|
|
|
Overview |
Crop Production |
Crop Pattern |
Crop Yield |
Irrigation |
Soil Management | Precision Farming |
Relevant Products |
Relevant Links
Studying Effective factors in selection of understory farming
lands and there effects on forest stands using GIs
Rahim maleknia
CMsc Student of Tehran university
M. namiranian
Pro. Of natural resourse faculty of Tehran university
J.feghhi
Pro. Of natural resourse faculty of Tehran university
Abstract
This study conducted for investigation on effective factors in selection of
understory farming lands locations and their effects on forest stands in central
zagros using GIS. in order to the goal, forest types and understory farming lands
surroundings were surveyed by GPS. Then gathered data were used as inputs
for GIS. Results show that understory farming lands are not limited in gentle
slope, but this factor somewhat is contribute in selection of farming land position.
Aspect, elevation and proximity to village do not play important role in position of
these area. These farming land result in high stands and decreasing canopy
cover percentage. in these location there are not any regeneration nether by
seed nor by shoot origion.
Introduction
Zagros forest with an area of 5 million ha account for almost 40% of the country's
forests and classified as semiarid forests. the main influence of these forests is
on water supply, soil conservation, climate alternation and socio _ economical
balance of entire country ( sageb talebi et al., 2004).seven first grade rivers
having 34.5 billion cubic meters water accounting for 40% of the total ground
water of the country initiate in zagros ( sageb talebi et al., 2004 , jazirei &ibrahimi
rastagi 2003 ). Ecological capability especially the possession of rich water
supplies has resulted in high population intensity in the region. 9.8 million People
reside in this region with 1.5 million living inside the forested area extensively
affecting the ecosystem ( sageb talebi et al., 2004).the forests are considered as
degraded forests with firewood , livestock feeding and understory farming as the
main causes( maleknia 2005, sageb talebi et al., 2004, jazirei & ebrahimi rostagi
2003, fatahi 1994).approximately 800 thousand ha ( near to 20 %) understory of
these this forests are used as non_irrigated farming lands(jazirei & ibrahimi
rostagi 2003, maleknia2006). Due to the soil conservation role of these forests
and decreasing the crown canopy by these farming understorys, these areas are
the main center of soil erosion. These farming area are not limited in gentle slope
and there are in steep slope too ( jazirei & ibrahimi rostagi 2003, maleknia 2006).
Zagros divided into two distinct regions based on the different oak species:
northern zagros and southern zagros. North zagros is exclusive site of Quercus
infectoria mixed whit Q. libani or Q. brantii or both. However, southern zagros is
the exclusive site for Q. brantii. Furthermore, northern zagros can be considered
more humid and colder than southern zagros.
These forests, often have open canopy ( sageb talebi et al., 2004, ghazanfari et
al., 2004, ebrahimi 1998). The most of forest have shut origin (coppice stand) and
seed origin forest, comprise minor proportion of this forests ( porhashemi 2003,
jazirei & ibrahimi rostagi, 2003).
This study conducted in southern zagros to investigate effective factors in Site
Selection of understory farming lands and effect of these areas on forest stand.
|
|
|