Distribution changes of woody plants in Western Iran as monitored by remote sensing and geographical information system: a case study of Zagros forest

The status of woody plants in dry-land systems is a fundamental determinant of key ecosystem processes. Monitoring of this status plays an important role in understanding the dynamics of woody plants in arid and semi-arid ecosystems. The present study determined the dynamism of the Zagros forests in Iran using Remote Sensing and Geographic Information System techniques and statistical science. The results show that the density of trees varied from 10 to 53 % according to the physiographic and climatic conditions of semi-arid regions. The best and lowest correlation between vegetation indices and forest density were obtained for the global environmental monitoring index (GEMI; R ² = 0.94) and soil adjust vegetation index (R ² = 0.81), respectively. GEMI is used to monitor land use changes over a 10-year period. Results show that 2720 ha² of forest have been destroyed by human interference and tillage on steep slopes during this period which also resulted in the loss of the fertile soil layer. GEMI determined the areas with a biomass of trees and could normally separate border regions with low biomass density of trees from regions without canopy cover. The results revealed that assessment of forest and vegetation cover in arid and semi-arid arduous forest regions using satellite digital numbers and ordinary sampling is subject to uncertainty. A stratified grouping procedure should be established to increase the accuracy of assessment.     

Prevalence,biology, and distribution pattern of Sarcocystis infection in water buffalo (Bubalus bubalis) in Iran

This study was conducted to determine the prevalence, distribution pattern, and the Sarcocystis species involved in slaughtered water buffaloes (Bubalus bubalis) in the Khuzestan, Iran by macroscopic and histological examination. The esophagus, heart, diaphragm, tongue, masseter, and thigh muscles were investigated. Esophagus and thigh muscles of only 3 of the 100 examined water buffaloes (3%) were infected with macroscopic Sarcocystis, whereas at microscopic level Sarcocystis were found in 83 of the 100 examined animals (83%). The highest prevalence rate of microscopic cysts was found in masseter muscle (57.1%) and then followed by tongue, diaphragm, esophagus, heart, and finally, thigh muscles (30.0%). There was no significant difference between males (83.6%) and females (82.0%) or between two investigated age groups (≤2 years old, 78% versus >2 years old, 88%). Based on the size of the sarcocysts, thickness of the walls and location of the cysts, Sarcocystis buffalonis as a macroscopic form and Sarcocystis levinei and Sarcocystis dubeyi as the microscopic forms were diagnosed in the examined muscles of the buffaloes of this area. Sarcocystis fusiformis was not seen in the examined organs of these buffaloes. The high prevalence rate of microscopic Sarcocystis in this region indicates that dogs have a more significant role than cats in transmission of these protozoa.