HR: 0830h
AN: GC31B-0191    [PDF]
TI: Modelling Tropical Forest Productivity Incorporating Spatial Variation And Diffuse Light Within 3-PG
AU: * Nightingale, J M
EM: Joanne.Nightingale@csiro.au
AF: Biophysical Remote Sensing Group, School of Geography, Planning and Architecture University of Queensland St Lucia, Brisbane, QLD 4072 Australia
AU: * Nightingale, J M
EM: Joanne.Nightingale@csiro.au
AF: Cooperative Research Centre for Greenhouse Accounting, Research School of Biological Sciences, Australian National University, Canberra, ACT 0200 Australia
AU: Hill, M J
EM: michael.hill@brs.gov.au
AF: Bureau of Rural Sciences, GPO Box 858, Canberra, ACT 2601 Australia
AU: Hill, M J
EM: michael.hill@brs.gov.au
AF: Cooperative Research Centre for Greenhouse Accounting, Research School of Biological Sciences, Australian National University, Canberra, ACT 0200 Australia
AU: Held, A A
EM: Alex.Held@csiro.au
AF: Environmental Remote Sensing Group CSIRO Land and Water, C.S. Christian Builing GPO Box 1666, Canberra, ACT 2601 Australia
AU: Phinn, S R
EM: s.phinn@uq.edu.au
AF: Biophysical Remote Sensing Group, School of Geography, Planning and Architecture University of Queensland St Lucia, Brisbane, QLD 4072 Australia
AU: Davies, I
EM: ian.davies@anu.edu.au
AF: Cooperative Research Centre for Greenhouse Accounting, Research School of Biological Sciences, Australian National University, Canberra, ACT 0200 Australia
AU: Roderick, M
EM: michael.roderick@anu.edu.au
AF: Cooperative Research Centre for Greenhouse Accounting, Research School of Biological Sciences, Australian National University, Canberra, ACT 0200 Australia
AU: Erskine, P
EM: p.erskine@uq.edu.au
AF: Rainforest Cooperative Research Centre, University of Queensland St Lucia, Brisbane, QLD 4072 Australia
AB: Rising concentrations of atmospheric carbon dioxide and potential increases in temperature and climatic extremes, have raised concern in the earth-science community, driving the need for better understanding of the exchange of carbon dioxide between the various Earth's ecosystems and the atmosphere. This interest has promoted the development and application of regional (1 to 10km2) and ecosystem (10 to 100km2) scale primary production models, based on plant growth and physiological principles. This research explores one such application of the 3-PG (Physiological Principles Predicting Growth) big-leaf model, to a number of pristine, restored and plantation rainforest sites located in North Queensland, Australia. Model parameters were derived for this specific tropical forest ecosystem and in addition, a variant of the model was developed to include a light-use efficiency modifier based on variations in diffuse radiation (3-PGSD, Satellite Diffuse). Diffuse radiation is derived from remotely sensed estimates of the fraction of photosynthetically active radiation (fPAR). Although the importance of diffuse light has been recognized by the agricultural community for many years, its effects had not yet been explored with large-scale terrestrial primary production models. In this paper, the theory behind the use of diffuse light in ecosystem production modelling is examined. Simulated estimates of monthly forest growth parameters, net primary production and ecosystem dynamics from both the 3-PG and 3-PGSD models are compared and contrasted. The merits of big-leaf models incorporating the effect of diffuse light dynamics versus more complex canopy layer and parameter-intensive models for ecosystem productivity assessment are discussed in relation to these results. This research also provides valuable information into modelling of tropical rainforest growth and productivity given there is a lack of knowledge and literature on the systematic assessment of the carbon pools and fluxes in these regions.
DE: 1640 Remote sensing
DE: 1699 General or miscellaneous
SC: Global Climate Change [GC]
MN: 2003 Fall Meeting