The Effect of Type of Marginal Land Use on the Plant Diversity
The objective of this study closely focuses on the
settlement of the effect of marginal land use on plant diversity. The
location of this study was Sar Firouze Abad region with rainfall of over
350 mm and slope of over 12%. Five treatments in terms of land use (exclusion
area, grazed range, fallow, annual medic cultivation, wheat cultivation)
done with the repetition of five times. The factors, such as the number
of species and the number of plant bases in each species in each sampling
were measured. The method used here is based upon complete randomized
design applying Duncan test and Raunchier method for classification of
plant species and also Shannon-Wiener index of diversity and homogeny
utilized. The results show that there are 76 species belonging to 60 genus
and 19 families spreading in the region under study. The most dominant
families are Fabaceae with 15 species covering 20% and Poaceae with 13
species covering 17%, respectively. According to Raunchier method the
life form of the region species can be classified as Therophytes 66%,
Geophytes 3%, Hemicryptophytes 26% and Chamaephytes 5%. The results also
illustrate that the treatment of exclusion area has the most plant diversity
in comparison with treatments of fallow, annual medic cultivation, wheat
cultivation and range grazed.
Nowadays, researchers regard rangelands primarily as a main
genetic bank. Sustainable bio-diversity proves to be the main objective
in this regard and it insists on the fact that living things diversity
should be preserved in possible ways. The change of rangelands into rain
feed lands demonstrates the destructive interference of man in natural
ecosystems led to the erosion of soil and cover and plant diversity. These
lands called marginal lands which are in fact buffer regions. They protect
main regions or rangelands like battlements. The establishment of permanent
residence by man and his cattle in these regions destroyed the natural
cover and increased the number of species bred by him. The relationship
between variety and sustainability has arisen a lot of discussions among
researchers (Eviner and Chapin, 2001; Waldhardt and Otte, 2003, 2004;
Cingolani et al., 2005; Wellstein et al., 2006). Many ecologists
maintain that the highs richness of species is viewed as one of the most
favorable features in every society or ecosystem. This feature is of high
significance in evaluating the methods concerning the issue of protection
of nature (Stoblgren, 2006). In order to measure diversity many factors
has been used invented, but perhaps the total number of species under
the name of richness of species is much more well-known (Magurran, 1988).
Naimi (2001) used satellite information in order to evaluate plant diversity
in Golestan National Park. He shoed that plant diversity factor is the
most effective one in analyzing floristic diversity. Chamani (1995) compared
and contrasted diversity using similar and dissimilar factors. He demonstrated
that mountain unites have the maximum level of diversity. Sharifie (1996)
performed a research on determining diversity and the richness of species
and classification of meadow. He made use of Whittaker method and cluster
analysis. He showed that diversity of plant cover observed more in grasslands.
Glichnia (2006) did a comparative study of variety and production of plant
cover bath in and of out of Robat Garabil of Golestan National Park. The
study carried out in key, critical and reference regions whose Topographical,
soil and climate conditions were nearly the same. He maintained that the
excessive grazing in critical region made diversity and product poor while
in key region due to moderate grazing is Reich and in reference region
due to lack of grazing plant diversity is poor but product is rich regarding
the rest of regions. The planning and Budgeting Organization carried out
a study on the cause of destruction on Chahar tang-e-Koshk-e-zar wetland.
The study revealed that the cause of destruction of this ecosystem was
due to the change of rich rangelands into farming lands and also excavation
for supply of water for irrigation purpose. This change in land use made
both rich flour of the region and plant diversity destroy. The destruction
of plant diversity caused the bio-diversity of the region where was once
a hunting-ground to vanish. So a serious damage was done to sustainable
development of the region. Delitti et al. (2005) studied the fire
effect on plant composition and productivity of shrub land of Valencia
Region (Spain). He demonstrated that all of these effects on plant composition
and productivity were negative and damaging. Otte (2005) made models of
plant diversity and richness in farming lands, grasslands and wetland
using GIS. Her model reveals the significance of diversity and richness
in ecosystems in terms of economic management of these lands. Kosins (2005)
carried out a research in Sweden and showed that the growth and variety
of plants of rangelands and grasslands managed in traditional ways are
23% more than lands under mechanized management. Eycott et al.
(2006) illustrated that one of the factors of sustainability in forests
is plant diversity in these lands which means a positive sequence. So
plant diversity is essential to sustainability of a ecosystem. It should
be noted that habitations of village margins and margins of farming lands
(marginal lands) can play a vital role in enriching and development of
various species of plants. But there is a little in formation on how such
habitations can effect on plant species. The issue of sustainable development
in agriculture together with the preservation of diversity and genetic
bank in lands changed in land use and also the study of the effects of
such uses is the object of this study.
MATERIALS AND METHODS
This study performed in Sarfirouze Abad rangelands in Kermanshah
province with geographical latitude 47 dgree and 6´ longitude 34 degree
and 15´, rainfall over 350 mm, altitude 1542 m and sleep 12%. The texture
of soil is loamy-clay. Five treatments in terms of the type of use including:
exclosure land (evidence), rangeland under grazing, fallow, annual medic
cultivation and wheat cultivation with repetition of five times were used
in farming year of 2005-2006. The measures of sampling are an area of
In each plot, factors such as: the number of plant bases
and the number of species were measured. The results of this study are
analyzed by SPSS computer program and Duncan test. The formulas for plant
diversity used here are:
here, Pi is the ratio of one species to all, LnPi log of
species ratio and S is the total number of species. In this index the
bigger number, the more diversity and the bigger values of J demonstrate
that the distribution of species is more consistent in the frame. So we
can conclude that it a satisfactory evidence for the suitable propagation
of plant species.
results demonstrated that there were total 76 species belonging to 60
genera and 19 families in the geographical region under study (Table
1). The richest families are Fabaceae with 15 species (20%) and Poaceae
with 13 species (17%), repetitively. Out of total number of existing species
in the region under study, 10% belong to Fabaceae family and sixteen percent
belongs to Poaceae family. With regard to abundance of genera and species,
the other plant families are Compositae, Rannunculaceae, Caryophyllaceae,
Euphorbiaceae, Lamiaceae, Boraginaceae and Apiaceae, respectively. Plant
species of the region can be classified with accordance to live form and
Raunchier method as 66% Therophytes, 3% Geophytes, 26% Hemicryptophytes
and 5% Chamaephytes. Duncan test showed that there was a significant difference
between treatments at the level of 1%. This occurred due to the number
of plant (Table
2). The exclosure treatment had the maximum number of plant. There
was also a significant difference between treatments at the level of 1%
regarding the plant diversity. With regard to Duncan test and the diversity
index of Shanon-Wiener, the treatment of exclosure pasture was more diverse
and equal than the rest of the treatments (Table
3). Shanon-Wiener index was used in treatment number six (the exclosure
pasture having the maximum diversity) to determine the effect of plot
positioning in sampling unit. The result also illustrated that the plot
number five had the maximum diversity and equally constancy.
The floristic list of plant species
observed in the geographical region under study
Analysis of variance for number
of plants and number of species
NS = Non Significant
Analysis of variance number of
plants and number of species based on Duncan test and plant
diversity based on Shanon-Wiener index in different treatment
Values with different letter(s)
are significantly different at p<0.05
The rainfall of the
region made the anticipation that the majority of plant species would
be Therophytes and annuals regarding Rankayer`s classification. This fact
also reported by other researchers because the region under study had
the driest days in a year (regarding Amberege`s classification). In this
climate plant species (their seeds) have to be buried into the ground
in order to survive in harsh season conditions and then grow again in
convenient temperature and rainfall. The dry climate and insufficiency
of rainfall also caused the dominance of Poaceae family due to their resistance
to dry climate. The diversity in annual medics and Trifoliate family in
the region under study made Fabaceae family have the most diversity due
to pass harsh dry season, burying their hard-cover seeds into the ground.
The Duncen test illustrated that there was the maximum number of plants
and plant diversity in the treatment of exclusion pasture approved by
Shanon-winer index. The treatment of exclosure pasture had the maximum
plant composition, consistency and the production of plants which agree
to Delitti`s (2005) study. This result differed slightly from Glichnia`s
(2006) because the comparison made by him was based upon the treatment
of exclusion under balanced grazing. It showed that the balanced grazing
caused natural harvest which controlled the competition among plants.
The studies done by Programming and Budgeting Organization and Kosins
(2005) demonstrated that diversity could be observable in the lands where
there were no human interferences and change in land use. Nowadays researchers
and scientists regard pastures as a genetic bank rather than a source
of cattle nourishment and so on. As the present study revealed, the exclosure
of pasture is the best way to protect plant cover in order to preserve
water, soil and plant diversity which keep safe genetic banks. It also
moderated climate conditions and safeguarded medical herbs, wild life,
an parks. The reason why the treatment of medic had more diversity than
the wheat treatment and fallow would be explained in terms of the fact
that this treatment was closer to the treatment of exclosure pasture.
The measurement of diversity and consistency in the treatment of exclosure
pasture demonstrated that the frame number five was more diverse and constant
than the rest of the frames. The reason was that this repetition located
in the low part of the slope. This region had deeper soil so it bore more
penetrating effect which provided better condition for the growth of plants.
Regarding Table 1, it can be claimed that Shanon-wiener index is not suitable
for measuring diversity and consistency in the regions where the number
of plants is small and this small number exists in all of the frames.
Result showed that there is minimum plant diversity and minimum number
of plant in the fallow treatment in comparison with other treatments.
Thus for a suitable development must avoid fallow land. It can be concluded
that the modern use of pastures as a genetic bank, protection of water
and soil, wild life, medical herbs, parks, moderation of climate and other
public benefits, except the supply of forage for cattle, support the idea
that they should be used as exclosure pastures. This can be generally
recommended for all pastures. The change of marginal lands into exclosure
pastures will be of high importance here.
1: Chamani, A., 1995. Investigation of diversity and richness on plant species in Golestan National Park. MS. Thesis, Gorgan University.
2: Cingolani, A.M., N.M. Imanuel and D. Sandra, 2005. Grazing effects on rangeland diversity: A synthesis of contemporary models. J. Ecol. Appl., 15: 757-773.
Direct Link |
3: Delitti, W., F. Anna, T. Louis and V. Ramon, 2005. Effects of fire recurrence in Quercus coccifera L. shrub lands of the valencia region (Spain): I. Plant composition and productivity. Plant Ecol., 177: 57-70.
Direct Link |
4: Eviner, V.T. and F.S. Chapin, 2001. Plant species provide vital ecosystem functions for sustainable agriculture. Rangeland management and restoration. J. California Agric., 55: 54-59.
Direct Link |
5: Eycott, A.E., A.R. Watkinson and P.M. Dolman, 2006. Ecological patterns of plant diversity in a plantation forest managed by clearfelling. J. Applied Ecol., 43: 1160-1171.
Direct Link |
6: Glichnia, H., 2006. Comparison of plant cover in index, reference and critical area in golestan national park and range's neighbor. J. Paguheshe Sazandegi, 30: 72-74.
7: Kosins, S.A.O., 2005. Plant Species Richness In Midfield Islets and Road Verges-The Effect Of Landscape Fragmentation. Department of Botany, Stockholm University, Sweden.
8: Magurran, A.E., 1988. Ecological Diversity and its Measurement. 1st Edn., Princeton University Press, Princeton, ISBN: 0691084858.
9: Naimi, B., 2004. Evaluation and creation of map of diversity and richness in plants of golestan national park by using TM data land sat shuttle. M.Sc. Thesis, Tarbiat Moddaress University.
10: Otte, A., 2005. Modules for the modeling of land-use dependent plant species diversity in cultural landscapes. Dipl.-Eng. Birgit Reger, Dipl.-Biol. Dietmar Simmering, Dipl.-Biol. Camilla Wellstein.
11: Sharifie, N.G., 1996. Investigation of plant diversity of prairie life form in ardabil. J. Paguheshe Sazandegi, 33: 26-31.
12: Stoblgren, T.J., 2006. Measuring Plant Diversity Lessons from the Field. Oxford University Press, UK.
13: Waldhardt, R. and A. Otte, 2003. Indicators of plant species and community diversity in grasslands. Agric. Ecosyst. Environ., 98: 339-351.
Direct Link |
14: Waldhardt, R. and A. Otte, 2004. Estimation and prediction of plant species richness in a mosaic landscape. Landscape Ecol., 19: 211-226.
Direct Link |
15: Wellstein, C., A. Otte and R.Waldhardt, 2007. Impact of site and management on the diversity of Central European mesic grassland. Agric. Ecosyst. Environ., 122: 203-210.
Direct Link |