Crassulacean Acid Metabolism Permutation and Survival of Caralluma Species (Apocynaceae) in Arid Habitats
Journal Title: Ecologia Balkanica - Year 2012, Vol 4, Issue 1
Abstract
Several species of the stem succulent Caralluma (Apocynaceae) are abundant perennials in arid regions of the Arabian Peninsula. These arid regions have a short wet season with erratic rainfall and are characterized by harsh climatic conditions of high temperature, high evaporation and sand storms. Work presented in this paper aimed at investigating importance of Crassulacean Acid Metabolism (CAM) for survival of three Caralluma species in their natural habitat. Investigations involved studying stomatal characteristics, stomatal diffusive conductance, chlorophyll fluorescence, and CAM in three species of Caralluma, namely C. acutangula (Decne.) N.E.Br., C. edulis (Edgew.) Benth. ex Hook.f., and C. subulata (Forssk.) Decne. Microscopic examination revealed a pattern of stomatal characteristics typical of CAM plants in these three Caralluma species. Results showed that these three Caralluma species were obligate CAM plants exhibiting this mode of photosynthesis during both the wet and the dry seasons. Under protracted water stress during the long dry season very low values of stomatal diffusive conductance and dampening of CAM acidification-deacidification cycles denoted the tendency of these three Caralluma species to shift from the obligate CAM physiotype to CAM-idling mode. Chlorophyll fluorescence measurements indicated that protracted water stress induced a reduction in Photosystem II (PSII) antenna efficiency and quantum yield in the three studied Caralluma species. This reduction of PSII activity occurred in concomitance with a marked rise in non-photochemical quenching of chlorophyll fluorescence denoting operation of non-photochemical energy dissipating mechanisms known to be important for photoprotection of the photosynthetic apparatus.
Authors and Affiliations
Yahya Masrahi, Turki Al-Turki, Osama Sayed
Върху консумацията на плодове от язовеца (Meles meles) (Mammalia: Mustelidae) през есенния период в Средна гора (България)
Проучването е проведено на базата на общо 1357 отделни идентифицирани плодове, събрани като костилки в екскременти от едно семейство язовци ([i]Meles meles[/i]) в Средна гора, северно от град Стара Загора през ноември, 2...
Using Analytical Hierarchy Process (AHP) for Prioritizing and Ranking of Ecological Indicators for Monitoring Sustainability of Ecotourism in Northern Forest, Iran
Ecotourism has been identified as a form of sustainable tourism which is expected to contribute to both conservation and development. Unfortunately, due to inadequate environmental assessment, many ecotourism d...
Distribution and Assessment of the Nature Conservational Status of the Nature Habitat 91Z0 „Moesian Silver Lime Forests” in SCI „Svishtovska Gora“ (BG0000576), Bulgaria
The protected zones or Site of community importance (SCI) are Natura 2000 areas which aim is to assure conditions for protection and survival of the most valuable and threatened species and habitats in Europe. Protected...
Study of Plant Species Composition of Grasslands in Mugla Village Region (Western Rhodopes, South Bulgaria)
The study presents data on the diversity of grass species in the region of the village of Mugla (the Western Rhodopes). One hundred forty-one species of higher plants belonging to 40 families were registered. (Apiaceae,...
Stochastic Modeling of Problematic Air Pollution with Particulate Matter in the City of Pernik, Bulgaria
Air quality in urban areas is an important prerequisite for a healthy environment. This paper focuses on the study of the problematic pollutant PM10 in the air over the city of Pernik in order to prevent the worsening of...