Short-term grazing exclusion in arid rangelands affected soil surface conditions, plant community diversity and ecosystem services

A Doghbage¹, Y Kouba², N Salemkour³, S Merdas^3,4, H Boukerker³, H Chenchouni^5,6, B Habib¹, R Safi³, A Djoughlafi¹, A Aidoud⁷, B Sakaa³, W Soufan⁸ and F A Belhouadjeb¹

¹ Centre de Recherche en Agropastoralisme (CRAPAST), 17000 Djelfa, Algérie
abdelghafour.doghbage@crapast.dz
² Department of Biology, University of Boumerdes
³ Scientific and Technical Research Center on Arid Regions Biskra 07000
⁴ Research Centre for Territory Planning, 25000 Constantine (CRAT), Algeria
⁵ Laboratory of Natural Resources and Management of Sensitive Environments ‘RNAMS’, University of Oum-El-Bouaghi, Oum-El-Bouaghi 04000, Algeria
⁶ Higher National School of Forests, Khenchela 40000, Algeria
⁷ Université Rennes 1-Unité mixte de recherche (UMR-CNRS) Ecobio. France
⁸ Plant Production Department, College of Food and Agriculture Sciences, King Saud University, P.O. Box 2460, Riyadh 11451, Saudi Arabia

Abstract

Rangelands, essential for forage production, face significant degradation due to intensive exploitation and climate uncertainties. This degradation diminishes ecosystem services, impacting socio-economic and environmental conditions severely. Protective enclosures show promise in rapidly regenerating degraded rangelands, though sustainable management requires organized herding practices to prevent rapid re-degradation post-restoration. Studies confirm the effectiveness of enclosures in improving pastures by allowing temporary rest periods, excluding animal access. Our research compares adjacent rangelands under free grazing and enclosure, aiming to assess ecological viability and services of protected pastoral ecosystems. Our findings highlight enhanced composition, floristic diversity, forage quality, soil conditions and plant cover in managed rangelands compared to free-grazed areas. This approach leads to significant biomass and pastoral productivity gains, such as approximately 3284 kg DM/ha and 228 UF/ha in Stipa tenacissima communities and 2989 kg DM/ha and 386 UF/ha in Legeum spartum communities, respectively. These results underscore the potential of protective enclosures in restoring and maintaining the health of steppe rangelands.

Keywords: degradation, ecosystem health, indicator, productivity, restoration, steppe rangelands

Introduction

Rangelands are vital for the environment, economy and human well-being, covering a significant portion of the Earth's surface. Sustainable management is crucial for these ecosystems, which heavily depend on forage production. Mediterranean rangelands have evolved under the influence of grazing and significant climatic variability over time (Perevolotsky et al 1998), fostering resilient plant communities capable of withstanding disturbances (Sternberg et al 2000). However, challenges such as excessive grazing and climate change threaten these ecosystems with potential land degradation (Li et al 2013). The unique conditions of Mediterranean rangelands, characterized by high climatic variability and grazing pressures, underscore the necessity for nuanced conservation approaches. Given the diverse nature of dry Mediterranean ecosystems (Alados et al 2006), tailored conservation measures are imperative.

The relationship between plant diversity and livestock grazing has been extensively studied, particularly in arid rangelands (Merdas et al 2021; Wang et al 2018; Boukerker et al 2022). Grazing significantly influences plant communities, its effects complex and contingent upon factors such as time, space, climate and evolutionary history. Grazing is recognized as a major contributor to biodiversity loss and land degradation in water-limited ecosystems (Rasmussen et al 2018). Environmental filters play a critical role in shaping community composition in arid and semi-arid rangelands (Ahlborn et al 2020). Conversely, prolonged grazing in low-productivity lands decreases species diversity (Milchunas et al 1988; Cingolani et al 2005), complicating predictions about rangeland dynamics (Oñatibia et al 2019; Pfeiffer et al 2019; Gao and Carmel 2020). Managing practices in arid environments are complex due to uncertainties involving herbivores, environmental variables and biodiversity interactions, necessitating further research for informed management.

Algeria's steppe rangelands, spanning approximately 15 million hectares, host diverse vegetation including Alfa, sagebrush, spartegrass and atriplex (Habib et al 2024; Boukerker et al 2021). To address management challenges, strategies like grazing exclusion perimeters have been implemented by the High Commissioner for the Development of the Steppe (HCDS) to restore grasslands. Grazing exclusion has successfully restored moderately degraded grasslands, potentially mitigating land degradation (Kouba et al 2024; Macheroum and Chenchouni 2022). This technique enhances soil carbon and nitrogen levels, leveraging the self-repairing capacity of grassland ecosystems by minimizing disturbances (Zhu et al 2016). However, its effectiveness in heavily degraded areas remains uncertain, warranting further evaluation.

Research indicates that rest periods achieved through rotational grazing or exclusion positively impact soil habitats by increasing organic matter and improving soil conditions (Vecchio et al 2019). Grazing exclusion practices show promise in revitalizing degraded grasslands, improving plant community traits and enhancing soil physicochemical properties (Wang et al 2018). A comprehensive assessment is necessary to gauge broader impacts on ecosystem health, including biodiversity conservation and functional performance.

This study aims to contribute to the discourse on grazing and plant diversity in Algeria's arid steppe rangelands. By examining grazing impacts within ecological frameworks, we seek to offer insights crucial for effective rangeland management and conservation practices. We hypothesize that grazing negatively affects biodiversity, soil conditions and plant biomass due to arid conditions and grazing pressures. Specifically, we explore the effects of grazing exclusion on soil surface conditions, its influence on plant diversity patterns and its potential to promote rangeland productivity.

Materials and Methods

Study site

The study site, located 400 km southwest of Algiers in arid steppe rangelands (Figure 1), ranges from 600 m to 1000 m in elevation. Soils are primarily Calcimagnesic and loamy-sand (Aidoud 1983). The climate is arid, influenced by Sahara Desert continental effects, with mean maximum (35°C) and minimum (-5°C) temperatures in July and January, respectively. Average annual rainfall is 184 mm, with a dry period spanning ten months (January-November).

Plant communities in the area are typical of arid steppe rangelands, dominated by perennial species like Artemisia herba-alba, Lygeum spartum, Stipa tenacissima and S. parviflora, alongside annual species such as Astragalus corrugatus, Bromus rubens, Malva aegyptia, Muricaria prostrata,Schismus barbatus and Senecio gallicus.

The region includes collective rangelands primarily used for livestock grazing. Historically, nomadic herders maintained these rangelands, but recent sedentarization has led to degradation. To restore degraded rangelands, Algerian authorities have adopted the nature-based "grazing exclusion" management practice due to its low investment, extensive reach, and simple implementation (Kouba et al 2021).

Figure 1. Location of the study area in arid steppe rangelands of Algeria. The green polygon represents the exclosure and the colored triangles show locations of sampled plant communities for free grazing (▼) and grazing exclusion (▲) management type, with 10 transects sampled for each community

Data sampling

In the study area, there is a 35,000 ha exclosure established in 1998 by HCDS, initially protected for 2 to 3 years as per grazing area regulations. Annually grazed for two months (April 15 to June 15), grazing depends on rainfall and perimeter productivity. Our study was conducted before grazing began, during peak vegetation growth. It compares adjacent rangelands: one freely grazed by livestock and one excluded from grazing, both similar in edaphic and climatic conditions (same vegetation and soil type).

Six plant communities near the exclosure borders were studied: Artemisia herba-alba (community A), Artemisia herba-alba - Legeum spartum (community AL), Legeum spartum (community L), Stipa tenacissima (community S), Stipa tenacissima- Artemisia herba-alba (community SA) and Stipa tenacissima- Stipa parviflora (community SS). Each community had 10 paired 10-m transects, five inside and five outside the exclosure, sampled using the points-quadrats method with 100 points per transect at 10-cm intervals.

For each point, soil surface conditions (presence of sand, litter, dry crust, coarse particles) and vegetation species were recorded following eflora Maghreb guidelines. Unidentified species were identified in the laboratory. Vegetation data was used to calculate transect-wise metrics including cover, species richness, evenness, perennial and annual species counts. This data also informed estimates of above-ground biomass, ecosystem productivity and pastoral value index.

The use of linear transects proved efficient in steppe environments due to their simplicity and speed of execution (Photo 1).

Photo 1. Sampling of flora in the study region, (A) grazing exclusion; (B) free grazing. (source original)

Estimation of measures of ecosystem services

In these steppic rangelands, the primary ecosystem service is forage production, which was assessed by quantitative and qualitative measures. Quantitative measures included percentage of vegetation cover and estimates of aboveground biomass and primary productivity per unit area and time. Aboveground biomass (kg DM ha-1) was estimated using allometric equations based on species-specific frequencies along transects, excluding rare species. Aidoud (1983) previously established regression equations correlating species-specific frequencies to aboveground biomass.

The pastoral value index, a qualitative measure of forage quality, ranks species based on their abundance (specific frequency) and nutritional quality (specific quality index). This index ranges from 0 (toxic or inedible species) to 10 (highly desirable species), reflecting their utility for sheep grazing. Aidoud (1983) determined specific quality indices through field surveys with local herders in Algerian high plains.

Overall, these assessments were conducted during an average year with annual rainfall ranging between 200 mm to 250 mm across sampled rangelands. The pastoral value index categorizes rangelands based on their suitability for grazing, incorporating species abundance and nutritional quality into a standardized assessment framework (Daget and Poissonet 1972; Djebaili et al 1992).

Where:

VP_i: pastoral value of the transect (i).

n: number of species in the transect (i).

R: vegetation cover (%) along the transect (i).

CS_i: Contribution (%) of a species (i) in a transect (i).

Is_i: specific quality index of species (i).

Productivity (UF ha-1 year-1) per transect was estimated based on vegetation cover (%). Aidoud (1983) established regression equations correlating productivity with vegetation cover for dominant steppes in Algerian high plains (Artemisia herba-alba, Legeum spartum , Stipa tenacissima). These equations were adapted for sampled plant communities in our study.

Statistical analysis

To assess the impact of short-term grazing exclusion on soil surface conditions, plant diversity and ecosystem services metrics across different plant communities, we conducted statistical analyses comparing exclosure interiors with adjacent open grazed areas. We employed independent t-tests and two-way ANOVA, treating management type and plant community type as factors with two and six levels, respectively. Normality and variance homogeneity were assessed with Shapiro-Wilk and Brown-Forsythe tests. Significantly different means (p< 0.05) were further analyzed using Tukey post hoc tests.

For variables like sand, litter, coarse particles and productivity that did not meet ANOVA assumptions, we utilized Aligned Rank Transform Analysis of Variance (Wobbrock et al 2011). This involved data alignment and ranking using functions from the ARTool R package, followed by post-hoc tests with the phia package's testInteractions function.

To identify characteristic species for each community within exclosure and grazed areas, we employed Indicator Species (IS) analysis (De Cáceres et al 2012). IS analysis assesses species fidelity and exclusivity within site groups, indicating species most associated with specific conditions. This was performed using the multipart function from the 'indicspecies' R package (De Cáceres and Legendre, 2009).

Compositional differences among plant communities and management types were visualized using two-dimensional non-metric multidimensional scaling (NMDS) based on Bray-Curtis dissimilarities. Convex hulls were added using the ordihull function. Pairwise comparisons were conducted using adonis from the vegan package (Oksanen et al, 2019) and pairwiseAdonis from the pairwiseAdonis package (Arbizu, 2020) to explore significant differences.

Finally, plant beta diversity's response to management and community types was evaluated with the betadisper function in vegan, followed by ANOVA and Tukey post hoc tests for pairwise comparisons. These comprehensive analyses provide insights into the ecological impacts of grazing exclusion in diverse plant communities.

Results

Effects of grazing exclusion on soil surface conditions Sand cover

Sand cover differed significantly between free grazing (FG) and grazing-excluded (GE) areas, with mean ± SD values of 39.7 ± 21.1 and 6.2 ± 11.4, respectively. In FG, SS exhibited the highest sand cover (66.4 ± 14.8), followed by A (50.8 ± 6.1), while L had the lowest (7.6 ± 8.5). In GE, A, AL and S showed no sand cover, with SS having the highest (29.2 ± 8.4). Two-way ANOVA indicated significant effects of Units (F (5, 48) = 25.79, p < 0.001), Managements (F(1, 48) = 214.92, p < 0.001) and their interaction (F(5, 48) = 7.15, p< 0.001). Tukey’s HSD post hoc tests grouped units into three distinct categories (Figure 2).

Plant litter cover

Overall, litter cover averaged (3.9±4.1) in FG and (4.4±4.4) in GE. The highest litter cover in FG was in SS (8.2±5.5) and the lowest in L (0.2±0.4). In GE, SA showed the highest (6.2±4) and S the lowest (0.2±0.4). ANOVA indicated significant variations with the 'Units' factor (F(5,48) = 3.02, p= 0.019) and interaction (F(5,48) = 2.55, p= 0.040); 'Management' had no significant effect (Figure 2).

Soil crust

Under FG, L had the highest dry crust cover (81.4±10.2), while S had none (19±29.9). In GE, AL had the highest (52.2±10.3) and SS the lowest (2.6±4.3), with a mean of (21.6±18.5). Significant variations were noted for 'Units' (F(5, 48) = 50.08, p< 0.001) and 'Units × Management' interaction (F(5, 48) = 49.90, p < 0.001); 'Management' had no significant effect (Figure 2).

Coarse particles cover

FG showed higher coarse particles cover (12±10) compared to GE (4.2±4.2). S had the highest FG value (24.8±5.9) and SS the lowest (1.6±1.5). In GE, SS had the highest (6.8±8.8) and L the lowest (2.4±2.9). ANOVA indicated significant effects for 'Units' (F(5, 48) = 7.19, p< 0.001), 'Management' (F(1, 48) = 32.30, p< 0.001) and 'Units × Management' interaction (F(5, 48) = 7.65, p< 0.001) (Figure 2).

Figure 2. Variation of elements reflecting soil surface conditions between management types (Grazed vs. Grazing-exclusion) and among plant community types and their interaction. Means in a point without a common superscript letter differ p< 0.05) as analyzed by two-way ANOVA and Tukey HSD test. A, Artimisiaherba-alba community; AL, Artemisia herba-alba-Legeumspartum community; L, Legeumspartum community; S, Stipa tenacissima community; SA, Stipa tenacissima-Artimisiaherba-alba community; SS, Stipa tenacissima-Stipa parviflora community

Effects of grazing exclusion on plant communities’ diversity

This study documented a total of 90 plant species across 23 botanical families, with Asteraceae, Poaceae, Fabaceae and Brassicaceae being the most prominent.

Richness

In FG, mean richness was 15.2±6.2, peaking at 25.4±2.7 in SA. In GE, SA exhibited the highest richness at 35.4±1.8, with a mean of 22.4±8.6. ANOVA revealed significant variations for 'Units' (F(5,48) = 22.04, p< 0.001), 'Management' (F(1,48) = 50.80, p< 0.001) and 'Units × Management' interaction (F(5,48) = 10.58, p< 0.001) (Figure 3).

Evenness

Evenness was 0.52±0.1 in FG and 0.49±0.1 in GE. ANOVA showed non-significant differences among 'Units' (F(5,48) = 0.38, p = 0.859), 'Management' (F(1,48) = 1.55, p = 0.219) and 'Units × Management' interaction (F(5,48) = 0.33, p = 0.894) (Figure 3).

Perennials

FG had 5.1±1.9 perennials, peaking at 7.2±0.8 in SS. In GE, mean perennials were 5.3±1.9, with the highest at 7±0.7 in L. Significant variations were found for 'Units' (F(5,48) = 16.27, P < 0.001) and 'Units × Management' interaction (F(5,48) = 8.92, p< 0.001), but not for 'Management' (F(1,48) = 0.68, p = 0.415) (Figure 3).

Annuals

FG had 10.1±5.9 annuals, while GE had 17.2±7.8, with SA showing the highest value in both (29.8±1.9 in GE). ANOVA indicated significant variations for 'Units' (F(5,48) = 20.79, p< 0.001), 'Management' (F(1,48) = 54.33, P < 0.001) and 'Units × Management' interaction (F(5,48) = 9.07, p< 0.001) (Figure 3).

Figure 3. Group means with 95% confidence intervals of diversity metrics. Means in a point without a common superscript letter differ (P< 0.05) as analysed by two-way ANOVA and Tukey HSD test. A. Artimisiaherba-alba community; AL, Artemisia herba-alba-Legeumspartum community; L, Legeumspartum community; S, Stipa tenacissima community; SA, Stipa tenacissima-Artimisiaherba-alba community; SS, Stipa tenacissima-Stipa parviflora community.

Effects of grazing exclusion on plant communities’ composition

Grazing exclusion's impact on plant communities’ composition was analyzed using NMDS ordination, revealing a stress value of 0.12 without distinct FG and GE clusters (Figure 4). Pairwise comparisons showed significant differences in species composition between FG and GE (p< 0.001). Among plant community types, significant differences (p< 0.05) were noted except for AL vs L, S vs SA and S vs SS (p= 0.555, p= 0.060, p = 0.405 respectively) (Table 1).

Assessment of plant community types on species beta diversity indicated significant differences (F = 5.32, p< 0.001) (Figure 5.a), while management types (FG vs GE) did not show significant differences (F = 0.24, p= 0.62) (Figure 5.b). Tukey’s HSD post hoc tests highlighted beta diversity differences in community combinations (L vs A, S vs A, SS vs L, SS vs S) (Figure 5.c).

Figure 4. Non-metric multidimensional scaling (NMDS) plot of species compositions of each plant community (A, Artimisiaherba-alba community; AL, Artemisia herba-alba-Legeumspartum community; L, Legeumspartum community; S, Stipa tenacissima community; SA, Stipa tenacissima-Artimisiaherba-alba community; SS, Stipa tenacissima-Stipa parviflora community) and each management type (i.e., grazed vs. grazing-exclusion). NMDS analysis based on dissimilarities calculated using the Bray-Curtis index. Black circles refer to the coordinates of sampled transects.

Figure 5. Effect of plant community (a) and management (b) types on species beta diversity by running the betadisper function (results of ANOVA tests are also included). PCoA1 and PCoA2 are the first and second sort axes in the “betadisper” analysis respectively. (c) shows differences in communities-means beta diversity as analyzed by Tukey HSD method (red bands depict significant differences).

Effects of short-term grazing exclusion on indicators species

Indicator species analysis identified 38 species; 24 favored grazing-excluded sites. In community A, six species were selected, half from grazed areas. AL had three species, all grazed-related. L, S and SA favored grazing-excluded species. SA had 20 indicator species, while SS had one for protected areas (Table 2).

Effect of grazing exclusion on ecosystem services

Vegetation cover

In free grazing areas (FG), mean vegetation cover (VC) was 26.5 ± 13.7, peaking at 45.7 ± 5.6 in SA. In grazing-excluded areas (GE), VC averaged 70.6 ± 17.6, with SA also showing the highest value. ANOVA indicated significant effects for Units (F(5, 48) = 17.72, p< 0.001), Management (F(1, 48) = 382.21, p< 0.001) and their interaction (F(5, 48) = 10.53, p< 0.001) (Figure 6).

Aboveground biomass

FG had mean biomass of 0.61 ± 0.38 kg DM ha-1, highest in AL (0.99 ± 0.37 kg DM ha-1) and lowest in L (0.25 ± 0.27 kg DM ha-1). In GE, biomass averaged 2.53 ± 0.98 kg DM ha-1, peaking in S (3.28 ± 1.09 kg DM ha-1) and lowest in AL (1.36 ± 0.32 kg DM ha-1). Significant effects were found for Management (F(1, 48) = 147.71, p< 0.001) and Units × Management interaction (F(5, 48) = 5.77, p< 0.001).

Aboveground primary productivity

FG showed highest productivity in SA (133.9 ± 24.3 Units), averaging 81.7 ± 41.4 for all communities. GE had highest in L (386.1 ± 101.4) and lowest in AL (150.5 ± 52.1). ANOVA revealed significant effects for Units (F(5, 48) = 5.25, p< 0.001), Management (F(1, 48) = 187.50, p< 0.001), and Units × Management interaction (F(5, 48) = 14.24, p< 0.001).

Pastoral value index (PVI)

FG mean PVI was 13.2 ± 7.4, peaking at 21.6 ± 3.4 in SA. In GE, mean PVI was 29.4 ± 10, highest in A (43.6 ± 6.3). Significant effects were observed for Units, Management and their interaction (ANOVA results not provided).

Figure 6. Comparisons of ecosystem services’ metrics between management types (Grazed vs. Grazing-exclusion) and among plant community types and their interaction. Means in a point without a common superscript letter differ (P < 0.05) as analyzed by two-way ANOVA and Tukey HSD test. A, Artimisiaherba-alba community; AL, Artemisia herba-alba-Legeumspartum community; L, Legeumspartum community; S, Stipa tenacissima community; SA, Stipa tenacissima-Artimisiaherba-alba community; SS, Stipa tenacissima-Stipa parviflora community

Results from the multiple factor analysis (MFA) showed in free grazing sites, the first axis explained 47.77% of variation, with the second axis explaining 24.42% (Fig. 7A). SA stood out for diversity, while L was distinct for surface conditions, showing no diversity differentiation. SS differed notably from L in surface conditions, though ecosystem services were similar. AL, S and A were closely aligned.

In grazing-excluded sites, the first two axes explained 64.60% of variance (axis one: 35.88%, axis two: 28.72%) (Fig. 7B). Most plant communities exhibited distinct structures, except A and S. AL was notable for ecosystem services, while SA showed high diversity. Surface conditions differentiated L and AL, while SS was distinctive for both axes (third quadrant). A and S exhibited similar patterns.

Figure 7. Multiple factor analysis (MFA) highlighting the relationships between plant communities and soil surface conditions, plant diversity and ecosystem services for free grazing (A) and grazing-exclusion (B) managements in arid steppe rangelands of Algeria

Discussion

The discussion focuses on the effects of grazing exclusion on plant community diversity, composition and ecosystem services. Grazing exclusion generally enhances floristic richness and diversity by preventing overgrazing-induced species loss and soil compaction (Le Floc'h and Aronson, 1995). Studies in various regions, such as Inner Mongolia and Maghreb steppes, support this, showing higher richness inside fenced areas compared to grazed ones (Le Houérou, 1979; Floret and Pontanier, 1982; Chaieb, 1989). Conversely, overgrazed areas exhibit lower diversity due to species depletion and soil degradation (Le Houérou,1974; Floret and Pontanier, 1982). Similar results have been obtained in studies on the effect of restoration techniques in Algerian steppe rangelands (Amghar et al 2012; Salemkour et al 2013; Khalid et al 2015; Salemkour et al 2016).

Floristic diversity metrics like evenness and species richness vary significantly between managed and freely grazed pastures (Dajoz, 1975; N’Zala et al, 1997). However, studies in Madagascar suggest increased diversity in grazed areas, highlighting nuanced ecological responses to grazing pressure (Rakotoarimanana and Grouzis, 2006). Moderate disturbance levels can enhance species diversity by improving soil conditions (Connell, 1978; Grime, 1979).

The presence of annual species in rested areas is facilitated by microclimatic conditions created by tussocks like Stipa tenacissima and Lygeum spartum, which enhance water availability (Maestre and Cortina, 2002; Cavieres et al, 2005). Furthermore, protected areas generally exhibit higher biomass production due to reduced defoliation and enhanced plant growth (Noy-Meir and Walker, 1986; Zöbisch et al 1999).

Pastoral productivity and the pastoral value index are significantly higher in managed areas due to better forage quality and increased species diversity (Garde and Senn, 1991; Acherkouk et al, 2012). Conversely, overgrazing depletes biomass and reduces forage availability, impacting pastoral productivity negatively (Akrimi and Neffati, 1993; Jauffret and Visser 2003).

Overall, grazing exclusion promotes ground cover recovery and vegetation health by allowing biological recovery processes to take place, mitigating erosion and promoting soil stability (Le Houérou, 1977). This recovery is crucial for sustaining ecosystem services in degraded rangelands, supporting biodiversity conservation and sustainable land use management (Belsky, 1992; Brown and Al Mazrooei, 2003; Jeddi and Chaieb, 2010).

Effects of grazing exclusion on soil surface conditions

Sand cover

Grazing exclusion significantly affects soil surface conditions, particularly sand, litter and coarse particle cover. In areas where grazing is excluded, there is minimal sand cover due to reduced trampling and enhanced soil stability (Ebrahimi et al, 2016). Conversely, free grazing areas exhibit higher sand cover, influenced by soil structure and wind dynamics typical of arid steppes (Bouarfa and Bellal, 2018; Merdas et al, 2019; Slimani et al, 2010).

Litter cover

Crucial for soil health, is higher in managed and protected areas where vegetation remains intact, promoting infiltration and germination during rainy seasons (Floret, 1981). In contrast, freely grazed pastures show lower litter cover due to grazing impacts that remove or disperse litter, negatively affecting soil fertility and organic carbon content (Gonzalez-Polo et al, 2009; Prieto et al, 2011). Protected areas act as "islands" of fertility, trapping sediments and nutrients with higher litter accumulation (Tongway et al, 1989).

Coarse particle cover

It increases under grazing pressure, associated with trampling that degrades soil structure and promotes erosion (Yong-Zhong et al, 2005; Carriere and Toutain, 1995). Overgrazing reduces biomass and exposes more bare soil, exacerbating soil erosion and altering soil texture towards coarser particles (Macheroum and Chenchouni, 2022).

Overall, grazing exclusion enhances soil stability and fertility by reducing sand cover, maintaining higher litter accumulation and minimizing coarse particle exposure. These findings underscore the ecological benefits of managing grazing practices to sustain soil health and ecosystem resilience in arid and semi-arid landscapes.

Conclusions

We conclude that grazing exclusion practices can be employed as an effective approach to rejuvenating degraded grasslands naturally, as the practice has improved plant community traits and enhanced soil physiochemical and biological properties of degraded grasslands. This improvement ensures both greater stability against various disturbances and proper functioning of the steppe ecosystem. In Algerian steppe rangelands, the natural forage from protected zones, as a priority ecosystem service targeted by public action, effectively helps to cover a considerable part of the forage deficit, at minimal cost compared with the market price.

Acknowledgment

The authors extend their appreciation to la Direction Générale de la Recherche Scientifique et du DéveloppementTechnologique (DGRSDT), Algeria, to Researchers Supporting Project number (RSP2024R390), King Saud University, Riyadh, Saudi Arabia and to the High Commissariat for the Development of the Steppe (HCDS), Algeria.

Conflicts of Interest

The authors declare no conflict of interest

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