An associational study of Illinois sand prairie . tera, which include many of the species of are: Spharagemon wyomingianum Melanoplus angustipennis Fsinidia fenestralis Ivlelanoplus flavidus Schistocerca alutacea Conocephalus robustus The predaceous species include three phytophilous species: Sinea diademaCoccinella 9-notataHippodamia parenthesis The ground forms are much more abundant: they include: Lycos ajf at if era Mutillids Fhidippus insolens Ammophila spp. Stachyocnemis apicalis Heterdon Alydus spp. Cistudo Cicindela formosa generosa Scalopus The blowsand association as
An associational study of Illinois sand prairie . tera, which include many of the species of are: Spharagemon wyomingianum Melanoplus angustipennis Fsinidia fenestralis Ivlelanoplus flavidus Schistocerca alutacea Conocephalus robustus The predaceous species include three phytophilous species: Sinea diademaCoccinella 9-notataHippodamia parenthesis The ground forms are much more abundant: they include: Lycos ajf at if era Mutillids Fhidippus insolens Ammophila spp. Stachyocnemis apicalis Heterdon Alydus spp. Cistudo Cicindela formosa generosa Scalopus The blowsand association as developed on the lee slope of blow-outs, though consisting of an abundant growth of plants and animals,is nevertheless quite dependent upon the physical environment, and m£jjybe exterminated in a v/inter of severe v/ind action. Several times I have seen lee slopes of blov/outs v/ith the horizontal roots of lastyears annuals exposed at the surface; this indicates that a depth of about three inches of sand has been blown away during the winter 1. The Deposit AssociationT:\e manner of deposition of sand on the lee side of a blowout isinfluenced greatly by the vegetation. If none is present the sandspreads out over the general level in a broad thin fan-shaped growing on the lee side of the blo\70ut, particularly if they bebunch-grasses, tend to check the velocity of the wind, vihioh thus isunable to carry its load. Sand is then deposited at the base of theplants. If now the plants, by upward grov/th, can continue to act asobstacles to the wind, the deposition of sand will continue also anda dune will gradually be built up. The obstacle grows upward with thedune. Many of the sand-prairie plants are efficient dune formers,and these species are quite com^ion in the deposit association. Theprincipal species are Rhus canadensis var. illinoensis, Fanicum vir-gatum, and Tephrosia virginiana. A Rhus dune, the side of which isbeing undermined by a large blowout, is shown in F
Size: 1332px × 1875px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookidassocia, booksubjecttheses
