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Citation: Louhaichi, M.; Gamoun, M.; Ben Salem, F.; Ouled Belgacem, A. Rangeland Biodiversity and Climate Variability: Supporting the Need for Flexible Grazing Management. Sustainability 2021, 13, 7124. https:// Abstract: Resting or grazing exclusion is an effective practice widely adopted to restore degraded, arid rangelands. To understand its eff...
Contexts in source publication
Context 1
... Tunisia has an arid Mediterranean climate with a mean long-term annual rainfall of 80 mm concentrated in autumn-spring (the growing season is September-April) and a dry summer lasting about 4 months during May-August [19]. In Tataouine, the study area (Figure 1), rainfall was 253 mm during the 2017/2018 season and 120 mm during the 2018/2019 season. The highest amount of rain occurred in a short period and was highly variable throughout the year and largely limited to November-April (Figure 2). ...
Context 2
... this study, the year with good rainfall played a more important role than any management mode in explaining species diversity. All species diversity indices (N 0 , N 1 , N 2 , and E 20 ) varied significantly with yearly climatic conditions, with higher values in the rainy year. Several recent studies showed that rainfall is a key driver of rangeland structure and function in arid areas [13,50,51]. ...
Context 3
... Tunisia has an arid Mediterranean climate with a mean long-term annual rainfall of 80 mm concentrated in autumn-spring (the growing season is September-April) and a dry summer lasting about 4 months during May-August [19]. In Tataouine, the study area (Figure 1), rainfall was 253 mm during the 2017/2018 season and 120 mm during the 2018/2019 season. The highest amount of rain occurred in a short period and was highly variable throughout the year and largely limited to November-April (Figure 2). ...
Context 4
... this study, the year with good rainfall played a more important role than any management mode in explaining species diversity. All species diversity indices (N 0 , N 1 , N 2 , and E 20 ) varied significantly with yearly climatic conditions, with higher values in the rainy year. Several recent studies showed that rainfall is a key driver of rangeland structure and function in arid areas [13,50,51]. ...
Citations
... Its blooming phase begins in late winter [4]. Southern Tunisia has an arid Mediterranean climate with a long-term annual rainfall of 80 mm concentrated in the growing season between September and April and a dry season lasting about 4 months from May to August [5]. It was previously reported that the content of secondary plant metabolites is not stable and depends on the growth stage, the part of the plant and the characteristics of the environment. ...
Anthyllis henoniana stems were harvested in two seasons: winter and spring (February and May 2021). In this study, we investigated the antioxidant (DPPH, ABTS, FRAP and TAC) and antimicrobial activities, total phenolic contents and total flavonoid contents of the obtained extracts (hexane, ethyl acetate and methanol). The results showed that ethyl acetate extract from stems harvested in winter exhibited the highest antioxidant activity, while ethyl acetate extract from the stems harvested in spring showed the most potent antibacterial and antifungal activities. To explain these differences, we investigated the phytochemical composition of these two extracts using liquid chromatography coupled with mass spectrometry. Therefore, 45 compounds were detected, from which we identified 20 compounds (flavonoids, triterpenoids, chalcones and phenolic acids); some were specific to the harvest month while others were common for both periods. Some of the major compounds detected in ethyl acetate (spring) were dihydrochalcone (Kanzonol Y, 8.2%) and flavanone (sophoraflavanone G, 5.9%), previously recognized for their antimicrobial effects. We therefore concluded that the difference in activities observed for the two harvest periods depends on the chemical composition of the extracts and the relative abundance of each compound.
... Using native species in restoration efforts is critical for recreating or maintaining healthy, resistant, and resilient ecosystems and communities [4]. Therefore, the development of methods for the large-scale plantations of selected genotypes of medicinal, pastoral, and forest species has become increasingly important in view of the need for the rehabilitation of marginal and degraded rangelands [5][6][7]. Regeneration of plants via in vitro tissue culture is considered to be an efficient approach for clonal plant propagation. Developing protocols for successful plant tissue culture is complicated because there are various interacting factors. ...
The growing demand for native planting material in ecological restoration and rehabilitation for agro-silvo-pastoral ecosystems has resulted in a major global industry in their sourcing, multiplication, and sale. Plant tissue culture is used for producing high-quality, disease-free, and true-to-type plants at a fast rate. Micropropagation can help to meet the increasing demand for planting material and afforestation programs. However, in vitro plant propagation is an expensive technique compared to conventional methods using suckers, seeds, and cuttings. Therefore, adopting measures to lower production costs without compromising plant quality is essential. This can be achieved by improving the culture media composition. Incorporating organic growth additives can stimulate tissue growth and increase the number of shoots, leaves, and roots in culture media. Organic growth supplementation speeds up the formation and development of cultures and yields vigorous plants. Plant regeneration from meristems (shoot tips and axillary buds) is a reliable way to produce true-to-type plants compared with callus and somatic embryogenesis regeneration, but in vitro culture environments can be mutagenic. Therefore, detecting somaclonal variations at an early stage of development is considered crucial in propagating plants. The genetic stability of in vitro regenerated plants needs to be ascertained by using DNA-based molecular markers. This review aims to provide up-to-date research progress on incorporating organic growth additives to enhance in vitro tissue culture protocols and to emphasize the importance of using PCR-based molecular markers such as RAPD, ISSR, SSR, and SCoT. The review was assessed based on the peer-reviewed works published in scientific databases including Science Direct, Scopus, Springer, JSTOR, onlinelibrary, and Google Scholar.
... Rangeland management strategies can be used as a tool to improve sustainability (Louhaichi et al., , 2021a. A growing number of studies have shown the positive contributions of grazing and how it can be a cost-effective practice for enhancing productivity, species diversity, and ecosystem health (Hodgson et al., 2005;Dorrough et al., 2007;Kohyani et al., 2008). ...
... Therefore, it is important to base grazing plans on the state of the vegetation cover rather than simply on the length of resting times. This result supports findings highlighting the need for flexible grazing management depending on weather and climate variability (Louhaichi et al., 2021a) and offers an opportunity to develop grazing strategies that exploit these results. ...
The aim of this study was to assess the impact of short grazing periods with high-stocking density on vegetation during weather conditions favorable to plant growth. Continuous grazing is widely practiced in Tunisian arid rangelands and across most drylands and deserts of the Middle East and North Africa. In the early 1990s, the Tunisian government combined a variety of incentives and restrictions on rangeland grazing practices and initiated a national strategy for rangeland improvement. The strategy emphasizes grazing exclusion for three consecutive years, a practice known locally as gdel. At the end of this period, grazing is allowed with no restrictions or with some guidelines. However, these regulations created discontent among pastoral communities, mainly when local rainfall conditions result in a considerable quantity of green biomass. High stocking-density grazing for a short period would help satisfy pastoralist concerns and achieve the government’s strategic goal. This study was implemented in three arid rangeland types of southern Tunisia that have been under restricted grazing for 2 years. Each area in the study was grazed for short periods in late May (about 7 days) with a flock of 150 head of sheep. Measurements of vegetation cover, forage productivity, density, and species richness were taken before and after grazing. Our results suggest that perennial vegetation is more stable under grazing than annual vegetation. The presence of annual species would enhance rangeland vegetation cover and diversity and at the same time offers an opportunity for livestock to select a high-quality diet rich in protein. Opportunistic grazing, applied to heterogeneous rangelands in late spring and the beginning of the annual temperature increase, encouraged animals to select annual plants due to their higher palatability, higher digestibility, and water content rather than heavily grazing perennial species. Perennial biomass materials that die and do not fall through rapid biological decay tended to decline with increased period of placement, resulting in further oxidation to CO2 which affects photosynthetic performance negatively and may eventually cause plant death. Trampling from high-density stocking enhances the litterfall rates and removes the oxidized plant material. These findings may contribute to strategies for addressing the extreme climatic variations that threaten rangeland and livestock sustainability.
