28 Hekstra. An Introduction to Climate.

The world bioses and natural vegetations are determined prima-
rily by climate (temperature and precipitation) and substrate
(minerals). Present regional landuse patterns now determine
dominant vegetation covers. Climate and natural vegetations
formed soils over ages. The process needs a healthy soil eco-
system to utilize the soil horizons by different plant rooting
with its associated microflora. Soil organic matter is essen-
tial for water and nutrient holding capacity of soils. Deser-
tification can equally much result from mineral deficiency as
from droughts. Landuse should obey to bioclimatic zonation and
to the ecophysiology of vegetations.


CONTENTS:

1. Landclassification 1
2. The ecology of soil formation 5
3. Soil ecosystems and agronomic consequences 9
References 17