Plant Paleoecology in Deep Time¹

Abstract

The paleoecology of plants as a modern discipline, distinct from traditional floristics or biostratigraphy, has undergone an enormous expansion in the past 20 years. In addition to baseline studies characterizing extinct plants and plant assemblages in terms of their growth habits, environmental preferences, and patterns of association, paleoecology has converged on neoecology and represents a means to extend our basic understanding of the world and to contribute to the theoretical framework of ecology, writ large. Reconstruction of whole plants, including studies of physiology and developmental biology, and analyses of biomechanics have become mainstays of autecological studies. Assemblage studies now are informed by sophisticated taphonomic models that have helped guide sampling strategies and helped with the interpretation of statistical data. Linkages of assemblage patterns in space and time with sedimentology, geochemical proxies for atmospheric composition and climate, paleosol analyses, and increasingly refined geochronological and sequence stratigraphic data have permitted paleoecologists to examine rates and extents of vegetational response to environmental change and to time intervals of quiescent climatic conditions. Studies of plant-animal interaction, explicit consideration of phylogenetic information in assessing assemblage time-space dynamics, and examination of ecological structure in terms of developing metabolic scaling theory are all having direct impact on paleoecological as well as neoecological studies. The growth of paleoecology shows no sign of diminishment-closer linkages with neoecology are needed.

A physiologically explicit morphospace for tracheid-based water transport in modern and extinct seed plants

“…Finally, the thickness-to-span ratio of tracheids from Lyginopteris, Callistophyton, and Medullosa reduces their ability to resist drought-induced embolism and implosion (Hacke and Sperry 2001, Hacke et al 2001a, Hacke et al 2001b. Although these cells' reduced ability to resist strong tensions does not directly correspond with a reduced degree of structural support, given the complex nature of biomechanical support in vascular plants (Carlquist 2001, Cichan 1986, DiMichele 1979, DiMichele and DeMaris 1987, DiMichele and Gastaldo 2008, Niklas 1992, Niklas and Spatz 2004, Rowe and Speck 2004, Rowe et al 1993), a stem composed of highly conductive, wide tracheids would not, by itself, contribute significant structural support to a plant.…”

Pennsylvanian ‘fossil forests' in growth position (T 0 assemblages): origin, taphonomic bias and palaeoecological insights

“…Clearly, to preserve a T° assemblage at all, burial must happen more rapidly than destruction of the vegetation by decay or through direct exposure to the elements (Gastaldo & Staub 1999;DiMichele & Gastaldo 2008;Gastaldo & Demko 2010 rapid rates of burial, capable of preserving T° assemblages, are normally restricted to one of three sedimentary contexts. Typical entombing fades include (1) volcanic ash-falls or surges and/or associated lava flows, (2) coastal flooding brought about by rapid eustatic sea-level rise, regional subsidence, or more often a combination of the two, and (3) fluvial processes including within-channel sedimentation, riparian crevasse splays, progradation of distributary lobes, and general sediment aggradation in low-lying areas of floodplains.…”

“…Libert in et al 2009). In this paper, we employ the term 'T° assemblages' (after Gastaldo et al 1995Gastaldo et al , 2004aGastaldo et al , 2006Johnson 2007;DiMichele & Gastaldo 2008) to describe fossil forests preserved in essentially the same spatial conformation as in life. This includes assemblages buried in place; that is, the remains of upright trees rooted in their original soils (autochthonous) and assemblages where all or some of the vegetation has been slightly displaced (e.g.…”

The epiphytic plants in the fossil record and its example from in situ tuff from Pennsylvanian of Radnice Basin (Czech Republic).

“…On the opposite, environments with fast accumulation of sediments are potential sites where vegetation can be buried in situ fast enough to preserve not only morphology but also life forms including the epiphytic one. This is especially the case of so-called T 0 horizons, which preserve T 0 plant assemblages (Gastaldo et al 1995(Gastaldo et al , 2004(Gastaldo et al , 2006Jonson 2007;DiMichele & Gastaldo 2008;Opluštil et al 2009aOpluštil et al , 2009b buried in a geological instant, i.e. virtually frozen in time.…”