Appendix B. Near-infrared reflectance spectroscopy calibrations between initial litter spectral properties and (a) litter decomposability and (b) litter quality. The indicated values refer to the number of samples (n); the mean of measured values (Mean); standard deviation of measured values (SD); standard error of calibration (SEC); R squared (R²); standard error of cross-validation (SECV); Math.: mathematical treatment of the spectral data: the first number is the order of the derivative function, the second is the segment length data points over which the derivative was taken, and the third is the segment length over which the function was smoothed; Number of terms: number of terms of the PLS models.
TABLE B1. Calibration statistics for the litter decomposability rate (k, in g·kg^{-1}·d^{-1}) ascertained on 86 litters in this study.
Constituent |
n |
Mean |
SD |
SEC |
R² |
SECV |
Math. |
Number of terms |
k |
86 |
9.35 |
3.83 |
1.43 |
0.862 |
1.69 |
2 10 10 |
7 |
TABLE B2. Calibration statistics for the chemical constituents (nitrogen, lignin, cellulose, and hemicellulose concentrations, in percentages) established on a large set of litter encompassing a very large array of species (Joffre et al. 1992, Gillon et al. 1993, 1999). These calibrations were applied to assess the initial quality of the 136 litters used in the present study.
Constituent |
n |
Mean |
SD |
SEC |
R² |
SECV |
Math. |
Number of terms |
N |
146 |
1.26 |
0.63 |
0.08 |
0.983 |
0.11 |
2 5 5 |
9 |
LIG |
258 |
24.7 |
11.0 |
2.8 |
0.936 |
3.1 |
2 5 5 |
9 |
CEL |
255 |
18.8 |
8.2 |
1.7 |
0.957 |
1.8 |
2 5 5 |
7 |
HEM |
90 |
11.5 |
6.0 |
1.7 |
0.916 |
2.0 |
2 5 5 |
10 |
LITERATURE CITED
Gillon, D., C. Houssard, and R. Joffre. 1999. Using near-infrared reflectance spectroscopy to predict carbon, nitrogen and phosphorus content in heterogeneous plant material. Oecologia 118:173–182.
Gillon, D., R. Joffre, and P. Dardenne. 1993. Predicting the stage of decay of decomposing leaves by near-infrared reflectance spectroscopy. Canadian Journal of Forest Research-Revue Canadienne de Recherche Forestiere 23:2552–2559.
Joffre, R., D. Gillon, P. Dardenne, R. Agneessens, and R. Biston. 1992. The use of near-infrared reflectance spectroscopy in litter decomposition studies. Annales des Sciences Forestieres 49:481–488.