Reconstructing Extinct Plant Water Use for Understanding Vegetation–Climate Feedbacks: Methods, Synthesis, and a Case Study Using the Paleozoic-Era Medullosan Seed Ferns

摘要: Vegetation affects feedbacks in Earth's hydrologic system, but is constrained by physiological adaptations. In extant ecosystems, the mechanisms controlling plant water used can be measured experimentally; for extinct plants recent geological past, use inferred from nearest living relatives, assuming minimal evolutionary change. deep time, where no close relatives exist, fossil material provides only information inferring use. However, mechanistic models must built on first principles and tested plants. Plants serve as a conduit movement soil to atmosphere, tissue-level construction gross architecture. No single feature, such stomata or veins, encompasses enough of complexity underpinning water-use physiology basis model functional all (or perhaps any) Rather, “functional whole plant” used. To understand interplay between relation environmental conditions investigated an plant, seed fern Medullosa ((Division Pteridospermatophyta), reviewing methods reconstructing variables leaf stem hydraulic capacity, photosynthetic rate, transpiration stomatal conductance, albedo. Medullosans had potential extremely high assimilation rates, transport, transpiration—rates comparable later angiosperms. When these growth gas exchange rates medullosans are combined with unique atmospheric composition late Paleozoic complex vegetation-environmental expected despite their basal phylogenetic position relative post-Paleozoic