Dean, 2008 - present, Faculty of Applied Sciences, American University of Technology.
Freelance Consultant and Project Developer, 1995 - present, Different governmental, national and international organizations.
Assistant & Associate Professor, 2000 - 2008, (USEK, NDU, LU, AUST, HAIGAZIAN).
Member, plant chief officer, & Vice Secretary General (currently) of the Friends of Nature, 1990 - present.
Member representative of Lebanon of the IUCN Species Survival Commission-
Conifer Specialist Group (SSC-CSG), 1999 - present.
Haber, R. M. & Semaan-Haber, M. (2010). Floral enchantment to Lebanon: Natural heritage from the Mediterranean spaces and species (II). Beirut: Terre du Liban.
Haber, R. M. & Semaan-Haber, M. (2010). Orchids of Lebanon: Natural heritage from the Mediterranean spaces and species (I). Beirut: Terre du Liban.
Semaan, M.T. & Dodd, R. (2008). Genetic variability and structure of the remnant natural populations of Cedrus libani (Pinaceae) of Lebanon. Tree Genetics and Genomes, 4, 757-766, DOI 10.1007/s11295-008-0148-y
Semaan, M.T. et al. (2006). War and biodiversity. In United Nations Development Program (UNDP), Lebanon, rapid environmental assessment for greening, recovery, reconstruction, and reform, 1 - 55. Beirut: UNDP.
Discovering and describing new plant species under the plant author name 'Semaan', since 2002.
Establishing first nature reserves by parliamentary law in Lebanon, 1992.
Pioneer Woman in Environmental Protection and Conservation Award from the National Commission for Lebanese Women in reward for a history of environmental activism for conservation of biodiversity and for pioneering establishment of nature reserves with Dr. Ricardus Haber, 2010.
AUB Alumni Author from AUB Alumni Literary Festival Award, honoring authors in the occasion of Beirut World Book Capital, 2010.
Fulbright Scholar from the Fulbright Commission (USA) for commitment for researching conifers and particularly Cedars of Lebanon for conservation purposes, 2003.