Document: WEI-3-59-2

The scale dependency of the relationship between litter quantity and nitrogen mineralization in forest ecosystems and landscapes.

FAN, W.* ¹, J.CHEN ² and K.D.BROSOFSKE ²

Richard Stockton College of New Jersey, Pomona, NJ 08240 ¹
Michigan Techonological University, Houghton, MI 49931 ²

Abstract:
There is an implicit disagreement among ecologists about the importance of litter quantity in relation to nitrogen mineralization of forest ecosystems. As a major component of ecosystem models predicting N mineralization, litter quantity is widely used to determine the amount of N mineralized. However, some studies suggested a poor correlation between litter quantity and N mineralization. In this study using data from the Great Lakes region, we evaluated the role of litter quantity in N mineralization by examining their relationships at three scales: Stand, landscape, and regional levels. Microclimate, soil properties including N mineralization, and forest inventory data were collected at 77 plots representing different plant communities in Chequanmegon National Forest, WI. Potential litter-fall quantity, litter redistribution and decomposition were examined using quantitative analysis on relationships to NDVI, canopy coverage, litter coverage, litter depth, litter quality (i.e., lignin/nitrogen ratio), organic matter depth, and total soil organic matter within and across landscapes. Published data were used for a similar analysis at a regional scale. No significant relationship (P>0.1) was found between N mineralization and litter quantity at stand level within each community, whereas a positive relationship (P=0.007) was found at landscape level across the plant communities. The result indicated that the effect of litter quantity on N mineralization is scale dependent.

Keywords: N mineralization, litter quantity

This abstract is being presented at: 10:30 AM in session:
Poster Session #5: Landscape Ecology.