Ecosystems

, Volume 15, Issue 2, pp 311–321 | Cite as

Soil Coverage Reduces Photodegradation and Promotes the Development of Soil-Microbial Films on Dryland Leaf Litter

  • Paul W. Barnes
  • Heather L. Throop
  • Daniel B. Hewins
  • Michele L. Abbene
  • Steven R. Archer
Article

Abstract

Litter decomposition is a central focus of ecosystem science because of its importance to biogeochemical pools and cycling, but predicting dryland decomposition dynamics is problematic. Some studies indicate photodegradation by ultraviolet (UV) radiation can be a significant driver of dryland decomposition, whereas others suggest soil–litter mixing controls decomposition. To test the influence of soil coverage on UV photodegradation of litter, we conducted a controlled environment experiment with shrub (Prosopis velutina) leaf litter experiencing two UV levels and three levels of coverage with dry sterile soil. Under these conditions, decomposition over 224 days was enhanced by UV, but increasing soil coverage strongly and linearly diminished these effects. In a complementary study, we placed P. glandulosa leaf litter in different habitats in the field and quantified litter surface coverage by soil films. After 180 days, nearly half of the surface area of litter placed under shrub canopies was covered by a tightly adhering film composed of soil particles and fungal hyphae; coverage was less in grassy zones between shrubs. We propose a conceptual model for the shifting importance of photodegradation and microbial decomposition over time, and conclude that (1) soil deposition can ameliorate the direct effects of UV photodegradation in drylands and (2) predictions of C losses based solely on UV effects will overestimate the importance of this process in the C cycle. An improved understanding of how development of the soil–litter matrix mediates the shift from abiotic (photodegradation) to biotic (microbial) drivers is necessary to predict how ongoing changes in land cover and climate will influence biogeochemistry in globally extensive drylands.

Keywords

carbon cycle decomposition dryland mesquite Prosopis photodegradation soil erosion soil–litter mixing ultraviolet radiation 

References

  1. Aerts R. 1997. Climate, leaf litter chemistry, and leaf litter decomposition in terrestrial ecosystems: a triangular relationship. Oikos 79:439–49.CrossRefGoogle Scholar
  2. Andrady AL. 1997. Wavelength sensitivity in polymer photodegradation. Adv Polym Sci 128:47–94.CrossRefGoogle Scholar
  3. Anesio AM, Denward CMT, Tranvik LJ, Graneli W. 1999. Decreased bacterial growth on vascular plant detritus due to photochemical modification. Aquat Microb Ecol 17:159–65.CrossRefGoogle Scholar
  4. Austin AT. 2011. Has water limited our imagination for aridland biogeochemistry? Trends Ecol Evol 26:229–35.PubMedCrossRefGoogle Scholar
  5. Austin AT, Araujo PI, Leva PE. 2009. Interaction of position, litter type, and water pulses on decomposition of grasses from the semiarid Patagonian steppe. Ecology 90:2642–7.PubMedCrossRefGoogle Scholar
  6. Austin AT, Ballaré CL. 2010. Dual role of lignin in plant litter decomposition in terrestrial ecosystems. Proc Natl Acad Sci USA 107:4618–22.PubMedCrossRefGoogle Scholar
  7. Austin AT, Vivanco L. 2006. Plant litter decomposition in a semi-arid ecosystem controlled by photodegradation. Nature 442:555–8.PubMedCrossRefGoogle Scholar
  8. Bloom AA, Lee-Taylor J, Madronich S, Messenger DJ, Palmer PI, Reay DS, McLeod AR. 2010. Global methane emission estimates from ultraviolet irradiation of terrestrial plant foliage. New Phytol 187:417–25.PubMedCrossRefGoogle Scholar
  9. Brandt LA, Bohnet C, King JY. 2009. Photochemically induced carbon dioxide production as a mechanism for carbon loss from plant litter in arid ecosystems. J Geophys Res 114:GO2004. doi:10.1029/2008JG000772.Google Scholar
  10. Brandt LA, King JY, Hobbie SE, Milchunas DG, Sinsabaugh RL. 2010. The role of photodegradation in surface litter decomposition across a grassland ecosystem precipitation gradient. Ecosystems 13:765–81.CrossRefGoogle Scholar
  11. Breshears DD, Whicker JJ, Johansen MP, Pinder JE. 2003. Wind and water erosion and transport in semi-arid shrubland, grassland and forest ecosystems: quantifying dominance of horizontal wind-driven transport. Earth Surf Proc Land 28:1189–209.CrossRefGoogle Scholar
  12. Butler MJ, Day AW. 1998. Fungal melanins: a review. Can J Microbiol 44:1115–36.CrossRefGoogle Scholar
  13. Cable J, Ogle K, Williams D, Weltzin J, Huxman T. 2008. Soil texture drives responses of soil respiration to precipitation pulses in the Sonoran Desert: implications for climate change. Ecosystems 11:961–79.CrossRefGoogle Scholar
  14. Caldwell MM. 1971. Solar UV irradiation and the growth and development of higher plants. Photophysiology 6:131–77.Google Scholar
  15. Couteaux MM, Bottner P, Berg B. 1995. Litter decomposition, climate and litter quality. Trends Ecol Evol 10:363–7.Google Scholar
  16. Day TA, Zhang ET, Ruhland CT. 2007. Exposure to solar UV-B radiation accelerates mass and lignin loss of Larrea tridentata litter in the Sonoran Desert. Plant Ecol 194:185–94.CrossRefGoogle Scholar
  17. Flint SD, Ryel RJ, Caldwell MM. 2003. Ecosystem UV-B experiments in terrestrial communities: a review of recent findings and methodologies. Agric For Meteorol 120:177–89.CrossRefGoogle Scholar
  18. Foereid B, Bellarby J, Meier-Augenstein W, Kemp H. 2010. Does light exposure make plant litter more degradable? Plant Soil 333:275–85.CrossRefGoogle Scholar
  19. Foereid B, Rivero MJ, Primo O, Ortiz I. 2011. Modelling photodegradation in the global carbon cycle. Soil Biol Biochem 43:1383–6.CrossRefGoogle Scholar
  20. Gallo ME, Sinsabaugh RL, Cabaniss SE. 2006. The role of ultraviolet radiation in litter decomposition in arid ecosystems. Appl Soil Ecol 34:82–91.CrossRefGoogle Scholar
  21. Hobbie SE. 1992. Effects of plant species on nutrient cycling. Trends Ecol Evol 7:336–9.PubMedCrossRefGoogle Scholar
  22. Kirschbaum MUF, Lambie SM, Zhou H. 2011. No UV enhancement of litter decomposition observed on dry samples under controlled laboratory conditions. Soil Biol Biochem 43:1300–7.CrossRefGoogle Scholar
  23. Lee H, Rahn T, Throop H. 2012. An accounting of C-based trace gas release during abiotic plant litter degradation. Glob Change Biol. doi:10.1111/j.1365-2486.2011.02579.x.
  24. McLeod AR, Fry SC, Loake GJ, Messenger DJ, Reay DS, Smith KA, Yun BW. 2008. Ultraviolet radiation drives methane emissions from terrestrial plant pectins. New Phytol 180:124–32.PubMedCrossRefGoogle Scholar
  25. Meentemeyer V. 1978. Macroclimate and lignin control of litter decomposition rates. Ecology 59:465–72.CrossRefGoogle Scholar
  26. Moody SA, Newsham KK, Ayres PG, Paul ND. 1999. Variation in the responses of litter and phylloplane fungi to UV-B radiation (290–315 nm). Mycol Res 103:1469–77.CrossRefGoogle Scholar
  27. Moody SA, Paul ND, Björn LO, Callaghan TV, Lee JA, Manetas Y, Rozema J, GwynnJones D, Johanson U, Kyparissis A, Oudejans AMC. 2001. The direct effects of UV-B radiation on Betula pubescens litter decomposing at four European field sites. Plant Ecol 154:27–36.CrossRefGoogle Scholar
  28. Moorhead DL, Reynolds JF. 1991. A general model of litter decomposition in the northern Chihuahuan Desert. Ecol Model 56:197–219.CrossRefGoogle Scholar
  29. Moorhead DL, Currie WS, Rastetter EB, Parton WJ, Harmon ME. 1999. Climate and litter quality controls on decomposition: an analysis of modeling approaches. Glob Biogeochem Cycles 13:575–89.CrossRefGoogle Scholar
  30. Okin GS. 2008. A new model of wind erosion in the presence of vegetation. J Geophys Res 113:G01021. doi:10.1029/2007JG000563.CrossRefGoogle Scholar
  31. Okin GS, Gillette DA. 2001. Distribution of vegetation in wind-dominated landscapes: implications for wind erosion modeling and landscape processes. J Geogr Res 106:9673–84.Google Scholar
  32. Okin GS, Parsons AJ, Wainwright J, Herrick JE, Bestelmeyer BT, Peters DC, Fredrickson EL. 2009. Do changes in connectivity explain desertification? Bioscience 59:237–44.CrossRefGoogle Scholar
  33. Pancotto VA, Sala OE, Cabello M, Lopez NI, Robson TM, Ballaré CL, Caldwell MM, Scopel AL. 2003. Solar UV-B decreases decomposition in herbaceous plant litter in Tierra del Fuego, Argentina: potential role of an altered decomposer community. Glob Change Biol 9:1465–74.CrossRefGoogle Scholar
  34. Pancotto VA, Sala OE, Robson TM, Caldwell MM, Scopel AL. 2005. Direct and indirect effects of solar ultraviolet-B radiation on long-term decomposition. Glob Change Biol 11:1982–9.Google Scholar
  35. Parton W, Silver WL, Burke IC, Grassens L, Harmon ME, Currie WS, King JY, Adair EC, Brandt LA, Hart SC, Fasth B. 2007. Global-scale similarities in nitrogen release patterns during long-term decomposition. Science 315:361–4.PubMedCrossRefGoogle Scholar
  36. Rozema J, Tosserams M, Nelissen HJM, Vanheerwaarden L, Broekman RA, Flierman N. 1997. Stratospheric ozone reduction and ecosystem processes: enhanced UV-B radiation affects chemical quality and decomposition of leaves of the dune grassland species Calamagrostis epigeios. Plant Ecol 128:284–94.Google Scholar
  37. Rutledge S, Campbell DI, Baldocchi D, Schipper L. 2010. Photodegradation leads to increased carbon dioxide losses from terrestrial organic matter. Glob Change Biol 16:3065–74.Google Scholar
  38. Smith WK, Gao W, Steltzer H, Wallenstein MD, Tree R. 2010. Moisture availability influences the effect of ultraviolet-B radiation on leaf litter decomposition. Glob Change Biol 16:484–95.CrossRefGoogle Scholar
  39. Throop HL, Archer SR. 2007. Interrelationships among shrub encroachment, land management and leaf litter decomposition in a semi-desert grassland. Ecol Appl 17:1809–23.PubMedCrossRefGoogle Scholar
  40. Throop HL, Archer SR. 2009. Resolving the dryland decomposition conundrum: some new perspectives on potential drivers. Prog Bot 70:171–94.CrossRefGoogle Scholar
  41. Uselman SM, Snyder KA, Blank RR, Jones TJ. 2011. UVB exposure does not accelerate rates of litter decomposition in a semi-arid riparian ecosystem. Soil Biol Biochem 43:1254–65.CrossRefGoogle Scholar
  42. Wainwright J. 2006. Climate and climatological variations in the Jornada Basin. In: Havstad K, Huenneke LF, Schlesinger W, Eds. Structure and function of a Chihuahuan Desert ecosystem. New York: Oxford. p 44–80.Google Scholar
  43. Wardle DA, Nilsson M-C, Gallet C, Zackrisson O. 1998. An ecosystem-level perspective of allelopathy. Biol Rev 73:305–19.CrossRefGoogle Scholar
  44. Whitford WG, Meentemeyer V, Seastedt TR, Cromack K, Crossley DA, Santos P, Todd RL, Waide JB. 1981. Exceptions to the AET model—deserts and clear-cut forest. Ecology 62:275–7.CrossRefGoogle Scholar
  45. Zepp RG, Erickson DJIII, Paul ND, Sulzberger B. 2007. Interactive effects of solar UV radiation and climate change on biogeochemical cycling. Photochem Photobiol Sci 6:286–300.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Paul W. Barnes
    • 1
  • Heather L. Throop
    • 2
  • Daniel B. Hewins
    • 2
  • Michele L. Abbene
    • 3
  • Steven R. Archer
    • 4
  1. 1.Department of Biological SciencesLoyola University New OrleansNew OrleansUSA
  2. 2.Department of BiologyNew Mexico State UniversityLas CrucesUSA
  3. 3.School of Forestry and Environmental StudiesYale UniversityNew HavenUSA
  4. 4.School of Natural Resources and the EnvironmentUniversity of ArizonaTucsonUSA

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