Photosynthetically active radiation measurements in pure pine and mixed pine forests in Poland

Abstract

Photosynthetically active radiation (PAR) has been measured in pure pine and mixed pine forests on 15 sites in two transects in Poland: the "climatic" (from the western to the eastern border), and the "Silesian" (from the most to the less polluted part of the country). PAR was measured by using the standard procedure developed by the USDA Forest Service's Forest Health Monitoring Program. At each forest site PAR was measured at the "central point" and at six points 7.3 m from the central point. PAR was also measured at three additional points (at the location of litterfall collection). Eight out of 15 forests were classified as pure pine, and 7 as mixed pine. Two series of measurements were completed in September/October 1994 and in July/August 1995. The first measurements showed that the mixed pine forests were more shaded than the pure pine forests. Average leaf area index (LAI) for mixed pine forests was 2.03 and 1.78 for pure pine. Mixed forests were characterized by greater seasonal changeability of LAI because of a higher amount of broadleaved trees and shrubs. LAI and transmitted PAR (TPAR) standard deviation on a particular forest site may be treated as an index of internal forest differentiation. The indexes differ between particular forests, but average values for pure pine and mixed pine forest are almost identical. The first attempt to correlate PAR indexes and other ecological indexes suggest that there is no correlation between PAR and litterfall and the rate of litter decomposition.

Parent Publication

• Proceedings of the International Symposium on Air Pollution and Climate Change Effects on Forest Ecosystems

Citation

Smialkowski, Jaroslaw. 1998. Photosynthetically active radiation measurements in pure pine and mixed pine forests in Poland. In: Bytnerowicz, Andrzej; Arbaugh, Michael J.; Schilling, Susan L., tech. coords. Proceedings of the international symposium on air pollution and climate change effects on forest ecosystems. Gen. Tech. Rep. PSW-GTR-166. Albany, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Research Station: 323-326