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Molecular Soil Biology
17
They are affected through vegetation type
(Mboukou-Kimbatsa et al., 2007), soil features
(Yong-Chun et al., 2006), weather conditions,
humidity (Davis et al., 2006), and sea level height
(Kurcheva, 1972). On the other hand, because of land
destruction, soil grinding and compressing which all
cause reduction in production as well the second
succession limitations (Warren and Zou, 2002).
Expanding and transforming soil alongside its
vegetation can be complex processes which bring
change and variation in soil features so that they can
affect both forest vegetation and its growth. Often
dividing soil function to different physical, chemical
and biological steps seems very difficult for their
reciprocal effects as well complex natures (Vesterdal
et al., 2013). Tree species affect in different ways the
biological, physical and chemical characteristics of the
soil (Antunes et al., 2008; Wang et al., 2009). There is
a non-significant relation between worms numbers,
biomass and soil C/N as well between earthworms
biomass and soil carbon, moreover a significant
positive link between worms numbers and their
biomass (Kooch et al., 2008, 2013).
The greatest variety and identity indexes relates to
smashed organic layer. Deeper in depth would cause
less in indices (Rahmani and Zare Maivan, 2004).
Natural jungle areas had more variety in contrast to
planed area for afforestation or the applied ones,
claimed by Pashani et al., (1991), and Muturi et al.,
(2009). In some other cases, soil invertebrates'
biomass and their varieties in different artificial
planted forest areas were more than the natural ones.
When soil pH increases, the conditions will improve
for soil invertebrates, likewise when soil macro-fauna
number and biomass increases, soil fertility improve
which it can bring better conditions for trees grow
(Bradford et al., 2002). Alder forestation shows the
more variety of diversity (Shannon-Wiener) and
evenness (simpson) and richness (margalef); however
cypress had the smallest amount in number (Agusto et
al., 2002, Chitii et al., 2007). Nitrogen raise causes
soil invertebrate increase. In some plots with more
nitrogen, not only there were seen greater amount of
macro-fauna biomass, but also they were bigger in
size (Cole and Bardgett, 2002).
Although it cannot be claimed just for nitrogen, since
they relate to some other factors such as bulk density
also soil moisture (Jones and Darrah, 1994). Jalilvand
and Kooch (2012) investigated earthworm abundant
and biomass considering some soil features, the
results showed that there is a positive and significant
relation between soil abundant, Macro-fauna biomass
and some other soil features such as its moisture and
nitrogen. Earthworms can be considered as a suitable
agent to evaluate how land control can affect
outgrowth dynamic and production, besides it is the
best factor in recognizing soil quality (Bird et al.,
2004; Richard, 2004, Muturi et al., 2009). Therefore
knowing more about its features in different
environments is very important. Whereas their
reduction in population and variety can bring negative
effects on soil structure, analysis flow, gas penetration
and exchange processes, then they can disturb plants
growth. Consequently we must identify these
creatures’ variety indexes in ecology, preservation
programs, habitat management and ecosystem
evaluation (Mohammad Nejad Kiasari et al., 2011;
Jalilvand and Kooch, 2012). These indices are very
useful to consider soil creatures' varieties in accordance
with pattern quality (Gongalsky et al., 2008).
Considering the importance of soil macro-fauna to
analyze humus and food cycle, the present research
has been done to assess forestation successfulness in
accordance with soil invertebrate varieties, the effects
of some species such as Cypress, Poplar, Maple, Alder
and Natural forest on macro-fauna abundance and
biomass as well their links to some other soil qualities.
1 Results
1.1 Soil macrofauna biodiversity
Investigating macro-faunas abundance (Table 1,
Figure 1) and biomass (Table 1, Figure 1) showed that
alder forestation was greatest in variety while cypress
showed the smallest one. Totally soil macro-fauna
abundance and biomass will decrease in alder, maple,
natural forest, poplar and cypress, respectively (Figure
1 and Figure 2). All the variety indices (except Margalef
abundance) showed a significant difference in two
different depths, 0~10 cm and 10~20 cm in accordance
with excess and biomass however the former one owned
the greatest amount (Figure 3 and Figure 4).
Molecular Sil Biology