Agroforestry Systems

, Volume 80, Issue 1, pp 41-60

First online:

Open Access This content is freely available online to anyone, anywhere at any time.

Plant-soil biodiversity relationships and nutrient retention in agricultural riparian zones of the Sacramento Valley, California

  • Anna Young-MathewsAffiliated withDepartment of Land, Air and Water Resources, University of California Email author 
  • , Steven W. CulmanAffiliated withDepartment of Land, Air and Water Resources, University of California
  • , Sara Sánchez-MorenoAffiliated withUnidad de Productos Fitosanitarios, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria
  • , A. Toby O’GeenAffiliated withDepartment of Land, Air and Water Resources, University of California
  • , Howard FerrisAffiliated withDepartment of Nematology, University of California
  • , Allan D. HollanderAffiliated withInformation Center for the Environment, University of California
  • , Louise E. JacksonAffiliated withDepartment of Land, Air and Water Resources, University of California


Forested riparian buffers in California historically supported high levels of biodiversity, but human activities have degraded these ecosystems over much of their former range. This study examined plant communities, belowground biodiversity and indicators of multiple ecosystem functions of riparian areas across an agricultural landscape in the Sacramento Valley of California, USA. Plant, nematode and soil microbial communities and soil physical and chemical properties were studied along 50-m transects at 20 sites that represented the different land use, soil and vegetation types in the landscape. Riparian zones supported greater plant diversity and nearly twice as much total carbon (C) per hectare compared to adjacent land managed for agricultural uses, but had generally lower soil microbial and nematode diversity and abundance. When woody plant communities were present in the riparian zone, plant diversity and species richness were higher, and soil nitrate and plant-available phosphorus levels were lower. Belowground diversity and community structure, however, appeared to depend more on plant productivity (as inferred by vegetation cover) than plant diversity or species richness. Greater plant species richness, nematode food web structure, total microbial biomass, woody C storage and lower soil nitrate and phosphorus loading were correlated with higher visual riparian health assessment scores, offering the possibility of managing these riparian habitats to provide multiple ecosystem functions.


Aboveground-belowground relationships Carbon storage Ecosystem function Nematodes PLFA