The PnET-Succession extension implements succession with cohorts defined by age ranges and including biomass per cohort. Most parameters are able to change over time, due to climate change for example.

Contact: Eric Gustafson, USDA Forest Service

Copyright: USDA Forest Service

Latest release: Version 4.0.1 — January 2021 (Download)

View User Guide (PDF)

Brief Description:

The PnET-Succession extension is based on the Biomass Succession extension of Scheller and Mladenoff (2004), embedding elements of the PnET-II ecophysiology model of Aber et al (1995) to simulate growth as a competition for available light and water, replacing the existing competition for “growing space” algorithms (De Bruijn et al. 2014). PnET (Photosynthesis and EvapoTranspiration) is a simple, lumped parameter model of carbon and water balances of forests (Aber and Federer 1992), built on two principal relationships: 1) maximum photo-synthetic rate is a function of foliar nitrogen concentration, and 2) stomatal conductance is a function of realized photosynthetic rate. PnET Succession uses one PnET simulation for each tree species-age cohort and uses water and light consumption by these cohorts to implement competition. PnET-Succession calculates resources in terms of Non-Structural Carbon (NSC) for each cohort in its PnET part and assumes that cohorts die when their NSC level drops below a threshold. The Biomass Succession extension also tracks dead biomass over time, divided into two pools: woody and leaf litter.

Developers: Arjan de Bruijn, Eric Gustafson, Brian Miranda, USFS and Purdue University

Lineage: First official release in LANDIS-II, v6.

How to Cite: Arjan de Bruijn, Eric J. Gustafson, Brian R. Sturtevant, Jane R. Foster, Brian R. Miranda, Nathanael I. Lichti, Douglass F. Jacobs, Toward more robust projections of forest landscape dynamics under novel environmental conditions: Embedding PnET within LANDIS-II. Ecological Modelling Volume 287, 10 September 2014, Pages 44–57

Compatible Disturbance Extensions: Base Fire, Base Harvest, Base Wind, Base BDA, Base Drought, Dynamic Fuels and Fire, Biomass Harvest, Biomass Insects, Biomass Fuels, Land Use+

Compatible Output Extensions: PnET Output, Cohort Statistics Output, Max Spp Age Output, Age Reclassification Output, Biomass Output, Biomass-by-Age Output, Biomass Reclassification Output