Influence of anthropic and eco-hydrological factors on the floristic diversity of the herbaceous vegetation around the temporary ponds in Ferlo,northern Senegal

Temporary ponds play substantial roles in preserving biodiversity in the Sahel.This study investigated the influence of anthropic and eco-hydrological factors on the plant diversity around two grazed ponds and one ungrazed pond in Ferlo,northern Senegal.Two phytoecological transects were established per pond.On each transect,homogenous herbaceous vegetation units were identified and characterized(herbaceous cover,exposure,soil texture,soil moisture and pH,average height and slope).The herbaceous flora comprised 55 species,41 genera and 22 families across the three ponds.Species of the Poaceae,particularly Eragrostis tremula and Enteropogon prieurii,mostly colonized the grazed ponds,while the ungrazed pond favored other families’species such as Achyranthes sp.,Commelina forsskaolii,Corchorus sp.The Shannon’s diversity index(H′)of Wendu Marodi(ungrazed pond)was slightly higher(4.9 bits)than that of Belel Lougal and Belel Sow(grazed ponds)with 4.8 and 4.5 bits,respectively.The equitability indices were relatively high in the three ponds(0.85,0.83 and 0.78).Eco-ecological factors distinguished four species’groupings:a Tribulus terrestris grouping colonizing the constraining and over-grazed zones,a Digitaria horizontalis grouping,and Chloris barbata grouping found in the transition zones,and an Achyranthes aspera grouping in the wetlands,where woody plants were strongly present and the anthropic action low.This study highlighted the importance of maintaining a landscape mosaic of ungrazed or semi-protected ponds and grazed ponds to preserve the herbaceous floristic diversity in the center of Ferlo(Senegal)and the Sahel in general.

Effects of fertilization on population density and productivity of herbaceous plants in desert steppe

In order to investigate the impacts of fertilization on population density and productivity on herbaceous plants in desert steppe, nitrogen （N）, phosphorus （P）, and N-P addition experiments were performed. Each fertilizer treatment included four addition levels, i.e., 0, 5, 10, and 20 g/m2. The results indicated that population density decreased as fertilization levels increased regardless of the sort of fertilizer. More specifically, total density as well as density ofArtemisia capillaris, Allium polyrhizum, and Enneapogon brachystachyus decreased significantly in 20 g/m2 treated plots, as compared with the control plots. Fertilization effects on aboveground and root biomasses were extremely similar to that found in population density; that is, both total aboveground biomass and aboveground biomasses for A. capillaris, A. polyrhizum, and E. brachystachyus were negatively correlated with increasing fertilization levels, with all determination coefficients （R2） greater than 0.80. Therefore, in the case of desert regions （annual precipitation 〈180 mm）, fertilization would inhibit population density and productivity of herbaceous plants.

The Effects of Ground Cover Mowing Height on the Fauna of Ground-dwelling Arthropods in Olive Grove

Ground dwelling insects,spiders,and other arthropods play an important role in agroecosystems as predators and saprophytic organisms.Their presence on the soil surface helps the biological control of pests,enhances organic matter decomposition and promotes biodiversity.Soil disturbance,particularly tilling and mowing has greatly affected the assemblage and abundance of epigeic arthropods.This study aimed to determine the effects of herbaceous vegetation cover mowing height on arthropods abundance and structure in olive orchards.The experimental site was divided into three zones(Z1,Z2,and Z3)regarding mowing heights(0 cm,10 cm,and 15 cm).This research was done in 2019 from the beginning of May untill the end of September.During this research,1490 individuals were recorded belonging to 6 classes,11 orders and 13 families.The number of individuals was higher in the zones Z2 and Z3 comparing with Z1.The highest number of individuals showed woodlices(Isopoda)comprising 67,5%of all individuals collected.There were significant differences in the number of Carabidae,Bleteliidae and Forficulidae between the zones of research.Unlike Forficulidae,higher heights of mown positively affected the population of Carabidae and Blateliidae.

Urban Park Soil and Vegetation: Effects of Natural and Anthropogenic Factors

Various soil surface components, such as trees, shrubs and biological crusts, and human recreational activities, e.g., barbecues and trampling by visitors, may divide the area of the urban park into smaller fragments/mieroenvironments, differentiated by their microenvironmental conditions, which may differ in soil and vegetation characteristics. The spatial changes in the soil and vegetation characteristics and their causes were investigated in an urban park located south of Tel Aviv-Jaffa, Israel. The area of the park is 0.5 km^2, including groves, a lake, lawns, and rest areas. Soil was sampled in nine microenvironments, of which seven were within the park： under Ceratonia siliqua trees （CsU）, under Ficus sycomorus trees （FLU）, rest area between tables under F. sycomorus （FIB）, rest area under tables under F. sycomorus （FIT）, open area with bare soil （OaS）, open area with biological crust cover （OaC）, and open area covered by herbaceous vegetation （OaV）. Two more microenvironments, planar and sloping open areas （CoP and CoS, respectively） in the vicinity of the park, were used as the controls. Electrical conductivity, concentrations of soluble ions （Mg^2＋, Ca^2＋, Na^＋, K^＋ and HCO3）, pH, contents of organic carbon, calcium carbonate and moisture, and grain size distribution were determined. In addition, herbaceous vegetation cover, number and diversity of herbaceous vegetation species were measured. It was found that soil properties and herbaceous vegetation characteristics varied within the park. Soil organic carbon, electrical conductivity, soluble salts, penetration depth, and vegetation characteristics were affected by human activities, mainly in the rest area between the tables. In contrast, the above characteristics were affected by natural factors mainly in the rest of the microenvironments, which were subjected to low levels of anthropogenic intervention. The heterogeneous structure of the park, as represented by the various microenvironments, offered new habitats and promoted the preservation of natural vegetation.

Changes in vegetation and soil properties following 6 years of enclosure in riparian corridors

Aims Riparian corridors play vital roles in the maintenance of biodiversity.Nonetheless,plant species diversity and vegetation coverage in riparian corridors are seriously threatened by increasing pressure owing to livestock consumption and anthropogenic disturbance;even the stability of river courses has been threatened.The establishment of enclosures is a widely used strategy to restore degraded grassland ecosystems,but its impact on degraded herbaceous riparian vegetation and soil properties remains unclear.The aim of this study was to evaluate whether species composition,richness,diversity,and soil properties can be recovered by the enclosure.Methods Twenty long-term monitoring sample plots were set in the Liaohe main stream river,Liaohe main stream river was enclosed for grazing and farmland exclusion in 2012.The height,coverage and individual numbers of plant were recorded for species richness and diversity evaluation from 2012 to 2017;soil nutrients were measured for comparative analysis in 2012 and 2017.We examined the effects of the establishment of enclosures on plant species diversity and soil properties from 2012 to 2017 in the riparian corridors of the Liaohe River system in China.Important Findings Plant species richness and diversity significantly increased from 2012 to 2017.The dominance of Asteraceae plants increased,while the abundance of Gramineae plants decreased over time.The difference in abundance increased each year since enclosure was implemented in 2012.The concentrations of phosphorus and potassium in the soil significantly decreased as a result of the combined effects of vegetation restoration and prohibition of farming practices following the establishment of enclosures.There was also a lag time related to the response of soil organic matter to the establishment of enclosures.In conclusion,our study provides new evidence regarding the response of species diversity,species composition and soil properties following riparian vegetation restoration efforts through enclosure development.