title: Decreased water flowing from a forest amended with calcium silicate.
abstract: Acid deposition during the 20th century caused widespread depletion of available soil calcium (Ca) throughout much of the industrialized world. To better understand how forest ecosystems respond to changes in a component of acidification stress, an 11.8-ha watershed was amended with wollastonite, a calcium silicate mineral, to restore available soil Ca to preindustrial levels through natural weathering. An unexpected outcome of the Ca amendment was a change in watershed hydrology; annual evapotranspiration increased by 25%, 18%, and 19%, respectively, for the 3 y following treatment before returning to pretreatment levels. During this period, the watershed retained Ca from the wollastonite, indicating a watershed-scale fertilization effect on transpiration. That response is unique in being a measured manipulation of watershed runoff attributable to fertilization, a response of similar magnitude to effects of deforestation. Our results suggest that past and future changes in available soil Ca concentrations have important and previously unrecognized implications for the water cycle.
authors.affiliation: Center for the Environment, Plymouth State University, Plymouth, NH 03264, USA. mbgreen@plymouth.edu
authors.forename: Mark B
authors.initials: MB
authors.lastname: Green
authors.forename: Amey S
authors.initials: AS
authors.lastname: Bailey
authors.forename: Scott W
authors.initials: SW
authors.lastname: Bailey
authors.forename: John J
authors.initials: JJ
authors.lastname: Battles
authors.forename: John L
authors.initials: JL
authors.lastname: Campbell
authors.forename: Charles T
authors.initials: CT
authors.lastname: Driscoll
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Fahey
authors.forename: Lucie C
authors.initials: LC
authors.lastname: Lepine
authors.forename: Gene E
authors.initials: GE
authors.lastname: Likens
authors.forename: Scott V
authors.initials: SV
authors.lastname: Ollinger
authors.forename: Paul G
authors.initials: PG
authors.lastname: Schaberg
mesh_terms: D018533:Biomass; D017610:Calcium Compounds / Q000378:metabolism*; D003247:Conservation of Natural Resources; D017753:Ecosystem; D004784:Environmental Monitoring; D006863:Hydrogen-Ion Concentration; D009513:New Hampshire; D017640:Silicates / Q000378:metabolism*; D012987:Soil / Q000737:chemistry*; D013997:Time Factors; D014197:Trees / Q000502:physiology*; D014867:Water / Q000737:chemistry*
chemical_list: D017610:Calcium Compounds; D017640:Silicates; D012987:Soil; D014867:Water; C031293:calcium silicate