scholarly journals Diversity and Dynamics of Plant Communities in Niger River Valley (W Regional Park)

Author(s):  
A. Mahamane ◽  
M. Zaman ◽  
M. Saadou ◽  
J. Lejoly
2018 ◽  
pp. 19-39
Author(s):  
M. A. Makarova

Geobotanical survey of floodplain natural complexes near gypsum outcrops in the Pinega river valley was done in 2015. Large-scale geobotanical map of the key polygon (scale 1 : 30 000) was composed. Typological units of vegetation were selected on the basis of the composition of dominant species and groups of indicator species. Homogeneous and heterogeneous territorial units of vegetation (serial series, combinations, environmental series) were used. 53 mapped unit types (25 homogeneous types and 28 heterogeneous types) were recognized. The floodplain vegetation consists of 17 homogeneous types of plant communities, 3 series, 14 combinations and 6 ecological series. The sites of old floodplain forests, such as willow forests with Urtica sondenii rare in the Arkhangelsk region and oxbow wet meadows with Scolochloa festucacea were identified.


1995 ◽  
Vol 25 (3) ◽  
pp. 399-434 ◽  
Author(s):  
Milan Chytrý ◽  
Oleg A. Anenchonov ◽  
Jiří Danihelka

2003 ◽  
Vol 97 (2) ◽  
pp. 209-212 ◽  
Author(s):  
R. Labbo ◽  
A. Garba ◽  
J. P. Louboutin-Croc ◽  
J. C. Ernould ◽  
B. Sellin ◽  
...  
Keyword(s):  

2020 ◽  
Vol 74 (4) ◽  
pp. 123-134
Author(s):  
TERESA GRAŻYNA WYŁUPEK ◽  
HANNA KLIKOCKA ◽  
MARIUSZ KULIK ◽  
HALINA LIPIŃSKA ◽  
ADAM GAWRYLUK

The paper describes the floristic diversity and specifies its use value in terms of feeding preferences of konik polski horses and their consumption of permanent grassland in a section of the Wieprz river valley in Roztocze National Park. The flora assessment was conducted by analyzing 79 phytosociological relevés using the Braun-Blanquet method. The results of phytosociological surveys made it possible to distinguish 7 complexes in the Phragmitetea class, 5 complexes and 1 plant community in the Molinio-Arrhenatheretea class, and 1 complex in the Nardo-Callunetea class. Natural values of the examined associations were described based on the total and average number of species in a phytosociological relevé, the Shannon-Wiener index, and the phytosociological structure of plant communities. The use value of dry weight of the analyzed meadows and pastures was estimated by means of the use value number (UVN) and taking into account the and yield size. The phytocoenoses identified in the meadows in the section of the Wieprz river valley under study exhibited high natural values (H’ = 3.20–4.62). The dry weight yields of the examined communities varied (from 1.32 to 5.37 t ha–1), but their sward usually had poor and very poor use value (UVN = from –0.55 to 5.8). Furthermore, it should be noted that the sward of wet meadows is readily consumed by the grazing animals, which contributes to the improvement of the natural and use value of meadows.


2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Tom Pennance ◽  
Fiona Allan ◽  
Aidan Emery ◽  
Muriel Rabone ◽  
Jo Cable ◽  
...  

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Muriel Rabone ◽  
Joris Hendrik Wiethase ◽  
Fiona Allan ◽  
Anouk Nathalie Gouvras ◽  
Tom Pennance ◽  
...  

Abstract Background Sound knowledge of the abundance and distribution of intermediate host snails is key to understanding schistosomiasis transmission and to inform effective interventions in endemic areas. Methods A longitudinal field survey of freshwater snails of biomedical importance was undertaken in the Niger River Valley (NRV) between July 2011 and January 2016, targeting Bulinus spp. and Biomphalaria pfeifferi (intermediate hosts of Schistosoma spp.), and Radix natalensis (intermediate host of Fasciola spp.). Monthly snail collections were carried out in 92 sites, near 20 localities endemic for S. haematobium. All bulinids and Bi. pfeifferi were inspected for infection with Schistosoma spp., and R. natalensis for infection with Fasciola spp. Results Bulinus truncatus was the most abundant species found, followed by Bulinus forskalii, R. natalensis and Bi. pfeifferi. High abundance was associated with irrigation canals for all species with highest numbers of Bulinus spp. and R. natalensis. Seasonality in abundance was statistically significant in all species, with greater numbers associated with dry season months in the first half of the year. Both B. truncatus and R. natalensis showed a negative association with some wet season months, particularly August. Prevalences of Schistosoma spp. within snails across the entire study were as follows: Bi. pfeifferi: 3.45% (79/2290); B. truncatus: 0.8% (342/42,500); and B. forskalii: 0.2% (24/11,989). No R. natalensis (n = 2530) were infected. Seasonality of infection was evident for B. truncatus, with highest proportions shedding in the middle of the dry season and lowest in the rainy season, and month being a significant predictor of infection. Bulinus spp. and Bi. pfeifferi showed a significant correlation of snail abundance with the number of snails shedding. In B. truncatus, both prevalence of Schistosoma spp. infection, and abundance of shedding snails were significantly higher in pond habitats than in irrigation canals. Conclusions Evidence of seasonality in both overall snail abundance and infection with Schistosoma spp. in B. truncatus, the main intermediate host in the region, has significant implications for monitoring and interrupting transmission of Schistosoma spp. in the NRV. Monthly longitudinal surveys, representing intensive sampling effort have provided the resolution needed to ascertain both temporal and spatial trends in this study. These data can inform planning of interventions and treatment within the region.


Geoderma ◽  
2013 ◽  
Vol 207-208 ◽  
pp. 193-204 ◽  
Author(s):  
Didier Michot ◽  
Christian Walter ◽  
Issifou Adam ◽  
Yadji Guéro

2017 ◽  
Vol 13 (13) ◽  
pp. 193
Author(s):  
Amadou Ndiaye ◽  
Yacouba Sangaré

The development of family farming is an important strategic option to support the food needs of the rural and urban populations. This is the reason it has been the subject of several studies which is based on characterization and typology to better orientate agricultural and rural development interventions. This study was conducted to characterize family farm in Mali and to determine the strategies to satisfy the country’s needs in rapport with the implementation of rural development. In doing this, field data were first collected in the family farms at Niono County (Niger River valley) and the Banamba County. After data collection, it was then analyzed in a systemic way. This analysis helps to characterize the family farm of Mali as a “Traditional peasant farm”. In Niono County, ‘peasant family farm’ which ensures its food self-sufficiency is centered on the production unit with an option of diversification. In Banamba County, “peasant family farm’ centered on unity of consumption develops food security strategy through pluri-activity. Thus, despite the intensity of government intervention, particularly in the area of Niger River Valley, malian “peasant family farmg” did not turn into “Modern family farm business”. In doing this, intervention for agricultural and rural development should move based on its strategies and practices from a sectorial approach to a systemic approach. This passage from the deterministic and holistic paradigm to the systemic and interactionist paradigm, should better redefine agricultural education and agricultural subsidy in relation with the structure of production.


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