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 Re: المسكيت (Re: أبوبكر عباس)
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من ورقة لدكتورة اخلاص بوتني:
أهداني اياها دكتور خالد عبد الله:
"Mesquite (P. Juliflora) was introduced into Sudan in 1917 from South Africa and Egypt and planted in Khartoum (Broun and Massey, 1929). The success attained in establishment of the tree and its abilities to tolerate drought and fix sand dunes provided the impetus for introduction of the tree into various agro ecologies with emphasis on dry areas (Broun and Massey, 1929). In 1938 the plant was introduced into Sinar, Fwar, EL foung (central Sudan), Elghaba, Lietti basin (northern Sudan), Sinkat, ELgalabat, Portsudan (eastern Sudan), Kordofan and Darfur (western Sudan) (Fig. 1). Late in 1947 and subsequently in 1965 mesquite was re-introduced into eastern Sudan, where it was planted in a green belt around Kassala (Abdel Barie, 1986). In New Halfa mesquite was introduced to protect the research farm at inception in 1966 (El Tayeb, et al., 2001). The prevailing drought in the 1970 s rejuvenated the interest in mesquite and further introductions, into eastern Sudan, were made to protect residential and cultivated areas. In 1974 mesquite seeds were broadcast by airplanes in around Kassala and further planted in protected forests (Elsidig, Abdelsalam and Abdelmagid, 1998). In the period 1978-1981 the tree was planted as shelterbelts at Portsudan and Tokar. Moreover,introductions were made into the White Nile province, western and central Sudan. The
tree was planted in shelterbelts around farms, irrigated schemes and along the Nile (Luukkanen et al., 1983) Several species of mesquite (P. chilensis, P. valutina, P. glandulosa var. terreyona, P.alba, P. pallida and P. articulata) were introduced, in the period 1978-1986, with the objective of selecting suitable species for the different ecological zones. Some of the species selected, had their seeds multiplied and distributed in western Sudan around El Obeid, and various other locations (El fadl, 1997). Mesquite seedlings failed to establish on sand dunes, but were well established within oases leading to lowering of water tables and suppression of native vegetation.
At present mesquite has become a noxious weed in Sudan (El houri, 1986). It has invaded both natural and managed habitats, including watercourses, floodplains, highways, degraded abandoned land and irrigated areas. The weed is more of a problem within central, northern and eastern Sudan. In the sandy soils of western Sudan, a part from localized foci, no problems of weedy invasion were reported (Elfadl and Luukkanen, 2003). Mesquite tends to establish, successfully, on clay or alluvial soils which have good water retention (Luukkanen et al., 1983). Currently mesquite infestations cover over 230 thousand hectare. The bulk of mesquite infestation (>90%) is in eastern Sudan, where livestock keeping and subsistence cultivation constitute the main source of income (Fig. 1). The plant is found in the Gash delta from Kassala northwards passing Wager and southwards up to the borders with Eriteria, in Atbara river, a long Khor Baraka extending from the delta up to 130 kilometers upstream and in water collection pits a long Kassala-Gadarif and Portsudan highway (Fig. 1). Rate of spread of the weed in eastern Sudan, as revealed by aerial photographs, successively taken, in 1962, 1978 and 1992 and a survey undertaken in 1996 was initially low. However, a substantial increase in rate of spread, 371 hectares per annum, was observed during 1978-1992. In 1992-1996 the average rate of spread increased to 460 hectares per annum (Elsidig, et, al., 1998). In most of the infested sites mesquite forms impenetrable thickets that smothered and excluded native vegetation and substantially changed community structure. Indigenous tree species were replaced by mesquite (Elsidig et al., 1998).
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| العنوان |
الكاتب |
Date |
| المسكيت | أبوبكر عباس | 10-12-16, 04:43 PM |
| Re: المسكيت | د.محمد بابكر | 10-12-16, 05:00 PM |
| Re: المسكيت | muntasir | 10-12-16, 05:05 PM |
| Re: المسكيت | أبوبكر عباس | 10-12-16, 05:05 PM |
| Re: المسكيت | أبوبكر عباس | 10-12-16, 05:43 PM |
| Re: المسكيت | حيدر حسن ميرغني | 10-12-16, 05:56 PM |
| Re: المسكيت | أبوبكر عباس | 10-13-16, 05:46 AM |
| Re: المسكيت | Mohamed E. Seliaman | 10-13-16, 07:08 AM |
| Re: المسكيت | أبوبكر عباس | 10-13-16, 01:35 PM |
| Re: المسكيت | أبوبكر عباس | 10-13-16, 01:41 PM |
| Re: المسكيت | أبوبكر عباس | 10-13-16, 01:44 PM |
| Re: المسكيت | muntasir | 10-13-16, 01:49 PM |
| Re: المسكيت | muntasir | 10-13-16, 01:51 PM |
 Re: المسكيت | Hatim Alhwary | 10-13-16, 02:13 PM |
| Re: المسكيت | أبوبكر عباس | 10-14-16, 02:13 AM |
| Re: المسكيت | عبدالحفيظ ابوسن | 10-14-16, 07:23 AM |
| Re: المسكيت | محمد أبوجودة | 10-14-16, 09:48 AM |
| Re: المسكيت | Kabar | 10-14-16, 09:50 AM |
| Re: المسكيت | أبوبكر عباس | 10-14-16, 10:03 AM |
| Re: المسكيت | أبوبكر عباس | 10-22-16, 09:22 AM |
| Re: المسكيت | أبوبكر عباس | 10-22-16, 10:19 AM |
| Re: المسكيت | Mohamed E. Seliaman | 10-23-16, 09:06 AM |
| Re: المسكيت | محمد أبوجودة | 10-23-16, 09:17 AM |
| Re: المسكيت | أبوبكر عباس | 10-23-16, 03:39 PM |
| Re: المسكيت | محمد أبوجودة | 10-24-16, 08:40 AM |
| Re: المسكيت | محمد أبوجودة | 10-29-16, 08:09 AM |
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أبوبكر عباس
فيس بوك
تويتر
انستقرام
يوتيوب
بنتيريست