Abstract: The study by the methods of in situ observation and laboratory analysis showed t
hat the micro-relief in salinization area of Songnen Plain area was composed of
 flat land, micro-slope land, depression margin, and depression. Isohum
usols distributed in depression, while alkalic halosols distributed in depressio
n margin, micro-slope land, and flat land. The exchangeable sodium percent (ESP
)
 in alkalized layer (15〖KG-*2〗-〖KG-*7〗30 cm) of alkaline soil in flat land w
as 60%, and the ma
ximal ESP in surface soil layer in micro-slope land could reach to 75%. The alk
a
lized soil layer in depression margin was mainly at the depth of 10〖KG-*2〗-〖K
G-*7〗30 cm, where
 the maximal ESP could reach to 30%〖KG-*2〗-〖KG-*7〗40%. Nearly no alkalized la
yer was found in t
he soil profile in depression. The soils developed on the four micro-relief uni
t
s had obvious differences in their water retention curves. The maximal saturatio
n moisture content in the soils of micro-slope land was only 25%, while that of
 
0〖KG-*2〗-〖KG-*7〗10 cm soil layer in depression reached to 45%. The freezing
-thawing process in
 different micro-relief units differed markedly, with the maximal frozen depth
i
n micro-slope land and depression being 157  and 136 cm, respectively. The su
r
face soil moisture content in depression increased from 20% before freezing to 5
0% during freezing period. Among the four micro-relief units, micro-slope land
 h
ad the most obvious variation of surface soil salt content during freezing-thaw
ing, with the increment after thawing being as high as 80%.

Key words: micro-scale pattern, alkalic halosols, water and salt translocation, secondary forest, clear cutting, selective cutting, soil CH₄ uptake flux, Northeast China forest area.