Community Biomass Research Articles

Biogeographic variation in environmental and biotic resistance modifies predicted risk of marine invasions by ships

IntroductionGlobal shipping has accelerated the spread of non-native species. Factors such as environmental filtering and interactions with local biota can affect invasion likelihood, yet their relative contribution to predicting invasion risk remains unresolved. To test how abiotic filters and an experimentally-derived measure of biotic resistance interact with propagule pressure, we developed an integrated model to evaluate their relative effects on invasion risk of marine biofouling organisms to different focal port regions. We predicted that environmental filtering impacts invasion risk when fewer but stronger connections are part of the network. Further, predation is a mechanism of biotic resistance, which can reduce invasion risk, with most pronounced effects predicted in the tropics that decline at higher latitudes.MethodsWe examined shipping traffic and predation impact at three coastal bioregions spanning 47-degrees of latitude al range in the Northeast Pacific (Alaska, California, and Panama). We used vessel traffic databases to characterize propagule pressure and construct a worldwide port network of marine shipping routes and ports. Environmental resistance was estimated using temperature and salinity data from donor and recipient regions. We further used standardized predator exposure experiments to quantify predation impact on fouling community biomass as an estimate of potential for biotic resistance. We then expanded on existing models of relative invasion risk to incorporate the probability that propagules will survive predation by local predators and overcome environmental filtering to generate a predicted invasion risk for each port.ResultsEnvironmental filtering in all regions and predation pressure in the tropics worked to reduce the invasion risk, resulting in markedly different cumulative risk profiles over time among regions.DiscussionIn an increasingly connected world with more vessel traffic, our results highlight that while the number and distribution of shipping routes are important to understand risk, abiotic and biotic filters can modify model predictions.

Modelling Fresh and Dry Weight of Aboveground Biomass of Plant Community and Taxonomic Group Using Normalized Difference Vegetation Index and Climate Data in Xizang’s Grasslands

Modelling Fresh and Dry Weight of Aboveground Biomass of Plant Community and Taxonomic Group Using Normalized Difference Vegetation Index and Climate Data in Xizang’s Grasslands

Effectiveness of artificial reefs in enhancing phytoplankton community dynamics: A meta-analysis

Artificial reefs (ARs) are widespread globally and play a positive role in enhancing fish communities and restoring habitat. However, the effect of ARs on phytoplankton, which are fundamental to the marine food chain, remains inconclusive. Conducting a literature review and meta-analysis, this study investigates how ARs influence phytoplankton community dynamics by comparing the biomass, density, and diversity of phytoplankton between ARs and natural water bodies across varying deployment durations, constituent materials, and climatic zones. The study findings suggest that, overall, ARs enhance the biomass, density, and diversity of phytoplankton communities, with no significant differences observed compared to natural water bodies. The enhancement effect of ARs on phytoplankton communities becomes progressively more pronounced with increasing deployment time, with the overall status of phytoplankton communities being optimal when artificial reefs are deployed for 5 years or longer. Concrete and stone ARs can significantly enhance the biomass and diversity of phytoplankton, respectively. The effect of ARs on phytoplankton diversity is unrelated to climatic zones. However, deploying ARs in temperate waters significantly enhances phytoplankton biomass, while in tropical waters, it significantly reduces phytoplankton density. The research findings provide practical implications for the formulation of artificial reef construction strategies tailored to the characteristics of different aquatic ecosystems, emphasizing the need for long-term deployment and appropriate material selection. This study offers a theoretical basis for optimizing AR design and deployment to achieve maximum ecological benefits.

Species richness and evenness of European bird communities show differentiated responses to measures of productivity.

Understanding patterns of species diversity is crucial for ecological research and conservation, and this understanding may be improved by studying patterns in the two components of species diversity, species richness and evenness of abundance of species. Variation in species richness and evenness has previously been linked to variation in total abundance of communities as well as productivity gradients. Exploring both components of species diversity is essential because these components could be unrelated or driven by different mechanisms. The aim of this study was to investigate the relationship between species richness and evenness in European bird communities along an extensive latitudinal gradient. We examined their relationships with latitude and Net Primary Productivity, which determines energy and matter availability for heterotrophs, as well as their responses to territory densities (i.e. the number of territories per area) and community biomass (i.e. the bird biomass per area). We applied a multivariate Poisson log-normal distribution to unique long-term, high-quality time-series data, allowing us to estimate species richness of the community as well as the variance of this distribution, which acts as an inverse measure of evenness. Evenness in the distribution of abundance of species in the community was independent of species richness. Species richness increased with increasing community biomass, as well as with increasing density. Since both measures of abundance were explained by NPP, species richness was partially explained by energy-diversity theory (i.e. the more energy, the more species sustained by the ecosystem). However, species richness did not increase linearly with NPP but rather showed a unimodal relationship. Evenness was not explained either by productivity nor by any of the aspects of community abundance. This study highlights the importance of considering both richness and evenness to gain a better understanding of variation in species diversity. We encourage the study of both components of species diversity in future studies, as well as use of simulation studies to verify observed patterns between richness and evenness.

Phytoplankton biomass responses to a marine heat wave align with altered nitracline depth

AbstractThe 2014–2015 warm anomaly (aka “the Blob”), the largest of periodic and intensifying marine heat wave (MHW) perturbations in the northeast Pacific, may provide some insight about the future warmer ocean. Here, we use mixed‐layer carbon estimates for total phytoplankton, major size classes and functional groups from 45 CalCOFI cruises to: (1) compare 2014–2015 MHW impacts in the southern California Current System to baseline estimates from 2004 to 2013 and (2) to test a space‐for‐time exchange hypothesis that links biomass structure to variability of nitracline depth (NCD). Seasonal and inshore‐offshore analyses from nine stations revealed almost uniform 2°C MHW warming extending 700 km seaward, fourfold to sixfold declines in nitrate concentration and 18‐m deeper NCDs. Phytoplankton C decreased 16–21% compared to 45–65% for Chl a, with the threefold difference due to altered C : Chl a. Among size classes, percent composition of nanoplankton decreased and picophytoplankton increased, driven by higher Prochlorococcus biomass, while Synechococcus and picoeukaryotes generally declined. Diatom and dinoflagellate C decreased in both onshore and offshore waters. Seasonally, the MHW delayed the normal winter refresh of surface nitrate, resulting in depressed stocks of total phytoplankton and nanoplankton, Synechococcus and picoeukaryotes during winter. Consistent with the space‐for‐time hypothesis, biomass variations for baseline and MHW cruises followed similar (not significantly different) slope relationships to NCD. All biomass components, except Prochlorococcus, were negatively related to NCD, and community biomass structure realigned according to regression slopes differences with NCD variability. Empirically derived biomass‐NCD relationships could be useful for calibrating models that explore future food‐web impacts in this coastal upwelling system.

Meta-analysis reveals the effects of microbial inoculants on the biomass and diversity of soil microbial communities.

Microbial inoculation involves transplanting microorganisms from their natural habitat to new plants or soils to improve plant performance, and it is being increasingly used in agriculture and ecological restoration. However, microbial inoculants can invade and alter the composition of native microbial communities; thus, a comprehensive analysis is urgently needed to understand the overall impact of microbial inoculants on the biomass, diversity, structure and network complexity of native communities. Here we provide a meta-analysis of 335 studies revealing a positive effect of microbial inoculants on soil microbial biomass. This positive effect was weakened by environmental stress and enhanced by the use of fertilizers and native inoculants. Although microbial inoculants did not alter microbial diversity, they induced major changes in the structure and bacterial composition of soil microbial communities, reducing the complexity of bacterial networks and increasing network stability. Finally, higher initial levels of soil nutrients amplified the positive impact of microbial inoculants on fungal biomass, actinobacterial biomass, microbial biomass carbon and microbial biomass nitrogen. Together, our results highlight the positive effects of microbial inoculants on soil microbial biomass, emphasizing the benefits of native inoculants and the important regulatory roles of soil nutrient levels and environmental stress.

Combined effects of herbicides and insecticides reduce biomass of sensitive aquatic invertebrates

The structure and biomass of aquatic invertebrate communities play a crucial role in the matter dynamics of streams. However, biomass is rarely quantified in ecological assessments of streams, and little is known about the environmental and anthropogenic factors that influence it. In this study, we aimed to identify environmental factors that are associated with invertebrate structure and biomass through a monitoring of 25 streams across Germany. We identified invertebrates, assigned them to taxonomic and trait-based groups, and quantified biomass using image-based analysis. We found that insecticide pressure generally reduced the abundance of insecticide-vulnerable populations (R2 = 0.43 applying SPEARpesticides indicator), but not invertebrate biomass. In contrast, herbicide pressure reduced the biomass of several biomass aggregations. Especially, insecticide-sensitive populations, that were directly (algae feeder, R2 = 0.39) or indirectly (predators, R2 = 0.29) dependent on algae, were affected. This indicated a combined effect of possible food shortage due to herbicides and direct insecticide pressure. Specifically, all streams with increased herbicide pressure showed a reduced overall biomass share of Trichoptera from 43 % to 3 % and those of Ephemeroptera from 20 % to 3 % compared to streams grouped by low herbicide pressure. In contrast, insecticide-insensitive Gastropoda increased from 10 % to 45 %, and non-vulnerable leaf-shredding Crustacea increased from 10 % to 22 %. In summary, our results indicate that at the community level, the direct effects of insecticides and the indirect, food-mediated effects of herbicides exert a combined effect on the biomass of sensitive insect groups, thus disrupting food chains at ecosystem level.

Short‐term grazing reduced community stability by decreasing community‐wide asynchrony and dominant species stability

AbstractThe effects of grazing on natural grasslands' plant composition, diversity, and productivity depend on the intensity of grazing. Besides grazing intensity, animal composition is also important. However, whether and how sheep grazing intensity affects the temporal biomass stability of plant communities is unclear. Here, we conducted a 5‐year grazing experiment to evaluate the effects of four grazing intensities on community biomass stability and the underlying mechanisms. Our results showed that the higher grazing intensity significantly decreased community biomass stability, community‐wide asynchrony, functional groups asynchrony, dominant species stability, and species dominance, but did not affect species richness. The results of structural equation modeling revealed that grazing decreased community biomass stability by decreasing dominant species stability and community‐wide asynchrony, which was attributable to the reduction in plant functional group asynchrony. Our results highlight the importance of functional group composition and dynamics in predicting the changes in community function in sheep grazing grassland ecosystems. Under continuous seasonal grazing conditions, the sustainable function and human services of grasslands in the agropastoral ecotone might decrease in the future.

Drought weakens the positive effect of plant diversity on community biomass

Abstract Drought can greatly impact the biodiversity of an ecosystem and play a crucial role in regulating its functioning. However, the specific mechanisms by which drought mediate the biodiversity effect (BE) on community biomass in above- and belowground through functional traits remain poorly understood. Here, we conducted a common garden experiment in a greenhouse, which included two plant species richness levels and two water addition levels, to analyze the effects of biodiversity on aboveground biomass (AGB), belowground biomass (BGB) and total biomass (TB), and to quantify the relationship between BEs and functional traits under drought conditions. Our analysis focused on partitioning BEs into above- and belowground complementarity effect (CE) and selection effect (SE) at the species level, which allowed us to better understand the impacts of biodiversity on community biomass and the underlying mechanisms. Our results showed that plant species richness stimulated AGB, BGB and TB through CEs. Drought decreased AGB, BGB and TB, simultaneously. In addition, the aboveground CE was positively associated with the variation in plant height. SEs in above- and belowground were negatively correlated with the community mean plant height and root length, respectively. Furthermore, drought weakened the aboveground CE by decreasing variation in plant height, resulting in a reduction in AGB and TB. Our findings demonstrate that the complementarity of species is an important regulator of community biomass in above- and belowground, the dynamics of biomass under environmental stress are associated with the response of sensitive compartments.

Freshwater input significantly reduces specific and functional diversity of small subarctic estuaries

Estuaries face mounting anthropic pressures. Climate change is projected to increase heavy precipitations, while agricultural and logging activities reduce land permeability, leading to more frequent flooding events that lower estuarine salinity. These hyposaline conditions pose physiological challenges for marine species, potentially reducing taxonomic diversity and biomass, and ultimately, ecosystem functions and services. Polar and subpolar estuaries, historically understudied, will undergo significant changes in freshwater discharge timing and variability due to predicted shifts from snow to rainfall regimes in these high latitudes. The investigation of biotic communities structure through functional traits is crucial for understanding biodiversity changes, evaluating ecosystem tolerance, and addressing the loss of function under stressful conditions. Therefore, our study aims to characterize the taxonomic and functional diversity of hard-substrate benthic communities along a salinity gradient in small subarctic estuaries. We hypothesize that communities closer to the riverine input will be less taxonomically diverse and abundant and with smaller individuals, leading to a loss of functions due to environmental filtering. To test our hypotheses, we measured traditional (biomass, taxonomic richness and diversity) and functional (functional richness and Rao's quadratic entropy) indices, as well as observed traits, of epibenthic hard-substrate macroalgae and macroinvertebrates along a four-level salinity gradient found in five small subarctic estuaries in Quebec (Canada). As predicted, freshwater inputs induced a decrease in biomass, taxonomic richness, functional richness, and Rao's quadratic entropy, with a fivefold reduction in total biomass of the epibenthic community from marine to low salinity zones. Freshwater inputs significantly shaped both taxonomic and functional trait structures, as the proportion of suspension feeders and long-distance dispersers decreased with rising freshwater inputs. While there was no clear trend for the size-class structure of invertebrate taxa, macroalgae were smaller at low salinities. Estuarine communities in subarctic regions may be vulnerable to future alterations in flooding patterns caused by global change, potentially affecting key ecosystem services such as suspended matter filtration. Functional trait indices were found to be efficient and serve as a valuable complement to taxonomic measures in detecting community shifts along salinity gradients, highlighting their usefulness in developing effective conservation and management strategies.

Relationships and Changes in Grassland Community Diversity and Biomass in the Pastoral Areas of the Two Rivers under Grazing Disturbance

Grazing affects plant community characteristics and the relationship between above-ground biomass and diversity, which has become a hot topic in grassland ecosystem research in recent years. The present study investigated grassland vegetation in the Two Rivers pastoral area based on 60 sampling points using sampling methods. The effects of grazing on the structural characteristics of plant communities were analysed using the α-diversity index, and the relationship between species diversity and the above-ground biomass of plant communities, as well as their changes, was explored. The results showed that grazing disturbance decreased the number of family species in the grassland plant communities and the similarity between communities; grazing activities significantly decreased the above-ground biomass of the grassland plant communities; the height and cover also showed a decreasing trend (p < 0.01), but the density of the grassland plant communities improved (p < 0.01). The Margalef index, the Shannon–Wiener index, and the Simpson index of the grassland plant communities all showed different degrees of decrease after grazing, while the Alatalo index showed an increase; biomass was positively correlated with the Margalef, Shannon–Wiener, and Alatalo indices and negatively correlated with the Simpson index (p < 0.01). Therefore, in the management and maintenance of grasslands, the impact of grazing on the structural characteristics of plant communities should be taken into account, and reasonable response policies should be implemented according to the actual local situation. This study provides a theoretical basis for grassland maintenance and management and the sustainable development of ecosystems in the pastoral areas of the two river sources of the Altay Mountains.

Effects of native species richness on reproduction of invasive Bidens pilosa vary with nutrient supply

BackgroundBoth increasing native species diversity and reducing nutrient availability can increase the ability of native plant communities to resist alien plant invasions. Furthermore, native species diversity and nutrient availability may interact to influence alien plant invasions. So far, however, little is known about the interactive effect of species diversity and nutrient availability on reproduction of alien invasive plants. We constructed native plant communities with one, four or eight species under low and high nutrient supply and then let them be invaded by the invasive alien plant Bidens pilosa.ResultsAt both high and low nutrient supply, increasing native species richness significantly increased aboveground biomass of the native plant community and decreased aboveground biomass and biomass proportion of the invader B. pilosa. Reproductive biomass of B. pilosa decreased significantly with increasing native species richness under high nutrient supply, but this effect was not observed under low nutrient supply. Net biodiversity effect on seed mass of B. pilosa decreased significantly with increasing native species diversity under high nutrient supply, but not under low nutrient supply. This was mainly because the selection effect became dominant with increasing species richness under high nutrient supply.ConclusionsOur study suggest that native species richness and nutrient supply can interact to influence reproduction of invasive alien plant species and that measures to help maintain a high level of native species richness and to reduce nutrient supply could be useful for efficient invasive plant control.

Th17-to-Tfh plasticity during periodontitis limits disease pathology.

Th17 cell plasticity is crucial for development of autoinflammatory disease pathology. Periodontitis is a prevalent inflammatory disease where Th17 cells mediate key pathological roles, yet whether they exhibit any functional plasticity remains unexplored. We found that during periodontitis, gingival IL-17 fate-mapped T cells still predominantly produce IL-17A, with little diversification of cytokine production. However, plasticity of IL-17 fate-mapped cells did occur during periodontitis, but in the gingiva draining lymph node. Here, some Th17 cells acquired features of Tfh cells, a functional plasticity that was dependent on IL-6. Notably, Th17-to-Tfh diversification was important to limit periodontitis pathology. Preventing Th17-to-Tfh plasticity resulted in elevated periodontal bone loss that was not simply due to increased proportions of conventional Th17 cells. Instead, loss of Th17-to-Tfh cells resulted in reduced IgG levels within the oral cavity and a failure to restrict the biomass of the oral commensal community. Thus, our data identify a novel protective function for a subset of otherwise pathogenic Th17 cells during periodontitis.

Plant functional traits modulate the effects of soil acidification on above- and belowground biomass

Abstract. Atmospheric sulfur (S) deposition has been increasingly recognized as a major driver of soil acidification. However, little is known about how soil acidification influences above- and belowground biomass by altering leaf and root traits. We conducted a 3-year S-addition experiment to simulate soil acidification in a meadow. Grass (Leymus chinensis (Trin.) Tzvelev) and sedge (Carex duriuscula C.A.Mey) species were chosen to evaluate the linkage between plant traits and biomass. Sulfur addition led to soil acidification and nutrient imbalances. Soil acidification decreased specific leaf area (SLA) but increased leaf dry-matter content (LDMC) in L. chinensis, showing a conservative strategy and thus suppressing aboveground instead of belowground biomass. However, in C. duriuscula, soil acidification increased plant height and root nutrients (N, P, S, and Mn), favoring competition for natural resources through enhanced above- and belowground biomass, i.e., adoption of an acquisitive strategy. Increased soil acidity resulted in an overall reduction in aboveground community biomass by 3 %–33 %, but it led to an increase in community root biomass by 11 %–22 % due to upregulation as a result of higher soil nutrient availability. Our results demonstrate that both above- and belowground plant biomass is affected by S-induced acidification. Understanding the linkage between plant biomass and functional traits contributes to a better understanding of plant–soil feedback in grassland ecosystems.

Different impacts of artificial thicketization of Caragana korshinskii and Hippophae rhamnoides on soil organic carbon in alpine grasslands of the Qinghai–Tibetan Plateau

Grassland shrub encroachment is known to change soil organic carbon (SOC) storage, but the effect of artificial thicketization on SOC in alpine grasslands of the Qinghai–Tibetan Plateau remains unclear. In this study, we investigated the effects of two common shrubs, leguminous Caragana korshinskii and non‐leguminous Hippophae rhamnoides, on SOC at a reforestation site on the Qinghai–Tibetan Plateau. While C. korshinskii had no significant effect on SOC content, H. rhamnoides significantly increased SOC content. In both shrub communities, there was a significant positive correlation between SOC content and the coverage, plant aboveground biomass, dominant plant species biomass, total and available nitrogen, total phosphorus, and proportion of water‐stable aggregate of greater than 250 μm. Structural equation modeling showed that the common path by which the two shrub communities affected SOC was that the dominant species affected soil structure and the available nitrogen content by influencing community biomass, which had indirect effects on SOC. Additionally, C. korshinskii participated in the regulation of SOC. This result provides an important empirical reference and key insights into the carbon cycling mechanisms of reforested grasslands on the Qinghai–Tibetan Plateau.

Species asynchrony maintains community stability under different warming conditions

Abstract Asymmetric seasonal warming, characterized by more pronounced temperature increases in winter than in summer, has become a critical feature of global warming, especially in cold and high-altitude regions. Previous studies have primarily focused on year-round warming, while comparatively less attention was paid to winter warming. However, a significant knowledge gap exists regarding the impacts of winter warming on ecosystem functions. To address this, we conducted an 8-year manipulated warming experiment in an alpine grassland on the Tibetan Plateau, employing three treatments: no warming, year-round warming and winter warming. We found that neither year-round warming nor winter warming significantly alters species richness at the community level. Notably, community biomass stability was maintained via species asynchrony. However, warming exerted significant effects on the plant abundance groups (dominant, common and rare species). Specifically, winter warming enhanced the stability of dominant species by increasing species asynchrony of dominant species, as the compensatory dynamics occurred between the grass and forbs. In contrast, year-round warming reduced the stability of common species, correlated with an increase in species richness and a decline in asynchrony among common species. Thus, our study underscores the capacity of alpine grassland to maintain community biomass stability via asynchrony dynamics of species under different warming conditions, although the stability of different abundance groups would be changed. Importantly, our results provide valuable insights for understanding the alpine grassland ecosystem on the Tibetan Plateau.

What drives growth responses of nitrogen and phosphorus (co-)limited primary producer communities?

The growth of autotroph communities is frequently (co-)limited by essential nutrients such as nitrogen (N) and phosphorus (P). Several mechanisms have been proposed to explain the observed co-limitation patterns at different levels of biological organization, especially at the biochemical level for individual species. When considering communities, the presence of different species and functional groups with contrasting physiologies and nutrient requirements leads to a more difficult understanding of the mechanisms involved in nutrient (co-)limitation. To investigate what drives co-limitation patterns and possible underlying mechanisms based on biomass responses in autotroph communities, we grew phytoplankton communities differing in species composition in experimental microcosms on three N:P ratios to impose different limiting conditions. Afterwards, N, P, both, or none were factorially supplied to the communities to test which nutrients were limiting growth. We measured the biovolume of single species in the communities to assess how they responded to nutrient additions and compared it to the response of the overall community biovolume. The types of nutrient (co-)limitation identified, i.e. the factorial limitation scenarios for community biomass were single N limitation or simultaneous co-limitation by N and P, and were strongly driven by the dominant species. The phytoplankton species in the communities responded differently to the nutrient addition treatments, i.e. they showed contrasting limitation outcomes and therefore likely different nutrient requirements. Our experiment indicates that phylogenetically distantly-related phytoplankton species grown in a community can have different resource use efficiencies and thus can be limited by different nutrients. We suggest that the dominance of species or groups with similar traits in nutrient requirements and acquisition is one of the leading mechanisms that determines the biomass pattern of nutrient (co-)limitation observed at the community level. This work also highlights the potential of predicting community growth limitation outcomes based on knowledge of nutrient use efficiencies of one or few dominant species, which can be a suitable tool for lake restoration and oligotrophication efforts.

Effects of Short-Term Nitrogen Additions on Biomass and Soil Phytochemical Cycling in Alpine Grasslands of Tianshan, China.

The nitrogen deposition process, as an important phenomenon of global climate change and an important link in the nitrogen cycle, has had serious and far-reaching impacts on grassland ecosystems. This study aimed to investigate the survival adaptation strategies of plants of different functional groups under nitrogen deposition, and the study identified the following outcomes of differences in biomass changes by conducting in situ simulated nitrogen deposition experiments while integrating plant nutrient contents and soil physicochemical properties: (1) nitrogen addition enhanced the aboveground biomass of grassland communities, in which Poaceae were significantly affected by nitrogen addition. Additionally, nitrogen addition significantly influenced plant total nitrogen and total phosphorus; (2) nitrogen addition improved the plant growth environment, alleviated plant nitrogen limitation, and promoted plant phosphorus uptake; and (3) there was variability in the biomass responses of different functional groups to nitrogen addition. The level of nitrogen addition was the primary factor affecting differences in biomass changes, while nitrogen addition frequency was an important factor affecting changes in plant community structure.

Local factors drive the richness, biomass and composition of benthic invertebrate communities in Neotropical reservoirs

Local factors drive the richness, biomass and composition of benthic invertebrate communities in Neotropical reservoirs

Impact of aridity rise and arid lands expansion on carbon-storing capacity, biodiversity loss, and ecosystem services.

Drylands, comprising semi-arid, arid, and hyperarid regions, cover approximately 41% of the Earth's land surface and have expanded considerably in recent decades. Even under more optimistic scenarios, such as limiting global temperature rise to 1.5°C by 2100, semi-arid lands may increase by up to 38%. This study provides an overview of the state-of-the-art regarding changing aridity in arid regions, with a specific focus on its effects on the accumulation and availability of carbon (C), nitrogen (N), and phosphorus (P) in plant-soil systems. Additionally, we summarized the impacts of rising aridity on biodiversity, service provisioning, and feedback effects on climate change across scales. The expansion of arid ecosystems is linked to a decline in C and nutrient stocks, plant community biomass and diversity, thereby diminishing the capacity for recovery and maintaining adequate water-use efficiency by plants and microbes. Prolonged drought led to a -3.3% reduction in soil organic carbon (SOC) content (based on 148 drought-manipulation studies), a -8.7% decrease in plant litter input, a -13.0% decline in absolute litter decomposition, and a -5.7% decrease in litter decomposition rate. Moreover, a substantial positive feedback loop with global warming exists, primarily due to increased albedo. The loss of critical ecosystem services, including food production capacity and water resources, poses a severe challenge to the inhabitants of these regions. Increased aridity reduces SOC, nutrient, and water content. Aridity expansion and intensification exacerbate socio-economic disparities between economically rich and least developed countries, with significant opportunities for improvement through substantial investments in infrastructure and technology. By 2100, half the world's landmass may become dryland, characterized by severe conditions marked by limited C, N, and P resources, water scarcity, and substantial loss of native species biodiversity. These conditions pose formidable challenges for maintaining essential services, impacting human well-being and raising complex global and regional socio-political challenges.