Matches in SemOpenAlex for { <https://semopenalex.org/work/W2013262004> ?p ?o ?g. }
- W2013262004 endingPage "198" @default.
- W2013262004 startingPage "173" @default.
- W2013262004 abstract "Although microbiotic crusts are known from many lowland deserts, they have apparently never been reported from alpine areas. This paper describes microbiotic crusts from an equatorial high Andean location (Páramo de Piedras Blancas) in Venezuela. The main objectives are to describe the basic characteristics of the crusts, to examine the properties of the soils on which they occur, and to discuss their possible geomorphic significance for paramo soils. Properties of crusts and of the soils beneath them were compared with those of adjacent bare soils at three sites, between 4360 and 4550 m altitude. Measurements on unconfined soil compressive strength and infiltration rates were taken in the field. Crust specimens were also gathered, and later examined and sectioned under a microscope to ascertain micromorphological details. Laboratory data included soil texture, organic matter content, color, pH, water-storage at field capacity, and stability of soil aggregates. Crusts formed discontinuous, garland-like patches parallel to contours, or covered small round soil buds, produced by frost sorting. Microbiotic crusts contained many plants, including an unclassified hepatic (genus Marsupella Dumort.), a moss (Grimmia longirostris Hook.), and several lichen species. Crusts consisted of a thin organic layer (5–35 mm) overlying mineral soil, and showed three parallel bands with diffuse boundaries. The outer layer had green-reddish brown, live plant shoots and stems with few fine mineral grains. The middle layer had anatomically recognizable dark-brown plant material and a greater content of mineral grains. The light-colored basal layer had little organic matter mixed with coarse mineral particles; it also contained many small orthovughs (vesicles) and some larger arched chambers, caused mainly by frost activity. Soils with a microbiotic crust were darker than bare soils. Organic matter content in crust areas was two to three times higher than in adjacent bare soil; pH dropped ∼ 0.3 units below crusts. Soils with crust had finer texture than bare ground: the content of fines in crusts was 1.5 times higher than in bare soils, but gravel in these was four times higher than below cryptogams. Indices of particle concentration showed that grains < 0.5-1 mm were more abundant in crusts. Finer soils in crusts may result from a combination of (a) prior random texture variation; (b) cryptogam colonization of fine-soil patches sorted by frost; (c) interception and capture of aeolian dust by cryptogams, especially by mosses; and (d) reduction of fine-particle erosion by crusts; as coarse grains are lost, mean particle size within crusts drops. Geomorphic effects of crusts were also significant: (a) Infiltration rates were 70% greater in crust than in noncrust soils (67.0 vs. 40.4 mm/min); (b) Crust soils stored more water at field capacity (48.7–88.4%) than bare areas (20.5–42%); (c) Crust soils had a higher resistance to raindrop erosion than bare areas (47.5 drops/0.1 g vs. 10.2 drops/0.1 g). Undisturbed crust specimens were even more effective in resisting drop impact, surviving up to 1100 drops/0.1 g; (d) Cryptogams increased soil compressibility more than 200%, from 54 g/cm2 in bare soils, to 118.1 g/cm2 in crust areas. All these geomorphic changes should result in lower rates of soil erosion in paramo areas with dense crusts. A pesar de que las costras microbióticas (criptogámicas) son comunes en muchos desiertos cálidos del mundo,éstas no ban sido aparentemente reportadas paraáreas alpinas. En este trabajo se describen las costras microbióticas de una localidad ecuatorial andina de alta montan˜a (Páramo de Piedras Blancas) en Venezuela. Los objetivos del estudio son describir las características básicas de las costras microbióticas, examinar las propiedades de los suelos en los queéstas se encuentran, y discutir la posible importancia geomorfológica de las costras para los suelos del páramo. Las propiedades de las costras fueron comparadas con las de suelos desnudos adyacentes en tres parcelas entre 4360 y 4550 in. Las mediciones de campo incluyen compresibilidad del suelo y tasas de infiltración. Especímenes de costras también fueron colectados, y más tarde examinados y seccionados bajo el microscopio para determinar sus detalles micromorfológicos. Los datos de laboratorio incluyen textura del suelo, contenido de materia organíca, color, pH, contenido de agua a capacidad de campo, y estabilidad de los agregados del suelo. En el páramo andino, las delgadas (5 a 35 mm) costras microbióticas están compuestas de diversas plantas, incluyendo una Hepática no clasificada del géneroMarsupella Dumort., un musgo (Grimmia longirostrisHook.) y varias especies de líquenes. Las costras microbióticas ejercen una influencia importante en varias propiedades pedológicas, que a su vez afectan diversos procesos geomorfológicos. Los suelos en las costras tienen un porcentaje de materia organica y partículas finas bastante mas alto que los suelos desnudos adyacentes. La materia orgánica es contribuida por el crecimiento de las plantas, mientras que la textura mas fina resulta de diferencias previas del substrato (incluyendo aquellas producidas por el escogimiento debido al frecuente congelamiento del suelo) y de la captura de material eólico fino (principalmente con diámetro menor de 0.5 mm) por las plantas de la costra criptogámica, especialmente por los musgos. Estas modificaciones pedológicas provocan: (1) tasas de infiltración mas altas enáreas con costras; (2) una mayor capacidad de retención de agua en los suelos de las costras microbióticas; (3) mayor resistencia al desprendimiento y erosion causados por el impacto de gotas de lluvia en las costras, comparadas con suelos desnudos adyacentes, y (4) una mayor agregación de los suelos en las costras, expresada en forma de una alta cohesividad y resistencia a la compresión. Todos estos efectos deberían resultar en reducidas tasas de erosion enáreas del páramo donde las costras microbióticas son densas y/o extensas." @default.
- W2013262004 created "2016-06-24" @default.
- W2013262004 creator A5029068068 @default.
- W2013262004 date "1997-12-01" @default.
- W2013262004 modified "2023-09-25" @default.
- W2013262004 title "Microbiotic crusts in the high equatorial Andes, and their influence on paramo soils" @default.
- W2013262004 cites W14100439 @default.
- W2013262004 cites W14735875 @default.
- W2013262004 cites W1506624442 @default.
- W2013262004 cites W180359954 @default.
- W2013262004 cites W1966294152 @default.
- W2013262004 cites W1977931725 @default.
- W2013262004 cites W1983475309 @default.
- W2013262004 cites W1996473836 @default.
- W2013262004 cites W2000455278 @default.
- W2013262004 cites W2001092767 @default.
- W2013262004 cites W2005633516 @default.
- W2013262004 cites W2014890025 @default.
- W2013262004 cites W2021079271 @default.
- W2013262004 cites W2026420867 @default.
- W2013262004 cites W2027112280 @default.
- W2013262004 cites W2031461115 @default.
- W2013262004 cites W2032085625 @default.
- W2013262004 cites W2069483320 @default.
- W2013262004 cites W2069761596 @default.
- W2013262004 cites W2078270642 @default.
- W2013262004 cites W2084320902 @default.
- W2013262004 cites W2110837947 @default.
- W2013262004 cites W2111048731 @default.
- W2013262004 cites W2125249668 @default.
- W2013262004 cites W2162599835 @default.
- W2013262004 cites W2313669489 @default.
- W2013262004 cites W2322362392 @default.
- W2013262004 cites W2323350655 @default.
- W2013262004 cites W2332716010 @default.
- W2013262004 cites W2335334770 @default.
- W2013262004 cites W2335684381 @default.
- W2013262004 cites W2428424466 @default.
- W2013262004 cites W2589172573 @default.
- W2013262004 cites W2593044698 @default.
- W2013262004 cites W2593263945 @default.
- W2013262004 cites W2600771695 @default.
- W2013262004 cites W2606865826 @default.
- W2013262004 cites W2608167815 @default.
- W2013262004 cites W277910265 @default.
- W2013262004 cites W2796516336 @default.
- W2013262004 cites W2800599355 @default.
- W2013262004 cites W38268523 @default.
- W2013262004 cites W4250026879 @default.
- W2013262004 cites W4251269097 @default.
- W2013262004 doi "https://doi.org/10.1016/s0341-8162(97)00040-4" @default.
- W2013262004 hasPublicationYear "1997" @default.
- W2013262004 type Work @default.
- W2013262004 sameAs 2013262004 @default.
- W2013262004 citedByCount "56" @default.
- W2013262004 countsByYear W20132620042012 @default.
- W2013262004 countsByYear W20132620042013 @default.
- W2013262004 countsByYear W20132620042014 @default.
- W2013262004 countsByYear W20132620042016 @default.
- W2013262004 countsByYear W20132620042017 @default.
- W2013262004 countsByYear W20132620042018 @default.
- W2013262004 countsByYear W20132620042020 @default.
- W2013262004 countsByYear W20132620042021 @default.
- W2013262004 countsByYear W20132620042022 @default.
- W2013262004 countsByYear W20132620042023 @default.
- W2013262004 crossrefType "journal-article" @default.
- W2013262004 hasAuthorship W2013262004A5029068068 @default.
- W2013262004 hasConcept C123677613 @default.
- W2013262004 hasConcept C127313418 @default.
- W2013262004 hasConcept C159390177 @default.
- W2013262004 hasConcept C159750122 @default.
- W2013262004 hasConcept C17409809 @default.
- W2013262004 hasConcept C175963888 @default.
- W2013262004 hasConcept C18903297 @default.
- W2013262004 hasConcept C199289684 @default.
- W2013262004 hasConcept C2776698055 @default.
- W2013262004 hasConcept C48743137 @default.
- W2013262004 hasConcept C86803240 @default.
- W2013262004 hasConceptScore W2013262004C123677613 @default.
- W2013262004 hasConceptScore W2013262004C127313418 @default.
- W2013262004 hasConceptScore W2013262004C159390177 @default.
- W2013262004 hasConceptScore W2013262004C159750122 @default.
- W2013262004 hasConceptScore W2013262004C17409809 @default.
- W2013262004 hasConceptScore W2013262004C175963888 @default.
- W2013262004 hasConceptScore W2013262004C18903297 @default.
- W2013262004 hasConceptScore W2013262004C199289684 @default.
- W2013262004 hasConceptScore W2013262004C2776698055 @default.
- W2013262004 hasConceptScore W2013262004C48743137 @default.
- W2013262004 hasConceptScore W2013262004C86803240 @default.
- W2013262004 hasIssue "3" @default.
- W2013262004 hasLocation W20132620041 @default.
- W2013262004 hasOpenAccess W2013262004 @default.
- W2013262004 hasPrimaryLocation W20132620041 @default.
- W2013262004 hasRelatedWork W2009754870 @default.
- W2013262004 hasRelatedWork W2053600111 @default.
- W2013262004 hasRelatedWork W2056877777 @default.
- W2013262004 hasRelatedWork W2062183949 @default.
- W2013262004 hasRelatedWork W2099637586 @default.