02796nas a2200325   4500008004100000245013100041210006900172260001200241300001400253490000700267520158900274653002601863653001901889653003001908653001901938653002501957653002301982100001902005700001802024700001802042700001802060700002402078700002002102700001902122700001602141700001802157700001402175700002102189856026002210       2015                        eng d00aInvestigating Devonian Trees as Geo-Engineers Of Past Climates: Linking Palaeosols to Palaeobotany and Experimental Geobiology0 aInvestigating Devonian Trees as GeoEngineers Of Past Climates Li  c07/2015  a787–8010 v583 a<p>We present the rationale for a cross-disciplinary investigation addressing the ‘Devonian plant hypothesis’ which proposes that the evolutionary appearance of trees with deep, complex rooting systems represents one of the major biotic feedbacks on geochemical carbon cycling during the Phanerozoic. According to this hypothesis, trees have dramatically enhanced mineral weathering driving an increased flux of Ca2+ to the oceans and, ultimately, a 90% decline in atmospheric CO2 levels through the Palaeozoic. Furthermore, experimental studies indicate a key role for arbuscular mycorrhizal fungi in soil–plant processes and especially in unlocking the limiting nutrient phosphorus in soil via Ca-phosphate dissolution mineral weathering. This suggests co-evolution of roots and symbiotic fungi since the Early Devonian could well have triggered positive feedbacks on weathering rates whereby root–fungal P release supports higher biomass forested ecosystems. Long-standing areas of uncertainty in this paradigm include the following: (1) limited fossil record documenting the origin and timeline of the evolution of tree-sized plants through the Devonian; and (2) the effects of the evolutionary advance of trees and their in&nbsp;situ rooting structures on palaeosol geochemistry. We are addressing these issues by integrating palaeobotanical studies with geochemical and mineralogical analyses of palaeosol sequences at selected sites across eastern North America with a particular focus on drill cores from Middle Devonian forests in Greene County, New York State.</p>
10aarbuscular mycorrhiza10aclimate change10aDevonian plant hypothesis10aDevonian trees10aland plant evolution10amineral weathering1 aMorris, J., L.1 aLeake, J., R.1 aStein, W., E.1 aBerry, C., M.1 aMarshall, J., E. A.1 aWellman, C., H.1 aMilton, J., A.1 aHillier, S.1 aMannolini, F.1 aQuirk, J.1 aBeerling, D., J.  uhttp://onlinelibrary.wiley.com/doi/10.1111/pala.12185/abstract;jsessionid=ADDF3457241BBBA0C261E716BA2BCFB9.f04t02?systemMessage=Wiley+Online+Library+will+have+intermittent+access+on+8th+August+2015+from+10%3A00-16%3A00+BST+%2F+05%3A00-11%3A00+EDT+%2F+17%3