<?xml version='1.0' encoding='utf-8'?>
<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>Madelon Florence Case</dc:contributor>
  <dc:contributor>Allison Karp</dc:contributor>
  <dc:contributor>Jasper Slingsby</dc:contributor>
  <dc:contributor>A. Carla Staver</dc:contributor>
  <dc:creator>Isa del Toro</dc:creator>
  <dc:date>2024</dc:date>
  <dc:description>&lt;ul class="unordered-list"&gt;&lt;li&gt;Increasing atmospheric CO&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;is changing the dynamics of tropical savanna vegetation. C&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;trees and grasses are known to experience CO&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;fertilization, whereas responses to CO&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;by C&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;grasses are more ambiguous.&lt;/li&gt;&lt;li&gt;Here, we sample stable carbon isotope trends in herbarium collections of South African C&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;and C&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;grasses to reconstruct&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;13&lt;/sup&gt;C discrimination.&lt;/li&gt;&lt;li&gt;We found that C&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;grasses showed no trends in&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;13&lt;/sup&gt;C discrimination over the past century but that C&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;grasses increased their&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;sup&gt;13&lt;/sup&gt;C discrimination through time, especially since 1950. These changes were most strongly linked to changes in atmospheric CO&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;rather than to trends in rainfall climatology or temperature.&lt;/li&gt;&lt;li&gt;Combined with previously published evidence that grass biomass has increased in C&lt;sub&gt;4&lt;/sub&gt;-dominated savannas, these trends suggest that increasing water-use efficiency due to CO&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;fertilization may be changing C&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;plant–water relations. CO&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;fertilization of C&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;grasses may thus be a neglected pathway for anthropogenic global change in tropical savanna ecosystems.&lt;/li&gt;&lt;/ul&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1111/nph.19868</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>New Phytologist Foundation</dc:publisher>
  <dc:title>Carbon isotope trends across a century of herbarium specimens suggest CO2 fertilization of C4 grasses.</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>