A prognostic phenology scheme for global terrestrial carbon cycle models

J Kaduk,M Heimann

doi:10.3354/cr006001

Abstract

This is the authors' final draft of the paper published as Climate Research, 1996, 6(1), pp. 1-19. Contents page of the issue available at http://www.int-res.com/abstracts/cr/v06/n1/

Highlights

The terrestrial biosphere represents a major compartment in the global carbon cycle with gross exchange uxes of 40 80 GtC per year 1 GtC=1012 kg Carbon Lieth 1975 which is about fty percent of the gross exchanges of the atmosphere with all global carbon pools
As a nal validation test we investigated the seasonal cycle of the atmospheric CO2 concentration generated by the net biospheric CO2 uxes of the new model using the atmospheric transport model TM2 Heimann and Keeling 1989, Heimann 1995
Both submodels are based on mechanistic descriptions of plant physiology and are forced with climate data

Summary

Introduction

The terrestrial biosphere represents a major compartment in the global carbon cycle with gross exchange uxes of 40 80 GtC per year 1 GtC=1012 kg Carbon Lieth 1975 which is about fty percent of the gross exchanges of the atmosphere with all global carbon pools. Anthropogenic activities such as de and a orestation, agricultural practices and burning of wood and fossil fuels interact signi cantly with the natural carbon cycling in the terrestrial vegetation. The simulation of consequences of climate change scenarios requires models which are based on plant physiology rather than on correlational methods. Correlations derived from contemporary data relating for example net primary productivity to climate e.g. the MIAMI model, Lieth 1975 are valid for the present assumed equilibrium state of climate and vegetation only. They cannot faithfully describe transient changes of vegetation caused by climate variations. Increased summer temperatures might have no direct e ect, warming of winter temperatures might lead to a delayed budburst of temperate trees since these require a winter chilling period with temperatures below ca. 5oC for rapid budburst in the following spring Murray et al 1989

Objectives

Results

Conclusion