An associational study of Illinois sand prairie . region. The edaphic extensions ofthe southv/estern faima thus find their outermost distribution in thesand areas of the humid districts, not only because the physical en-vironment is suitable, but because the competition of the species ofthe humid fauna is negligible. Distribution of Sand Beetles. Sand regions occur locally over practically all of this country,and as the physical conditions are similar in all of these areas, aconsiderable number of the plant and animal species of the sand asso-ciations are to several or many of the loca
An associational study of Illinois sand prairie . region. The edaphic extensions ofthe southv/estern faima thus find their outermost distribution in thesand areas of the humid districts, not only because the physical en-vironment is suitable, but because the competition of the species ofthe humid fauna is negligible. Distribution of Sand Beetles. Sand regions occur locally over practically all of this country,and as the physical conditions are similar in all of these areas, aconsiderable number of the plant and animal species of the sand asso-ciations are to several or many of the localities. This cori-mon element of sand areas consists for the greater part of speciesthat are especially adapted to the sand environment, and which usual-ly are found nowhere else. These species thus have very extensivethough discontinuous ranges. For purposes of comparison v/ith the sand region of the Illinoisriver valley, beetle lists from other sand areas v/ere consulted, and certain distinctive sand species of the Illinois region v/ero listed. 73 in the table on page TT Jor each sand area in which they lists are by no means complete and the absence of a record doesnot mean that the apecies is necessarily absent. The results show: 1. That the sand associations are to be classed with the arid for- mation of the prairie - they are Upper Sonoran. 2. That many of the species extend as far east as the Atlantic coast. Extensive sand deposits occur along the entire many western forms have migrated along the Atlanticborder north from the Gulf region. 3. That the proportion of western species in an association gradu- ally decreases with distance north and east. 4. That the Illinois river region and the Lake Michigan region in northern Indiana have very closely related sand associations,most of the characteristic species being common to both areas 5. Records not included in this table shov/ a very close relation- ship between the Illinois river sand associa
Size: 1332px × 1875px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, bookidassocia, booksubjecttheses
