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دراسة بيئية للدايتومات الملتصقة على بعض النباتات المائية في هور العودة ضمن محافظة ميسان جنوب العراق == A Study On The Ecology of Epiphytic Diatom On Some Aquatic Plants In Al - Auda Marshes / Maysan Province / Southern Iraq
Author name:
الاء عيسى موسى البوعجي
Supervisor name:
جنان شاوي الحساني
General topic:
Biology
Specific topic:
Environment
Degree:
Master
University:
University of Baghdad - College Of Science For Girls
Language:
Arabic
University location:
Baghdad
First pages:
24T2935 - p.pdf
Abstract:
اجريت الدراسة الفصلية على الدايتومات الملتصقة على النباتات المائية لثلاث مواقع في هور العودة ضمن محافظة ميسان جنوب العراق (من شهر تشرين الاول 2013 لغاية شهر تموز 2014) نظرا لاهمية الدايتومات في الانظمة البيئية المائية والاهمية البيئية لاهوار العراق على مس | Seasonal study on the quality and quantity of epiphytic Diatoms was conducted in the Al - Auda marsh within Maysan Province throughout one year from October 2013 to July 2014.These Diatoms have an important role in biotic ecosystems. Three taxa of aquatic plants were selected (Phragmites australis Trin ex stand, Ceratophyllum demersum L. and Typha domengensis Pers) in three sites within Al - Auda Marsh; these sites were Al - Adleh, Al - Auda and Um - Almashahef. Also, the study included measuring physical and chemical factors of all the study sites, such as : temperature (air and water), power of hydrogen (pH), total hardness(TH), Calcium (Ca), Magnesium (Mg), turbidity (Tur.), light penetration(LP), depth of water (D), total dissolved suspend material (TDS), total suspended solids (TSS), total alkalinity (TA), dissolved oxygen (DO), total nitrogen (TN) and total phosphorus (TP) and reactive Silicate (SiO3). The mean ranges of the studied factors were recorded : air temperature (10 - 38 C°), water temperature (13 - 34 C°), pH (7.1 - 8.6), TH (672 - 3800mg/l), Ca (97.8 - 264.5 mg/l), Mg (125.1 - 896.13mg/l), Tur.(7.62 - 30.7NTU), LP(46 - 113cm), D (190 - 413cm), TDS (1170 - 3075 mg/l), TSS (0.02 - 0.08 mg/l). while TA (207.5 - 300mg/l), DO (6.4 - 13.5 mg/l), TN (2.41 - 8.58µg/l), TP (0.013 - 0.23 µg/l) and SiO3(101 - 776.77 µg/l).Results of the study indicated presence of 111 taxa of epiphytic diatoms, which belonged to 13 families and 26 genus (one family and two genus of centric diatoms, 12 families and 26 genus of pennate diatoms).The present study recorded 21 species that were found only on one host plant, 20 species that were found on two host plants and 70 species that were found on all host plants, nine of diatoms taxa were present in all host plants among all study seasons which are Achnanthes minutissima, Cocconeis placentula var. euglypta, Cyclotella meneghiniana, Synedra affinis, Syneda ulna , Gomphonem parvulum, Mastogloia smithii var. amphicephala, E. zebra var. porcellus, Rhopalodia gibba.One of the diatoms taxa was recorded in the present study is new to Iraqi flora, the new record of diatom include one taxa of Achnanthidiaceae family (Achnanthes exigua var. constricta). The results of this study included description of the basic characteristics of this taxa with complete photographic documentation.It was evident, from the results, that the morphological form of host plants influenced the number of the attached epiphytic diatoms. C. demersum had attracted 92 diatoms taxa(35%) while the lowest number was 82 taxa (31%) attached by Typha domengensis. The seasonal variation of diatoms growth was evident. Spring 2014 was characterized by the highest number of attached taxa (69 on P. australis - 11%) whereas the lowest number was observed on C. demersum (32 taxa - 5.4%) in autumn 2013.Numbers of epiphytic diatoms fluctuated among study sites, seasons and aquatic plants. The total number of epiphytic diatoms on P. australis ranged between 0.73×104 cell/gm wet weight in summer 2014 at Al - Auda and 406.89104 cell/gm wet weight in spring 2014 at Um - Almashahef. C. demersum recorded highest total number 513.9 ×104 cell/gm wet weight in winter2014 at Al - Adleh, while the lowest total number was 0.1×104 cell/gm of wet weight was recorded in the spring 2014 at Um - Almashahef. While total number of taxa on T. domengensis ranged (0.84 - 427.89) ×104 cell/gm wet weight in summer and winter 2014 at Um - Almashahef.Fluctuations in the total number of main epiphytic diatoms families were observed on all aquatic host plants throughout the study period. The higher total number(92.59×104 cell/gm of wet weight) of diatoms recorded in Achnanthidiaceae family in summer 2014 on P. australis and lower total number (0.28×104 cell/gm of wet weight) on same plant observed in Rhoicospheniaceae family in spring 2014. C. demersum showed highest total number (95.15 ×104 cell/gm of wet weight) in Fragilariaceae family in spring2014, while the lower total number (0.3×104 cell/gm of wet weight) was in family Rhoicospheniaceae in autumn 2013. Individual of Achnanthidiaceae family were recorded as highest total number (168.57×104 cell/gm of wet weight) on T. domengensis in Achnanthidiaceae family in the winter of 2014, but lower total number (0.28×104 cell/gm of wet weight) recorded in Coscinodiscaceae family in the same season. The study showed highest values for richness index (3.77) in the spring of 2014 for epiphytic diatom on C. demersum in Al - Auda site, while lower richness index recorded was (0.6) on T. domengensis in theautumn of 2013 at Um - Almashahef. Shannon - Weaver index ranged (0.24 - 2.45) for epiphytic diatom on P. australis during winter of 2014 at Um - Almashahef and autamn 2013 at Al - Auda, respectively. Highest values for Evenness index were recorded (0.28) for epiphytic diatom on C. demersum in the spring of 2014 at Um - Almashahef site, while for the same site lower values recorded was (0.03) on T. domengensis in winter 2014. Higher percentage for Jaccard similarity index (63.2%) obtained between epiphytic diatoms hosted on T. domengensis and lower percentage of similarity (28.9%) found among the common taxa of epiphytic diatoms on C. demersum, and highest percentage for Jaccard similarity index between host plants was (70%) between P. australis and C. demersum while lower percentage of similarity(67%) was obtained between T. domengensis and C. demersum.
