46 research outputs found
Estimation of conservation value of myrtle (Myrtus communis) using a contingent valuation method: a case study in a Dooreh forest area, Lorestan Province, Iran
Background: Around 2000 plant species occur naturally in Lorestan Province of which 250 species are medicinal and
myrtle is one of them. Myrtle is a shrub whose leaves and fruits have medicinal value and thus, if managed and
harvested properly, could produce sustained economic benefits. In recent years, however, over half of the myrtle site
areas was destroyed, due to inappropriate management and excessive harvesting practices. Thus, coming up with a
practical harvesting approach along with identifying those factors damaging the sites, seems to be very crucial.
Methods: In our investigation, we calculated the conservation value per hectare of myrtle in the Dooreh forest area in
Lorestan Province. Using the Contingent Valuation (CV) and Double Bounded Dichotomous Choice (DBDC) methods,
we determined the willingness to pay (WTP) for myrtle conservation. The WTP was estimated with a logit model for
which indices were obtained based on a maximum precision criterion.
Results: The results showed that 86.67 per cent of people were willing to pay for the conservation of these myrtle
sites. Average monthly WTP per family was calculated as 102,525. Among the variables of the model presented,
education had a positive impact, while the amount proposed for payment and family size had a negative impact on
the WTP.
Conclusions: Our estimate of the value of myrtle conservation should provide justification for policy makers and
decision making bodies of natural resources to implement policies in order to conserve the natural sites of this species
more effectively.
Keywords: Conservation value, Myrtle, Contingent valuation method, Double Bounded Dichotomous method, Logit mode
A survey on some risk factors and evaluation of their impacts on streptococcosis in rainbow trout farms in east of Mazandaran province (Haraz River)
One of the most important bacterial fish diseases which has caused some outbreaks in rainbow trout farms in Iran is streptococcusis .The farmers were suffering from huge economic losses due to the disease outbreaks in different rainbow trout farms in Iran. The aim of our study was to determine rate of streptococcusis incidence in different stage of growth in farmed rainbow trout in Haraze River, Mazandaran province. Fish and water samples were randomly collected and measured of randomly in10 selected farms, monthly throughout a year. After clinical observations, Isolation and recognition of strep strains were made using biochemical tests. Some Environmental factors include Nitrate, Nitrite, Temperature, pH, Ammonia and DO measured during sampling periods. According to our results 4.6% of juvenile samples showed clinical singe of streptococcusis while only0.7% of them had strep. Contamination .These rates in adult samples were 8.9 and 1 percent respectively. Major isolated bacterial strain was Streptococcus uberis. Incidence of streptococcusis in rainbow trout 20% affected by fluctuation of Nitrite, temperature and DO. Management of these factors can decrease rate of disease outbreaks
Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990-2017 : a systematic analysis for the Global Burden of Disease Study 2017
Background: The Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017) includes a comprehensive assessment of incidence, prevalence, and years lived with disability (YLDs) for 354 causes in 195 countries and territories from 1990 to 2017. Previous GBD studies have shown how the decline of mortality rates from 1990 to 2016 has led to an increase in life expectancy, an ageing global population, and an expansion of the non-fatal burden of disease and injury. These studies have also shown how a substantial portion of the world's population experiences non-fatal health loss with considerable heterogeneity among different causes, locations, ages, and sexes. Ongoing objectives of the GBD study include increasing the level of estimation detail, improving analytical strategies, and increasing the amount of high-quality data. Methods: We estimated incidence and prevalence for 354 diseases and injuries and 3484 sequelae. We used an updated and extensive body of literature studies, survey data, surveillance data, inpatient admission records, outpatient visit records, and health insurance claims, and additionally used results from cause of death models to inform estimates using a total of 68 781 data sources. Newly available clinical data from India, Iran, Japan, Jordan, Nepal, China, Brazil, Norway, and Italy were incorporated, as well as updated claims data from the USA and new claims data from Taiwan (province of China) and Singapore. We used DisMod-MR 2.1, a Bayesian meta-regression tool, as the main method of estimation, ensuring consistency between rates of incidence, prevalence, remission, and cause of death for each condition. YLDs were estimated as the product of a prevalence estimate and a disability weight for health states of each mutually exclusive sequela, adjusted for comorbidity. We updated the Socio-demographic Index (SDI), a summary development indicator of income per capita, years of schooling, and total fertility rate. Additionally, we calculated differences between male and female YLDs to identify divergent trends across sexes. GBD 2017 complies with the Guidelines for Accurate and Transparent Health Estimates Reporting. Findings: Globally, for females, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and haemoglobinopathies and haemolytic anaemias in both 1990 and 2017. For males, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and tuberculosis including latent tuberculosis infection in both 1990 and 2017. In terms of YLDs, low back pain, headache disorders, and dietary iron deficiency were the leading Level 3 causes of YLD counts in 1990, whereas low back pain, headache disorders, and depressive disorders were the leading causes in 2017 for both sexes combined. All-cause age-standardised YLD rates decreased by 3·9% (95% uncertainty interval [UI] 3·1–4·6) from 1990 to 2017; however, the all-age YLD rate increased by 7·2% (6·0–8·4) while the total sum of global YLDs increased from 562 million (421–723) to 853 million (642–1100). The increases for males and females were similar, with increases in all-age YLD rates of 7·9% (6·6–9·2) for males and 6·5% (5·4–7·7) for females. We found significant differences between males and females in terms of age-standardised prevalence estimates for multiple causes. The causes with the greatest relative differences between sexes in 2017 included substance use disorders (3018 cases [95% UI 2782–3252] per 100 000 in males vs s1400 [1279–1524] per 100 000 in females), transport injuries (3322 [3082–3583] vs 2336 [2154–2535]), and self-harm and interpersonal violence (3265 [2943–3630] vs 5643 [5057–6302]). Interpretation: Global all-cause age-standardised YLD rates have improved only slightly over a period spanning nearly three decades. However, the magnitude of the non-fatal disease burden has expanded globally, with increasing numbers of people who have a wide spectrum of conditions. A subset of conditions has remained globally pervasive since 1990, whereas other conditions have displayed more dynamic trends, with different ages, sexes, and geographies across the globe experiencing varying burdens and trends of health loss. This study emphasises how global improvements in premature mortality for select conditions have led to older populations with complex and potentially expensive diseases, yet also highlights global achievements in certain domains of disease and injury. Funding: Bill & Melinda Gates Foundation
Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017.
The Global Burden of Diseases, Injuries and Risk Factors 2017 includes a comprehensive assessment of incidence, prevalence, and years lived with disability (YLDs) for 354 causes in 195 countries and territories from 1990 to 2017. Previous GBD studies have shown how the decline of mortality rates from 1990 to 2016 has led to an increase in life expectancy, an ageing global population, and an expansion of the non-fatal burden of disease and injury. These studies have also shown how a substantial portion of the world's population experiences non-fatal health loss with considerable heterogeneity among different causes, locations, ages, and sexes. Ongoing objectives of the GBD study include increasing the level of estimation detail, improving analytical strategies, and increasing the amount of high-quality data. METHODS: We estimated incidence and prevalence for 354 diseases and injuries and 3484 sequelae. We used an updated and extensive body of literature studies, survey data, surveillance data, inpatient admission records, outpatient visit records, and health insurance claims, and additionally used results from cause of death models to inform estimates using a total of 68 781 data sources. Newly available clinical data from India, Iran, Japan, Jordan, Nepal, China, Brazil, Norway, and Italy were incorporated, as well as updated claims data from the USA and new claims data from Taiwan (province of China) and Singapore. We used DisMod-MR 2.1, a Bayesian meta-regression tool, as the main method of estimation, ensuring consistency between rates of incidence, prevalence, remission, and cause of death for each condition. YLDs were estimated as the product of a prevalence estimate and a disability weight for health states of each mutually exclusive sequela, adjusted for comorbidity. We updated the Socio-demographic Index (SDI), a summary development indicator of income per capita, years of schooling, and total fertility rate. Additionally, we calculated differences between male and female YLDs to identify divergent trends across sexes. GBD 2017 complies with the Guidelines for Accurate and Transparent Health Estimates Reporting
Global, regional, and national incidence, prevalence, and years lived with disability for 354 diseases and injuries for 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017
The Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD 2017) includes a comprehensive assessment of incidence, prevalence, and years lived with disability (YLDs) for 354 causes in 195 countries and territories from 1990 to 2017. Previous GBD studies have shown how the decline of mortality rates from 1990 to 2016 has led to an increase in life expectancy, an ageing global population, and an expansion of the non-fatal burden of disease and injury. These studies have also shown how a substantial portion of the world's population experiences non-fatal health loss with considerable heterogeneity among different causes, locations, ages, and sexes. Ongoing objectives of the GBD study include increasing the level of estimation detail, improving analytical strategies, and increasing the amount of high-quality data.; We estimated incidence and prevalence for 354 diseases and injuries and 3484 sequelae. We used an updated and extensive body of literature studies, survey data, surveillance data, inpatient admission records, outpatient visit records, and health insurance claims, and additionally used results from cause of death models to inform estimates using a total of 68 781 data sources. Newly available clinical data from India, Iran, Japan, Jordan, Nepal, China, Brazil, Norway, and Italy were incorporated, as well as updated claims data from the USA and new claims data from Taiwan (province of China) and Singapore. We used DisMod-MR 2.1, a Bayesian meta-regression tool, as the main method of estimation, ensuring consistency between rates of incidence, prevalence, remission, and cause of death for each condition. YLDs were estimated as the product of a prevalence estimate and a disability weight for health states of each mutually exclusive sequela, adjusted for comorbidity. We updated the Socio-demographic Index (SDI), a summary development indicator of income per capita, years of schooling, and total fertility rate. Additionally, we calculated differences between male and female YLDs to identify divergent trends across sexes. GBD 2017 complies with the Guidelines for Accurate and Transparent Health Estimates Reporting. Globally, for females, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and haemoglobinopathies and haemolytic anaemias in both 1990 and 2017. For males, the causes with the greatest age-standardised prevalence were oral disorders, headache disorders, and tuberculosis including latent tuberculosis infection in both 1990 and 2017. In terms of YLDs, low back pain, headache disorders, and dietary iron deficiency were the leading Level 3 causes of YLD counts in 1990, whereas low back pain, headache disorders, and depressive disorders were the leading causes in 2017 for both sexes combined. All-cause age-standardised YLD rates decreased by 3·9% (95% uncertainty interval [UI] 3·1-4·6) from 1990 to 2017; however, the all-age YLD rate increased by 7·2% (6·0-8·4) while the total sum of global YLDs increased from 562 million (421-723) to 853 million (642-1100). The increases for males and females were similar, with increases in all-age YLD rates of 7·9% (6·6-9·2) for males and 6·5% (5·4-7·7) for females. We found significant differences between males and females in terms of age-standardised prevalence estimates for multiple causes. The causes with the greatest relative differences between sexes in 2017 included substance use disorders (3018 cases [95% UI 2782-3252] per 100 000 in males vs s1400 [1279-1524] per 100 000 in females), transport injuries (3322 [3082-3583] vs 2336 [2154-2535]), and self-harm and interpersonal violence (3265 [2943-3630] vs 5643 [5057-6302]). Global all-cause age-standardised YLD rates have improved only slightly over a period spanning nearly three decades. However, the magnitude of the non-fatal disease burden has expanded globally, with increasing numbers of people who have a wide spectrum of conditions. A subset of conditions has remained globally pervasive since 1990, whereas other conditions have displayed more dynamic trends, with different ages, sexes, and geographies across the globe experiencing varying burdens and trends of health loss. This study emphasises how global improvements in premature mortality for select conditions have led to older populations with complex and potentially expensive diseases, yet also highlights global achievements in certain domains of disease and injury
Investigation on increment and wood production of Cupressus sempervirens L. var. horizontalis in Kordkuy plantation forest
This study was conducted to determine the increment and wood production of 22-year-old cypress plantation in Kordkuy region in the north of Iran. Thirty sample plots, each 200m2 area were selected at 101 ha of Cypress man-made forest which was planted in 2mÍ2m spacing. The samples were taken by systematic random method. In each sample plot, diameter at breast height (DBH) of whole trees and height of witness trees were measured. Moreover, 53 trees were selected as sample trees based on classified diameter in sample plots and felled trees. The data were analyzed with SPSS and Excel softwares. Results showed that the survival rate was 58.72%. The quantitative parameters were calculated and revealed that mean DBH, mean height, basal area, volume and annual volume increment were 15.2cm, 14.02m, 24.35cm2 ha-1, 157.31 silve and 7.15 silve ha-1 y-1, respectively. Results showed the studied plantation compare to Cypress plantations in other parts of the country is promisin
Modeling rings width of Alder, Walnut and Brutian Pine and some climatical variables (case study: Darabkola Forest)
In this study effect of several environmental factors on growth rings width of three planted species, including: Alnus subcordata (22 year old), Juglans regia (21 year old) and Pinus brutia (15 year old) was investigated. In chronology studies, at first accordance among samples (15 samples for each species) was obtained then Average Species Sensitivity (ASS), Trees Correlation (TC), Expressed Population Signal (EPS), Signal-to-Noise Ratio (SNR)MS values were calculated. The purpose of this research was to develop a regression model in relation to effects of temperature, precipitation, actual evapotranspiration, Torentveit heat index, relative humidity (by month, season and growth period) on annual ring growth width in Educational and Experimental Forest of Sari Natural Resources Faculty. Overall, 162 independent climatical variables (temperature, precipitation, evapotranspiration, etc.) and 45 dependent variables (growth ring width) were analyzed. Results of variance analysis showed that there is a significant relationship between the three species in respect to their uniform growth ring width. Using filtration methods in multiple regression analysis, variables with lowest coefficient variation and highest coefficient indication were selected step by step. Results showed that growth rings width is positively correlated with summer maximum humidity in J. regia, but is negatively correlated with December maximum temperature and February evapotranspiration and is positively correlated with summer maximum humidity in A. subcordata whereas is negatively correlated with February humidity in P. brutia. These correlations are accordance with the ecological restrictions of the species. Finally, a multiple regression model was developed for each species and its accuracy was confirmed, based on model calibration results
Sustainable development of reforestation using goal programing and fuzzy- AHP
The purpose of this study was to investigate reforestation projects based on the principles of sustainable development in the Darabkola watershed in Mazandaran province. Therefore, a goal programming model was used for the consideration of multiple goals. A fuzzy hierarchical process was used to compute the weights of different criteria. The criteria and indicators were determined according to principles of the sustainable development, including those related to economy, environment, production, biodiversity conservation, forest health, and forest cover (e.g., various indicators such as net present value, carbon balance, annual increment of diameter, stem biomass, basal area, diameter variation, mass stability, and ecological productivity). The tree species comprised Acer velutinum, A. cappadocicum, Fraxinus excelsior, Juglans regia, Quercus castaneifolia, Alnus subcordata and Pinus brutia. The results of goal programming model showed that the areas of afforestation with different species were changed compared to the ecological capability assessments. The results showed a zero ha potential for maple, which was initially defined 590.197 ha based on the assessment of ecological potential. In addition, the results revealed 120.17 ha increase (547 vs. 667.21) for F. excelsior, 470.02 ha increase (535.96 vs. 1005.99) for A. cappadocicum and 89.72 ha reduce (416.30 vs. 326.57) for Quercus castaneifolia. The reforested area was unchanged for the other species such as J. regia, A. subcordata and P. brutia. Therefore, a total area of 3091.01 ha was suggested for the afforestation according to the results of goal programming model
Allometric equations for estimating standing biomass of Avicennia marina in Bushehr of Iran
Today, it is important to use of ecological indicators, such as biomass for recognizing the special status of ecosystems, such as mangrove forests and also monitoring and evaluating changes through a specific period. Because using the direct method of evaluating biomass would be destructive, it is common in all similar area to use determine exact Allometric equations by using the statistical relationship between the structural characteristics of trees and their biomass and use these equations to estimate the biomass of trees. The aim of this study is estimate the aboveground biomass of mangroves and determine Allometric models for Nayband area in Bushehr, located in southern Iran. A number of mangrove trees were randomly selected. Collar diameter, crown diameter and tree height of standing trees were measured. After logging and weighing fresh weight, dry weight, trunk and branches were obtained in laboratory and biomass of components was calculated. The relationship between quantities feature of trees and biomass for determination of allometric equation was studied by using linear, power and exponential regression. The equations were compared with each other based on the different modeling parameters. The highest significant correlation was found between crown diameters and dry weight (R > 0.90). The best equations were obtained by means of an exponential and power regression models (R2adj> 0.90). The models were obtained from explained factor, suggests that there might be a relationship between the characteristics of mangrove trees and biomass