جستجوی مقالات مرتبط با کلیدواژه « ترسیب کربن » در نشریات گروه « اکولوژی »

Ecosystem services are usually divided into four categories: (a) provision services, (b) regulating services, (C) cultural services and (d) supporting services. Ecosystem services are managed in agroecosystems primarily for food production. But, agricultural ecosystems provide provision, regulating and cultural services for human society. These services respond strongly to human socio-economic needs. Quantifying the various services and functions of agroecosystems is one of the most important effective strategies in order to increase attention pay to these services. Therefore, the purpose of this study was evaluation and quantification of ecosystem services in wheat (Triticum aestivum L.) agroecosystems of Dasht-e-Naz, Sari.

This experiment was performed as an unbalanced completely design in wheat agroecosystems of Dasht-e-Naz, Sari (Mazandaran province), during 2019-2020. In this study, 9 wheat plots with 4 cultivars including Tirgan, Ehsan, Collector and N-92-9 were surveyed and monitored. In this study, some ecosystem services such as insect and weed biodiversity (using Shannon-Weiner, Simpson, Margalf, Uniformity and Menhinick indices), soil microbial respiration, carbon sequestration, organic matter, abundance of earthworms, grain yield, protein content oxygen production, and soil protection (by the stability of aggregates) were evaluated and quantified. Soil samples were taken from a depth of 0-30 cm before wheat planting in November 2019 and after harvest in June 2020 for assessment of rate of microbial respiration, organic matter and carbon sequestration. Also, oxygen production was estimated based on net primary production. Sampling of yield and plant biodiversity was harvested based on W pattern and with quadrate 0.5 × 0.5 m2. All samples were moved to the crop research laboratory of Gorgan University of Agricultural Sciences and Natural Resources and the plant flora was determined by genus and species names.

The results showed that crop management and performance of intensive agricultural system were effective on providing many services of ecosystems in wheat fields of Dasht-e-Naz, Sari. These services are influenced by several factors such as cultivar type, crop rotation, tillage, etc. The results showed that the effect of different cultivars was significant on grain yield and protein percentage. The highest percentage of grain protein as a provision service was obtained from Ehsan cultivar (12.15%) and the lowest content was obtained about 11.42% from N-92-9 cultivar. The highest wheat grain yield and oxygen production were calculated from plots under Collector cultivar. In additional, the highest amount of carbon sequestration (2.33 ton/ha) and microbial respiration rate in before planting and after harvest (76.46 and 38.52 mg CO2 per kg of soil per day, respectively) belonged to plot 15. Also, it was determined that plot 15 was better than other plots from soil protection service view based on the diameter mean weight index (MWD) and the geometric mean diameter index (GMD). In this research, three beneficial insects (biodiversity assessment) were observed such as Coccinella septempunctata Linnaeus and Aphidius matricariae, and Chrysoperla carnea. The highest values of Shannon-Weiner and uniformity indices of weeds were as 2.63 and 0.82 in plots 23 and 15, respectively. Furthermore, Shannon-Weiner and uniformity indices of insect communities were obtained as 2.07 and 0.94 from plot 22, respectively.

 Generally, carbon sequestration, organic matter, microbial respiration, earthworm abundance, aggregate stability index, average weight diameter (MWD) and geometric mean diameter index (GMD) were better in plots 14 and 15 under wheat cultivation  than other plots. The results of this study showed that crop management and implementation of intensive agricultural system were effective in providing many ecosystem services in wheat fields in Dasht-e Naz region of Sari. So that, these services were affected by several factors such as cultivar, crop rotation and tillage methods.
Acknowledgment
The authors gratefully acknowledge the financial support of Gorgan University of Agricultural Sciences and Natural Resources and Dr. Hamid Sakinin for his help.

The carbon sequestration project has sought to increase the empowerment and livelihoods of indigenous peoples with the goal of mobilizing people and involving local communities in the conservation, restoration and exploitation of the principles of natural resources. Therefore, rural livelihood index is one of the most important and important factors used in measuring and evaluating the living conditions of rural communities. The present study, while identifying the components of rural livelihoods, seeks to investigate the effects of carbon sequestration on the livelihoods of local communities in the Til Abad watershed of Golestan province. This is a descriptive-survey study that the statistical population is 2097 households of 6 target carbon sequestration villages in the study area, 317 of which were selected using Morgan table as sample size. Questionnaire was the main research measurement tool whose validity was confirmed by experts' opinions and its reliability was calculated based on Cronbach's alpha. According to the results, the livability of local communities and its dimensions (employment and income, infrastructure facilities and services, participation, solidarity, trust, education and skills, attachment and location) at both the time before and after project implementation. Carbon sequestration was significantly different at 99% confidence level. Therefore, based on the results of the research, by developing appropriate planning and supportive policies for local communities, efforts can be made to increase the livability of rural communities in order to take an effective step towards rural development.

Valuing ecosystem functions provides conditions to prevent them from considering them as worthless. To achieve the research goal, first, the value of the production, regulatory and recreational functions of the study area has been estimated, and then the value of biodiversity was estimated using the Choise Experiment approach and the simple conditional logit model. The research results showed that the minimum economic value of each hectare of ecosystem services provided in this area is estimated at 1132.76 million Rials. The Recreational function has the highest value among other studied ecosystem services and has assigned to himself.71.5% of value share of services. The willingness to pay the annual final payment for biodiversity is estimated at 174,430 Rials per person, that feature of improving the condition of animal species has been the most important feature from the visitors' point of view. Therefore, the biodiversity value of each hectare of the studied area is estimated at 49 million Rials. Monetary values should be placed along with ecological knowledge and social value in order to give a correct approach to practical studies and actions of conservation. Therefore, it is emphasized that the value of 157867.2 billion Rials estimated for the central Alborz protected area is the minimum value that could be extracted due to the limitations.

 Characteristics such as the high levels of agrobiodiversity, the efficiency of the nutrition, and also variety in ecological and socio-economic functions have altered home gardens into the appropriate model for achieving a sustainable agricultural system. So far, fewer studies in relation to these features have been done in home gardens of dry and semi-arid regions. Protection of diversity with a particular emphasis on agricultural biodiversity is fundamental to sustainable development in food production and hence food security. Expansion of industrial agriculture in the form of monoculture for the purpose of maximizing the yield with the aid of high-yielding varieties and intensive use of inputs has hampered the ecological functions of food production systems worldwide. This problem can be overcome by the application of a wide array of ecological agriculture practices, of which food production in home gardens is only one of them. This environmentally sound practice is an old system of land use almost in all parts of the world with a wide range of dimensions. A combination of different plants, from herbs to trees and in cases with poultry and other low-weight animals, provides a complex sustainable system of food production. This type of subsistence food production is based on local knowledge and normally is part of the residential area or, to the, low input. Food produced in this system is consumed locally, and women are the main element in both production and marketing. Exchanges of experience and knowledge, seed, and also tools, and labors are very common in neighboring communities. The purpose of the present study was to investigate the agrobiodiversity of home gardens in an arid environment of Khorasan Razavi Province.Materials and

Data collection for this study was based on the fieldwork with the distribution of questioners. For this purpose, 17 villages from 3 highly populated counties of Mashhad/ Quchan and Nyshabour were selected, and 164 questioners were distributed with a face-to-face procedure. After the collection and validation of data, only 136 questionnaires were selected, data were extracted, and finally, an analysis was carried out. Afterward, the Shannon biodiversity index, Simpson index, and species richness were calculated. The amount of carbon sequestered was also calculated by an equation referred to in the literature. For the calculation of biodiversity indices, the area under cultivation of each species was used. Based on the available previous studies, seven basic functions for home gardens were assigned.

Results showed the highest Shannon index of species diversity equal to 1.88 for the county of Neishabour; however, the highest functional diversity was found in Quchan. More the 79 percent of changes in the Shannon index are caused by changes in species richness. Stepwise regression analysis revealed that changes in species richness, home area, and household population were the factors that caused 84 percent of changes in functional diversity. Home gardens in these three counties sequester 8.1 tons of carbon dioxide per hectare, and this amount showed a decreasing trend where the distance from the vehicle roads was increased.

It was revealed that with taking distance from the main roads, the amount of carbon dioxide (kg per m2) decreased by tree species.AcknowledgmentsThe authors acknowledge the financial support of this project (grant number 2/19719) by the Vice President for Research and Technology, Ferdowsi University of Mashhad, Iran.

An attempt to estimate the real value of a set of environmental goods and services, particularly forests are needed that at present, various pressures from economic incentives and goals have been the basis for their destruction and deterioration. Therefore, this study tries to investigate the amount of degradation of vegetation and fixed organic carbon per hectare and its value with social cost approach in the Chuman and Kani Goizhan Dams and the water transfer system between them, as part of study of environmental impact assessment. In this study, sampling was done by random block method. 18 pieces of sample with size of 20 × 60 meters were taken in Chuman and Kani Goizhan and for the water transfer system, 8 pieces of 10 × 60 meters sample were harvested. Empirical formula were used to estimate carbon storage and sequestration based on dry biomass of trees. The results showed that the amount of carbon sequestration in Chuman and Kani Goizhan and the water transfer system between two regions were 0.336, 0.37 and 0.44 ton /hectare/year, respectively. Considering 132.12 dollars per tons of carbon sequestration, as social cost of 2015 year, the carbon sequestration value of each section is estimated to be 44.39, 48.88 and 58.13 dollars/ hectare/year respectively. In general, it can be said that the value of the dam damage is 45418.89 dollars annually due to the destruction of forests and lack of carbon absorption and sequestration (about 343.67 tons per year) in the study area with 852.41 hectares, which should at least be offset by creating suitable forests in suitable areas with appropriate species selection.

In this study 30 coppice oak trees(Quercus brantii Lindl.) with least diameter of 5 centimeteres were chosen with random classification. Characteristics such as the number of sprouts, the diameter, total height, and the large and small diameter of crown were measured. For this purpose, the diameter ranges of the oak trees were devided into 5 cm classes and at least the growth factors of 3 trees from each class were measured. The wet weights of different organs including leaf, branch and trunk or main stem were also measured. Soil samples of all plots were analysed in the laboratory and the amount of carbon in these samples were measured. Also samples of the different organs of the trees were analysed to estimate the amount of net Carbon. The results of this study showed that the amount of percent net Carbon sequestrated was 27.81 tons/ha, of which 16 tons belonged to soil and 11.82 tons was sequestrated by the trees' organs. There figures are equivalent to 102.09 and 43.14 tons/ ha of Co2, respectively. There was significant differences between the trunks and the other organs as well as between diameter classes of sprouts in terms of the amount of sequestrated Carbon. The economic value of the sequestrated Carbon amounted to 6193.94 US$, its yearly value was about 154.84 US$. This study showed that Kamfirooz forest area has a great potential for Carbon sequestration.

Management practices such as soil tillage can be used as a suitable alternative to reduce the crisis and increase the amount of organic carbon in the soil, along with the improvement of soil physicochemical properties. Long use of the conventional tillage system leads to reduced organic carbon content, soil destruction, reduced water penetration into the soil, and ultimately increased water erosion and wind. It has been established that disturbing the soil through tillage operations is not actually required to obtain good crop yields, and also a major portion of energy (25–30%) in agriculture is utilized for either field preparation or crop establishment, where conventional tillage is mostly followed. The rising cost of fuel and availability of effective package of practices for conservation tillage are now redefining tillage in Iran in recent years. However, the impact of conservation tillage on soil physical environment is not always positive and varies from one soil to the other and also between the cropping systems.Plant residues, by replacing or providing nutrients in the soil, maintain soil fertility, increase organic matter, water capacity, improve physical, chemical and biological properties creating diversity in management methods and different forms of exploiting resources. In other words, increasing agricultural diversity is one of the best and most effective ways to achieve sustainable production.The present investigation was therefore undertaken to determine the effects of tillage and crop residue management on soil bulk density and chemical properties in intercropping of corn and bean under Shahrekord's climatic conditions.

This study was conducted to evaluate the effects of different tillage levels and crop residue management on total nitrogen, organic carbon, available P and K, bulk density and carbon sequestration of soil compared to the beginning of the experiment. Hence, an experiment was performed using split- split plot based on a randomized complete block design with three replications in Agricultural Research Field of Shahrekord during 2016–2017. Tillage with three levels (conventional, minimum, and no-tillage) and four levels of crop residues (0, 30, 60, and 90% of straw yield of wheat) and five intercropping patterns including corn and bean sole cropping, corn and bean ratio with 2:2, 3:1 and 1:3 were considered as main, sub and sub-sub plots, respectively. Total Nitrogen content (TN), available P, available K, and bulk density were measured by the Kejldahl (Bremner, 1970) and Olsen methods (Olsen et al., 1954), flame photometry and Black (1965) procedures, respectively. Data analysis included the analysis of variance and mean comparisons using LSD which carried out using SAS software.

Increasing compaction of tillage with soil degradation mineral decomposition and plant residues reduced total nitrogen, organic carbon, available potassium and soil bulk density. The highest and the lowest available K were related to no-tillage treatment, 90% of crop residue and 2:2 ratio and conventional tillage treatment, sole cropping, and without crop residue respectively. The lowest soil bulk density related to conventional tillage, 90% residue, and 3:1 ratio. Conservation of plant residues through protective tillage over time will increase soil organic matter, which will reduce the bulk density of the soil. The highest and the lowest soil carbon sequestration were computed in no-tillage treatment, 90% of crop residue and 2:2 with 4154.33 kg.ha-1 and conventional tillage,without crop residue and bean sole cropping with 836.33 kg.ha-1, respectively.

Investigation showed that the no-tillage treatments and intercropping increased the efficiency of environmental resources and improved the soil nutrient, significantly. The highest organic carbon and total nitrogen were achieved 1:3 and 2:2 ratio, which is indicative of the excellence of intercropping compared to sole cropping. The amount of organic carbon has shown an increase in soil fertility using no-tillage with the conservation of residues and increase percent of bean in intercropping.

Carbon dioxide (Co2) is the most important greenhouse gas that human activities have increased its concentrations in the atmosphere. Carbon sequestration in tree cover, vegetation, and corresponded soil is considered the easiest and economically most practical solution to reduce atmospheric carbon dioxide. Therefore, this research was done to investigate carbon sequestration capability of tree and herbaceous cover and soil of roadside of Khorramabad-Andimeshk Highway. In order to achieve objectives, four transects with 100 m distances from each other were established perpendicular to the highway and on each transect eight square plots were laidout with intervals 1, 30, 50 and 70 m . Also in the vicinity of these transects, land without tree cover and vegetation were selected as control plot. Within each plot, carbon sequestration was measured in tree and herbaceous cover and soil (0-30 cm depth). The results showed that the values of carbon sequestration with resoect to the increasing distance from the highway were 104.30, 41.15, 33.76 and 29.01 tons per hectare for trees respectively, 49.03, 155.36, 82.43, and 113.03 tons per hectare for herbaceous cover respectively, 32, 17, 39.82, 47.37, and 47.80 tons per hectare for soil respectively and 6.18 tons per hectare for bare soil. According to obtained results, it is observed that the highest value of carbon sequestration in highway roadside is related to trees. Also in each of the study components, herbaceous cover was allocated maximum carbon sequestration values.

Due to its multifunctional nature agriculture play important roles in ecological processes such as carbon sequestration, flood control, groundwater recharge, nutrient cycling, and purifying water, soil and air in addition to providing food, feed and fiber. These cover almost all ecological services provided by natural ecosystems, including provisioning services, regulating services, supporting services and cultural services (MEA, 2005). Provisioning services are the products obtained from ecosystems, including food, fiber and fuel. Regulating services are the benefits arising from the regulation of ecosystem processes, such as climate regulation, water purification, pollination and the control of pests and diseases. Cultural services are the non-material benefits people obtain from ecosystems, as spiritual enrichment, recreation and aesthetic experiences. Supporting services are those services necessary for the production of all other ecosystem services, such as soil formation and nutrient cycling (Norris et al., 2010). However, most of these services are not recognized and their values are hidden to the society. On the other hand, unlike natural ecosystems that only produce positive ecological services, agro-ecosystems also contribute to some negative externalities e.g. emission of greenhouse gases, leaching of chemicals into soil and water resources and reduction of biodiversity that should be taken into account (Norris et al., 2010). Economic valuation of these services makes them attractive for the society and policymakers to pay more attention towards conservation of ecosystem services. In Iran, studies on ecosystem services are scared and in global scale researches are mainly focused on natural ecosystems. In this study the economic value of ecological services as well as negative environmental externalities of wheat fields were estimated in the Khorasan Razavi province.
Information was extracted from questionnaires collected from 40 fields varying in area, management and inputs level. Using these data economic value of feed and food, carbon sequestration, oxygen production, biodiversity, water retention and tourism together with greenhouse gas emission and nitrogen and phosphorous leakage as environmental externalities was quantified. Calculations were based on standard methods described by Millennium Ecosystem Assessment. Economic values were estimated as international dollar as proposed by De Groot et al. (2012) and reported as equivalent national price.
The mean value of the total agroecosystem services of wheat fields excluding externalities, were estimated as 66.85×106 Rls.ha-1.y-1. The value of non-marketable services was 3.46 times more than food and feed and on average atmospheric services (oxygen production and carbon sequestration) contributed up to 62% of total value while biodiversity and provisional services included 9.3 and 21% of total, respectively and the other services below 5%. Net value of services was increased with increasing field size. However, doubling field size resulted in 50% increase in net value because larger fields were more intensified leading to higher negative impacts. Economic value of services was significantly dependent on wheat total dry matter and yield. Nonlinear relation was found between wheat yield and total value of services where a break point was found at yields above 4 t.ha-1. However, negative externalities were increased linearly with increasing both total dry matter and grain yield.
Results of this study indicated that despite to intensive management wheat production systems of Khorasan province are able to provide several regulating and supporting services and their economic value is 3-4 folds higher than provisional services harvested as grain and feed. However, negative externalities will be increased in more intensified fields with higher yield. Feeding a growing human population is obviously critically important and can only be done by recognizing and embracing the concept that food production systems are embedded within ecosystems. They depend on ecosystem services and have ecosystem impacts. Promotion of multifunctional characteristics of agroecosystems to maintain high yield together with ecological services, should be considered as an alternative for conventional management practices.

Modelling allometric equations for saplings of hybrid poplar clone produce a highly accurate estimate of pure productivity and C sequestration, leading to better sales and determination of the capacity of cellulose resources and bio-energy pools. Twenty five cuttings with 25 cm length were planted within a 1×1 m2 area in the Talookola nursery, Sari, in 2011. Ten saplings were selected from the two diameter classes (0-1, 1.1-2 cm). After separating the roots and stems, they were oven-dried at 85ºC for 48 hours. According to the diameter distribution, 24 and 6 saplings, respectively, from each diameter class were uprooted. Collar diameter and height were the twe variables used to model allometric equations. Carbon factor was obtained directly by exposing the wood samples in the oven and was estimated based on organic carbon to organic material ratio. Collar diameter and height were the variables to model allometric equations. The results of allometric modelling showed that multivariate linear model including natural logarithm of diameter, logarithm of height and diameter logarithm square with mean C factor of [C] = 0.44 is the optimal equation (R2adj = 0.732; CF = 1.056) for C sequestration of superior saplings.

This experiment was performed to evaluate the carbon (C) balance and global warming potential (GWP) as affected by tillage methods، maize residual management and nitrogen levels. For this purpose، a field experiment was conducted as row split-plot arrangement based on randomized complete block design with three replications in Ferdowsi University of Mashhad، Iran in 2011 and 2012. The experimental treatments were tillage systems (conventional and reduced tillage) and residual management (remaining and leaving of maize residual) assigned to main plots and different levels of urea fertilizer (0، 150، 300 and 450 kg. ha-1) was randomized as subplot in tillage treatment. The results showed that carbon sequestration was affected by residual treatment in both years and residual management × N fertilizer interaction in second year. Addition of residual in soil was caused to increasing 48% and 69% of C sequestration in first and second years، respectively. Across the treatments، residual management had the highest effect on C balance. So، C balance was positive in remaining maize residual and that was negative in leaving condition. GWP was higher under conventional tillage، residue remaining and higher N fertilizer levels in comparison with reduced tillage، residue leaving and lower N fertilizer application.

Evaluation of carbon input is one of the most important factors for estimating soil carbon changes and potential for carbon sequestration. To evaluate the net primary productivity (NPP) and soil carbon input in agricultural eco-systems of Iran, data for yield, cultivated area, harvest index (HI) and shoot /root ratio in different crops including: wheat, barley, maize, cotton, rice, alfalfa and chickpea were obtained for different provinces. Then, allocated carbon to different organs of plant were calculated based on carbon allocation coefficients and finally, the net primary productivity based on carbon (NPPc) was calculated. The ratio of NPPc that was annually returned to soil was considered as carbon annual input. The results showed that the maximum amount of NPPc for wheat, barely and alfalfa were obtained in Khazari climate for rice, chickpea and cotton was achieved in warm-wet climate and for maize was gained in warm-dry climate. In all regions of Iran, chickpea had the lowest effect on NPPc and consequently on carbon sequestration. The highest amount of carbon input per unit area among studied crops and different regions were observed in Khazari region for alfalfa whereas, the lowest carbon input per unit area was relation to chickpea in cold region. The lowest gap between actual and potential of carbon sequestration was observed in alfalfa whereas wheat, rice and cotton showed the most gap by 0.4, 0.38 and 0.37, respectively.

Carbon is the most important of greenhouse gas that in recent decades increasing of it has been caused earth warming in the atmosphere. Warming has devastating effects on lives and was caused destruction of natural ecosystems, occurrence of drought, climatic and ecological imbalance. Carbon sequestration in plant biomass and soils under the biomass is the most simple and cheapest possible way to reduce levels of this atmospheric gas. Since agricultural lands cover the most of area of countries such as Iran, This study was performed with aim of assessment of wheat (Triticum aestivum) carbon sequestration potential. Sampling of vegetation and soil were performed with random-systematic method with 30 plots 0.5 × 0.5 m2 and along 3 transect of 100 meters. The evaluations of shooted and rooted organs of wheat were performed complete sampling. Also for study of soil carbon sequestration were attempted to 5 profiles digging with depth by 30 cm under plant samples along each transect. After transfer to the laboratory, the different organs of plant were separated from each other that were obtained 120 samples. After drying in oven, carbon sequestration coefficients each of the four plant organs (spikes, stems, leaves, roots) were determined with combustion method separately. Organic carbon of soil samples was determined using the Walcky- Black. Results showed that the amount of carbon sequestration in different organs had significant difference (P>0.05) and spikes and roots had the largest and lowest carbon sequestration potential respectively. Also, the amount of carbon sequestration in plant biomass was 1.884 ton/ ha, and in the soil was 16.332 ton/ ha which shows the ability of this plant in carbon sequestration and reduce greenhouse gas in the study area. According to results of this research and area of under cultivation of this plant in Iran, it with high power of carbon sequestration have important role of reduce greenhouse gases.