Du är här

Belowground consequences of vegetation change and their treatment in models

Författare:
  • R B Jackson
  • H J Schenk
  • E G Jobbagy
  • J Canadell
  • G D Colello
  • R E Dickinson
  • T Dunne
  • C B Field
  • P Friedlingstein
  • M Heimann
  • K Hibbard
  • D W Kicklighter
  • A Kleidon
  • R P Neilson
  • W J Parton
  • O E Sala
  • Martin Sykes (Professor)
Publiceringsår: 2000
Språk: Engelska
Sidor: 470-483
Publikation/Tidskrift/Serie: Ecological Applications
Volym: 10
Nummer: 2
Dokumenttyp: Artikel
Förlag: ECOLOGICAL SOCIETY OF AMERICA

Sammanfattning

The extent and consequences of global land-cover and land-use change are increasingly apparent. One consequence not so apparent is the altered structure of plants belowground. This paper examines such belowground changes, emphasizing the interaction of altered root distributions with other factors and their treatment in models. Shifts of woody and herbaceous vegetation with deforestation, afforestation, and woody plant encroachment typically alter the depth and distribution of plant rests, influencing soil nutrients, the water balance, and net primary productivity (NPP). For example, our analysis of global soil data sets shows that the major plant nutrients C, N, P, and K are more shallowly distributed than are Ca, Mg, and Na, but patterns for each element vary with the dominant vegetation type. After controlling for climate, soil C and N are distributed more deeply in arid shrublands than in arid grasslands, and subhumid forests have shallower nutrient distributions than do subhumid grasslands. Consequently, changes in vegetation may influence the distribution of soil carbon and nutrients over time (perhaps decades to centuries). Shifts in the water balance are typically much more rapid. Catchment studies indicate that the water yield decreases 25-40 mm for each 10% increase in tree cover, and increases in transpiration of water taken up by deep roots may account for as much as 50% of observed responses. Because models are increasingly important for predicting the consequences of vegetation change, we discuss the treatment of belowground processes and how different treatments affect model outputs. Whether models are parameterized by biome or plant life form (or neither), use single or multiple soil layers, or include N and water limitation will all affect predicted outcomes. Acknowledging and understanding such differences should help constrain predictions of vegetation change.

Disputation

Nyckelord

  • Biology and Life Sciences

Övrigt

Published
Yes
  • ISSN: 1051-0761

Box 117, 221 00 LUND
Telefon 046-222 00 00 (växel)
Telefax 046-222 47 20
lu [at] lu [dot] se

Fakturaadress: Box 188, 221 00 LUND
Organisationsnummer: 202100-3211
Om webbplatsen

LERU logo U21 logo