Search Results (421)

Grassland restoration through grazing exclusion is a key strategy for enhancing soil organic carbon (SOC) sequestration, yet the dynamic contributions of plant- versus microbial-derived carbon (C) remain incompletely understood. We hypothesized that with increasing restoration duration, microbial-derived C would become a major contributor to SOC relative to plant-derived C, and that the relative proportion of bacterial necromass would increase compared to fungal necromass. To explore this, we investigated a 25-year restoration chronosequence (3, 10, 19, 25 years) of a degraded typical steppe on Kastanozem soil in Inner Mongolia, China. While acknowledging the inherent limitations of a space-for-time substitution approach, such as potential unquantified variations in initial pre-enclosure soil conditions and plant species composition, we used lignin phenols, amino sugars, and PLFA analysis to estimate the dynamics of plant- and microbial-derived C. Grassland restoration was associated with significant increases in total PLFAs (15.4–58.8%), bacterial PLFAs (14.5–82.4%), lignin phenols (16.9–91.8%), and estimated microbial-derived C (5.0–8.8 g kg⁻¹). Based on these specific biomarker estimates, which track only a subset of total C and do not equal 100% of the SOC pool, microbial-derived C accounted for 52.8–63.3% of SOC, compared to 10.1–15.5% for plant-derived C. Within the estimated microbial-derived C, the bacterial fraction increased over the restoration chronosequence, while the fungal fraction declined. Correlational analyses, including structural equation modeling, indicated that soil pH, bulk density, SOC, and microbial biomass were key factors closely associated with both C sources. Our findings suggest that microbial-necromass C, particularly from bacteria, is a major contributor to SOC accumulation during long-term grassland restoration in this semi-arid typical steppe, and that grazing exclusion can enhance SOC sequestration under the studied conditions and biomarker-based estimations. Full article

Mediterranean phryganic ecosystems have been shaped for centuries by recurrent herbivory, yet the long-term ecological consequences of grazing cessation remain insufficiently resolved, particularly in protected island landscapes where conservation management often assumes that exclusion promotes recovery. In these drylands, the removal of grazing redirect assembly processes through shifts in dominance, heterogeneity, and functional strategy expression. Here, we use more than three decades-long grazing discontinuity within the Petrified Forest of Lesvos, an insular Mediterranean geopark, to examine how long-term herbivore exclusion reorganizes plant communities across taxonomic and functional dimensions. By integrating floristic inventories, multivariate community analysis, mixed-effects modeling, indicator species analysis, and community-weighted trait approaches, we reconstruct the ecological signature of grazing release in phryganic ecosystems. Long-term exclusion was associated with a broader species pool and a greater representation of protected taxa, while ungrazed communities exhibited lower Shannon and Simpson diversity, greater compositional dispersion, and a marked shift in dominance structure linked to the expansion of Sarcopoterium spinosum. Community differentiation was accompanied by directional reorganization of functional trait structure, with ungrazed plots characterized by taller vegetation and increased leaf and inflorescence length, indicating release from recurrent biomass removal and a transition toward more structurally expansive strategies. These results show that grazing exclusion does not simply enhance biodiversity, but reorganizes Mediterranean plant communities into an alternative ecological state shaped by altered competitive hierarchies, shrub-mediated filtering, and relaxed herbivory. In disturbance-structured island ecosystems, therefore, the ecological outcomes of protection depend not only on whether grazing is removed, but on how strongly community organization has historically depended on its continued presence. Full article

Microzooplankton grazing is a key regulator of phytoplankton standing stock and the export of particulate organic carbon (POC) in the ocean, yet its spatial coupling with phytoplankton growth across shelf-basin gradients remains underexplored in marginal seas. Using 43 dilution experiments in the South China Sea (SCS), this study systematically examined the spatial variability and environmental drivers of phytoplankton growth rate (μ) and grazing mortality rate (m) as well as the resulting grazing impact (m/μ) across shelf, slope, and basin habitats. Results show a significant seaward decline in m (shelf: 0.73 ± 0.53 d⁻¹; basin: 0.27 ± 0.19 d⁻¹; p < 0.01), while μ decreased non significantly (shelf: 0.88 ± 0.53 d⁻¹; basin: 0.70 ± 0.18 d⁻¹; p = 0.49). Consequently, growth and grazing were strongly coupled on the shelf (r = 0.82, p < 0.01) but completely decoupled in the basin (r = 0.21, p = 0.46), coinciding with a shift toward picophytoplankton dominance and reduced grazing pressure. We also found that export efficiency was positively correlated with both m/μ and m, highlighting the important role of microzooplankton grazing in carbon export, but that the overall carbon export flux itself was also shaped by nutrient-driven changes in POC recycling. These findings underscore the role of bottom-up nutrient forcing and top-down grazing impact in controlling carbon export in the SCS. Full article

Integrated crop–livestock systems (ICLS) that couple crop production, cover crops, and grazing present a promising strategy for soil organic carbon (SOC) sequestration. Long-term assessments of SOC change under ICLS management are limited. This study quantified SOC stocks from management systems typical of the warm, humid southern Midwest, USA, including conventional continuous cereal crop production, permanent pasture, hardwood forest, and decadal-scale ICLS management. The ICLS consisted of no-till production of corn silage with a winter ryegrass cover crop grazed by cattle. We hypothesized greater SOC stocks in the ICLS relative to conventional management, with the greatest increase in surface horizons. Soil cores were collected to a depth of 120 cm, subset into 0–30 cm, 30–60 cm, and 60–120 cm sections, and analyzed for SOC, particulate, and mineral-associated organic matter. Results demonstrated that after 15 years, ICLS SOC stocks were significantly greater than conventionally managed fields and comparable to those of permanent pasture and hardwood forest. The SOC differences were predominantly in the upper 30 cm. Using a space-for-time approach, we calculated an average annual SOC accrual rate of 1.3 Mg C ha⁻¹ yr⁻¹, similar to estimated sequestration rates from biogeochemical model simulations. The majority of additional SOC was allocated to particulate organic matter. Significantly greater mineral-associated organic carbon was also observed. Stable carbon isotope data indicated the ryegrass cover crop was likely the primary source of additional SOC in the ICLS. These findings demonstrate the potential of ICLS to increase SOC and enhance soil health over decadal timescales. Full article

The espinal agroforestry system is a valuable grazing resource for sheep and cattle in the Mediterranean region of central Chile. It is characterized by a woody stratum dominated by Vachellia caven and an herbaceous grassland stratum that together provide important ecological services. Despite its relevance for extensive livestock production, ongoing land-use change threatens the integrity of the espinal agroforestry system, underscoring the need for sustainable management strategies to enhance productivity. This study assessed the long-term impacts of improved management practices in a representative espinal agroforestry system, including annual fertilization, supplementary cereal crop integration, and progressive increases in stocking rate, on plant diversity and soil carbon storage in Cauquenes, Maule Region, Chile (35°58′ S, 72°17′ W), during 2014–2019. A production system was established on 10 ha of espinal grassland, complemented by 1 ha of supplementary crop rotation (oat–purple vetch intercropping and triticale). Due to the scale of the system, a single experimental unit was used; however, multiple sampling areas were evaluated over time to assess the botanical composition, forage yield, and soil carbon. Grasslands were annually fertilized with phosphorus, potassium, and boron. The forage yield in spring ranged from 2 to 4 t dry matter ha⁻¹ year⁻¹ over six years, with strong interannual variability driven by rainfall. The stocking rate increased progressively from 2 to 8 sheep ha⁻¹ and lamb live weight from 80 to 370 kg ha⁻¹ over six-years. The grassland botanical composition shifted markedly, with increased abundance of annual legumes (Trifolium subterraneum, Medicago polymorpha) and Leontodon leysseri. Supplementary crops yielded between 6.0 and 10.5 t DM ha⁻¹, while soil organic carbon increased from 1.6% to 2.2%. These results demonstrate that sustainable intensification of the espinal system can enhance productivity while maintaining environmental sustainability. Full article

Although bud banks are key components of vegetation regeneration in degraded alpine meadows, their relationships with soil conditions on the Qinghai–Tibet Plateau remain insufficiently understood. In this study, we investigated bud bank composition and density, plant functional group biomass, soil physicochemical properties, and soil microbial biomass across five degradation stages of alpine meadows in a long-term controlled grazing experiment. Field sampling was conducted in mid-August 2021, and the relationships between bud bank densities, plant biomass, and soil variables were evaluated using comparative statistical analyses, redundancy analysis, and structural equation modeling. Bud bank density increased from non-degraded to moderately degraded meadows, reaching 3075 buds m⁻², but declined sharply in severely degraded meadows to 183 buds m⁻². Regarding distinct bud types, rhizome and tiller bud densities peaked in moderately degraded alpine meadows (1217 and 1750 buds m⁻², respectively), whereas dicot bud density peaked in lightly degraded meadows. Bud bank density was positively associated with higher soil moisture content and negatively associated with increased soil bulk density. Moreover, bud bank density was positively correlated with soil organic carbon, total phosphorus, ammonium nitrogen, and soil microbial biomass carbon, nitrogen, and phosphorus. Our findings indicate that soil conditions may favor the maintenance of high bud bank density in moderately degraded meadows with high soil moisture, low bulk density, and more nutrient-rich soil conditions in moderately degraded meadows. Overall, our results indicate that alpine meadow degradation influences belowground regenerative capacity through changes in soil conditions and associated shifts in bud bank dynamics. Therefore, assessments and restoration of degraded alpine meadows should consider bud bank persistence in addition to aboveground vegetation characteristics. Full article

Yacuri National Park (YNP) is a Ramsar site located within Ecuador’s Podocarpus-El Cóndor Biosphere Reserve. The Park faces critical threats from illegal mining, livestock grazing, wildfires and the harvesting of wax palms. This study employed participatory action research to co-design a Communication, Education and Public Engagement (CEPA) plan with park managers and local communities as equal partners. Moving beyond traditional, top-down information campaigns, the CEPA framework establishes a co-governance model that integrates indigenous knowledge with local socio-economic realities. The plan implements four targeted interventions: (1) strengthening community fire brigades (BRICOM); (2) promoting culturally appropriate alternatives to Holy Week wax palm harvesting; (3) establishing participatory waste management; and (4) engaging tourists as conservation allies through experiential learning. Strategic alliances with municipalities, universities, and civil society organizations provide institutional backing and secure resources, while a participatory monitoring system using SMART indicators tracks behavioral and ecological outcomes. Ultimately, the findings demonstrate that conserving culturally complex, biodiverse landscapes requires social legitimacy, environmental justice and equitable power-sharing. Recognizing local communities as co-managers is essential to ensuring the long-term protection of Andean ecosystems. Full article

The main scope of the present study is to assess the environmental and economic outcomes of applying distinct Climate-Smart Agricultural (CSA) practices in apple cultivation. Thus, four different CSA practices, including organic farming, cover crops, floral bands, and grazing, were selected, and their environmental and economic performance was evaluated and compared to that of a conventional apple orchard system (baseline). Specifically, Life Cycle Assessment (LCA) and Life Cycle Costing (LCC) methodologies were applied to assess the environmental and economic sustainability of the studied systems, respectively. Among the studied practices, grazing exhibited the best environmental performance among the modeled scenarios (approximately 25% decrease in greenhouse gas emissions compared to the baseline under the assumed conditions), followed by organic farming that significantly decreased eutrophication- and ecotoxicity-related impacts. Similarly, organic farming and grazing exhibited the best economic performance in the concept of the present study, with the total profit per hectare rising to approximately 5300 € and 4300 €, respectively, compared to the value of 3700 € of the conventional apple orchard. The results suggest that the implementation of CSA practices has the potential to improve the environmental and economic performance of apple orchards under the modeled conditions. Full article

Urban coastal wetlands along the Peruvian Pacific coast are increasingly affected by urban expansion, pollution, and hydrological alterations, compromising their ecological integrity. In this context, the spatiotemporal variation of the aquatic macrophyte community and its relationship with limnological conditions and drivers of change were evaluated in the Santa Rosa wetland (Chancay, Lima). The objective is to evaluate the spatiotemporal variation of the aquatic macrophyte community in the Santa Rosa wetland and analyze its relationship with physicochemical limnological variables and drivers of change. Sampling was conducted during two contrasting hydrological seasons in 2022: T1 (low-water season) and T2 (high-water season), at six sampling points (P1–P6). Physicochemical variables (water depth, temperature, pH, conductivity, total dissolved solids—TDS, total suspended solids—TSS, dissolved oxygen—DO, turbidity, nitrate—NO₃⁻, ammonium—NH₄⁺, phosphate—PO₄³⁻, and dissolved organic matter—DOM) were measured, and the relative abundance of aquatic macrophytes was evaluated. Drivers of change were identified through direct observation and a structured matrix, with phosphate a PCoA performed to summarize spatiotemporal trends. Data were analyzed using Principal Component Analysis (PCA), Co-inertia analysis, and Multi-Response Permutation Procedures (MRPP). Significant spatiotemporal variation was observed in physicochemical parameters (p < 0.05), with moderate covariation between the two matrices (RV = 0.47). A total of ten aquatic macrophyte species were recorded, with higher abundance of Pontederia crassipes and Pistia stratiotes in T1, and Hydrocotyle ranunculoides and Bacopa monnieri in T2. The most relevant drivers of change were solid waste, livestock grazing, organic contamination, and urban expansion. Spatial heterogeneity was observed in the drivers of change affecting the Santa Rosa wetland, forming a mosaic of areas with different impact profiles. Despite multiple anthropogenic pressures, the Santa Rosa wetland maintains a limnological structure and a functionally coupled macrophyte community, suggesting that essential ecological processes are maintained within the temporal scope of this study. The observed covariation between physicochemical conditions and vegetation confirms the persistence of essential ecological processes, even within an altered urban context. This study demonstrates that integrating biotic components, limnological variables, and drivers of change is fundamental to understanding and monitoring the ecological dynamics of urban wetlands along the Peruvian coast. Full article

The Numidian cypress (Cupressus sempervirens var. numidica, C. numidica hereafter) is a rare, almost unknown, endemic taxon of Tunisia whose conservation has long been hampered by human activities, taxonomic uncertainty and limited ecological knowledge, with only 64.33 ha of its populations remaining. Although recent genetic studies have confirmed its native status and long-term isolation, detailed information on its distribution, population structure and threats remain lacking. This study provides the first comprehensive assessment of C. numidica across its remaining range. Field surveys revealed that the species persists in only three small, fragmented forests, Bou Abdallah, Sidi Amer, and Dir Satour, covering a total of 64.33 ha. Soil analysis revealed some differences among sites, with Bou Abdallah showing higher clay content and Dir Satou exhibiting the highest levels of nitrogen, organic carbon, Olsen P, and available Mn and Mo. Climatic analyses indicate a semi-arid Mediterranean environment with pronounced summer droughts and a clear warming trend. Trees showed widespread damages, due to intensive grazing, tree cutting, crown dieback (drought), and pest and pathogen attacks. Natural regeneration was limited, and the condition of affected trees ranged from moderate to severe, with Bou Abdallah showing the highest levels of degradation. Notably, the severe fungal pathogen Seiridium cardinale, causal agent of cypress canker, was detected on C. numidica for the first time, highlighting an urgent conservation concern. Our results point to a staged conservation approach over time. In the immediate term (within 1 year), urgent monitoring and management of S. cardinale is needed. In the short term, efforts should focus on protecting carefully selected areas, about 5–10 regeneration microsites per forest, from grazing to support natural regeneration, reduce ongoing soil degradation, and establish clonal and seed-production plantations along with long-term seed storage. In the long term, the survival of C. numidica will only be possible with the active involvement of local communities, through awareness campaigns, adapting traditional practices such as gdel, and developing small-scale ecotourism that provides sustainable livelihoods while reinforcing support for conservation. Full article

Livestock production systems are considered some of the most environmentally degrading due to greenhouse gas (GHG) emissions and their contribution to poor air, soil and water quality, amongst other impacts. Advanced manure treatment technologies are required in response to intensification of dairy production worldwide, and the considerably greater volumes of manure generated that require collection and management. Similarly, in Australian dairy systems cows spend more time off pasture, with increased collection of larger manure volumes from a range of contained housing facilities. Adoption of advanced treatment is required to capture nutrients at risk of loss, and ideally to valorise manure to support uptake of these technologies. This review describes the generation of manure and the manure sources found in commercial Australian systems, including grazing-based and intensive dairy farms, supporting zero grazing. The review draws on manure data from pasture-based industries elsewhere and summarises their properties for comparison with Australian systems. Manure treatments that recover and retain nutrients, water and energy are reviewed. These include additives, mechanical/chemical/membrane separation, thermochemical and biological treatments which produce organic and inorganic soil amendments, clarified or potable water, gases (N₂, H₂), biofuels and energy. The review describes the technical and operational details of the technologies, and where there are opportunities for the Australian dairy industry. Treatment technologies need to be validated for Australian systems based on the collated data of local manure properties, as differences with international manure data have been observed. The relative costs, technological maturity, and the benefits and challenges associated with adoption are discussed. Many advanced technologies are ready for adoption, but others are experimental or at pilot stage and relative costs range from low to very high. However, to accurately assess feasibility of manure treatments, environmental, and production benefits should be balanced against capital and operating expenses and account for costs associated with current management. For large intensive farms, implementing advanced manure technologies may be required to ensure approval to operate/expand and to meet regulatory compliance. Future research for the Australian industry should investigate nutrient retention and further develop separation treatments incorporating chemical and mechanical technologies. Bioconversion of manure through insect composting as well as investigating co-digestion opportunities to enhance biogas production would support famers currently using these systems. Full article

Active conservation management is widely applied in ecosystems affected by biological invasions, where outcomes depend primarily on how management regimes shape the vegetation structure. Grazing is a common tool in floodplain marsh meadows, but differences between grazing regimes are rarely assessed at spatial scales sensitive to internal community organization. Here, we compared the fine-scale structural diversity of two Amorpha fruticosa-invaded marsh meadows managed under contrasting conservation grazing regimes differing in livestock species, grazing intensity, and grazing dynamics. Vegetation was sampled using microcoenological methods along circular transects of contiguous 5 × 5 cm microquadrats. The fine-scale structure of the vegetation was quantified using the Juhász–Nagy spatial series framework, focusing on compositional diversity (CD) and associatum (AS), complemented by Shannon diversity. Differences between grazing regimes were evaluated using nonparametric tests complemented by effect size estimation. The patterns of species occurrence and Shannon diversity were similar between sites, indicating a similar species composition. In contrast, JNP-derived structural metrics showed consistent directional differences, with moderate to large effect sizes for selected structural indicators, despite nonsignificances. These results indicate that conservation grazing primarily influences fine-scale structural organization rather than species composition, highlighting the value of structure-oriented metrics in evaluating management effects in invaded marsh meadows. Full article

Alpine wetlands are highly sensitive to climate warming and anthropogenic disturbances such as grazing, highlighting the urgent need to identify operational indicators for monitoring soil functional changes. In this study, the Zequ National Wetland Park on the Qinghai–Tibet Plateau was selected as the study area. At the plot scale (n = 66), vegetation structure (aboveground biomass, vegetation height, and coverage), soil nutrient properties (soil organic carbon (SOC), total nitrogen (TN), total phosphorus (TP), ammonium nitrogen (NH₄⁺–N), nitrate nitrogen (NO₃⁻–N), available phosphorus (AP)), soil enzyme activities (β-glucosidase (BG), N-acetylglucosaminidase (NAG), and acid phosphatase (ACP)) were measured simultaneously. Spearman correlation analysis and redundancy analysis (RDA) were applied to examine their statistical relationships. Descriptive statistics revealed pronounced variability among plots, with aboveground biomass ranging from 115.43 to 1505.27 g·m⁻², AP from 0.75 to 70.23 mg·kg⁻¹, and BG activity from 0.25 to 14.71 μmol·g⁻¹·h⁻¹, indicating strong spatial heterogeneity in alpine wetlands. Both correlation and RDA results consistently showed that nutrient availability—particularly inorganic nitrogen and AP—was more closely associated with soil enzyme activities, whereas total nutrient contents exhibited a relatively limited ability to explain short-term variations in soil functional processes. These findings suggest that a combined indicator framework integrating nutrient availability and soil enzyme activities has strong potential for the early detection of soil quality changes and degradation in alpine wetlands, thereby providing quantitative support for sustainable wetland management and restoration assessment. Full article

Crop residues can harbor pathogens, making winter sanitation essential for sustainable viticulture. The grass–sheep–grape system could improve vineyard health through microbial optimization. To evaluate this, we assessed the effects of sheep feeding on fallen leaves on the occurrence of grape diseases through greenhouse experiments and used high-throughput-sequencing to compare microbial communities in grape fallen leaves and sheep feces, aiming to determine whether winter grazing reduces residue-borne pathogens. The results revealed that sheep grazing in vineyards significantly reduces the occurrence of grape leaf and cluster diseases, as well as a fundamental difference in microbial structures between leaves and feces, with no fungal taxa detected in the feces. The number of shared bacterial OTUs was minimal, while feces contained significantly more unique bacterial OTUs than fallen leaves. Additionally, bacterial diversity was significantly higher in feces than in fallen leaves. Sheep feces harbored a substantial number of highly efficient cellulose-degrading anaerobic bacteria, which may enhance organic matter conversion efficiency, and promote nutrient cycling in vineyards. Moreover, the grazing process directly reduced several pathogenic fungi associated with grape leaf, fruit, and root diseases. Functional analysis further indicated that fecal bacterial communities were primarily enriched in core metabolic and genetic processing functions, while leaf microbes were more involved in microbial interactions and secondary metabolism. More importantly, no function guilds of plant pathogenic fungi were present in feces. Overall, winter sheep grazing in vineyards can remove fallen leaves, not only reducing the risk of pathogen transmission but also potentially introducing beneficial bacterial communities. This study provides a feasible strategy for organic vineyard management in winter, and offers important insights for promoting sustainable vineyard production. Full article

Subsoil (30–100 cm) soil organic carbon (SOC) is a poorly constrained but potentially significant component of terrestrial carbon budgets. While controls on subsoil SOC are likely to differ from those affecting topsoil, few studies have quantified them. This study quantified subsoil (30–100 cm) SOC stocks and identified the controls on its spatial distribution across perennial grazing systems in northeast New South Wales, Australia. SOC was measured to 1 m depth across 54 long-term perennial pasture grazing paddocks on nine farms. A Random Forest regression model was then used to determine the relationship between subsoil SOC and drivers represented by the scorpan model of soil formation. Subsoil SOC contributed ~50% of total SOC stocks in the top metre of soil, with a median of 65.8 t ha⁻¹ stored in subsoil. Our study found that drivers of SOC input and turnover (subsoil total nitrogen, 10–30 cm SOC content, and climate), as well as pedogenic processes influencing SOC stabilisation (weathering index), were the most important factors in the determination of subsoil SOC content. This contrasts with previous findings where abiotic factors linked to parent material and soil properties were the major controls on subsoil SOC distribution and highlights links between both input and stabilisation in perennial grazing systems. Full article