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Simulating Forest Dynamics of Lowland Rainforests in Eastern MadagascarEcological modeling and forecasting are essential tools for the understanding of complex vegetation dynamics. The parametric demands of some of these models are often lacking or scant for threatened ecosystems, particularly in diverse tropical ecosystems. One such ecosystem and also one of the world's biodiversity hotspots, Madagascar's lowland rainforests, have disappeared at an alarming rate. The processes that drive tree species growth and distribution remain as poorly understood as the species themselves. We investigated the application of the process-based individual-based FORMIND model to successfully simulate a Madagascar lowland rainforest using previously collected multi-year forest inventory plot data. We inspected the model's ability to characterize growth and species abundance distributions over the study site, and then validated the model with an independently collected forest-inventory dataset from another lowland rainforest in eastern Madagascar. Following a comparative analysis using inventory data from the two study sites, we found that FORMIND accurately captures the structure and biomass of the study forest, with r(squared) values of 0.976, 0.895, and 0.995 for 1:1 lines comparing observed and simulated values across all plant functional types for aboveground biomass (tonnes/ha), stem numbers, and basal area (m(squared)/ha), respectively. Further, in validation with a second study forest site, FORMIND also compared well, only slightly over-estimating shade-intermediate species as compared to the study site, and slightly under-representing shade-tolerant species in percentage of total aboveground biomass. As an important application of the FORMIND model, we measured the net ecosystem exchange (NEE, in tons of carbon per hectare per year) for 50 ha of simulated forest over a 1000-year run from bare ground. We found that NEE values ranged between 1 and -1 t Cha(exp -1)year(exp -1), consequently the study forest can be considered as a net neutral or a very slight carbon sink ecosystem, after the initial 130 years of growth. Our study found that FORMIND represents a valuable tool toward simulating forest dynamics in the immensely diverse Madagascar rainforests.
Document ID
20180002935
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Armstrong, Amanda (Virginia Univ. Charlottesville, VA, United States)
Fischer, Rico (UFZ Unweltforschungszentrum Leipzig-Halle G.m.b.H. Leipzig, Germany)
Huth, Andreas (UFZ Unweltforschungszentrum Leipzig-Halle G.m.b.H. Leipzig, Germany)
Shugart, Herman (Virginia Univ. Charlottesville, VA, United States)
Fatoyinbo, Temilola (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
May 16, 2018
Publication Date
April 18, 2018
Publication Information
Publication: Forests
Volume: 9
Issue: 4
ISSN: 1999-4907
Subject Category
Geosciences (General)
Report/Patent Number
GSFC-E-DAA-TN56049
Funding Number(s)
CONTRACT_GRANT: NNG11HP16A
Distribution Limits
Public
Copyright
Other
Keywords
Forest Productivity
Forest Modeling
Tropical Rainforest