Foliar Physiognomic Record of Climatic Conditions during Dormancy: Climate Leaf Analysis Multivariate Program (CLAMP) and the Cold Month Mean Temperature

Abstract

A B S T R A C TThe extent to which the leaves of woody dicots encode in their physiognomy the climatic conditions that exist during dormancy was tested by sampling 20 sites along an approximately west-east transect across European Russia, the Crimean Peninsula, Western Siberia, and central Eastern Siberia. This transect encompassed the most extreme mean annual temperature range recorded in the modern world where vegetation exists. Climate Leaf Analysis Multivariate Program (CLAMP) revealed little change in calibration of the warm month mean temperature compared with the PHYSG3AR data set derived from less extreme sites primarily in North America and Japan, but significant change with respect to the cold month mean temperature (CMMT) calibration. Although CLAMP underestimated the CMMT by up to 9ЊC in the coldest sites, the addition of the transect sites improved CLAMP's performance at low temperatures. This suggests that winter cold is encoded in foliar physiognomy even though the leaves are functional only during the late spring and summer months. This increase in performance was, however, at the cost of decreasing precision. Precipitation predictive capabilities were only slightly affected, but calibration of key climatic variables such as enthalpy, used in determining palaeoaltitude, remained more or less unchanged after the inclusion of the cold transect samples.

Refining CLAMP — Investigations towards improving the Climate Leaf Analysis Multivariate Program

“…Techniques for the quantitative reconstruction of palaeoclimatic conditions during the Cenozoic and the Cretaceous, in particular, have attracted a considerable amount of scientific interest. Although much work has been devoted to this kind of research, it has to be kept in mind that so far all methods and approaches have their own limitations and shortcomings and that perhaps there will never be an optimal, universally applicable and absolutely reliable technique for the quantitative estimation of palaeoclimatic parameters from fossil plants (e.g., Mosbrugger and Utescher, 1997;Wilf, 1997;Wilf et al, 1998;Wiemann et al, 1998;Uhl et al, 2007aUhl et al, , 2007bTraiser et al, 2005Traiser et al, , 2007Spicer et al, 2004;Spicer, 2000Spicer, , 2007Yang et al, 2007). This is largely due to complex spatial and temporal variations in the natural environment and plant adaptations that require finite time to equilibrate, and ultimately are compromise solutions to often conflicting environmental constraints (Spicer, 2007;Spicer et al, 2009).…”

“…A. Wolfe (1990Wolfe ( , 1993Wolfe ( , 1995 and subsequently refined by various authors (e.g., Kovach and Spicer, 1995;Stranks and England, 1997;Wolfe and Spicer, 1999;Spicer et al, 2004;Spicer 2000Spicer , 2007Spicer et al, 2009). Methodologically, CLAMP is a development of Leaf Margin Analysis (LMA).…”

Plant Paleoecology in Deep Time1

“…Often, visual or descriptive renderings of the inferred parent vegetation were made, generally representative of the species pool or even of the regional biome, although not explicitly stated or even recognized as such (e.g., Davies, 1929;Becker, 1972). The addition of sedimentological context to species lists greatly refines such studies, restricting the inferred assemblages to those taxa that grew in or proximate to the environment of deposition, thus making the list more representative of actual life communities (e.g., Hickey & Doyle, 1977;Scott, 1978;Wing, 1984;Spicer et al, 2002). The most representative reconstructions, both visual and statistical, are based on data, quantitative and presence-absence, from field samples.…”

“…Vegetation and landscapes vary enormously in systematic composition, plant density, and vegetational architecture on continental spatial scales, influenced by climatic, topographic, and edaphic controls. Yet, plant remains are preserved only under a relatively strict sedimentological and geochemical subset of all possible conditions (Gastaldo, 1992a(Gastaldo, , 1994Spicer, 1988Spicer, , 1989. These conditions greatly reduce the likelihood of fossilization for many types of plant assemblages, depending on landscape position and climate.…”

“…In general, plant parts preserved in fluvio-lacustrine settings are derived from vegetation directly adjacent to and fringing the body of water. But in such environments, the potential exists for the assemblage to include allochthonous elements that have been transported greater distances, depending on the geographical and altitudinal position of the lake (e.g., Spicer & Wolfe, 1987) and the proximity of tributaries debouching into principal river channels (e.g., Gastaldo et al, 1987). Hence, it is imperative that an integrated geologic, taphonomic, and paleontologic approach be used to understand any assemblage prior to interpretation.…”