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Molecular Soil Biology (online), 2013, Vol. 4 No.2, 7-15
ISSN 1925-2005
http://msb.sophiapublisher.com
7
Research Report Open Access
Effects of Pit and Mound Landscape on Soil Ecosystem Engineers at Local
Scales-a Case Study in Hyrcanian Forest
Yahya Kooch
1
, Seyed Mohsen Hosseini
2
, Jahangard Mohammadi
3
,
Seyed Mohammad Hojjati
4
1. Assisstant Professor of Forestry, Tarbiat Modares University, Iran
2. Associate Professor of Forestry, Tarbiat Modares University, Iran
3. Associate Professor of Soil Sciences, Shahrekord University, Iran
4. Assistant Professor,University of Natural Resources and Agriculture Sciences of Sari, Iran
Corresponding author email:
yahya.kooch@modares.ac.ir;
Authors
Molecular Soil Biology, 2013, Vol.4, No.2 doi: 10.5376/msb.2013.04.0002
Received: 11 Jan., 2013
Accepted: 23 Jan., 2013
Published: 27 Apr., 2013
This is an open access article published under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction
in any medium, provided the original work is properly cited.
Preferred citation for this article:
Kooch et al., 2013, Effects of Pit and Mound Landscape on Soil Ecosystem Engineers at Local Scales-a Case Study in Hyrcanian Forest, Molecular Soil
Biology, Vol.4, No.2 7-15 (doi: 10.5376/msb.2013.04.0002)
Abstract
Earthworms comprise a major proportion of the total invertebrate biomass in terrestrial ecosystems and they are often
called "ecosystem engineers". Felling of trees by wind occurs continually in forest ecosystems. Many of trees are uprooted by
windthrow, annually. The uprooting of old trees creates multiple microsites (e.g. pit and mound landscape) that are main source for
soil heterogeneity. Efforts have been made in this study to determine the impact of pit and mound landscape on earthworm
assemblages. Due to, the experimental forest station of Tarbiat Modares University studied that is located in Mazandaran province,
northern Iran. For this purpose, twenty hectare areas considered and numbers of thirty four uprooted trees were found. Five
microsites were distinguished including mound top, mound wall, pit bottom, pit wall and closed canopy. Soil samples were taken at
0~15 cm, 15~30 cm and 30~45 cm depths from all microsites using core soil sampler with 81 cm
2
cross section. Soil pH, water
content, organic carbon, total nitrogen and carbon to nitrogen ratio measured in the laboratory. The earthworms were collected
simultaneously with the soil sampling by hand sorting method. As a result, in this study soil characters changes had significantly
impact on earthworm abundance at local scales. Earthworm's (epigeic, anecic and endogeic) density and biomass had more amounts
in pit bottom whereas, no earthworms found in mound top and wall microsites. Principle Component Analysis (PCA) performed on
earthworm population and environmental variables showed that water content and C/N ratio are potential indicators of earthworm
abundance change.
Keywords
Forest disturbance; Tree uprooting; Earthworm; Soil character; PCA
1 Introduction
Soil organisms are known to affect plant growth by
enhancing mineralisation of soil organic matter and
modifying physical and chemical properties of soil
(Bardgett et al., 2005). Within soil organisms,
earthworms are in term of biomass and activity among
the most important detritivores in terrestrial ecosystems
(Edwards, 2004). They are also known to affect plant
growth, generally positively, via five main
mechanisms (Brown et al., 2004; Laossi et al., 2010):
(1) an increased mineralization of soil organic matter
(2) the production of plant growth substances via the
stimulation of microbial activity; (3) the control of
pests and parasites; (4) the stimulation of symbionts
and (5) modifications of soil porosity and aggregation,
which induces changes in water and oxygen
availability to plant roots. Earthworms have been
viewed as ecological engineers (Kooch and Jalilvand,
2008) and their activities profoundly affect soil
physical and biological properties that can directly or
indirectly alter plant-related processes such as
resourceallocation, growth and recruitment (Szlavecz
et al., 2011). Earthworms of the family
Lumbricidae
are ubiquitous inhabitants of terrestrial ecosystems,
with the majority of species found in the Holarctic:
from Canada and the USA through to Eurasia and
Japan (Nechitaylo et al., 2010).
Earthworms are subject to physical, chemical and
biological changes in soil, so they have a major role in
soil structure and performance (Rahmani, 2000).