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These data products are being distributed free of charge. Recipients have a responsibility to:

1. Pledge not to use any these data in any product which will be sold.
2. Acknowledge the University of New Hampshire, EOS-WEBSTER Earth Science Information Partner (ESIP) as the data distributor when using the data in subsequent models or publications.

Summary:

Natural disturbances and human land-use activities have a large impact on the structure, dynamics and fluxes of ecosystems at a variety of scales. As a result, ecosystems are more heterogeneous in important ways than is explained by climatic and edaphic factors alone. A critical impediment to incorporating relevant fine-scale detail in large-scale models is the problem of scaling-up. We developed a new individual-based terrestrial ecosystem model, the Ecosystem Demography Model (ED), that addresses these issues. ED predicts both ecosystem structure (e.g. above and below-ground biomass, vegetation height and basal area, and soil carbon stocks) and corresponding ecosystem fluxes (e.g. NPP, NEP and evapotranspiration) from climate, soil and land-use inputs. The model consists of integrated sub-models governing processes such as leaf-level physiology, plant allocation, allometry, phenology, dispersal, the effects of fire disturbances, and below-ground sub-models for soil carbon dynamics and hydrology. Using a new method for scaling-up it is possible to predict ED's large-scale behavior without simulating the fate of every plant individually. ED is being used to examine how climate and edaphic factors, natural disturbances, and human land-use practices affect ecosystem structure and fluxes. Coupled versions are in development to consider potential feedbacks to the atmosphere.

Available Data Sets:

Table 1

Spatial & Temporal Scales

Amazon Dataset

The Amazon data set has a grid cell size of 1 degree by 1 degree. This dataset covers southern Latin America and the northern half of South America from 15 degrees N to 15 degrees S and spans from 30 degrees W to 85 degrees W longitude. The data represent a snapshot the time period covered by the input variables (see below): 1987-1988.

Data Format

Amazon Dataset

The full dataset contains 30 rows by 55 columns of floating point data. The fill value for missing data and sea mask is –9.9.

Variable Description:

a) Potential Soil Carbon

Ecosystem Demography Model (ED) estimates of potential average soil carbon (kg C m^-2), including litter and necromass, at 1 degree resolution. These estimates include the effects of natural disturbances such as windthrow and fire, but do not include the effects of human landuse.

b) Potential Live Biomass

Ecosystem Demography Model (ED) estimates of potential average live biomass (kg C m^-2) at 1 degree resolution. These estimates include the effects of natural disturbances such as windthrow and fire, but do not include the effects of human landuse.

c) Potential Net Primary Production

ED estimates the potential net primary production per grid cell (kg C m^-2 yr^-1), on a monthly basis. These estimates include the effects of natural disturbances such as windthrow and fire, but do not include the effects of human landuse.

Model Inputs:

Amazon Dataset

For the Amazon dataset, the model was run using data from ISLSCP I (see below). The data for 1987 and 1988 were averaged into a single average year.

ISLSCP I Initiative Data:

The International Satellite Land Surface Climatology Project (ISLSCP) Initiative I data sets provide modelers with many of the fields required to prescribe boundary conditions, and to initialize and force a wide range of land-biosphere-atmosphere models. All of the data have been processed to the same spatial resolution (1 deg. x 1 deg.), using the same land/sea mask and steps have been taken to ensure spatial and temporal continuity of the data. The data sets cover the period 1987-1988 at 1-month time resolution for most of the seasonally varying quantities and at 6-hourly resolution for the near-surface meteorological and radiative forcings.

The data sets were taken from the ISLSCP CD and are organized into the five groups listed below:

1. Vegetation

2. Hydrology and Soils

3. Snow, Ice, and Oceans

4. Radiation and Clouds

5. Near-Surface Meteorology

ISLSCP I website:

1. http://daac.gsfc.nasa.gov/CAMPAIGN_DOCS/ISLSCP/islscp_i1.html
2. http://daac.gsfc.nasa.gov/

References:

ED:

Hurtt GC, Moorcroft PR, Pacala SW, Levin SA. (1998) Terrestrial models and global change: challenges for the future. Global Change Biology 4:581-590.

Moorcroft PR, Hurtt GC, Pacala SW (2000). Scaling rules for vegetation dynamics: a new terrestrial biosphere model for global change studies. Ecological Monographs. In press.

ISLSCP I:

Meeson, BW, et al. (1995). ISLSCP Initiative I—global datasets for land-atmosphere models, 1987-1988, CD, NASA.

Sellers, PJ, et al. (1995). An overview of the ISLSCP Initiation I global datasets. In: ISLSCP Initiative I—global datasets for land-atmosphere models, 1987-1988, CD, NASA.

Data Providers:

Dr. George C. Hurtt, Complex Systems Research Center; Institute for the Study of Earth, Oceans and Space; Morse Hall; University of New Hampshire; Durham, New Hampshire 03824; Ph: 603.862.1792; Fax: 603.862.0188; Email: george.hurtt@unh.edu

Dr. Paul Moorcroft, Department of Ecology and Evolutionary Biology; Princeton University; Princeton, NJ 08544; Ph: 609.258.6886; Fax: 609.258.1334; Email: paul@eno.princeton.edu

Latest Data Update:

12/14/2000

Last Doc. Updated:

8/17/2001

Doc. Updated By:

Shannon Spencer

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