Variation in Plant Diversity along a Watershed in the Semi-Arid Lands of North Africa

Abstract

Plants are a vital part of the world’s biological diversity and have great economic and cultural importance. Plant biodiversity balances ecosystems, protects watersheds, mitigates erosion, affects climate, and provides shelter for many animal species. This study aimed to determine plant diversity in relation to the soil properties of semi-arid rangelands along a gradient at the watershed scale in the Oued Chabro, Algeria. Plants and soil were sampled at 27 points distributed in three sampling sites (upstream, midstream, and downstream). The floristic data was analyzed using species richness estimators, life forms, spatial occurrence, and multiple factor analysis. Moreover, the effects of soil properties on the taxonomic structure of plant communities in the sampling sites were analyzed using Pearson correlations. The characterized flora included 42 plant species classified into 18 families, and Asteraceae (38.1%), Poaceae (14.3%), Brassicaceae (7.1%), Amaranthaceae (4.8%), and Chenopodiaceae (4.8%) were the most representative in terms of species. The species Atractylis delicatula was dominant (relative abundance = 81.5%). The upstream site was characterized by a high vegetation cover, high species abundances, and richness in plant families and genera. Significant correlations were observed in this area between the number of genera, number of families, number of species, family richness, Pielou evenness index, and Simpson’s concentration index. The upstream site was characterized by chamaephytes and phanerophytes; 16 species were exclusively present in this section. Two species were found in the midstream site and one (Scolymus hispanicus) was found in downstream site. The upstream site was positively correlated with plant litter, the midstream with barren soil, and the downstream study area was negatively correlated with coarse-grained materials and vegetation cover. This study demonstrated that differences in life forms, richness, and diversity exist among the three sampling sites due to the soil differences and the positions along the watershed.

Study of plant biodiversity and spatial distribution of spontaneous vegetation in semi-arid region (Tebessa Province. Northeast Algeria)

“…Amaranthaceae. and Chenopodiaceae were the most representative [30]. Since 1960. the steppe regions of North Africa have been subject to increasing desertification.…”

Cedar vascular flora of Djebel Maadid. Floristic analysis – Conservation

“…We utilized the minimum area method (GUINOCHET, 1973), which determines the area required for a floristic sample (LACOSTE, SALANON, 2005). This methodology has been applied by various authors, such as Hammada (2007) in the study of Morocco's wetlands vegetation; Hamel et al (2013) regarding the rare and endemic vascular flora of the Edough peninsula (Northeastern Algeria); Zedam (2015) focusing on endemic flora in the Chott El Hodna wetland (North Algeria); Zedam;Fenni (2021) in an advanced research on vascular flora in the highlands of Algeria; Larbi et al (2021) concerning the floristic and phytogeographical diversity of a cedar forest in Djurdjura (North Algeria); and Souahi et al (2022) exploring the variation in plant diversity along a watershed in a semi-arid region (Northeastern Algeria). For each encountered species in any survey, we assigned a semi-quantitative coefficient using the abundance-dominance scale (BRAUN-BLANQUET et al, 1952;GILLET, 2000).…”

Predicting spatial variability of species diversity with the minimum data set of soil properties in an arid desert riparian forest

“…Our study suggested that soil salinity affected the spatial variability of species diversity. This was because soil salinity is one of the most important factors affecting plant distribution in arid desert regions (Chenchouni, 2017;Souahi et al, 2022). The scarce annual precipitation and the high osmotic pressure generated by perennial drought often led to increasing salt concentrations in the soil surface (Souahi et al, 2022), which in turn influenced the distribution of plants and the species composition of communities.…”

“…This was because soil salinity is one of the most important factors affecting plant distribution in arid desert regions (Chenchouni, 2017;Souahi et al, 2022). The scarce annual precipitation and the high osmotic pressure generated by perennial drought often led to increasing salt concentrations in the soil surface (Souahi et al, 2022), which in turn influenced the distribution of plants and the species composition of communities. It was well known that nutrient availability was one of the main determinants of plant diversity in arid desert regions (Reynolds and Haubensak, 2009).…”

“…This can be confirmed by the results of SOC in this study that SOC was the second factor determining the change of plant diversity. SOC was the most important indicator of soil nutrition, and its high value indicated that there were more nutrients available for plant to absorb and utilize in the soil (Souahi et al, 2022). In addition to SSC and SOC, SAP, STP and SNN were also affected spatial variation in species diversity in the arid desert regions.…”