This study examines the commitments of African countries that would support improved soil security and soil health. Measures for agroforestry, erosion control, grassland management, soil organic ...carbon (SOC), and wetlands were assessed within the frameworks of the Rio Conventions. By analyzing national commitments in Land Degradation Neutrality (LDN) targets, and biodiversity (Aichi) targets, and Nationally Determined Contributions (NDCs), submitted until January 31, 2024, the research identifies the extent and quantification of these commitments. Results reveal a varying emphasis on these measures across different national targets, with significant focus on agroforestry, grassland, SOC, and wetland conservation in LDN targets and NDCs. Where quantified commitments for a single measure have been set across LDN, NDC, and biodiversity targets, the necessity of national coordination in setting, planning, and monitoring sustainable soil management commitments is highlighted. The study concludes that implementing sustainable soil management practices remain pivotal for achieving agricultural and environmental goals in Africa, thereby calling for a unified approach to leverage existing commitments towards setting future priorities in soil health and soil condition, drawing attention to the critical need for integrated national processes to ensure effective implementation and monitoring of these commitments.
Transitions from semiarid grassland to shrubland states are among the most widely recognized examples of regime shifts in terrestrial ecosystems. Nonetheless, the processes causing ...grassland–shrubland transitions and their consequences are incompletely understood. We challenge several misconceptions about these transitions in desert grasslands, including that (a) they are currently controlled by local livestock grazing and drought events, (b) they represent severe land degradation, and (c) restoration of grassland states is impossible. Grassland–shrubland transitions are the products of multiple drivers and feedback systems, both ecological and social, interacting at multiple scales of space and time. Grass recovery within shrubland states—with and without shrub removal—produces novel ecosystems that are dissimilar from historical grasslands but that provide important ecosystem services. Projected increases in climate variability are likely to promote the further displacement of perennial grasses by xerophytic shrubs. This article offers guidelines for managing grassland–shrubland transitions in the face of changing biophysical and socioeconomic circumstances.
Both climate change and agricultural intensification are drivers of global nutrient cycles and biodiversity loss. A potentially great environmental threat can arise when these two drivers interact, ...for example, when farmers try to compensate reduced soil nutrient availability due to drought by the application of liquid organic fertiliser. As dry soils don't hold back nutrients very well, this approach can lead to nitrate leaching and potentially also to the pollution of drinking water. However, little is known about leaching from dry but fertilised grassland soil, and how this is affected by land use intensity and plant diversity.
In this mesocosm study, we transferred 60 grassland sods differing in past land use intensity to a greenhouse and treated them with severe drought, fertilisation and both together. Drought was induced by almost entirely stopping irrigation for seven weeks. Fertilisation was done by three applications of slurry summing up to 168 kg total nitrogen per hectare (111 kg NH4-N). We assessed nutrient leaching risk with ion-exchange resin (IER) bags installed in the soil of all mesocosms. IER bags were retrieved after drought and extracts were analysed for concentrations of nitrate, ammonium, phosphate and potassium.
Fertilisation partially buffered drought-induced losses in yield. However, the interaction of fertilisation and drought resulted in a drastic increase in nitrate leaching risk when soils are rewetted (>300%), while neither drought nor fertilisation alone were significant. Ammonium concentrations followed the same trend as nitrate, but less pronounced. Phosphate and potassium concentrations were not affected by the treatments. Past land use was hardly related to soil nutrient concentrations, rather was plant diversity. However, results indicate that plant diversity was not driving nitrate and ammonium concentrations under drought and/or fertilisation. This study reveals grassland fertilisation during drought to be a severe environmental problem due to significantly increased nitrate leaching risk.
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•Grassland fertilisation during drought buffers yield losses, but depicts a severe threat to groundwater safety.•Fertilisation or drought alone did not affect nutrient leaching from clay-rich soils.•However, their interaction lead to a drastic increase in nitrate leaching risk.•Plant diversity was much closer related to soil nutrient concentrations than past land use intensity.•Interactions among climate change and land-use intensification might put clean drinking water at risk.
•Benefit for single objective varies under different management practices.•Trade-off among multiple objectives varies under different management practices.•The overall benefit does not change due to ...the existence of trade-off.
Developing sustainable management practices for alpine grassland on the Qinghai-Tibetan Plateau is a key challenge related to the protection of regional ecological environments, the provision of husbandry production and the improvement of pastoralist welfare. This challenge requires researchers and policymakers to seek options that optimize benefits among multiple objectives in ecological, productivity and livelihood dimensions. In this study, we developed a novel tool to value the overall benefits and trade-offs of ecological protection, livestock production and pastoral welfare from four types of grassland management practices mainly used on the Qinghai-Tibetan Plateau: individual grassland management (IGM), joint household grassland management (JHGM), shareholding cooperative grassland management (SCGM) and communal grassland management (CGM). The results showed that JHGM led to the highest ecological benefits, while CGM led to the highest benefits for livestock production and livelihood welfare. SCGM resulted in the lowest level of trade-offs as well as relatively high total benefits among multiple objectives in the ecological, productivity and livelihood dimensions. The results of this study provided empirical evidence that the effect of trade-offs among multiple objectives varied with different grassland management practices. We argue that grassland management practices may be biased if a single objective (i.e., ecological protection, livestock production provision or pastoral welfare improvement) is stressed due to the high level of trade-offs among them. The SCGM showed great potential to balance multiple objectives if properly designed.
1. Grazing is one of the most widespread forms of intensive management on Earth and is linked to reductions in soil health. However, little is known about the relative influence of herbivore type, ...herbivore intensity and site productivity on soil health. This lack of knowledge reduces our capacity to manage landscapes where grazing is a major land use. 2. We used structural equation modelling to assess the effects of recent (cattle, sheep, goats, kangaroos and rabbit dung) and historic (cattle, sheep/goat livestock tracks) herbivore activity on soil health at 451 sites across 0.5 M km² of eastern Australia. We assessed the direct and indirect effects of increasing herbivore intensity, using dung and livestock tracks, on 15 morphological, physical and chemical attributes that are indicative of soil health, and we used these attributes to derive three indices representing the capacity of the soil to maintain its structural integrity (stability), cycle nutrients (nutrients) and maintain water flow (infiltration). 3. Grazing had negative effects on the three soil health indices, but these effects varied with productivity. Grazing intensity was associated with strong reductions in the stability and nutrient indices under low productivity, but these effects diminished with increasing productivity. Herbivore effects on individual attributes varied in relation to productivity level and were strongly herbivore specific, with most due to cattle grazing, and to a lesser extent, sheep, goats and rabbits. Few effects due to kangaroos or historic grazing by livestock were observed. 4. Synthesis and applications. Our study shows that livestock and rabbits degrade soil health through grazing, and its effects are strongest under low or moderate productivity; however, kangaroo effects are benign. Our findings support calls for resource management agencies to consider site productivity, as well as herbivore type and intensity, when developing strategies to manage grazing by livestock, and feral and native herbivores.
Despite progress in trait‐based ecology, there is limited understanding of the plant traits that structure semi‐arid grasslands. In particular, it remains unclear how traits that enable plants to ...cope with water limitation are related to traits that influence other key functions such as herbivore defence and growth. The hypothesis that drought and herbivory exert convergent selection pressures is supported for morphological traits, but largely untested for structural, physiological and phenological traits. Drought and economic traits can also covary, but where and to what degree remains uncertain.
Here we address these uncertainties in semi‐arid shortgrass steppe and mixedgrass prairie, the largest remaining grasslands in North America. Using a broad selection of traits for 37 of the most common plant species in each ecosystem, we ask whether traits that confer drought tolerance, avoidance and escape covary with herbivore resistance traits and economic traits.
Results reveal that both drought tolerance and escape are coordinated with other functions, but in opposite fashion. Drought‐tolerant species (low leaf osmotic potential and high leaf dry matter content, LDMC) were also herbivore resistant (high leaf toughness and cellulose) and at the ‘slow’ end of the economic spectrum (low leaf nitrogen, leaf phosphorus and high stem density). Conversely, drought escape via early senescence was associated with lower drought tolerance, lower herbivore resistance and ‘fast’ economic traits. Drought avoidance, as indicated by thick leaves, may also be associated with lower drought tolerance (LDMC). Senescence date and LDMC appear to be key traits in these semi‐arid grasslands, differentiating species along multiple axes of function.
Synthesis. Covariation between drought, herbivory and economic traits means that, of the many potential trait combinations, few actually exist within these grasslands. Consequently, changes in land management and climate should have predictable effects on drought resistance, forage quality and productivity in the western Great Plains.
Trait covariation in two semi‐arid grasslands demonstrates that plant strategies for coping with water limitation are closely tied to both herbivore resistance and plant economics. Drought‐tolerant species have tough, high‐cellulose leaves and lie at the slow end of the economic spectrum. Drought‐escaping species have contrasting characteristics. Management and climate should therefore have predictable effects on forage quality and drought resistance.
Grasslands contribute greatly to biodiversity and human livelihoods; they support 70% of the world's agricultural area, but are heavily degraded by human land use. Grassland restoration research and ...management receives less attention than forests or freshwater habitats, although grasslands are critical for sustaining ecosystems multifunctionality and capacity to support biodiversity. In this article, we introduce a Special Issue which considers major trends and prospects in grassland restoration. We identified three key topics: First, restoration must confront widespread seed and site limitations, and new monitoring methods, including remote sensing techniques, are critical for restoration projects. Second, we highlight that restored grasslands typically require ongoing disturbance management and that research is required to determine optimal approaches for implementing this management during restoration. Third, global and regional restoration agendas should be harmonized with site‐level goals, and syntheses of current knowledge and research needs must guide grassland restoration across scales. We also identify research gaps to be filled, and challenges which grasslands face in the future: (1) a need for careful target vegetation selection and climate‐adaptive restoration; (2) lack of knowledge in dynamics and restoration of several regions and grassland types, including drylands and (sub)tropical regions; (3) increased importance of species arrival sequence, and high stochasticity of species establishment; and finally (4) issues of post‐restoration management to guarantee long‐term sustainability of restored sites. A new generation of research and restoration projects to bridge these gaps is necessary to mitigate environmental challenges spanning localities to the globe as we commence the UN Decade on Ecosystem Restoration.
Experiments showed that biodiversity increases grassland productivity and nutrient exploitation, potentially reducing fertiliser needs. Enhancing biodiversity could improve P-use efficiency of ...grasslands, which is beneficial given that rock-derived P fertilisers are expected to become scarce in the future. Here, we show in a biodiversity experiment that more diverse plant communities were able to exploit P resources more completely than less diverse ones. In the agricultural grasslands that we studied, management effects either overruled or modified the driving role of plant diversity observed in the biodiversity experiment. Nevertheless, we show that greater above- (plants) and belowground (mycorrhizal fungi) biodiversity contributed to tightening the P cycle in agricultural grasslands, as reduced management intensity and the associated increased biodiversity fostered the exploitation of P resources. Our results demonstrate that promoting a high above- and belowground biodiversity has ecological (biodiversity protection) and economical (fertiliser savings) benefits. Such win-win situations for farmers and biodiversity are crucial to convince farmers of the benefits of biodiversity and thus counteract global biodiversity loss.
There are increasing calls to provide greenspace in urban areas, yet the ecological quality, as well as quantity, of greenspace is important. Short mown grassland designed for recreational use is the ...dominant form of urban greenspace in temperate regions but requires considerable maintenance and typically provides limited habitat value for most taxa. Alternatives are increasingly proposed, but the biodiversity potential of these is not well understood. In a replicated experiment across six public urban greenspaces, we used nine different perennial meadow plantings to quantify the relative roles of floristic diversity and height of sown meadows on the richness and composition of three taxonomic groups: plants, invertebrates, and soil microbes. We found that all meadow treatments were colonized by plant species not sown in the plots, suggesting that establishing sown meadows does not preclude further locally determined grassland development if management is appropriate. Colonizing species were rarer in taller and more diverse plots, indicating competition may limit invasion rates. Urban meadow treatments contained invertebrate and microbial communities that differed from mown grassland. Invertebrate taxa responded to changes in both height and richness of meadow vegetation, but most orders were more abundant where vegetation height was longer than mown grassland. Order richness also increased in longer vegetation and Coleoptera family richness increased with plant diversity in summer. Microbial community composition seems sensitive to plant species composition at the soil surface (0–10 cm), but in deeper soils (11–20 cm) community variation was most responsive to plant height, with bacteria and fungi responding differently. In addition to improving local residents’ site satisfaction, native perennial meadow plantings can produce biologically diverse grasslands that support richer and more abundant invertebrate communities, and restructured plant, invertebrate, and soil microbial communities compared with short mown grassland. Our results suggest that diversification of urban greenspace by planting urban meadows in place of some mown amenity grassland is likely to generate substantial biodiversity benefits, with a mosaic of meadow types likely to maximize such benefits.
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