Plant evolution, floral diversity and the response of plants to environmental stress in deep time

ABSTRACT This chapter will highlight a series of lithographs produced by Franz Unger and Josef Kuwasseg that emphasize how Unger used plants to represent different periods of earth history. While Henry De la Beche is credited with the first depiction of ancient life through art (Duria antiquior), Unger’s work was the first to illustrate how plants could be used as indicators of changes in life history. In collaboration with artist Josef Kuwasseg, he embarked on a project entitled The Primitive World in Its Different Periods of Formation that consisted of 14 lithographs that were published in 1851. The title was unique in that it combined the concepts of a “primitive world,” or the widely accepted contemporary idea of undifferentiated deep time, with our modern concept of different periods of earth history. Unger selected periods for this project based upon major strata, but his botanical roots led him to emphasize the importance of plants in each lithograph. The series begins with the “Transition Period,” or the strata that contain the most fossil evidence to develop a reconstruction, and ends with a depiction of the arrival of man in a plant-filled world. This series of lithographs offers a unique contribution to the history and philosophy of geology as Unger recognized the importance of plants to our understanding of geology and deep time in the nineteenth century.

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Rapid response to anthropogenic climate change by Thuja occidentalis: implications for past climate reconstructions and future climate predictions

PeerJ ◽

10.7717/peerj.7378 ◽

2019 ◽

Vol 7 ◽

pp. e7378 ◽

Cited By ~ 5

Author(s):

Rebekah A. Stein ◽

Nathan D. Sheldon ◽

Selena Smith

Keyword(s):

Climate Change ◽

Environmental Stress ◽

Carbon Isotope ◽

Fossil Record ◽

Carbon Assimilation ◽

Plant Evolution ◽

Mean Annual Precipitation ◽

Climate Variables ◽

Air Concentration ◽

Thuja Occidentalis

Carbon isotope values of leaves (δ13Cleaf) from meta-analyses and growth chamber studies of C3 plants have been used to propose generalized relationships between δ13Cleaf and climate variables such as mean annual precipitation (MAP), atmospheric concentration of carbon dioxide ([CO2]), and other climate variables. These generalized relationships are frequently applied to the fossil record to create paleoclimate reconstructions. Although plant evolution influences biochemistry and response to environmental stress, few studies have assessed species-specific carbon assimilation as it relates to climate outside of a laboratory. We measured δ13Cleaf values and C:N ratios of a wide-ranging evergreen conifer with a long fossil record, Thuja occidentalis (Cupressaceae) collected 1804–2017, in order to maximize potential paleo-applications of our focal species. This high-resolution record represents a natural experiment from pre-Industrial to Industrial times, which spans a range of geologically meaningful [CO2] and δ13Catm values. Δleaf values (carbon isotope discrimination between δ13Catm and δ13Cleaf) remain constant across climate conditions, indicating limited response to environmental stress. Only δ13Cleaf and δ13Catm values showed a strong relationship (linear), thus, δ13Cleaf is an excellent record of carbon isotopic changes in the atmosphere during Industrialization. In contrast with previous free-air concentration enrichment experiments, no relationship was found between C:N ratios and increasing [CO2]. Simultaneously static C:N ratios and Δleaf in light of increasing CO2 highlights plants’ inability to match rapid climate change with increased carbon assimilation as previously expected; Δleaf values are not reliable tools to reconstruct MAP and [CO2], and δ13Cleaf values only decrease with [CO2] in line with atmospheric carbon isotope changes.

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Endemism in Wyoming plant and insect herbivore communities during the early Eocene hothouse

Paleobiology ◽

10.1017/pab.2019.18 ◽

2019 ◽

Vol 45 (3) ◽

pp. 421-439 ◽

Cited By ~ 1

Author(s):

Ellen D. Currano ◽

Esther R. S. Pinheiro ◽

Robert Buchwaldt ◽

William C. Clyde ◽

Ian M. Miller

Keyword(s):

River Basin ◽

Census Data ◽

Leaf Damage ◽

Insect Herbivore ◽

Published Data ◽

Early Eocene ◽

Deep Time ◽

Wind River Basin ◽

Tropical Environments ◽

Floral Diversity

AbstractThe warm, equable, and ice-free early Eocene Epoch permits investigation of ecosystem function and macro-ecological patterns during a very different climate regime than exists today. It also provides insight into what the future may entail, as anthropogenic CO2 release drives Earth toward a comparable hothouse condition. Studying plant–insect herbivore food webs during hothouse intervals is warranted, because these account for the majority of nonmicrobial terrestrial biodiversity. Here, we report new plant and insect herbivore damage census data from two floodplain sites in the Wind River Basin of central Wyoming, one in the Aycross Formation (50–48.25 Ma) at the basin edge (WRE) and the second in the Wind River Formation in the interior of the basin (WRI). The WRI site is in stratigraphic proximity to a volcanic ash that is newly dated to 52.416 ± 0.016/0.028/0.063 (2σ). We compare the Wind River Basin assemblages to published data from a 52.65 Ma floodplain flora in the neighboring Bighorn (BH) Basin and find that only 5.6% of plant taxa occur at all three sites and approximately 10% occur in both basins. The dissimilar floras support distinct suites of insect herbivores, as recorded by leaf damage. The relatively low-diversity BH flora has the highest diversity of insect damage, contrary to hypotheses that insect herbivore diversity tracks floral diversity. The distinctiveness of the WRE flora is likely due to its younger age and cooler reconstructed paleotemperature, but these factors are nearly identical for the WRI and BH floras. Site-specific microenvironmental factors that cannot be measured easily in deep time may account for these differences. Alternatively, the Owl Creek Mountains between the two basins may have provided a formidable barrier to the thermophilic organisms that inhabited the basin interiors, supporting Janzen's hypothesis that mountain passes appear higher in tropical environments.

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A new deep-time historical perspective of the terrestrial water cycle that is needed to solve UPH #1:

10.5194/egusphere-egu2020-10606 ◽

2020 ◽

Author(s):

Shannon Sterling

Keyword(s):

Water Availability ◽

Historical Perspective ◽

Time Perspective ◽

Hydrological Cycle ◽

Water Cycle ◽

Plant Evolution ◽

Surface Zone ◽

Critical Surface ◽

Deep Time ◽

Water Cycling

<p>This work could contribute to solve UPH #1: is the hydrological cycle regionally accelerating/decelerating under climate and environmental change, and are there tipping points (irreversible changes)?</p><p>This fundamental question hinges upon the Nature of the hydrologic cycle itself, and for which a geological perspective is needed.&#160; To begin to solve this problem, we thus must have a clear picture of how the water cycle has changed throughout Earth&#8217;s History.&#160; However, current narratives of the history of Earth's water cycle lack a coherent description of how life altered water cycling on land. Here I review a body of evidence of plant evolution events in Earth's history and propose how rainfall runoff mechanisms evolved through five key evolutionary phases.&#160; This review reveals that for most of Earth's history, water cycling on land was likely very different from today, with fewer mechanisms available to store water between rainfall events in the critical surface zone, with implications for water availability and surface climate.&#160; A key tipping point occurred during the Silurian-Devonian periods with the greening of the planet. This deep-time perspective illustrates the step-by-step process through which plants optimized the water cycle in which it increased the distribution in space and time, culminating in the development of forests in the late Devonian. Lastly, I review how the past may serve as a key to the future, discussing how the historical perspective illustrates key areas needed to improve our current conceptualization of water availability so that we may better understand and predict changes of water availability during the Anthropocene.</p>

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Skeletons and Ocean Chemistry: The Long View

Ocean Acidification ◽

10.1093/oso/9780199591091.003.0009 ◽

2011 ◽

Author(s):

Andrew H. Knoll ◽

Woodward W. Fischer

Keyword(s):

Plant Evolution ◽

Saturation State ◽

Deep Time ◽

Glacial Ice ◽

Time Estimates ◽

Run Off ◽

Marine Carbonate ◽

Sedimentary Carbonate ◽

Co2 Degassing

In present-day seas, animals, algae, and protozoa are threatened by ocean acidification, amplified in many regions by seawater warming and hypoxia (Doney et al . 2009 ). Many species may be affected adversely by 21st-century environmental change, but a decade of research suggests that the hypercalcifying animals responsible for reef accretion may be especially vulnerable to an acidity-driven decrease in the saturation state (Ω; see Box 1.1) of surface seawater with respect to calcite and aragonite. The geological record reveals that natural changes in the marine carbonate system have affected the evolution and abundance of calcifying organisms throughout the Phanerozoic Eon (542 million years (Myr) ago to the present). This being the case, we can use our understanding of the dynamic behaviour of the carbon cycle and the stratigraphic comings and goings of reef-building organisms to inform us about what, if any, lessons can be drawn from the long-term past and applied to our nearterm future. If there is one thing that geology makes clear it is that the earth and its biota are in a continual state of change. Because of its relationship to climate, the partial pressure of CO2 (pCO2) in the atmosphere has been of particular interest to geologists and geochemists, but direct measurement of ancient CO2 levels is impossible for intervals older than those recorded in glacial ice preserved today near the poles and at high altitude (Petit et al . 1999). Therefore, deep-time estimates of pCO2 rely on models, broadly constrained by geochemical proxy data. For example, the widely applied models of Berner and colleagues (e.g. GEOCARB III; Berner and Kothavala 2001; Berner 2006; Fig. 4.1C) estimate fluxes of carbon from one reservoir to another, based on geochemical proxies (mainly isotope ratios and abundances of sedimentary carbonate and organic carbon), and then calculate successive steady states of the system through time. Additional parameters are considered, including estimates of carbon fluxes due to erosion, river run-off, plant evolution, volcanic weathering, global CO2 degassing, and land area; these also influence the model results.

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