Citation(s) in RCA: 403] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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GRAETZ RD, TONGWAY DJ. Influence of grazing management on vegetation, soil structure and nutrient distribution and the infiltration of applied rainfall in a semi-arid chenopod shrubland. AUSTRAL ECOL 1986. [DOI: 10.1111/j.1442-9993.1986.tb01405.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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