جستجوی مقالات مرتبط با کلیدواژه « غنای گونه ای » در نشریات گروه « اکولوژی »

Diversification through the use of intercropping systems is known to enhance stability. Intercropping is potentially able to reduce pests and weeds, increase the system production and increase the exploitation of available environmental resources, compared to monocultures. Ronald and Charles (2012), stated that weeds biomass decreased in the intercropping of maize and squash, due to squash ghosting on weeds. They also reported that the intercropping of pelargoniums (Pelargonium sp.) and mint (Mentha arvensis L.) decreased weed growth and biomass.

This experiment was conducted in 2014-2015 growing season based on a randomized complete block design with three replications at Agricultural Research Station, Faculty of Agriculture, Ferdowsi University of Mashhad. Experimental treatments were 1 row lettuce + 1 row alyssum (1:1), 2 row lettuce + 2 row alyssum (2:2), 3 row lettuce + 3 row alyssum (3:3), monocultures of lettuce and alyssum. Alyssum transplants were sown on 08/04/2015 and lettuce transplants were sown on 21/04/2015 in rows with a distance of 50 cm. During the growing season, composition of weed species together with weed density and dry matter were measure at 2 time in randomly sampled 0.6×0.6 m quadrates. Using the species frequency Margalef richness index and several diversity indices including Shannon- Weiner and Simpson’s index and species evenness were calculated for each treatment.

At first and second sampling, the highest density of weeds was observed in 2 row Lettuce + 2 row alyssum (2:2) with 282.4 and 122.03 plant per square meter, respectively. The lowest density of weeds was observed through the first and the second sampling, respectively, in Lettuce monoculture with 111.11 plant per square meter and in 1 row lettuce + 1 row alyssum (1:1) with 41.66 plant per square meter, respectively. In the first sampling, highest and lowest the Shannon-Wiener diversity index were observed in 2 row lettuce + 2 row alyssum (2:2) and 3 row lettuce + 3 row alyssum (3:3) with 0.53 and 0.35, respectively. In the second sampling, highest and lowest the Shannon-Wiener diversity index were observed, in 1 row lettuce + 1 row alyssum (1:1) and 2 row lettuce + 2 row alyssum (2:2) with 0.37 and 0.12, respectively. Also, in the first sampling, highest and lowest the Simpson’s diversity index were observed, in 2 row lettuce + 2 row alyssum (2:2) and 3 row lettuce + 3 row alyssum (3:3) with 0.66 and 0.44, respectively. In the second sampling, highest and lowest the Simpson’s diversity index were observed, in 2 row lettuce + 2 row alyssum (2:2) and alyssum monoculture with 0.46 and 0.05, respectively. In the first sampling, highest and lowest the Shannon-Wiener evenness index were observed, in 2 row lettuce + 2 row alyssum (2:2) and 3 row lettuce + 3 row alyssum (3:3) with 0.41 and 0.25, respectively. In the second sampling, highest and lowest the Shannon-Wiener evenness index were observed in lettuce monoculture and 2 row lettuce + 2 row alyssum (2:2) with 0.31 and 0.11, respectively. In the first sampling, highest and lowest the Margalef richness index were observed, in lettuce monoculture and 3 row lettuce + 3 row alyssum (3:3) with 1.48 and 0.98, respectively. In the second sampling, highest and lowest the Margalef richness index in 1 row lettuce + 1 row alyssum (1:1) and alyssum monoculture with 1.63 and 0.53, respectively.

The results showed that the ecological characteristics of ecosystems such as diversity and density of weeds were affected by row intercropping patterns. In almost all cases except Margalef species richness index, intercropping 2 row lettuce + 2 row alyssum was better compared to other patterns of cropping. It can be concluded that the most important advantage of intercropping is stability of canopy structure in terms of weeds and crop population and therefore enhancing the competition ability of the crops.

There are various vegetation sampling methods regarding objectives of Management at forests. To aim of this study, we undertook a comparative study at Shineh Ghelaee protected forest at middle Zagros using single-scale sampling, single-scale sampling based on transects, and multi-scale sampling methods to investigate the herbaceous layer diversity. In order to know the situation of the region and compare the performance of different sampling methods, richness and diversity indices, the mean of conservatism coefficient and floristic quality index, and the conservation status of plant species in the region were calculated and compared with three sampling methods. The results indicated that Poaceae, Asteraceae, and Fabaceae were the most important families based on the number of species and chorological studies revealed that the most species belonged to the Irano-Turanian zone, The results also showed the life-form of plants dominated by therophytes in this region. Also, the results revealed that the greatest abundance of conservative species (Coefficient of conservatism:1-3 and belonging to the first category of coefficients conservatism), observed by three sampling methods, whereas the total number of plant species,  endemic vascular plant species, diversity indices, evenness index, mean CC and FQI were higher at single -scale sampling method results. In the percent study, it seems that different sampling methods can influence the identification of endemic species, mean CC and FQI, and diversity indices, As a result to study vegetation in areas we suggest that single-scale sampling, single-scale sampling based on transect, and multi-scale sampling methods have the same efficiency in small and homogenous areas with floristic surveying goals, whereas single-scale sampling methods are more appropriate to measure mean CC, diversity indices and FQI.

Parishan International Wetland is one of the most important freshwater wetlands in Iran, which is on the list of endangered wetlands (Montreux) due to its complete drying up and habitat changes. This research was carried out in 2018 and 2019 to investigate changes in species diversity of waterbirds and it’s relationships with water surface in PIW. Semi-winter census data were collected from the Department of Environmental, Iran. Data were analyzed using the Species Diversity and Richness (SDR-IV) software. Species diversity indices including (Shannon-Wiener and Simpson D), species richness (Margalef and Minhinick) and evenness (Pielou and Simpson E) were calculated in a period of 31 years from 1998 to 2018. Trend of changes of the wetland reservoir surface and land use have been investigated, using satellite images. Results showed that diversity indices had an increasing trend during the years 1988 to 2001 and a decreasing trend from 2001 to 2018. Diversity indices reached lowest value in 2012 with the decrease of the wetland catchment area. The average values of 5-year period ​​of all indices from 1989 to 2008 did not differ significantly, but apart from the Minhinick index, other indices in the period of 2009-2013 and 2014-2018 had significantly lower values. (P<0.5). The wetland reservoir surface had been increasing from 1988 to 2000. From 2001 to 2018, except for the years 2005 to 2007, the trend was decreasing and from 2009, it has had almost no water areas. It was suggested that increasing the surface and depth of the wetland, diversity of incoming water resources, determining the ownership of the surrounding lands, implementation of monitoring programs, evaluation of operational plans and training of stakeholders are the most important strategies to restore biodiversity of wetland waterbirds.

To manage and conserve biodiversity, comprehensive knowledge of spatial patterns of species richness and diversity and effective factors on them is necessary. The changes of diversity and richness indices at an altitudinal gradient (700 meters) in Persian oak (Quercus brantii Lindl.) forests “Taf catchment in Khoram Abad” was investigated in this study. The physiographic and soil properties, and tree canopy cover were measured by the two 500 m2 sampling plots in each 100 m altitudinal classes. The three randomly located subplots (4m2), was used to investigate the ground herbal layer in each sampling plot. Based on the results there is not any significant correlation between richness, evenness, and diversity indices with altitude and slope, while a negative significant correlation was seen between evenness and diversity indices with tree canopy cover. Contrary to the absence of correlation between evenness and diversity indices with soil properties, there is a positive correlation between the amount of soil clay and silt and negative correlation between soil OC, K, N, and sand with richness indices. The results of PCA analysis showed that the amount of K, P, OC, saturated water content, pH, altitude, and tree canopy cover are the most important environmental factor in the study area. Despite the absence of specific patterns in richness, and diversity indices along the altitude gradient, the findings show that tree canopy cover affects evenness and diversity indices, and the soil properties affect richness indices.

Identification of plants in an area is essential for other studies such as ecological research, ecosystem management and plant conservation. In this study, the flora and plant diversity of Qezel Ozan- AqDagh altitude gradient rangelands, Khalkhal County in southern Ardabil province were investigated. For the study of flora, plant samples were collected and identified. Field harvesting were carried out in 2018, then chorology and life form of the species were determined. Then, richness, evenness and diversity indices were measured in the elevation classes. Based on the results, 31 family, 105 genera and 137 plant species were identified in the study area. Asteraceae (25 species), Poaceae (18 species), Fabaceae (16 species) and Lamiaceae (13 species) are the most important family in the region. The palnts life spectra based on Raunkiaer’s method showed that hemicryptophytes and trophytes were the most abundant biological forms in the region with 46% and 35%, respectively. In addition, results showed 47% of the species belonged to Iranian and Turanian vegetative zone. Among the vegetative forms, forbs had the highest abundance (73.72% of species). The results of analysis of numerical indices of species diversity and richness showed that these indices complied the Humped-shape pattern and at the different elevation classes have significant differences. The highest numerical values of diversity indices of Simpson (0.78), Shannon-Wiener (1.87) and richness indices of Menhinic (1.49) and Margalf (2.37) obtained in middle elevation class. The evenness index also showed an inverse relationship with elevation. The results of this study can be used to suggest plant species for restoration of the study area and similar areas.

Mansourieh and Sharifieh are two recently dried wetlands in Khuzestan province, that have become important dust sources. This study was carried out in Sharifieh and Mansourieh wetlands to assess the vegetation condition and trend, following the implementation of water spreading and artificial recharge in recent years. To evaluate changes in vegetation, five transects of 100 meters, 50 meters apart, were established in the water spreading site in a random systematic manner, and data was collected from 30 permanent plots for six times between 2017-2019. Species richness and diversity indices were measured using the coverage percentage factor. The results obtained in Mansourieh showed a significant difference between the water spreading site and the non-irrigated site. Simpson and Shannon indices showed a gradual increase in species diversity following the implementation of flood spreading by means of Shahid Poursharifi Channel. Likewise, in Sharifieh wetland, Shannon and Simpson diversity indices improved in response to the enhancement of species richness and decreasing dominance (from two dominant species to over 20 species). In Sharifieh, we obtained a significant difference between the years 2017 and 2018 in terms of diversity indices. In general, the flood spreading areas will experience an improvement in native vegetation, which will be translated into reduced dusts storm frequency and severity.

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.

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.

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.

Modern agricultural systems have adverse effects on environmental aspects of production and ecosystem health. Loss of biodiversity due to monoculture is one of these adverse consequences. Biodiversity and agriculture are strongly interrelated. While biodiversity is critical for agriculture, sustainable use of biodiversity corresponds to agricultural structure and function, and thus is an indicator for farming practices. Indeed, biodiversity is considered as a vital component of sustainable agriculture from the food security, nutrition, and livelihoods viewpoints. Agricultural expansion and intensification led to biodiversity loss in agroecosystems and reduction in the types and levels of ecosystem services (ES) that people benefit from. Considering the importance of biodiversity in sustainable agricultural systems and variability of agroecosystems in Zanjan province, the goal of this study was biodiversity assessment of crop and horticultural products in this province.

Agrobiodiversity research, of Zanjan province was evaluated at the county level and it was classified to two groups; agronomy and horticulture. For this purpose necessary data for assessment of biodiversity indices, including cropping area and types of crop and horticultural species for eight county in Zanjan province were obtained from Jihad Agriculture Management of these counties, statistics and information center, statistical report of Jihad Agriculture Ministry, and interviews with experts, managers and farmers during 2016. All crude data entered to excel program and then, some biodiversity such as Shannon, Simpson, Berger-Parker, Sorenson's similarity, uniformity, total number of species and the total number of individuals in all species were calculated according to their equations. Data analysis was performed by Excel var. 2010 and Canoco softwares.

The results showed that the highest and lowest values of Shannon index were calculated in Khoramdarah (2.14) and Khodabandeh (0.87) countiesin crop products section, respectively. Also, in the garden products section, the highest and lowest amounts of this index were related to the Tarom (0.99) and Khoramdar (0.62) counties, respectively. In terms of Simpson's index, the highest amount was obtained in Khoramdar county for crop products section (0.83) and Tarom county (0.81) for horticultural products section. The Berger-Parker index had the highest value in Khodabandeh (0.80) and Khoramdarah (0.79) countiesrelated to crops and horticultural products, respectively. According to the Sorenson similarity index for crops products, the highest similarity was found between Abajrood and Abhar, also, the highest level of similarity was found between Zanjan and Mahneshan for garden section. In assessment of the biodiversity indicators with the climatic condition of the Zanjan province, it was determined that in crops products, the biodiversity affected by precipitation and relative humidity, but in the horticultural products, it was strongly influenced by the minimum temperature and relative humidity. The variability of Shannon and Simpson were related to relative humidity, minimum, maximum and average annual temperatures in crops production section, but, these indicators were more related to maximum and average annual temperatures in garden products section. The results of this study indicated that biodiversity indices for some townships were not favorable in Zanjan province.

The diagram of the analysis redundancy (RDA) showed that the most biodiversity indicators were more correlated with maximum temperature and relative humidity among crops and gardens products.These results indicated that biodiversity has decreased in many regions and it was reached to lowest value. From this viewpoint, we have to understand the ability of biodiversity to support ecosystems such as agroecosystems and sustainable agriculture ecosystem by providing numerous services. Therefore, educating and encouraging farmers to use of crops types can improve the biodiversity services for suitability of agricultural systems in Zanjan province.

We are thankful to Jihad Agriculture organization of Zanjan province, and Gorgan University of Agricultural Sciences and Natural Resources (GUASNR) for all their companions and supports.

Application of organophosphate pesticides especially diazinon is a common phenomenon that cause pollution wide area of terrestrial and aquatic ecosystem. Therefore, an investigation of the effect of this organophosphorus pesticide on some beneficial soil microorganisms was investigated. In a laboratory research, diazinon in the concentration of 0, 4, 12, 50 mg.kg-1 was added to the soil and incubated. Then the soil sampled in different time of incubation, after preparing proper dilution, fungi, actinomycete, pseudomonas, intestinal bacteria and azotobacter cultivated in the specific medium in three replicates. The analysis was considered as completely randomized design (repeated measurement test). The effect of diazinon on biodiversity index of the cultivable microorganisms also evaluated.  In comparison to the control, after application of 4 mg.kg-1 diazinon in the soil the frequency logarithm of actinomycete and azotobacter decreased and pseudomonas increased. The frequency logarithm of intestinal bacteria and fungi were similar to untreated soil. In concentration of 12 and 50 mg.kg-1 the frequency logarithm of all the studied microorganisms reduced. Soil richness in the treatment of 4 mgkg-1 diazinon was more than control and significantly decreased in other concentrations. Biological diversity and evenness decreased in all concentrations of applied diazinon but dominance index increased in comparison with the control. Therefore, most studied soil microorganisms were incompatible with these concentrations of pesticide and this could reduce soil health and fertility.

One of the main objectives of organic agriculture is low negative effect on the environment and according to this issue, maintaining biodiversity is one of the key responsibilities of this agriculture system. Disuse of chemical fertilizers and using mechanization with less intensity caused significant increase in biodiversity in organic agriculture. Insect's diversity can help in biological control of pests, pollination and biological control of weeds and diseases. This study was performed based on the key role of insects in ecosystem function, especially in organic agro-ecosystems and effective factors for biodiversity of them and also with respect to the high potential for progressing of organic agriculture in Iran. The purpose of the study was to identify different families of insects in conventional and organic fields for wheat and potato crops in Fariman city. The study was carried out in wheat and potato fields at Fariman city in 2012. In order to collect insects, we used a sweet net with a diameter of 50 cm in 10 different regions of the fields. Sampling was performed after 45, 75 and 105 days after planting. Sampling was conducted which it covers total farm area. Shannon-weaver index, Simpsons reciprocal and Margalef indexes were used to calculate the insect’s biodiversity and Pielou and Simpson were used to calculate the species evenness. Relative frequency (pi) was used to determination of dominant species in each agro-ecosystem and the species with the highest relative frequency was considered as dominant species. In order to compare the alpha and beta diversity between two organic and conventional systems, we fitted the power function for species richness as a dependent variable and sampling number as an independent variable. The results of the wheat farm showed that the total number of collected insects’ families during the growing season in the organic farm was higher than the conventional farm (2047 number of insects from 41 families vs. 1928 from 34 families, respectively). From total families, 32 families were the same in both organic and conventional wheat systems and 9 families were collected from the only organic farm. Two families were observed only on the conventional farm. Species richness was the same in both organic and conventional at first stage of sampling, but in the organic system, it was higher at the second and third stage of sampling. Insects’ diversity in the conventional farm was higher than organic based on obtained values for alpha diversity. Calculated beta diversity in the organic system was higher than conventional. In fact, beta diversity is the increasing rate of the species richness per increasing of sampling number and the high value of beta diversity in the organic system indicates that species richness and biodiversity of the organic system were higher than conventional at total farm area. In potato organic and conventional farms, 435 insects (from 18 families) and 787 insects (from 22 families) were collected, respectively. From total trapped families, 15 families were the same in both organic and conventional systems, 7 families only were in conventional farm and three families observed only in the organic farm. Therefore, species diversity in conventional system was higher in comparison with the organic system in the potato crop. Two families were introduced as dominant species in the organic farm with a relative frequency of 17% and 15.6%, respectively and Miridae family was dominant species in the conventional farm as 27.8% of relative frequency. Alpha diversity in conventional system was higher than organic. Beta diversity in conventional system was higher in 45 and 75 days after planting, but it was lower in 105 days after planting than organic. In total, the results showed that alpha and beta diversity were higher in conventional than organic. It seems that the reason for higher biodiversity in conventional compared to organic was related to failure to comply with the organic principles in potato farm. It can be concluded that the move towards organic agriculture, in addition to preserving and enhancing biodiversity in agricultural ecosystems, has led to a reduction in using chemical pesticides and, as a result, the reduction of environmental pollution will be followed by the sustainability of agricultural production.

A biodiversity investigation was carried out in the wild pistachio research forest located in southwest of Fars Province between 52˚ 30́́ to 52˚ 40́́ longitude and 29˚ to 29˚ 15́ latitude in an areaof 9374 Ha area. 72 sampling transects fifty meters long were designated using systematic-random design. In each sampling plot a list of bush, shrub, and tree species and their abundance were recorded. The area was divided into 3 slope levels (level 1: >10%., level 2:10%-30%., and level 3: <30 %), 4 aspects levels (north, east, south, and west) and 3 altitudinal levels (level 1: >1,800 m., level 2: 1,800–2,000 m., and level 3: <2,000 m. a.s.l.) using ARC GIS softwear. Data were analyzed using different indices of heterogeneity, richness and evenness by PAST software and were compared in each of the abovedivisions. Gratest heterogeneity and richness indices were observed in area with slope greater than 30%. Results show that the area with 10-30 percent slope has the highest uniformity. Also, indices of heterogeneity and richness showed that north aspect has higher value than the other directions. Evenness indices indicate that the east direction has greater uniformity. Diversity indices among altitudinal levelrevealed that diversity,eveness and richness in altitudes greater than 2000 meter above see level  is more than other altitudinal levels. The results showed that the vegetation diversity of the region are affected by the physiographical condition.

To study the weed population indexes of onion (Allium cepa L.) monoculture systems in the Jiroft area, four onion continuous monocultures, including less 3 (S1), 3-5 (S2), 5-8 (S3), more than 8 (S4) years and long-term fallow (F) were sampled by systematic randomized method in three stages: before sowing, 60 days after planting and 30 days after harvest, during 2015-2016. Of the 28 weed species, 16 species were observed in all systems. The analysis of variance showed that the monoculture system had a significant effect on the density of the weed species including Cyperus rotundus, Malva neglecta, Heliotropium europium and Chenopodium murale and the density of these species were was 14.64, 14.16, 13.90 and 11.97 weeds per square meter, respectively. Increasing the in monoculture duration from three to more than eight years led to enhancing increased the density of the weed species. The assessment of the onion monoculture duration had a significant effect on the weed diversity indexes. The maximum indexes of Simpson, Shannon, Menhinick and evenness in the S4 system were 0.92, 2.76, 0.90 and 0.99, respectively, and they were the lowest in the F system (0.78, 0.89, 0.78, and 0.95, respectively). In general, the onion continuation cropping increased the weed density of each weed and significantly enhanced the species diversity indexes.

  Agrobiodiversity has been operated as a foundation for sustaining food production systems and ecosystem services function in human societies. Biodiversity is known as a source for the environmental process and ecosystem services. Ecologists believe that increasing the species richness in farms is the cause of ecological stability in crops. Many studies have been done in relation with the importance of crop diversity. Most of them stated that crop diversity is one the main key to form ecosystem services in ecological ecosystem. Economically, polyculture can reduce production risk. Furthermore, crop diversity can lead to increase productivity by several procedures such as pest control and soil fertility. Eventually, crop diversity brings economic stability. The purpose of this study, was to calculate crop diversity using the biodiversity indices in Kermanshah province. Kermanshah province is located in west of Iran with latitude of 33 to 35 and longitude of 45 to 47 and covers 2.5 million hectares. Crop data includes planting area in 13 cities during 1999 and 2010. Thirteen cities in the area were evaluated in the study, including Eslamabad, Paweh, Jawanroud, Dalahu, Ravansar, Sarpol-e Zahab, Sonqor, Sahneh, Qasr-e Shirin, Kermanshah, Kangawar, Gilan-e Gharb, Harsin. Crop data was obtained from ministry of agriculture. In order to quantify crop diversity, Species richness, Shannon, Simpson, Simpson evenness and Sorenson similarity, indices were calculated. We used the planting area of varoiuse crops to calculate the indices. The Ecological Methodology software was applied to calculate mentioned indices. According to our study, 19 crop species was planted in study area. Wheat was highest planted crop followed by wheat, chickpea, barley and corn so that 51% of planted area was devoted to wheat and 33% was devoted to chickpea. All the 19 crop species was classified into eight families. Leguminos, Poaceae and Solanaceae had highest number of species, respectively. Poaceae (71%) and Leguminos (25%) were highest in terms of planting area. The results of present study demonstrated that 23% of crops type was planted as irrigated and 77% as dry farming. Moreover, 14 species were categorized as summer crops and five species as winter crops. Species richness was 19 across the province. Species richness in Sahneh (19 species), Kermanshah (17 species) and Sarpol Zahab (17 species) were highest. A big difference was obtained between Species richness in irrigated lands (19) and drylands (8), irrigated lands was more that drylands. It may be as result of water availability in irrigated lands. Shannon index was acquired 1.92 in Kermanshah province and highest value was obtained in irrigated land of Pave (2.56) and followed by Sahneh (2.52) and Harsin (2.48). Shannon index in irrigated lands (2.51) was more than drylands (1.48). These findings may attribute to water availability; the crops such as sugar beet (Beta vulgaris L.) , potato (Solanum tuberosum L.) , cucumber (Cucumis sativus L.) , alfalfa (Medicago sativa L.), canola (Brassica napus L.) and paddy would plant if water is available for irrigation. Among the cities, highest Simpson evenness was belonged to dry lands of Ravansar (0.92) and Kermanshah (0.7). It implied that there is no dominant crop in these area or crops are uniformly distributed across the area. However, in other cities wheat (Triticum aestivum L.) is dominated; so, evenness is low. Shannon index was highest for kitchen garden and it was around 2.1 followed by cereals (1.07), forage (0.97), industrial crops (1.33) and beans (0.18). Finally, correlation between Shannon and Simpson indices (0.78**) and species richness and evenness (-0.85**) were calculated. Wheat and chickpea (Cicer arietinum L.) are the most popular crops and are cultivated in Kermanshah province (west of Iran), however, these plants are dominance than others. Cultivate monoculture systems in the province has increased the vulnerability of agricultural systems and for the low diversity, the risk of pests, diseases, and weeds are high than diverse systems

Exclosure is considered as a management method to improve vegetation. This study aimed to evaluate the effects of exclosure on species diversity in Zayanderod dam station in Chadegan, Isfahan. The study area was stratified based on the various management types and slope directions, and samples were collected randomly in each layer. Four perpendicular transects, 500m in length were established along the gradients. Fifteen plots (1×1.5m) were established along each transect. The cover percentage, density and scientific name of the perennial species and the management condition were recorded in each plot. Diversity index of Simpson and Shannon, richness indices of Margalef and Menhinick, Simpson evenness indice, and Parametric methods (curve of frequency) were calculated in the two grazed and ungrazed areas. Independent t-test was used to compare the diversity indices. CCA Analysis was used to evaluate the relationships between species and management factors with the diversity indices. The results showed that although the diversity, richness and evenness indices in the exclosure area were more than the grazed area, there was no significant difference between the diversity and evenness indices in the areas. The log-normal was the significant fitted graph in the study area which represents relatively stable societies. The ordination results showed that grazing area and exclosure area are well separated from each other and confirmed the higher richness in the exclosure site.

This study aimed to compare plant species diversity indices (diversity and richness) and some physico-chemical properties of soil among forest, ecotone and rangeland habitats. Vegetation sampling was done randomly at each habitat. One dominant community was selected in each habitat and one key area was distinguished in each community and 8×1m2 plots were randomly established in each key area. In each plot, the list of existing plants and cover percentage for each species were determined and soil samples were taken from depths of 0-10 cm. The Shannon-Wiener and Simpson diversity indices and Margalef and Menhinic richness indices were estimated using PAST software. Physical and chemical characteristics of the soil were compared at three sites by analysis of variance (One Way ANOVA). The results showed that the lowest and highest values of all species diversity and richness were occurred in forest and ecotone habitats, respectively. Bulk density, sand and pH value of soil were significantly the highest in the rangeland. The percentage of clay and organic carbon in forest habitat were higher than the two other habitats. This study revealed the importance of ecotone in preserving the diversity and species richness.

Agricultural biodiversity has spatial, temporal and scale dimensions especially at agro-ecosystem levels. These agro-ecosystems that are used for agriculture are determined by three sets of factors: the genetic resources (biodiversity), the physical environment and the human management practices. Most agricultural areas can be returned to their natural landscape after subsequent generations. Studies on spatial patterns of species diversity are fundamental to biological conservation. Agricultural biodiversity is essential to satisfy basic human needs for food and livelihood security and it is active lymanaged by farmers and many components need human interference (Maguran, 1996).
FAO estimates that 75% of crop varieties have been lost during the last 100 years. One third of the 6.500 domestic livestock races are endangered. The genetic erosion of crops and livestocks threatens food security.
Plant diversity of usually evaluated by many indexes of which Shannon index is the most important ones. This index in agroecosystem rarely exists. Koocheki et al. (2004) and Nassiri Mahallati et al. (2005) in comprehensive surveys evaluated agrobiodiversity of agricultural systems at species variety and cropping systems for Iran and they found that the diversity at all levels have been declining due to introduction of new agricultural technology. In consideration to the lack of studies, this study was conducted in order to evaluate the biodiversity of agronomical and horticultural productions in Isfahan province and to assess relation of biodiversity and climate.
This study was performed for Isfahan province in 2014. For this purpose, 24 regions of the province were selected. Planting area, species richness, species evenness and alpha and beta diversity of different agronomical and horticultural productions were determined. The information about agronomical and horticultural planting area for different regions of Isfahan was gathered. Agronomical crops were classified to seven groups; cereal, pulses, vegetable, forage, industrial crops and medicinal plants and horticultural plant classified into 2 groups; temperate and tropical fruits. The Shannon index was calculated based on the cultivated area as equation 1. For determination of distribution condition of the crops we used from evenness index. Alpha and beta diversity was calculated by spices richness- area equation for different climate of province.
The result showed that tropical fruits (76.2%) and cereal (59.36%) showed the highest planting area and medicinal plants (1.09%) were included the lowest planting area in Isfahan province. Semirom and Borkharomeymeh regions had the highest and lowest horticultural planting area, respectively. The highest planting area of agronomical products was observed in Isfahan and the lowest amount of the trait was gained in Khorobiabanak. The highest species richness in horticultural plants was in Kashan, Lenjan and Natanz (17 species) regions and the lowest was obtained in Aranobidgol (with three species) regions, respectively. This condition was in line with climate of the regions. Ardestan and Isfahan regions were contained the highest (29 species) and Khorobiabanak had the lowest (11 species) species richness of agronomical plants. The highest and lowest species evenness of horticultural productions was gained in Isfahan (0.83) and Semirom (0.192), respectively. Felavarjan, Khomeinishahr, Kashan, Nain and Najafabad regions had the highest and Isfahan region was contained the lowest species evenness of agronomical productions. Many study demonstrated that there is a positive and high correlation between species evenness and diversity. This condition was true for our study. The forage and vine crop showed the highest (0.929) and lowest (0.442) Shannon indices, respectively. The lowest and highest alpha diversity were observed in moderate and desert-hot climates, respectively. It because that the planted crop in moderate climate was higher than desert-hot climate. Desert-moderate climate was obtained the highest beta diversity.
The results showed that tropical fruits and cereal were content the main planting area and medicinal plants were included the lowest planting area of Isfahan. The highest species richness in horticultural plants was in Kashan, Lenjan and Natanz regions. Ardestan and Isfahan regions were contained the highest and Khorobiabanak had the lowest species richness of agronomical plants. The highest and lowest species evenness of horticultural productions was gained in Isfahan and Semirom, respectively. The lowest and highest alpha diversity was observed in moderate and desert-hot climates, respectively. Desert-moderate climate was obtained the highest beta diversity.

Measuring the diversity of plant functional types, identifying their characteristics, and their classification will help to identification of woodland germination capacity and implementing appropriate range management programs. The study was designed to measure the species diversity and to identify plant functional types in three adjacent ecological sites in Shimbar or Shirin Bahar region. During winter, spring and summer since 2013 to 2014, the data regarding the percentage of species coverage were taken from 106 plots using stratified random sampling method in the south facing slopes, north facing slopes and the wetland. Species diversity (Alpha diversity) and habitat diversity (Beta diversity) were measured using PAST and SDR softwares. According to the Shannon-Wiener and Simpson indices the greatest species diversity were found in the wetland, south slopes and north slopes respectively. Species richness was higher in northern slope than northern slopes and the lowest in wetland. For classifying and determining response of vegetation to environmental factors and identifying plant functional types, about 66 resistance to disturbance characters were measured and subjected to clustering by Ward method in R software. The annual and perennial species were classified into 21 and trees and shrubs to 8 classes.

Mites are the best representative of soil arthropods because they are the most diverse in terms of ecological niche and behavior. In this study, abundance and biodiversity of laelapid soil mites were evaluated in eight sites in Saman and Shahrekord, with each site including an orchard and a farmland. There was a significant difference in the Shannon-Wiener diversity index of laelapid mites among different land uses. The maximum value of this index was (0.44) in soil of elm trees in Shahrekord. The Margalef species richness index was highest (0.64) in an almond orchard in Saman. The maximum amount of the Simpson index was (0.39) in the almond orchard of Saman. The regression line equations and coefficient of determination between the soil organic matter and biodiversity indices were calculated. The results showed that the coefficient of determination (r2= 0.73) for soil organic matter and the Simpson index was higher than that of other indices. Therefore, it could be concluded that the response of laelapid soil mites conforms to the management practices of farmlands, changes in abundance of species, and biodiversity indices.

Knowledge about plant communities and their relationships with ecological factors is one of the most important issues in conservation ecology particularly in the recent decades. The current investigation aimed to study the vegetation ecology of Palangan habitat in Aghdagh Protected area, Ardabil province. In order to collect species and environmental data, a total of 45 plots along a 1500 m elevational gradient and an interval of 100 m were surveyed. Braun-Blanquet scales were used to evaluate vegetion cover of each plot. Floristic and ecological characteristics of the area were studied along elevational gradient using DCA ordination and TWINSPAN classification methods. Four vegetation groups detremined in TWINSPAN were also identified in the DCA diagram and their species and environmnetal characters have been evalyated by one-way ANOVA. Based on these anlayses, altitude and slope were the most important ecological factors affecting the vegetation of the area. Endemicity values are not significatly changed among different altitudinal belts, but in stead, the number of therophytes and plants with wide distributional ranges are significam,ty different along elevation. The relatiohsip between altitude and species richness, like to other mountainus systems, show almost unimodal pattern which peaks at 1800 m.

This study was done to investigate the effects of utilization types (private property, collective property, council property) on plant species richness and diversity in summer Plour rangeland in Mazandaran province. The topographical properties of sampling sites in three units of exploitation (Bazam- Mozak, Ghazi Mazraee and Chapak Khas) were the same (same slope, aspect and altitude). Within each unit, 30 plots (1m2) were established in order to studying diversity indices and the type and number of species were recorded. Biodiversity indices (Shannon, Simpson), richness indices (Menhinick, Margalef) and uniformity indices (Equitability) were calculated. Also, three Whittaker plots were established in each sampling site. The data were analyzed using linear and group regression model. The results showed that collective property had an unpleasant effect on biodiversity species. While, private property and council property worked the same and better than the first one. Results of species richness using Whitaker plot showed that Private property (Bazram - Mozak), collective property (Gapak - Khas), council property (Ghazi - Mazraea) had higher richness respectively and their differences were significant (P