Introduction
Leaf Area Index
(LAI) measures the amount of leaf material in an ecosystem,
which imposes important controls on photosynthesis, respiration,
rain interception, and other processes that link vegetation
to climate. Consequently, LAI appears as a key variable
in many models describing vegetation-atmosphere interactions,
particularly with respect to the carbon and water cycles
(GCOS, 2004). The interest in information on LAI distribution
and changes has grown substantially in recent decades, due
to its intrinsic importance and the emerging capability
for LAI estimation over large areas using satellite measurements.
ECV
LAI standards report
As requested
by UNFCCC SBSTA/COP for its 23rd Session in Montreal, November
2005, GTOS is undertaking the assessment of the status of
the development of standards for each of the essential climate
variables in the terrestrial domain. The following report,
documentation and other material have been compiled for
Leaf area index. We very much welcome your comments and
inputs in improving and completing the analysis for biomass.
Please send any material and comments to the GTOS
Secretariat.
References
Listed
below are the major references that have been identified
in regards to methodology and standards for leaf area index.
Please inform us if you are aware of any other documentation
or material which could be considered.
Breda,
N.J. 2003. Ground-based measurements of leaf area index:
a review of methods, instruments and current controversies.
Journal of Experimental Botany 54: 2403-2417.
GCOS.
2004. Implementation plan for the Global Observing System
for Climate in support of the UNFCCC. Report GCOS –
92 (WMO/TD No. 1219). 136p.
Jonckheere,
I., Fleck, S., Nackaerts, K., Muysa, B., Coppin, P., Weiss,
M., and Baret, F. 2004. Review of methods for in situ leaf
area index determination Part I. Theories, sensors and hemispherical
photography. Agricultural and Forest Meteorology 121: 19–35.
Morisette,
J.T., Baret, F., Privette, J.L., Myneni, R.B., Nickeson,
J.E., Garrigues, S., Shabanov, N.V., Weiss, M., Fernandes,
R.A., Leblanc, S.G., Kalacska, M., Sánchez-Azofeifa,
G.A., Chubey, M., Rivard, B., Stenberg, P., Rautiainen,
M., Voipio, P., Manninen, T., Pilant, A.N., Lewis, T.E.,
Iiames, J.S., Colombo, R., Meroni, M., Busetto, L., Cohen,
W.B., Turner, D.P., Warner, E.D., Petersen, G.W., Seufert,
G., and Cook, R. 2006. Validation of Global Moderate-Resolution
LAI Products: A Framework Proposed Within the CEOS Land
Product Validation Subgroup. IEEE Transactions on Geoscience
and Remote Sensing 44: 1804-1817.
Weiss
M., Baret, F., Smith, G.J., Jonckheere, I., and Coppin,
P. 2004. Review of methods for in situ leaf area index (LAI)
determination. Part II. Estimation of LAI, errors and sampling.
Agricultural and Forest Meteorology 121: 37–53.
Relevant
Web links
We welcome
links to sites relevant to leaf area index measurements.
