Calibration and application of FOREST-BGC in a Mediterranean area by the use of conventional and remote sensing data

The current work deals with the use in a Mediterranean environment of a simulation model of forest ecosystem processes which was originally created for temperate areas (FOREST-BGC). The model was calibrated and applied on two deciduous forest stands in Tuscany (Central Italy) by using conventional and remote sensing data as inputs. First, information on the two stands needed to initialise the model was derived from different sources, while meteorological data were extrapolated from a nearby station by an existing procedure (MT-Clim). Temporal profiles of leaf area index (LAI) were then derived both from direct ground measurement and from the processing of NOAA-AVHRR NDVI data. The model was calibrated using stand transpiration values obtained for 1997 by a sap flow method. Next, its performances were tested against the same transpiration values measured in 1998. The results obtained indicate that FOREST-BGC is capable of simulating water fluxes of Mediterranean forests when suitable LAI profiles are considered. Moreover, the derivation of these profiles from NDVI data can improve the model performance probably due to an enhanced consideration of the effects of the typical Mediterranean summer water stress. These results support the final objective of the work, which is the development of a procedure capable of integrating conventional and remote sensing data to operationally simulate water and carbon fluxes on a regional scale.

[1]  Achim Grelle,et al.  Test of a modified Shuttleworth-Wallace estimate of boreal forest evaporation , 1999 .

[2]  S. Running,et al.  A general model of forest ecosystem processes for regional applications I. Hydrologic balance, canopy gas exchange and primary production processes , 1988 .

[3]  Steven W. Running,et al.  Remote sensing of temperate coniferous forest leaf area index The influence of canopy closure, understory vegetation and background reflectance , 1990 .

[4]  S. Running,et al.  FOREST-BGC, A general model of forest ecosystem processes for regional applications. II. Dynamic carbon allocation and nitrogen budgets. , 1991, Tree physiology.

[5]  Edward B. Rastetter,et al.  Forest Ecosystems, Analysis at Multiple Scales, 2nd Edition , 1999 .

[6]  A. Granier,et al.  Water balance, transpiration and canopy conductance in two beech stands , 2000 .

[7]  S. Running,et al.  An improved algorithm for estimating incident daily solar radiation from measurements of temperature, humidity, and precipitation , 1999 .

[8]  B. Holben.  Characteristics of maximum-value composite images from temporal AVHRR data , 1986 .

[9]  C. Field,et al.  Scaling physiological processes: leaf to globe. , 1995 .

[10]  F. M. Danson,et al.  Estimating the stem carbon production of a coniferous forest using an ecosystem simulation model driven by the remotely sensed red edge , 2000 .

[11]  Ramakrishna R. Nemani,et al.  Testing a theoretical climate-soil-leaf area hydrologic equilibrium of forests using satellite data and ecosystem simulation , 1989 .

[12]  S. Running,et al.  8 – Generalization of a Forest Ecosystem Process Model for Other Biomes, BIOME-BGC, and an Application for Global-Scale Models , 1993 .

[13]  Jan Čermák,et al.  Measured sap flow and simulated transpiration from a poplar stand in Flanders (Belgium) , 1999 .

[14]  Ramakrishna R. Nemani,et al.  Mapping regional forest evapotranspiration and photosynthesis by coupling satellite data with ecosystem simulation , 1989 .

[15]  R. Ceulemans,et al.  Radial patterns of sap flow in woody stems of dominant and understory species: scaling errors associated with positioning of sensors. , 2002, Tree physiology.

[16]  J. David,et al.  Estimates and measurements of evaporation from wet, sparse pine forest in Portugal , 1999 .

[17]  W. Bouten,et al.  Evaluation of transpiration models with observations over a Douglas fir forest , 2001 .

[18]  Fabio Maselli,et al.  Definition of Spatially Variable Spectral Endmembers by Locally Calibrated Multivariate Regression Analyses , 2001 .