meric vector</p></dd>

  <dt><code>forest</code></dt>
<dd><p>forest type, a factor with levels <code>birspr</code>
      <code>mixdec</code> <code>pine</code> <code>sprbir</code> <code>sprpin</code> <code>spruce</code></p></dd>

  <dt><code>weather</code></dt>
<dd><p>weather type, a factor with levels <code>cloud</code>
      <code>moist</code> <code>nice</code> <code>rain</code></p></dd>
 <dt><code>litho</code></dt>
<dd><p>lithological
      type, a factor with levels <code>camsed</code> (Cambro-Silurian s