159Introduetionny..r..7, 0 ee ee ee ee ee ee CRU LL 122 
2.48 cale OF MOISEUTE rer ee eme ebiess messe: see 123 
NORA RER ae cie asis-bersenleseruel 125 
DLN SPECLESESTOUDS-< en ee Eee tea oho lo te Erde ee Zu aie verse 129 
CS DECIOS Te ee ee ee ee RER 138 
3=Scale20f5SHOWECOVELINE en ee ee ee een een ne CCE 141 
A ADDECIES ER ee este casse seat s eieisle aus io 20 Peas 0 eae RE 142 
DÉS PECIESKEROUPSTE Re et dencre emsiseee cieleleie scie ee seams 146 
Caml ITE IF OEMS aor nee nn Verben nee ee crée cn eececcc: LE 152 
Æ Number of species and density of species... . 2... CLR 157 
ConcludinséremarkS Bra Nee nen ne a ce 158 
Degree of acidity in the Icelandic types of vegetation........... 160 
Blantegeography. and agriculture on ee 163 
Appendix: Temperature Conditions in the upper Soil Strata................. 165 
DIA Ale eects Sik oie ie este wielcit ER - 175 
ERECT CHIE EC ER ELU eee ie eines one N ls ee 183 
