The Investigation of Functional Diversity Effect on Composition, Density and Diversity Indices of Weeds in some Medicinal Plants

Document Type : Scientific - Research

Authors

1 Department of Agrotechnology, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran

2 Department of Agronomy, Payame Noor University, Iran

3 Department of Horticultural Sciences, Faculty of Agricultural Sciences and Engineering, University of Tehran, Karaj, Iran.

4 Department of Agrotechnology,Faculty of Agriculture, Ferdowsi University of Mashhad, Iran

Abstract

Introduction
Nowadays, with increasing tendency to monoculture of medicinal and horticultural plants, the range of genetic diversity in agricultural ecosystems has decreased. Conventional agricultural activities with simplification of ecosystems makes ecosystems more unstable and more sensitive to environmental hazards. Therefore, the promotion of biodiversity in these systems is effective for their recovery and sustainability. The purpose of designing sustainable agricultural ecosystems is to integrate ecosystem components in such a way that maintains and strengthens the biodiversity, productivity and self-regulatory capacity of the agricultural ecosystem. Functional diversity is achieved by using different functional species with different roles in agroecosystems. The role of weeds in increasing diversity in agroecosystems is very important because they are closely associated with many of the crops and genetic exchange between them. The presence of weeds in the crop ecosystem reduces genetic vulnerability through strategy of environmental diversification as well as the occurrence of resistance mechanisms.
Materials and Methods
In order to investigate the effect of some medicinal plants on weed density and diversity, an experiment was conducted based on a complete randomized block design with three replications at the agricultural research station, Ferdowsi University of Mashhad, Iran, during 2012 and 2013. Treatments included 13 medicinal species (Origanum vulgar, Hyssopus officinalis, Tanacetum parthenium, Echinacea purpurea, Ruta graveolens, Althea officinalis, Hypericum perforatum,Trigonella foenum-graecum, Oenothera erythrosepala, Malva sylvestris, Securigera securidaca, Achillea millefolium and Digitalis purpurea).After tillage, land preparation and leveling, each plant was cultivated in strips of 10*3 meters. After complete establishment of the plants in order to achieve the desired density, thinning operations were performed on each strip. The distance between the test strips was 0.5 m. Seeds of all studied plants were sown in April 2012. In both cropping years to study the diversity of weeds, a part of each plot with dimensions of 0.5 m was separated and remained without weeding and in all plots of medicinal plants, density and dry weight of weeds was determined at two stages of vegetative and reproductive growth of medicinal plants. Also, physiological and morphological characteristics such as height, leaf area and dry weight of plants in each plot were measured. In order to calculate the diversity of weeds, the type of weed species and their density were determined in quadrates with dimensions of 40*40 cm. Then the weeds in each plot were harvested separately and transferred to the laboratory and were placed at 70 °C for 48 hours to determine the dry weight. Shannon, Margalf and Simpson diversity indices were used to quantify weed diversity.
 
Results and Discussion
The results indicated that the effect of medicinal species on total weed density and weight was significant. The highest and the lowest dry weed weight was obtained in Digitalis purpurea (39.4 g.m-2) and Tanacetum parthenium (3.2 g.m-2), respectively. The highest total weed density was observed in Malva sylvestris, Securigera securidaca, Digitalis purpurea and Hyssopus officinalis. Malva sylvestris had the highest weed richness (four species) that it was not significantly different with Securigera securidaca and Achillea millefolium. During different sampling years and stages, the highest Shannon index was obtained in Achillea millefolium (0.48) that it was not different with Malva sylvestris, Securigera securidaca, Hyssopus officinalis, Hypericum perforatum, Digitalis purpurea and Echinacea purpurea, significantly. Also, the highest margalof index was obtained in Malva sylvestris, Achillea millefolium and Hyssopus officinalis (4.05, 4.03 and 3.33, respectively). Studied medicinal species for weed diversity divided to 5 groups in 75% similarity level.
Despite the importance of biodiversity for the stability of natural ecosystems and agroecosystems, increasing species and functional diversity, simultaneously, is necessary to improve agroecosystem’s function. Keep the limited weed population in field increase functional diversity of agricultural landscapes but, this profit must reach equilibrium with the risk of decreasing crop production due to competition with weeds.

Keywords


Adinehei, M., Bazoobandi, M., Ghorbani, R., and Hajmohammad Nia, K., 2012. Investigation of weed distribution and diversity in cotton field of Esarayen. Iranian Journal of Field Crops Research 10(1): 53-63. (In Persian with English Summary).
Albrecht, H., 1995. Changes in arable weed flora of Germany during the last five decades. In: Proceedings of the 9th EWRS Symposium, Budapest. p. 41-48.
Altieri, M.A., 1999. The ecological role of biodiversity in agroecosystems. Agriculture, Ecosystems and Environment, 74: 19-31.
Asadi , G.A., Azizi, E., and Ghorbni, R., 2013. Effect of planting pattern and manure rates on diversity and density of weeds in spinach and garlic fields. p. 242-245. In: 5th Iranian Weed Science Conference, 24-26 August 2013, Karaj, Iran. (In Persian with English Summary)
Azizi, G., Koocheki, A., Nassiri Mahallati, M., and Rezvani Moghaddam, P., 2009. The effect of crop diversity and nutrient resource on weed composition and density in different cropping pattern. Iranian Journal of Field Crops Research 7: 115-125. (In Persian with English Summary)
Benton, T.G., Vickery, J.A., and Wilson, J.D., 2003. Farmland biodiversity: Is habitat heterogeneity the key?. Trends in Ecology and Evolution18: 182–188.  
Diaz, S., and Cabido, M., 1997. Plant functional types and ecosystem function in relation to global change. Journal of Vegetation Science 8: 463-474.
Dyer, A.R., Goldberg, D.E., Turkington, R., and Sayre, C., 2001. Effects of growing conditions and source habitat on plant traits and functional group definition. Functional Ecology 15: 85-95.
Edim, H., Sarani, M., and Minbashi Moeini, M., 2010. Determining weed maps and population characteristics of irrigated wheat fields for Sistan and Baluchestan province. Weed Research Journal 2(1): 1-14. (In Persian with English Summary)
Esfandiari, H., Tabatabaee, R., Minbashi Moeini, M., and Nooralizadeh, M., 2013. Investigation of diversity, density and dominant weed species of irrigated barley fields of Isfahan, using GIS (geographic information system). p. 428-431. In 5th Iranian Weed Science Conference, 24-26 August 2013, Karaj, Iran. (In Persian with English Summary)
Gliessman, S.R., 1998. Agroecology: Ecological Process in Sustainable Agriculture. Ann Arbor Press, Ann Arbor, MI. 400 p. 
Hasanejad, S., Mohammad Alizadeh, H., Mozaffarian, V., Chayichi, M.R., and Minbashi Moinni, M., 2009. Survey of density and abundance for barely field’s weeds in Azarbayjan -e- shargi province. Journal of Iranian Weed Science 5(1): 69-90. (In Persian with English Summary)
Jahani Kondori, M., Koocheki, A, Nassiri Mahallati, M., and Rezvani Moghaddam., 2012. The investigation of effect of some chemical characteristics of soil on weed diversity index in wheat fields of east Mashhad. Journal of Agroecology 4(2): 91-103.
Koochaki, A., Nassiri Mahallati, M., Tabrizi, L., Azizi, G., and Jahan, M. 2006. Assessing species and functional diversity and community structure for weeds in wheat and sugar beet in Iran. Iranian Journal of Field Crop Research 4:105-129. (In Persian with English Summary)
Koocheki, A., Nassiri Mahallat, M., Hasanzadeh Aval, F, Mansoori, H., Amiri, S.R., Zarghani, H., and Karimian, M., 2013. The investigation of vegetables biodiversity in Iran’s agroecosystems. Applied Ecology 2(4):1-11. (In Persian with English Summary)
Koocheki, a., Nassiri Mahallati, M., Asgharipoor, M.R., and Kodashenas, A., 2004 a. Biodiversity of fruits and vegetables in Iran. Iranian Field Crop Research 2(1): 79-87. (In Persian with English Summary)
Koocheki, A., Nassiri Mahallati, M., Jahani Kondori, M., and Broomand Rezazadeh, Z., 2011. The study of biodiversity of industrial crops in Iran. Iranian Journal of Field Crop Research 9(3): 301-309. (In Persian with English Summary)
Koocheki, A., Nassiri, M., Jahanbin, G., and Zarae, A. 2004 b. Diversity of crop cultivars in Iran. Desert 9(1): 49-67. (In Persian with English Summary)
Lagerlof, J., and Wallin, H., 1993. The abundance of arthropods along 2 field margins with different types of vegetation composition—An experimental-study. Agriculture Ecosystems and Environment 43: 141–154.
Magurran, A.E., 1988. Ecological diversity and its measurements. Princeton University Press, Princeton, NJ, 179 p.
Martinez-Ghersa, M.A., Ghersa, C.M., and Satorre, E.H. 2000. Coevolution of agriculture systems and their weed companions: implication for research. Field Crops Research 67: 181-190.
Matinzadeh, H., Alimoradi, L., and Bahari Kashani, R., 2011. The investigation of species, functional and structural diversity of orchard’s weeds in Fariman. Journal of Weed Ecology 2(1): 19-31. (In Persian with English Summary)
Naseri, H.R., Azarnivand, H., Zehtabian, G., Ahmadi, H., and Jafari, M., 2010. Investigation of relation between some physical and chemical soil properties and marginal vegetation communities of playa. Rangeland 3(4): 652-667.
Nassiri Mahallati, M., Koocheki, A. Rezvani Moghaddam, P., and Beheshti, A., 2001. Agroecology. Ferdowsi University of Mashhad, Iran, 460 p. (In Persian)
Nekahi, M.Z., Soltani, A., Siyahmarguei, A., and Bagherani, N., 2013. Identification and determining diversity and dominant index of wheat fields’ weed flora in Bandar Gaz, Golestan province. p. 492-495. In 5th Iranian Weed Science Conference, 24-26 August 2013, Karaj, Iran. (In Persian with English Summary)
Norozzadeh, Sh., Rashed Mohasel, M.H., Nassiri mahallati, M., Koocheki, A., and Abbaspour, M., 2008. Evaluation of species, functional and structural diversity of weeds in wheat fields of Northern, Southern and Razavi Khorasan provinces. Iranian Field Crop Research 6(2): 471-485. (In Persian with English Summary)
Noss, R.F., 1990. Indicators for monitoring biodiversity: A hierarchical approach. Conservation Biology 4:355–364.     
Poggio, S. L., Satorre, E. H., and de la Fuente, E. B., 2004. Structure of weed communities occurring in pea and wheat crops in the Rolling Pampa (Argantina). Agriculture, Ecosystems and Environment 103: 225-235.
Porheidar Ghafarbi, S., and Hassannejad, S., 2013. Identification and survey of weeds community indices in alfalfa fields of Shabestar. Journal of Agricultural Knowledge and Sustainable Production 23(3): 71-87. (In Persian with English Summary)
Raheb, S., Mablaghi, M., and Golain, B., 2012. The effects of some cover crops on weeds diversity changes in citrus orchards of Northern Iran. Research Achievements for Field and Horticulture Crops 1(1): 51-60. (In Persian with English Summary)
Storkey, J., and Cussans, J.W., 2007. Reconciling the conservation of in-field biodiversity with crop production using a simulation model of weed growth and competition. Agriculture, Ecosystems and Environment 122: 173–182.
Thomas, C.F.G., and Marshall, E.J.P., 1999. Arthropod abundance and diversity in differently vegetated margins of arable fields. Agriculture, Ecosystems and Environment 72: 131–144.
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