User talk:Mohamed Dadamouny

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Age Structure and Population Dynamics of Moringa peregrina, an Economically Valuable Medicinal Plant
''' Zaghloul, M.S., Moustafa, A.A., Dadamouny, M.A.

Several threats affect Moringa peregrina populations and lead to high mortality, low recruitment, and poor survival rates. To conserve M. peregrina, understanding the populations’ dynamics is fundamental. Four Wadis in Southern Sinai, Egypt, representing the known local geographic distribution were surveyed and selected for the study. Age of cross-cuts were identified and used to establish the linear regression age-radius relationship. The estimated ages (based on their radii) of sampled trees were used to determine the age distribution and construct a static life table. The age structure of populations consisting of multiple cohorts was used to estimate the survival patterns of the various age groups. Tree size distribution and relation with age structure were studied also. The results showed that the growth rings can be taken as regular time markers and the tree size can be used to expect the age class of the tree. The study revealed that M. peregrina grows very slowly and that the estimated oldest tree is more than 380 years old. The age structure results showed unhealthy shrinking populations with sharp decline in the last 20-40 years and high rate of mortality among the young and the old trees. The study came out with a conclusion that unless conditions have been changed, these populations will permanently disappear.

Reference: Zaghloul, M.S., Moustafa, A.A., Dadamouny, M.A. (2011). Age Structure and Population Dynamics of Moringa peregrina, an Economically Valuable Medicinal Plant, Egyptian Journal of Botany, NIDOC.