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தொகுதி 4, பிரச்சினை 1 (2016)

கட்டுரையை பரிசீலி

The Walia Ibex (Capra walie)

Wale Mengistu

Walia ibex is endemic mammals of Ethiopia confided to Semien Mountain National Park. It is ungulate of a mediumsized mammal, showing a marked sexual dimorphism and lives between 2600 - 3900 m asl mountains of the park. The main threats of this species are human encroachment, habitat loss, livestock grazing and hunting. The population trend is fluctuating. However, currently; it is slightly increasing. Walia ibex is listed as endangered category in IUCN Red List Threatened species. Currently, it is conserved in the park which is administered by both federal and Regional Government. However, for effective conservation of this species, establishing the buffer zone, prohibit hunting, prevent possible Hybridization with goats, Captive-breeding and Awareness creation programs should be proposed and implemented soon.

கட்டுரையை பரிசீலி

Importance of Non Timber Forest Production in Sustainable Forest Management and Its Implication on Carbon Storage and Biodiversity Conservation in Case of Ethiopia

Solomon MM

Non-timber forest products (NTFPs) are biological resources of plant and animal origin, harvested from natural forests, manmade plantations, wooded land, farmlands, and trees outside forests and or domesticated. These products are vital sources of income, nutrition and sustenance for many forest-based communities around the world. This paper tries to review available and accessible literatures on role of NTFPs in sustainable forest management and its implication on carbon storage and Biodiversity conservation in case of Ethiopia. Including Sociological Approach, Economic Approach, Ecosystem Approach, Technological Approach and its related services (biodiversity conservation and carbon sequestration). The use of Non Timber Forest Products (NTFPs) has received attention in light of their Perceived potential to address both poverty reduction and tropical forest conservation. Moreover, management of NTFPs, factors that hamper sustainable managements of NTFPs. It was suggested that better management and utilization method has to be set for diversifying products benefit for the local community.

ஆய்வுக் கட்டுரை

Effect of Cadmium on the Embryonic Development and Hatching Rhythm of Big Fin Squid Sepioteuthis lessoniana, Lesson (1830) from Palk Strait, East Coast of India

Vasanthi LA, Revathi P, Munuswamy N and Ramaswamy Babu R

In the present study, the impact of cadmium on embryonic development, morphology of eggs and newly hatched larvae of the Sepioteuthis lessoniana were described using the laboratory-reared specimens originating from Thondi, South East coast of India. The eggs were exposed to a concentration of 25 μg Cd/L for up to hatching. The average incubation period of the eggs varied between 18-23 days and the estimated mean temperatures were 18.6 ± 0.7°C for control, and 19.2 ± 1.1°C for Cd exposed groups. The results revealed that a total hatching rate of 99.2 ± 1.6% was achieved in control group and only 65.2 ± 8.8% in treated group. The deformities of the paralarvae were illustrated with light and scanning electron microscopy. In conclusion, the present concentration exhibited toxic effects to the eggs and paralarvae of S. lessoniana. Therefore, Cd level as high as we used in this study could give good information on dangerous Cd levels on squid.

ஆய்வுக் கட்டுரை

Distribution and Disease Prevalence of Coral Associated Bacteria at Some Impacted Red Sea Reefs

Al-Hammady MAM and Mohamed MH

Prevalence and distribution of coral disease were surveyed in three impacted sites at Red Sea coast. Prevalence were significant difference between studied reefs (ANOVA; F = 10.777, p < 0.0001). Sites closed to oil pollution (sites 1 and 2) displayed much higher levels of disease prevalence (25.3% ± 8.3 2 and 18.5% ± 3.1, respectively), than site 3 that close to landfilling (12.9% ± 2.1). Totally, 99coral braches, representing 20 species affected by at least 12 diseases. However, site 3 is characterized by the highest diversity (Simpson’s Index = 0.081) and highest percentage cover of life coral (35.2% ± 11.4) showed the lowest coral diseases number (3). In opposite, 10 coral diseases were recorded at site 1, and 8 coral diseases at site 2. While, the coral disease atramentous necrosis attained the highest prevalence percentage at sites 1 and 2 (3.2% and 4.5%, respectively), did not recorded at site 3. Sediment damage disease recorded the highest prevalence percentage at site 3 (5.1%), but did not record at sites 1 and 2. Diseases having lowest percentage cover were white band disease (sites 1 and 2) and white tips disease. The most commonly distributed disease (atramentous necrosis) infected five corals in site 1 and six corals in site 2. The least commonly distributed disease (white tips) infected only two corals (Acropora humilis and Acropora formosa) at site 3. The genus Porites at sites was particularly vulnerable to all diseases. However, Galaxea fasicularis at site 3 recorded the highest percent cover of sediment damage disease. Coral disease atramentous necrosis is always associated with Vermetidae predation and Tridacna boring. While, Drupels predation is associated with skeletal eroding band. Aggressive filamentous algal overgrowth is associated with sediment damage disease at site 3. The pathogenic bacterium isolated from the diseased Stylophora pistillata, Porites sp., and Acropora sp., referred to as Vibrio fischeri.

ஆய்வுக் கட்டுரை

Impact of Enclosure on Plant Species Composition and Biomass Production in Ewa Woreda of Afar Region State, Ethiopia

Mohammed Abdulatife Ibrahim

This study was conducted to know the impact of enclosure on plant covers dynamics and biomass production in Ewa district. A total of 13 species of grasses, 2 species of legumes, and 4 species of other herbaceous plants were identified in both grazing areas. Of the grass species, 15.3%, 30.8%, 38.6% and 15.3% were highly desirable, desirable, less desirable and undesirable respectively. The grass species dominant in communal grazing areas were Chryspogon plumolosus (22.1%) and Tragus beteronianus (20.6%) whereas Cenchrus ciliaris (21.2%) was dominant in the enclosure area. A higher (P<0.05) total grass biomass production and total herbaceous biomass production were obtained in the enclosure areas than in communal grazing areas while in case of non-grass biomass production, there was no any significant different (P<0.05) between the two grazing areas. In general, the result showed that in species composition and biomass production communal grazing areas have deteriorated which may need an immediate intervention, while the enclosure areas need a sustainable conservation of their present condition by considering alternative management that allows selectively and carefully timed utilization.

ஆய்வுக் கட்டுரை

Renovated Breeding Habitat use in Wild & Captive-bred Populations of an Endangered Desert Pupfish

Layla Al-Shaer, Andrew Bloch, Timothy Paciorek, Zachary Carroll, Andrew Black and Murray Itzkowitz

The Leon Springs pupfish (Cyprinodon bovinus) is an endangered fish endemic to Diamond Y Spring in west Texas. To mitigate the negative effects of habitat loss, Diamond Y Spring was renovated to maintain and provide additional breeding habitat. Monsanto Pool, an extant location where C. bovinus have become extirpated, was also renovated in order to increase breeding habitat. After Monsanto Pool was renovated, captive-bred C. bovinus were reintroduced to this location to both increase the range of this species, and evaluate whether captive release is a viable option. These conservation efforts have led to the unique opportunity to evaluate the efficacy of habitat renovations in wild and captivebred populations of C. bovinus, occurring in natural and renovated breeding habitats at two separate locations. The overarching question asked was, is it better to renovate an unoccupied site and introduce captive-bred individuals, or to expand an occupied site that would allow the current population to grow? Habitat use and spawning in three different breeding areas were compared, and specific ecological factors were measured at each site in order to determine if any coincided with observed C. bovinus location preferences. Wild C. bovinus in the natural breeding habitat spawned more, had more spawns per individual male, and had greater territorial stability than wild or captive-bred C. bovinus in renovated habitats. Differences in social system stability and reproductive success between sites may be due to variation in their ability to adapt to a renovated site as well as the ecological makeup of the habitat.

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