Increasing Plant Diversity Research Articles

Litter removal increases plant diversity by promoting both native and exotic forbs in heavily invaded coastal sage scrub in Southern California, U.S.A.

Litter produced by exotic grasses is known to negatively impact native species through multiple mechanisms. While litter removal is a potential restoration tool to recover native species, the effects of litter removal on overall plant community structure are not well understood as most studies focus on native species recovery. In a litter removal experiment in Southern California, U.S.A., we found that plant communities receiving litter removal treatment differed in species composition from control plots and had 4.4% higher native forb relative abundance and 7.0% higher exotic forb relative abundance, on average. These changes in exotic and native forb abundance with litter removal altered community structure by increasing overall Shannon diversity, while only having a modest positive effect on overall species richness. In contrast, we found no effect of litter removal on the species richness or Shannon diversity of native species. Taken together, these findings suggest that in herbaceous systems litter removal is likely to alter community composition primarily by increasing the abundance of native and exotic forbs already present in the community, rather than by allowing the establishment of new native species. Our study adds to a growing body of literature demonstrating that litter produced by exotic grasses inhibits native forbs in California grasslands and coastal sage scrub and highlights a potential trade‐off between controlling exotic grass invaders and controlling exotic forb invaders. If managing for increased species diversity is the goal, litter removal may be an appropriate intervention to move plant communities toward a more diverse state.

Increasing plant diversity enhances soil organic carbon storage in typical wetlands of northern China.

Soil organic carbon plays an important role in climate change mitigation, and can be strongly affected by plant diversity. Although a positive effect of plant diversity on soil organic carbon storage has been confirmed in grasslands and forests, it remains unclear whether this effect exists in wetlands. In this study, we investigated plant diversity, soil properties and soil organic carbon across five typical wetlands of northern China, to test the effect of plant diversity on soil organic carbon and clarified the regulators. Increasing plant diversity significantly increased belowground biomass of wetland plant communities, and both soil organic carbon content and storage were significantly positively related to wetland plant diversity. The positive effect of plant diversity was influenced by belowground biomass of wetland plant communities, soil microbial biomass carbon, and soil properties, especially soil water content and bulk density. The structural equation model showed that soil organic carbon storage was dominantly affected by microbial biomass carbon, plant diversity and biomass, with standardized total effects of 0.66 and 0.47, respectively, and there was a significant positive relationship between soil organic carbon and microbial biomass carbon. These results suggest that increasing plant diversity can potentially promote the ability of wetlands to store organic carbon in soils. The findings highlight the importance of plant diversity on soil organic carbon in wetland ecosystems, and have implications for managing wetlands to increase carbon sinks and to mitigate global climate change.

Impact of the origin of sites planted with hybrid poplar on plant community composition and diversity

Intensively managed fast-growing tree plantations may affect plant diversity, and we have little knowledge on how it is affected by site origin in order to better orientate site selection for their establishment. The aim of this study was thus to determine the impact of site origin on plant diversity in intensively managed hybrid poplar plantations. We investigated vascular and non-vascular plant communities within fast growing hybrid poplar plantations (PEH) established on abandoned agricultural lands (AAL) with herbaceous or shrubby vegetation, and on previously forested lands, and compared them to adjoining non-afforested surrounding sites. Our results show that PEH plantations established on herbaceous and shrubby AALs had similar or higher plant diversity even though they contained no forest species after 15 years. When established on previously forested lands, PEH plantations favored the establishment of ruderal species compared to their non-reforested equivalents, but plant diversity and richness tended to decrease following plantation establishment. Thus, if site selection is made to preserve or increase plant diversity, abandoned agricultural lands should preferentially be chosen rather than previously forested sites to install intensively managed hybrid poplar plantations.

Crucial role of fungi in environmentally sustainable agriculture

To produce more, better and safer food we must be able to do so while promoting the sustainable use of agricultural resources. The increase in agricultural production is currently through the use of pesticides, fertilizers, and developments in plant breeding and genetic skills. In naturally existing ecosystems, rhizospheric soils have biological living beings to favor the plant development, nutrient assimilation, stress tolerance, disease deterrence, carbon seizing and others. Fungi are among the most widely distributed organisms on Earth and are of great environmental importance. Mycorrhizal fungi, bacteria, actinomycetes, etc. solubilize nutrients and assist the plants in uptake by roots. Amongst them, vesicular/arbuscular mycorrhizal fungi (AMF) have key roles in the natural ecosystem, as the majority of the terrestrial plants form association with AMF. This symbiosis confers benefits directly to the host plant’s growth and development through the acquisition of phosphorus (P) and other mineral nutrients from the soil. They may also enhance the protection of plants against pathogens, increase plant diversity and have the potential to enhance plant growth under stressful environments. In this article, the sustainability and environmental aspects of agriculture, and the basic concepts of fungi will be reviewed to justify our point of view about the tremendous importance of fungi towards an environmentally sustainable agriculture.

Effects of mound building and caching by steppe mouse (Mus spicilegus Petényi) on the vegetation in agroecosystems

Several rodent species are considered ecosystem engineers. They exert profound changes in agroecosystems by disturbing the soil during their activities. The steppe mouse (Mus spicilegus) inhabits various agroecosystems and constructs conspicuous mounds for overwintering using piled up plant material and soil. These mounds are widespread in many agroecosystems and may significantly affect the vegetation. In our study, we evaluated the effect of mound building activity of the steppe mouse on the vegetation of agroecosystems in Hungary. We sampled the cache content of 90 mounds in total located in old fields, alfalfa fields, and annual crop fields, and surveyed the aboveground vegetation of the mounds and their surrounding undisturbed matrix in 39 paired plots. Mice cached large amounts of seeds belonging mostly to weeds. In total we found 50,413 germinable seeds of 30 species in the cache content samples. However, the mound vegetation and the cache shared only a few species, suggesting that seeds cached by the mice do not contribute to the regenerating vegetation on the mounds. Soil disturbance by mice created distinct vegetation patches with species composition and structure different from the neighbouring undisturbed matrix. Early secondary successional vegetation patches on mounds introduced small-scale heterogeneity into the homogenous agricultural landscape, increased plant diversity and provided distinct flower resources for pollinators. The detected differences in the aboveground vegetation between the mound and the matrix in the studied habitats suggest that the steppe mouse acts as a facultative engineer species in agroecosystems.

Plant diversity drives positive microbial associations in the rhizosphere enhancing carbon use efficiency in agricultural soils

Expanding and intensifying agriculture has led to a loss of soil carbon. As agroecosystems cover over 40% of Earth’s land surface, they must be part of the solution put in action to mitigate climate change. Development of efficient management practices to maximize soil carbon retention is currently limited, in part, by a poor understanding of how plants, which input carbon to soil, and microbes, which determine its fate there, interact. Here we implement a diversity gradient by intercropping undersown species with barley in a large field trial, ranging from one to eight undersown species. We find that increasing plant diversity strengthens positive associations within the rhizosphere soil microbial community in relation to negative associations. These associations, in turn, enhance community carbon use efficiency. Jointly, our results highlight how increasing plant diversity in agriculture can be used as a management strategy to enhance carbon retention potential in agricultural soils.

Water addition but not reduction alters plant biomass-diversity relationship.

The relationship between plant aboveground biomass and diversity typically follows a unimodal pattern, showing a positive correlation in resource-poor habitats and a negative correlation in resource-rich environments. Precipitation is a crucial resource for both plant biomass and diversity in terrestrial ecosystems. However, the impact of precipitation changes on the relationship between plant biomass and diversity remains unclear. We conduct a water addition field experiment in a semiarid grassland and identify a unimodal relationship between plant biomass and species richness under ambient conditions. Water addition delays the declining phase of this unimodal curve and shift it upward compared to ambient conditions. Our meta-analysis of water addition experiments conducted across major biomes worldwide (grassland, shrubland, desert, and forest) supports this finding, while water reduction does not alter the biomass-diversity relationship. Water addition increases biomass in all climate but only increases species richness in arid and semiarid climate. Similarly, water reduction decreases biomass in all climate but only reduces species richness in arid and semiarid climate. Species richness in dry subhumid and humid climate does not change significantly. Furthermore, our field experiment shows that water addition increases plant diversity while decreasing soil inorganic nitrogen levels. The increase in one resource, such as water, leads to the scarcity of another, such as nutrient, thus postponing the declining phase of the plant biomass-diversity relationship typically observed in resource-rich habitats. Our research contributes to predicting the plant biomass-diversity relationship under changing precipitation conditions and highlights the complex interplay between water availability, nutrient level, and plant diversity.

Grasses don’t always win: Short-term effects of fertilization on taxonomic and functional diversity of a Mediterranean annual grassland

Nitrogen pollution has increased dramatically over the last decades, becoming a major contributor to biodiversity loss and compositional changes globally. While the main effects of excessive nutrients on plant communities are well established, Mediterranean grasslands have been less studied despite their high levels of biodiversity. Moreover, evidence has shown that the impacts of nutrients may depend on additional factors, namely soil conditions and grazing, increasing the uncertainty about the effects of increasing nutrient availability in these systems. In this work, we assessed the short-term effects (1 year) of fertilization in an extensively grazed oak open woodland (called montado, or dehesa), in Spain. Plots comprised a complete randomized design with four treatments: control (not fertilized), fertilization with nitrogen at a rate of 100 kg N ha−1, fertilization with phosphorous (50 kg P ha−1) and fertilization with both N and P (100 kg ha−1 N + 50 kg ha−1 P). We assessed changes in plant species composition and functional diversity and evaluated the association between species and fertilization treatments with an indicator species analysis. Our results showed that species diversity increased with NP fertilization and that forbs in particular increased in cover and richness. SLA and seed mass also showed differences compared to the control. The Community-weighted mean and functional dispersion of groups based on growth form and N-fixing ability were not influenced by fertilization. Two species were significantly associated with fertilized plots: the spiny forb Carlina racemosa and the latex-producing forb Tolpis barbata. Our study suggests that short-term fertilization may alleviate nutrient limitations in these systems, increasing plant diversity, although longer-term studies are needed to understand the effects of a continuous increase in nutrient availability.

Holocene Neolithic human activity shaped ecosystem functions through the altering of vegetation traits in Zhejiang, eastern China

Since the Holocene, long–term human activities have altered the composition, structure, and function of ecosystems, yet uncertainty remains regarding the underlying mechanism of a variety of vegetation responses to both natural and anthropogenic forces. In this study, we collected and categorized 37 fossil pollen records from Zhejiang, a region characterized by continuous Neolithic Cultures in eastern China, into natural and human–impacted sites. The aim was to reconstruct past long–term changes in plant traits and to investigate variations in ecosystem functioning under the pressure of natural climate shifts and anthropogenic disturbances. Our findings reveal that, during the Holocene, plant functional traits at natural sites gradually adapted to warmer and wetter conditions, with the natural functional dispersion (FDis) showing a steady decrease between 9.0 and 4.0 cal ka BP. At human–impacted sites, intensified human activities gradually transformed the landscape from forest to grassland and shrubland, allowing light–demanding vegetation to thrive due to extended canopy gaps. Pioneer plants flourished in the secondary succession, leading communities to exhibit more aggressive resource acquisition strategies compared to a natural community. With the progression of agriculture towards intensive practices, ancestors might have expanded their original ecological niches by shaping a landscape encompassing a gradient of grasslands, shrublands, and forests, leading to an increase in plant diversity and a reversal in the trend of decreasing FDis. Higher functional diversity is considered a potential factor in maintaining ecosystem stability. Neolithic human activities, by modifying plant composition, community structure, and shaping landscape gradients, probably contributed to enhancing the stability of past terrestrial ecosystems.

Effects of plant diversity and community structure on ecosystem multifunctionality under different grazing potentials in the eastern Eurasian steppe

Grazing potential represents the potential carrying capacity of steppe livestock production. Understanding the impact of changes in plant diversity and community structure on ecosystem multifunctionality (EMF) at different grazing potentials is crucial for the sustainable management of steppe ecosystems. We examined the associations between plant diversity, community structure, above-ground ecosystem multifunctionality (AEMF), and below-ground ecosystem multifunctionality (BEMF) at various grazing potentials. Our assessment employed generalized linear mixed-effects models and structural equation models to determine the impact of these factors on ecosystem multifunctionality. Our study results indicated that ecosystem multifunctionality differed depending on the level of grazing potential and decreased as grazing potential declined. The impact of plant diversity and community structure on above- and below-ground ecosystem multifunctionality varied. Plant diversity and community structure correlated more with AEMF than BEMF. Plant diversity had the most significant effect on EMF under high grazing potential, while community structure had the greatest effect on EMF under moderate and low grazing potential. These improve our understanding of the correlation between steppe plant diversity, community structure, and above- and below-ground ecosystem multifunctionality. This understanding is necessary to develop strategies to increase plant diversity or regulate community structure and the sustainability of steppes.

Effects of experimental drought and plant diversity on multifunctionality of a model system for crop rotation

In low-diversity productive grasslands, modest changes to plant diversity (richness, composition and relative abundance) may affect multiple ecosystem functions (multifunctionality), including yield. Despite the economic importance of productive grasslands, effects of plant diversity and environmental disturbance on multifunctionality are very rarely quantified. We systematically varied species richness, composition, and relative abundance of grassland ley communities and manipulated water supply (rainfed and drought) to quantify effects of diversity and environmental disturbance on multifunctionality. We then replaced the grassland leys with a monoculture crop to investigate ‘follow-on’ effects. We measured six agronomy-related ecosystem functions across one or both phases: yield, yield consistency, digestibility and weed suppression (grassland ley phase), legacy effect (effect on follow-on crop yield), and nitrogen fertiliser efficiency (full rotation). Drought reduced most ecosystem functions, although effects were species- and function-specific. Increased plant diversity affected mean performance, and reduced variation, across the six functions (contributing to multifunctional stability). Multifunctionality index values across a wide range of mixture diversity were higher than the best monoculture under both rainfed and drought conditions (transgressive over-performance). Higher-diversity, lower-nitrogen (150N) mixtures had higher multifunctionality than a low-diversity, higher-nitrogen (300N) grass monoculture. Plant diversity in productive grasslands is a practical farm-scale management action to mitigate drought impacts and enhance multifunctionality of grassland-crop rotation systems.

Drivers of Spontaneous Plant Communities in Urban Parks: A Case from Nanjing, China

Urban plant diversity is one of the key elements for sustainable urban development. Urban plant landscapes not only create a variety of experiences for residents but also have a positive effect on their physiology and psychology. In order to better introduce nature into urban green spaces, this study conducted a field survey in Nanjing, China, to analyze the current situation of spontaneous plants in Nanjing’s urban green spaces and propose a plant planning strategy that takes into account both ecology and residents’ well-being. This study surveyed the herbaceous plant resources in 96 sample plots in nine typical urban parks in Nanjing, and recorded 284 plant species in 192 genera and 78 families. The research results show that the differences in plant diversity, richness, and evenness among urban parks in Nanjing are significant; combined with cluster analysis and ranking results, the total area of urban parks, green space construction time, lighting conditions, and management frequency have an impact on plant communities. Further analysis of the species composition of plant communities showed that moderate management frequency in urban parks can increase plant diversity. With the advantages of both high ecological benefits and low management costs, a model of “artificial plants + native spontaneous plants” was finally proposed for the planting of herbaceous plants in sustainable urban green spaces.

Chronic anthropogenic disturbance mediates the bottom-up influence of plant diversity on arthropods in tropical forests.

Understanding how primary productivity and diversity affect secondary productivity is an important debate in ecology with implications for biodiversity conservation. Particularly, how plant diversity influences arthropod diversity contributes to our understanding of trophic cascades and species coexistence. Previous studies show a positive correlation between plant and arthropod diversity. The theory of associational resistance suggests that plant herbivory rate will decrease with increasing plant diversity indicating feedbacks between primary diversity, productivity, and secondary productivity rates. However, our understanding of how these relations are mediated by anthropogenic disturbance is still limited. We surveyed 10 forest sites, half of which are disturbed by fire, logging, and tree pruning, distributed in two climatic zones in Benin, West Africa. We established 100 transects to record plant species and sampled arthropods using pitfall traps, ceramic plates with bait, and sweeping nets. We developed a structural equation model to test the mediating effect of chronic anthropogenic disturbance on plant diversity and how it influences arthropod diversity and abundance. Arthropod diversity increased but arthropod abundance decreased with increasing intensity of disturbance. We found no significant bottom-up influence of the plant diversity on arthropod diversity but a significant plant diversity-arthropod abundance relationship. Some arthropod guilds were significantly affected by plant diversity. Finally, herbivory rates were positively associated with arthropod diversity. Synthesis. Our results highlight how chronic anthropogenic disturbance can mediate the functional links between trophic levels in terms of diversity and productivity. Our study demonstrated a decoupled response of arthropod diversity and abundance to disturbance. The direct positive influence of plant diversity on herbivory rates we found in our study provides counter-support for the theory of associational resistance.

Design principles for multi‐species productive grasslands: Quantifying effects of diversity beyond richness

Abstract Productive grasslands in temperate regions have relied strongly on low plant diversity with high management intensity and fertiliser inputs. Increasing plant diversity can provide high yields of digestible forage for livestock production with lower environmental impacts, and thus represents a diversity‐dependent nature‐based solution that can deliver multiple ecosystem functions. Sharing lessons from the design of managed, productive grassland communities, we address the following questions: how can we identify combinations of plant species that best deliver a selected function or multiple functions? and; when is community composition more important than species richness? We describe approaches that separate plant diversity into its underlying components: species richness, composition and relative abundance. Disentangling these three components facilitates a more nuanced understanding of how diversity can contribute to the design of diversity‐dependent nature‐based solutions.

Plant diversity increases spatial stability of aboveground productivity in alpine grasslands.

Plant diversity can significantly affect the grassland productivity and its stability. However, it remains unclear how plant diversity affects the spatial stability of natural grassland productivity, especially in alpine regions that are sensitive to climate change. We analyzed the interaction between plant (species richness and productivity, etc.) and climatic factors (precipitation, temperature, and moisture index, etc.) of alpine natural grassland on the Qinghai-Tibetan Plateau. In addition,we tested the relationship between plant diversity and spatial stability of grassland productivity. Results showed thatan increase in plant diversity significantly enhanced community productivity and its standard deviation, while reducing the coefficient of variation in productivity. The influence of plant diversity on productivity and the reciprocal of productivity variability coefficient was not affected by vegetation types. The absolute values of the regression slopes between climate factors and productivity in alpine meadow communities with higher plant diversity were smaller than those in alpine meadow communities with lower plant diversity. In other words, alpine meadow communities with higher plant diversity exhibited a weaker response to climatic factorsin terms of productivity, whereas those with lower plant diversity showed a stronger response. Our results indicate that high plant diversity buffers the impact of ambient pressure (e.g., precipitation, temperature) on alpine meadow productivity, andsignificantly enhanced the spatial stability of grassland productivity. This finding provides a theoretical basis for maintaining the stability of grassland ecosystems and scientifically managing alpine grasslands under the continuous climate change.

A global meta-analysis on the effects of organic and inorganic fertilization on grasslands and croplands.

A central role for nature-based solution is to identify optimal management practices to address environmental challenges, including carbon sequestration and biodiversity conservation. Inorganic fertilization increases plant aboveground biomass but often causes a tradeoff with plant diversity loss. It remains unclear, however, whether organic fertilization, as a potential nature-based solution, could alter this tradeoff by increasing aboveground biomass without plant diversity loss. Here we compile data from 537 experiments on organic and inorganic fertilization across grasslands and croplands worldwide to evaluate the responses of aboveground biomass, plant diversity, and soil organic carbon (SOC). Both organic and inorganic fertilization increase aboveground biomass by 56% and 42% relative to ambient, respectively. However, only inorganic fertilization decreases plant diversity, while organic fertilization increases plant diversity in grasslands with greater soil water content. Moreover, organic fertilization increases SOC in grasslands by 19% and 15% relative to ambient and inorganic fertilization, respectively. The positive effect of organic fertilization on SOC increases with increasing mean annual temperature in grasslands, a pattern not observed in croplands. Collectively, our findings highlight organic fertilization as a potential nature-based solution that can increase two ecosystem services of grasslands, forage production, and soil carbon storage, without a tradeoff in plant diversity loss.

Glacier retreat triggers changes in biodiversity and plant–pollinator interaction diversity

Due to global warming, the worldwide retreat of glaciers is causing changes in species diversity, community composition, and species interactions. However, the impact of glacier retreat on interaction diversity and ecological networks remains poorly understood. An integrative understanding of network dynamics may inform conservation actions that support biodiversity and ecosystem functioning after glacier extinction. Here, we address how glacier retreat affects the frequency, diversity, and complexity of plant–pollinator interactions, both directly and indirectly through biodiversity change. We surveyed flower visitors (pollinators) and analyzed pollination networks across a gradient of 170 years of glacier retreat (Mont Miné glacier, Valais, Switzerland) which ranges from patchy grasslands to closed forests. We reported a strong impact of glacier retreat on both plant and pollinator communities. Notably, the diversity of plant–pollinator interactions was sharply affected by glacier retreat: interaction diversity increased few years after glacier retreat, but it ultimately decreased in late stages dominated by forests. In contrast, we found that plant–pollinator network complexity did not change with glacier retreat. Our results indicate that the development of plant–pollinator networks is a two-phases process. In the first phase, glacier retreat makes space to plant colonization. This initial increase in plant diversity drives the increase in pollinator and interaction diversity. The second phase is characterized by turnover as woody species encroaches and dominates the community, decreasing the diversity of plant species in ultimate instance. The local decrease of plant diversity leads to a local decrease in pollinator and interaction diversity. Slowing down woody encroachment and enhancing flower diversity, which is initially supported by the glacial landscape, may be key strategies for halting the erosion of ecological networks while increasing biodiversity and ecosystem functioning. Our research thus can help resolve the overarching question of how to conserve ecosystems once glaciers are extinct, pointing toward a composite role of both habitat structure and biological functions.

Plant growth-defense trade-offs are general across interactions with fungal, insect, and mammalian consumers.

Plants face trade-offs between allocating resources to growth, while also defending against herbivores or pathogens. Species differences along defense trade-off axes may promote coexistence and maintain diversity. However, few studies of plant communities have simultaneously compared defense trade-offs against an array of herbivores and pathogens for which defense investment may differ, and even fewer have been conducted in the complex natural communities in which these interactions unfold. We tested predictions about the role of defense trade-offs with competition and growth in diversity maintenance by tracking plant species abundance in a field experiment that removed individual consumer groups (mammals, arthropods, fungi) and added nutrients. Consistent with a growth-defense trade-off, plant species that increased in mass in response to nutrient addition also increased when consumers were removed. This growth-defense trade-off occurred for all consumer groups studied. Nutrient addition reduced plant species richness, which is consistent with trade-off theory. Removing foliar fungi increased plant diversity via increased species evenness, whereas removal of other consumer groups had little effect on diversity, counter to expectations. Thus, while growth-defense trade-offs are general across consumer groups, this trade-off observed in wild plant communities does not necessarily support plant diversity maintenance.

Multi-Trophic Species Diversity Contributes to the Restoration of Soil Multifunctionality in Degraded Karst Forests through Cascading Effects

The biodiversity–ecosystem function (BEF) relationship is the basis for studying the restoration of degraded ecosystems, and the simultaneous assessment of multi-trophic-level biodiversity and ecosystem multifunctionality relationship is more conducive to unravelling the restoration mechanism of degraded ecosystems, especially for degraded forest ecosystems with harsh habitats and infertile soils such as karst. In this study, we evaluated the biodiversity and soil multifunctionality (SMF) of degraded karst forests (scrub, SB; secondary growth forests, SG; old-growth forests, OG) in the Maolan National Nature Reserve, China, using 30 sample plots. Biodiversity and soil multifunctionality (SMF) at three trophic levels (plant–soil fauna–soil microorganisms), were assessed through vegetation surveys and soil sampling. One-way ANOVA showed that SMF increased with natural restoration, but multi-trophic level biodiversity showed different trends. Pearson’s correlation analysis showed a positive correlation between plant species diversity and SMF (p < 0.001), whereas soil fauna and soil microorganisms were negatively correlated with SMF. Structural equation modeling revealed a cascading effect of the multi-trophic level on the stimulation of the SMF during restoration. Only soil microorganisms exhibited a direct driving effect on SMF (p < 0.001), whereas plants indirectly influenced soil microorganisms through soil fauna, which subsequently affected the SMF. Although we observed the negative effects of increased plant diversity on soil fauna and soil microbial diversity in terms of quantitative relationships, the increase in soil fauna species and the evenness of soil microbial function still contributed to SMF restoration. This study revealed the cascading effects of multi-trophic diversity in promoting SMF restoration and emphasized that soil microbes are key to unraveling restoration mechanisms and processes, whereas soil fauna is an important intermediate link.

Microclimate modulation: An overlooked mechanism influencing the impact of plant diversity on ecosystem functioning.

Changes in climate and biodiversity are widely recognized as primary global change drivers of ecosystem structure and functioning, also affecting ecosystem services provided to human populations. Increasing plant diversity not only enhances ecosystem functioning and stability but also mitigates climate change effects and buffers extreme weather conditions, yet the underlying mechanisms remain largely unclear. Recent studies have shown that plant diversity can mitigate climate change (e.g. reduce temperature fluctuations or drought through microclimatic effects) in different compartments of the focal ecosystem, which as such may contribute to the effect of plant diversity on ecosystem properties and functioning. However, these potential plant diversity-induced microclimate effects are not sufficiently understood. Here, we explored the consequences of climate modulation through microclimate modification by plant diversity for ecosystem functioning as a potential mechanism contributing to the widely documented biodiversity-ecosystem functioning (BEF) relationships, using a combination of theoretical and simulation approaches. We focused on a diverse set of response variables at various levels of integration ranging from ecosystem-level carbon exchange to soil enzyme activity, including population dynamics and the activity of specific organisms. Here, we demonstrated that a vegetation layer composed of many plant species has the potential to influence ecosystem functioning and stability through the modification of microclimatic conditions, thus mitigating the negative impacts of climate extremes on ecosystem functioning. Integrating microclimatic processes (e.g. temperature, humidity and light modulation) as a mechanism contributing to the BEF relationships is a promising avenue to improve our understanding of the effects of climate change on ecosystem functioning and to better predict future ecosystem structure, functioning and services. In addition, microclimate management and monitoring should be seen as a potential tool by practitioners to adapt ecosystems to climate change.