Biology

Abstract: Phytoplankton community and limnochemistry of Lake Hashengie, a closed basin, lake situated at about 2100 m asl in Southern zone of Tigray regional state (Ethiopia), were investigated from September 2010 to early June 2011 and the fish potential yield was ...

Abstract: Zooplanktons are an important link between phytoplankton primary production and consumers at the higher levels of the trophic cascade (ie, secondary consumers). Furthermore, they may impact the pathways of energy flow and matter circulation in ...

Abstract: Worldwide, salinity affects 100 million ha of arable lands and this area is expanding. In this study, a pot experiment was conducted to assess the effect of different salinity levels on germination and seedling growth of grass pea (Lathyrus sativus) ...

Abstract: Understanding the pattern and process related to biodiversity is a greatest challenge to the science of biological conservation. Furthermore, diversity of tropical aquatic ecosystems is severely threatened by anthropogenic activities. What is more, the ...

There is evidence that human beings are familiar with use of animals and plants for food, cloth, medicine, etc. since the distant past. In Ethiopia, many ethnic communities which are dispersed all over the country has been totally dependent on local traditional medicinal system for their health care. Thus, the aim of this study was to take an ethno zoological field survey among Tigray people (main tribal group of Degu'a Tembien). In order to document the ethno zoological information about animal and their products prevalent among the people in Degu'a Tembien district, a study was carried out from September, 2010 to January, 2011. Data was collected through semi-structured questionnaire and open interview with 25 purposively selected respondents. Then the name of animal and other ethno zoological information were documented. Based on the ethno zoological survey, a total of 23 animal species were used in 45 different medicinal purposes including cold, weakness, burn, cough, paralysis and blister and for other religious/and ritual purposes. Based on the ethno zoological survey, 9 mammals, 7 birds, 1 reptile, 5 arthropods are used in traditional zootherauptics in the study area. Furthermore, the meat of cow used to relieved fever and cough has the highest FL (96%) and House fly has the lowest FL (20%) used to treat. Some endemic and rare species such as Abyssinian black winged love bird (Agapornis taranta) and Ethiopian Highland Hare (Lepus starcki) are also mentioned as important medicinal resources in trado-zootherauptic practices. The results showed that ethno zoological practices have been an important alternative medicinal practice for the people residing in the study area. So, there is an urgent need to properly document to keep a record of the ethno zoological knowledge of the area. It is hoped that this information will be useful for further research in the field of ethno zoology, ethno pharmacology and conservation point of view.

"The diversity of tropical aquatic ecosystems is severely threatened by anthropogenic activities. What is
more, the continuum of most of the tropical river is interrupted by several man-made activities
contributing to adverse effects which hamper the provision of good quality water. This study was
conducted to assess the influence of water quality on the diversity and distribution of
macroinvertebrates in Highland stream of Tigray region. A total of 42 taxa of benthic
macroinvertebrates were recorded. Among which Trichoptera (31%) and Ephemeroptera (16%) were the
dominant taxa. Furthermore, species diversity is positively correlated with water quality. Generally, low
macroinvertebrate diversity was observed in the stream section with overall water degradation and
anthropogenic disturbance Thus, man-made activities may have caused changes among the
physicochemical parameters which led to depletion of benthic macroinvertebrate biota in Illala stream.
Thus, we recommend that effluent from the town should be carefully managed."

Birds are among the best known parts of the earth’s biodiversity. This study was conducted in three
selected church forests located in different agroclimate zones (Kola, Weyna Dega and Dega) in Tigray
region, Northern Ethiopia to investigate the community composition and abundance of residential
birds. Data collection was carried out between November 2011 and March 2012 for a period of five
months, two days in a month for each study site for a total of 30 days. Line transects and point count
techniques were employed. Observation on birds was taken twice a day (in the early morning from
06:00 to 09:30 h and late in the afternoon from 16:30 to 18:30 h for a total of six hours in a day. A total of
65 bird species were recorded. Of the recorded bird species, 5 were endemic to Ethiopia. Diversity and
community similarity of birds were calculated using the Shannon–Weiner diversity index and
Sorenson’s similarity index respectively. The mean bird species diversity was highest in Giorgis
Church forest (H'=3.42) and lowest in Michael Church forest (H'=2.42). A significant difference in
diversity of birds between Giorgis and Michael church forests (t=7.707, n=5, p<0.05), Giorgis and
Endakidanemeheret Church forests (t=3.492, n=5, p<0.05) was observed while no significant difference
was observed in diversity of birds between Michael and Endakidanemeheret Church forests (t=-0.361,
n=5, p=0.737). More bird species evenness (1.08) was observed in Giorgis Church forest and low in
Endakidanemeheret Church forest (0.88). The bird community similarity of the three church forests
were very small (Css=0.11).

Salinity is one of the major stresses especially in arid and semiarid regions, which severely limit crop production. It impairs seed germination, reduces nodule formation, retards plant development and reduce crop yield. Salinity affects germination and physiology of crops due to osmotic potential which prevents water up take and by toxic effect of ions on embryo viability. This study was conducted to assess the effect of salinity on germination of chickpea (Cicer arietinum L.) in the laboratory of Mekelle University by using NaCl and Na2So4 to simulate salinity and tape water as control group. The seeds of chickpea (Cicer arietinum) landraces were collected from Hagereselam and Samre. Then 10 seeds of chickpea from both sites were treated in each salt concentration in 3 replications designed by using complete random block design. The result of the experiment showed that the concentrations of salt have a negative impact on the germination and growth of chickpea, as a result when the...

Life is a study in contrasts between randomness and determinism. Scientists often reconcile the stochastic and the deterministic by appealing to the statistics of large numbers for variations among individuals in a population. And in natural populations, variation in most characters takes the form of a continuous phenotypic range rather than discrete phenotypic classes. In other words, the variation is quantitative, not qualitative. Mendelian genetic analysis is extremely difficult to apply to such continuous phenotypic distributions, so statistical techniques are employed instead. A major task of quantitative genetics is therefore to determine the ways in which genes interact with the environment to contribute to the formation of a given quantitative trait distribution. Furthermore, the genetic variation underlying a continuous character distribution can be the result of segregation at a single genetic locus or at numerous interacting loci that produce cumulative effects on the phe...

The use of Phosphate solubilizing microorganisms as a phosphorus biofertilizer improves the soil fertility and increases the crop production, which is mostly achieved by Rhizobium phosphate solubilizing bacteria. The objective of this study was to isolate and phenotypically characterize the beneficial Rhizobium bacteria from root nodules of lentil rhizospheres. A total of 16 soil samples were collected from two districts of South Eastern Tigray Zone, northern Ethiopia. Nodules were collected from lentil roots after 45 days of growth in the green house. A total of eight rhizobia bacterial strains were isolated and identified by employing standard morphological, cultural, biochemical and physiological characterization techniques of identification for phosphate solubilizing bacteria. All strains were gram negative, motile and did not absorb Congo red. On the other hand, the tested isolates were negative for citrate, urease and positive for hydrogen sulphide tests. Similarly, all the is...

... Record Details. Record ID, 380584. Record Type, conference. Author, MEHERETU YONAS; M D&amp;amp;#x27;AES; H LEIRS; Jean Poesen [801000877101] - Ghent University biblio@ugent.be; J DECKERS; Jan Nyssen [802000198480] - Ghent University Jan.Nyssen@UGent.be. ...