Use of near-infrared reflectance spectroscopy (NIRS) in palaeoecological studies of peat

Bulk density, degree of humification, % moisture content and the % occurrence of plant macrofossils were determined down a single peat core. Near-infrared reflectance spectroscopy (NIRS) was used to obtain spectra for each sample and calibration equations were developed between the conventional analyses and the NIRS spectra using modified partial least squares and stepwise regressions. Conventional analyses were then correlated with values predicted from these equations, with regression coefficients ranging from 0.98 for degree of humification to 0.85 for Ericales roots. An attempt was also made to determine the minimum number of samples required to produce a useful calibration for each variable. Where successful, this ranged from one sixth to one third of the available samples and in each case represented a significant potential for time-saving. NIRS is a potentially valuable technique in palaeoecological studies of pest, enabling the nondestructive analysis of large numbers of samples.