Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

Plant Life of Paricutin Volcano, Mexico, Eight Years After Activity Ceased

Willis A. Eggler
The American Midland Naturalist
Vol. 69, No. 1 (Jan., 1963), pp. 38-68
DOI: 10.2307/2422843
Stable URL: http://www.jstor.org/stable/2422843
Page Count: 31
  • Read Online (Free)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Plant Life of Paricutin Volcano, Mexico, Eight Years After Activity Ceased
Preview not available

Abstract

Paricutin Volcano, Michoacan, Mexico, began erupting on February 20, 1943, and ceased on March 4, 1952. The present report covers observations made in 1959 and 1960 on plants of the area. By 1959 former forests in the volcanic area were usually well along toward being freed of ash, except where enough pine trees had survived to supply a blanket of needles which stopped erosion. Where ash was removed prevolcanic plants resumed growth, and new ones became established. Old fields were more nearly level than forested areas and they were relieved of much less of their ash mantle. Plants never invaded old fields where any ash mantle remained, except where old soil or animal droppings had improved conditions. But plants were also able to get started if other plants already grew there. Primary succession had begun on the oldest lava flows in 1950. By 1960, 33 species of plants were growing on the lava flows. There was a dense shrub and herb growth on certain hornitos near the cinder cone. Vascular plants were first observed on the cinder cone in February, 1957, when two species were seen. Twenty-eight species were present by 1960. Disseminules of nearly all pioneer plants on the lava flows, hornitos, and cinder cones are known to be wind carried. Only two have fleshy fruits and were probably disseminated by birds. Determination of nitrogen content of ash samples collected from ash fields, lava flows, and the cone indicated the following. There was always at least a minimal amount of nitrogen in the samples analyzed, probably enough to nourish plants. The lowest value was 15.2 ppm; the highest 277.7 ppm. A significant part of the nitrogen was in the form of soluble compounds, as indicated by increasing concentration with greater depth in areas without plants. Where plants were present the nitrogen content near the surface was significantly greater than at greater depths. This was true under mosses as well as under vascular plants. This indicated that plants here concentrate nitrogen compounds in upper soil layers.

Page Thumbnails

  • Thumbnail: Page 
38
    38
  • Thumbnail: Page 
39
    39
  • Thumbnail: Page 
40
    40
  • Thumbnail: Page 
41
    41
  • Thumbnail: Page 
42
    42
  • Thumbnail: Page 
43
    43
  • Thumbnail: Page 
44
    44
  • Thumbnail: Page 
45
    45
  • Thumbnail: Page 
46
    46
  • Thumbnail: Page 
47
    47
  • Thumbnail: Page 
48
    48
  • Thumbnail: Page 
49
    49
  • Thumbnail: Page 
50
    50
  • Thumbnail: Page 
51
    51
  • Thumbnail: Page 
52
    52
  • Thumbnail: Page 
53
    53
  • Thumbnail: Page 
54
    54
  • Thumbnail: Page 
55
    55
  • Thumbnail: Page 
56
    56
  • Thumbnail: Page 
57
    57
  • Thumbnail: Page 
58
    58
  • Thumbnail: Page 
59
    59
  • Thumbnail: Page 
60
    60
  • Thumbnail: Page 
61
    61
  • Thumbnail: Page 
62
    62
  • Thumbnail: Page 
63
    63
  • Thumbnail: Page 
64
    64
  • Thumbnail: Page 
65
    65
  • Thumbnail: Page 
66
    66
  • Thumbnail: Page 
67
    67
  • Thumbnail: Page 
68
    68