Calculate Potential Net Primary Production (NPP)

Calculates potential NPP using various models including Miami, NCEAS, and Rosenzweig. All model coefficients are read from `NPP_model_coefs` (loaded by `load_general_data()`) rather than hardcoded in the function.

Usage

calculate_potential_npp(Dataset)

Arguments

Dataset

A data frame containing climate data with columns:

TMP

Mean annual temperature (degrees C).

WaterInput_mm

Total water input: precipitation + irrigation (mm).

AET_mm

Actual evapotranspiration (mm).

Value

A data frame with calculated NPP values from different models in Mg DM/ha.

Details

Requires the following objects from `load_general_data()`: - `NPP_model_coefs` — model parameters (Miami, NCEAS, Rosenzweig) - `Residue_kgC_kgDM_Wo` — C content of woody residues for DM conversion - `Residue_kgC_kgDM_W` — C content of non-tree residues for DM conversion

Models implemented: - **Miami** (Lieth 1975): min of temperature and precipitation limits - **NCEAS tree** (Del Grosso et al. 2008, Table 1): min(F_MAP, F_MAT) for both TNPP and ANPP - **NCEAS non-tree** (Del Grosso et al. 2008, Table 2): precipitation-only saturating functions for TNPP and ANPP - **Rosenzweig** (1968): log-linear model based on AET

References

Lieth, H. (1975) Modeling the Primary Productivity of the World. In: Primary Productivity of the Biosphere, Springer.

Del Grosso, S. et al. (2008) Global potential net primary production predicted from vegetation class, precipitation, and temperature. Ecology 89:2117-2126.

Rosenzweig, M.L. (1968) Net Primary Productivity of Terrestrial Communities: Prediction from Climatological Data. Am Nat 102:67-74.

Examples

if (FALSE) { # \dontrun{
load_general_data()
climate_data <- data.frame(TMP = 15, WaterInput_mm = 800, AET_mm = 700)
npp_results <- calculate_potential_npp(climate_data)
} # }