See more from this Session: Symposium--Partnering Soil Science and Statistics, Ways to Avoid Statistical Malpractice In Soil Research: I
Monday, October 17, 2011: 4:45 PM
Henry Gonzalez Convention Center, Room 209, Concourse Level
Statistical certainty with respect to litter decay pattern, process, and replication is presently elusive at the global and regional scale. Many of the axiomatic litter decay theories are northern temperate forest centric. In order to truly understand the implications of climate and land-use change on soil carbon production and retention it is necessary to expand our understanding of climatic, chemistry, and soil ecological drivers of litter decomposition beyond these systems into arid, dessert, arctic, and agricultural settings to name a few. Statistical robustness and future allocation of resources are the primary objectives of this presentation. To address these issues an exhaustive global review of 194 studies of leaf and Coarse Woody Debris (CWD) from 1960 to the present was conducted. This data-set included 1,431 leaf and 212 CWD annual decay constants (|k|) citations with an average of 317 ± 559 g m-2 yr-1. Leaves on average decay nearly an order-of-magnitude faster than CWD (349 ± 573 v. 37 ± 61). While the two are positively correlated across plant families the limited availability of the latter makes for a tenuous albeit significant relationship. In all regions sans the United States there was a linear relationship between number of families and genus investigated, with an average of 1.4 genuses per family, however, the United States data focused on approximately 80 genus and only 30 families. Ninety-six percent of the data-set was derived from studies of dicots and gymnosperms with the remainder comprised of monocot, fern, and lichen studies. From a growth-form perspective 92% of the data constituted dominant and sub-canopy trees or associated shrubs relative to the 8% that addressed understory perennial or annual herbs. Given these gaps in our climatic, chemical, and biological understanding of leaf and CWD decay drivers, a power analysis will be performed to assess the number of citations needed to overcome said gaps.