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<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>Jeanne C. Chambers</dc:contributor>
  <dc:contributor>Jeffrey L. Beck</dc:contributor>
  <dc:contributor>Matthew L. Brooks</dc:contributor>
  <dc:contributor>Brian A. Mealor</dc:contributor>
  <dc:creator>David A. Pyke</dc:creator>
  <dc:date>2016</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;Human land uses are the primary cause of the introduction and spread of exotic annual &lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Bromus &lt;/i&gt;&lt;span&gt;species. Initial introductions were likely linked to contaminated seeds used by homesteading farmers in the late 1880s and early 1900s. Transportation routes aided their spread. Unrestricted livestock grazing from the 1800s through the mid-1900s reduced native plant competitors leaving large areas vulnerable to &lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Bromus&lt;/i&gt;&lt;span&gt; dominance. Ecosystems with cooler and moister soils tend to have greater potential to recover from disturbances (resilience) and to be more resistant to &lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Bromus &lt;/i&gt;&lt;span&gt;invasion and dominance. Warmer and drier ecosystems are less resistant to &lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Bromus&lt;/i&gt;&lt;span&gt; and are threatened by altered fire regimes which can lead to &lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Bromus&lt;/i&gt;&lt;span&gt; dominance, impacts to wildlife, and alternative stable states. Native Americans used fire for manipulating plant communities and may have contributed to the early dominance of &lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Bromus&lt;/i&gt;&lt;span&gt; in portions of California. Fire as a tool is now limited to site preparation for revegetation in most ecosystems where &lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Bromus&lt;/i&gt;&lt;span&gt; is a significant problem. Once &lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Bromus&lt;/i&gt;&lt;span&gt; dominates, breaking annual grass/fire cycles requires restoring fire-tolerant perennial grasses and forbs, which can compete with &lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Bromus&lt;/i&gt;&lt;span&gt; and resist its dominance. Current weed management policies often lack regulations to prevent further expansion of &lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Bromus&lt;/i&gt;&lt;span&gt;. Research is needed on how and where livestock grazing might help increase perennial grass and forb cover and density to create ecosystems that are more resistant to &lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Bromus&lt;/i&gt;&lt;span&gt;. Also, studies are needed to ascertain the role, if any, of oil and gas development in contributing to the spread of &lt;/span&gt;&lt;i class="EmphasisTypeItalic "&gt;Bromus&lt;/i&gt;&lt;span&gt;.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1007/978-3-319-24930-8_11</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Springer International Publishing</dc:publisher>
  <dc:title>Land uses, fire, and invasion: Exotic annual Bromus and human dimensions</dc:title>
  <dc:type>chapter</dc:type>
</oai_dc:dc>