Plant Diversity Research Articles

Ethnobotanical survey and scientific validation of liver-healing plants in northeastern Morocco.

Liver diseases represent a significant global health challenge, with primary causes including excessive alcohol consumption, infections, chemotherapy, and autoimmune disorders. Medicinal plants, due to their natural bioactive compounds, hold promise for developing effective treatments and preventive measures against liver ailments. This study aimed to document the use of herbal remedies in northeastern Morocco for liver diseases and correlate these uses with scientific evidence through a bibliometric analysis. An ethnobotanical survey was conducted in remote communities of northeastern Morocco from October 2020 to January 2022. A total of 189 informants were interviewed using semi-structured questionnaires to gather information on local medicinal plants used for liver ailments. The data were analyzed using four ethnobotanical quantitative indices: use value (UV), familial use value (FUV), informant consensus factor (ICF), and fidelity level (FL). Additionally, a bibliometric analysis was performed to evaluate the scientific support for the ethnopharmacological uses documented. The survey identified 45 plant species from 26 different families used in the treatment of liver diseases. The most frequently utilized species were Cuminum cyminum L. (UV = 0.1065), Allium sativum L. (UV = 0.1015), Salvia officinalis L. (UV = 0.0761), Asparagus officinalis L. (UV = 0.0558), and Ziziphus lotus (L.) Lam. (UV = 0.0457). The Apiaceae family showed the highest familial use value (FUV = 0.1066), followed by Alliaceae (FUV = 0.1015). Liver congestion had the highest informant consensus factor (ICF = 0.83), followed by hepatic colic (ICF = 0.80). Bibliometric analysis revealed that 61% of the plants identified had documented pharmacological effects related to liver health. The study demonstrates that traditional knowledge in northeastern Morocco encompasses a rich diversity of medicinal plants used to treat liver diseases. The high ICF values indicate a strong consensus among informants on the efficacy of these remedies. The correlation between ethnopharmacological use and scientific validation for a significant portion of these plants suggests their potential as reliable therapeutic agents for liver conditions. However, further scientific investigations are necessary to confirm their efficacy and safety in clinical settings. This research contributes valuable information for future studies on the therapeutic potential of these plants. This ethnobotanical survey provides a comprehensive database of medicinal plants used in northeastern Morocco for liver diseases. The findings highlight the potential of these plants in developing novel treatments for hepatic conditions, although further research is essential to substantiate their therapeutic claims.

Contribution of homegardens in the conservation of local plant diversity in a Brazilian quilombo

Contribution of homegardens in the conservation of local plant diversity in a Brazilian quilombo

Soil seedbanks are shaped by the timing of fires in a Mediterranean‐type ecosystem

Abstract Many plants rely on soil seedbanks to persist in fire‐prone ecosystems. However, knowledge of plant responses to fire is largely based on above‐ground dynamics. Quantifying how fire influences the seedbank of a diverse range of species will improve fire management. Here, we aim to understand how the timing of fires influences species occurrence in the soil seedbank, and how this relates to species traits, in a Mediterranean‐type ecosystem. We sampled the soil seedbank across 57 sites that represent a range of fire frequencies (1–9 fires in 81 years) and time since fire (1–81 years). Through a 15‐month germination experiment, we identified 39,701 germinates from 245 plant species. Using nonlinear models, we quantified the responses of 75 species' soil seedbanks to fire history and compared these to above‐ground responses. Fire influenced species' soil seedbanks according to seed longevity and species' life‐history traits. We observed a response of 15 species' seedbanks to time since fire: All were species with long‐lived seed, including eight annuals, five resprouters and an obligate seeder. Similarly, we observed a response of 17 species' seedbanks to fire frequency, 16 of which had long‐lived seed. Extensive periods without fire (>40 years) increase seedbank availability for annuals that form a long‐lived seedbank, and frequent fire (every ≤15 years) depletes it. We did not detect a consistent influence of fire on species from several other functional types. Many (53%) species found in the soil seedbank were not found in the above‐ground vegetation, and seven of the 22 modelled displayed an above‐ground influence of fire. Synthesis and applications: Fire frequency influences the probability of species occurrence in the soil seedbank. Frequent fire depletes seed availability of species that depend on long‐lived soil seedbanks for persistence. Yet, other species, including perennials with short‐lived seed storage, appear to be resilient to the frequency of fires experienced to date. We suggest fire management should aim to generate variation in fire frequencies within the landscape, including areas of low fire frequency, tailored to maintain rich plant diversity within the soil seedbank.

Effects of Grazing on Plant Diversity and Their Carbon Stocks in Different Types of Grasslands

With the drying and warming of the climate and irrational grazing, various types of grasslands in Inner Mongolia have been degraded to different degrees, and different management modes will inevitably affect the plant diversity and vegetation carbon stock of soil grasslands. To clarify the changes and influencing factors of plant diversity and carbon stock in different types of grasslands under different management modes, plant species composition, aboveground biomass, and vegetation carbon were analyzed based on 18 sentinel monitoring stations across three different types of grasslands in Inner Mongolia. The results showed that grazing increased the dominance of typical grassland and desert grassland, whereas meadow grassland decreased, and the evenness index and Shannon Wiener diversity index increased less in meadow grassland and desert grassland. Grazing decreased graminaceous biomass in meadow grassland and typical grassland, whereas it increased in desert grassland. Above-ground vegetation and below-ground root carbon stocks were much higher than those in grazing areas, 1.5 and 1.2 higher, respectively, but vegetation carbon stocks in long-term grazing sites were significantly lower than those in short-term grazing. Further, the structural equations showed that the effects of geographic location, climatic factors, and soil factors on the biomass and vegetation carbon stocks of the three grassland types differed significantly. The results can provide a reference for the ecologically sustainable development of grassland and the optimization of management mode.

Reassessing the Early Devonian flora from Consthum Quarry (Luxembourg)

The Early Devonian plant fossil record provides evidence of large vegetation turnover events in addition to rapid morphological and anatomical changes among vascular plants. The Ardenno-Rhenish Massif has historically yielded a vast number of these plant fossils allowing us to obtain a nearly unparalleled snapshot of Early Devonian vegetation. Nonetheless, the interest for describing or redescribing fossil floras from this region has waned in recent years despite their inherent value to understand Early Devonian plant diversity dynamics. Here, we describe a newly collected macrofossil flora from the middle Emsian Schuttbourg Formation at Consthum Quarry (Luxembourg). Six different plant macrofossil taxa were identified, including Drepanophycus spinaeformis and Psilophyton cf. princeps, in addition to putative macroalgal and fungal remains. The flora also includes other equivocal specimens resembling Sawdonia, Huvenia and Zosterophyllum. The composition of the assemblage is extremely similar, at generic level, to older Pragian–early Emsian and coeval floras from nearby localities, which indicates that there was no major floral turnover until the latter part of the Emsian in this region. Taxonomic descriptions also highlight many of the underlying issues in identifying Early Devonian sterile specimens. Inconsistencies in plant fossil identifications from this region call for a thorough revision of Belgian and German floras that together could provide a high-resolution picture of plant diversity changes in the Early Devonian.

Perennial species diversity, ecosystem carbon stocks and carbon income in coffee-based agroforestry systems along an elevation gradient in South-eastern Ethiopia

In the current context of deforestation, coffee-based agroforestry system (CAFS) is credited for climate change (CC) mitigation and biodiversity conservation while supporting local livelihoods. Despite integrating shade tree species in CAFS, empirical studies to support this assertion are inadequate in Eastern Africa, and hence, its ecosystem services provisions are less understood. We evaluated perennial species diversity, carbon (C) stocks in the biomass and soil organic C (SOC) along an elevation gradient of 72 plots of shade coffee, while 36 plots were selected for without-shade coffee systems within three elevations, namely, low (1600–1750 masl), mid (1750–1850 masl) and high (1850–2000 masl) elevations in Southeastern Ethiopia. The perennial species diversity and biomass, SOC, fine root and litter C stocks were evaluated. Perennial species Shannon diversity significantly differed among the studied elevations (p < 0.001). Shaded coffee had significantly higher ecosystem C stocks than without shaded coffee systems (p < 0.05). The highest C stocks were found in the soil in both coffee systems. However, we found a weak relationship between the Shannon diversity and biomass C. The C income in shaded coffee was 70 % higher than without shaded coffee systems. The present study showed that shaded coffee accumulates more C and provides additional benefits from C credits. Hence, CAFS deliver ecosystem services that enhance biodiversity conservation and CC mitigation while generating an additional C income for farmers. However, we learned that the impact of perennial plant diversity on C stock and C income is context and site-specific.

Rapid Assessment of Riparian Vegetation at Calyawan River, Barangay Andap, Municipality of New Bataan, Davao de Oro Province, Philippines

Aims: The aim of this study was to examine the vegetation found along the riverbanks of the Calyawan River in Barangay Andap, Municipality of New Bataan, Province of Davao de Oro, Philippines using the transect walk method. The goals were to determine the variety and abundance of the flora along the riverbank, evaluate the conservation status of the discovered plant species, and suggest measures for safeguarding and preserving the riparian environment. Study Design: The study employed a transect walk method to carry out an initial survey of the riparian vegetation. A 1-kilometer transect was conducted along the riverbanks of the Calyawan River to gather qualitative and quantiatative measurements of plant diversity. The evaluation took place on December 20, 2022. This approach facilitated a quick and systematic examination of the vegetation along the riverbanks. Place and Duration: The study was carried out on the riverbanks of the Calyawan River in Barangay Andap, Municipality of New Bataan, Province of Davao de Oro. The fieldwork was conducted on December 20, 2022. The region can be reached by using the Compostela-Montevista-Mati Boundary Road. Methodology: The transect walk approach was employed to record the riparian flora during the survey. Plant species were identified and photographed, but no tangible plant specimens were collected. The obtained data encompassed the identification of fern and angiosperm taxa and families encountered along the transect. The conservation status assessments were conducted using the pre-existing classifications of the species. Results: A rapid assessment revealed the presence of 49 distinct genera of ferns and angiosperm plants belonging to 30 different families along the transect. Out of these, 74% of the riparian plant genera that were identified were found to be endemic to the region. The assessment of the riparian plants' conservation status indicated that 37% were classed as vulnerable, 30% as least concern, 22% as other threatened species, 10% as endangered, and 1% were not categorized. Although the sample time was short, these findings emphasize the abundance and importance of the riparian flora in terms of conservation. Conclusion: The initial study conducted along the riverbanks of Calyawan River indicated a notable variety of plants that grow along the river, with a large number of species that are unique to that area. Many identified plants have a conservation status that emphasizes the necessity for heightened sampling efforts and monitoring in order to gain a more comprehensive understanding of and safeguard this rich ecosystem. Considering the clear human-induced stresses on the forest fragments in the region, it is advisable to enhance and broaden conservation efforts in order to protect the riparian vegetation and guarantee its ongoing existence.

From Stand to Forest: Woody Plant Recruitment in an Andean Restoration Project.

The growing deforestation of tropical forests requires the implementation of restoration actions capable of assisting the recovery of biodiversity and the functioning of these ecosystems. This research aimed to identify the environmental factors that influence the abundance and diversity of woody plant recruitment in an Andean forest restoration project in Medellin (Colombia). Data from woody plant individuals taller than 80 cm were collected in 22 plots of 200·m-2. The environmental factors selected were edaphic variables, plantation structure, slope, elevation, prior land use, and landscape forest cover. Generalized linear models (GLM) were used to analyze recruitment densit and Linear Mixed Models (LMM) to assess recruited species richness, diversity, and dominance. Woody plant recruitment attributes in our study area were similar to those of secondary succession in an Andean forest, but planted trees contributed little to recruitment density and diversity. While recruitment density was affected by slope, canopy closure, and landscape forest cover, recruitment diversity was influenced by physical (bulk density) and chemical (pH, aluminum, Cation Exchange Capacity) edaphic factors, planted tree diversity (species richness and composition), canopy closure, and the mortality rate of planted trees. We conclude that sites with lower mortality rates of planted trees and denser canopies enhance both recruitment density and diversity, indicating a synergy between active restoration and passive regeneration processes.

Livestock grazing modes induced the rapid differentiation of community recruitment in alpine meadow

Herbivores moderate grazing is a fundamental driver of plant diversity maintenance in grassland ecosystems. However, the effects of grazing with different herbivores on plant community composition and recruitment are still little known. Here, we conducted a field moderate grazing experiment to examine the effects of different grazing modes under moderate intensity in the cold season, including sheep grazing (SG), yak grazing (YG), and mixed grazing by sheep and yak (MG), on plant community composition and recruitment. Results showed that all grazing modes significantly decreased plant cover and average height of standing plant litter. Additionally, herbivores grazing significantly increased species richness but decreased community evenness (P < 0.05), with highest richness and evenness found in YG and SG plots, respectively. The trends of increasing aboveground biomass of common and rare species groups were most pronounced in the SG plots relative to the YG and MG plots. MG promoted the increasing of the common species group. From community recruitment, moderate grazing increased the sexual recruitment and decreased the asexual recruitment, and MG significantly inhibited the recruitment of asexual seedlings. Meanwhile, all grazing modes increased the species of poor palatability. These findings imply that the cold-season grazing with moderate intensity facilitated a rapid divergence succession of alpine meadow community by regulating the relative abundance of common and rare species, as well as the asexual seedlings recruitment induced by the removal of standing plant litter. Consequently, the cold-season grazing with different herbivores under moderate intensity can be used as a management tool to modulate grassland community structure and maintain species diversity in alpine grassland ecosystem.

Serjania piscatoria (Paullinieae, Sapindaceae) as a symbol of vascular variants polymorphism

Abstract Serjania is the only genus of the Paullinieae tribe that exhibits all patterns of vascular variants and includes S. piscatoria which shows a complex vascular structure that has intrigued botanists for centuries. Here, we analysed the stem development of S. piscatoria in an evolutionary context. We studied four individuals using standardized anatomical techniques and employed DNA sequencing to determine the species’ phylogenetic position. Additionally, we explored the evolution of stem developmental diversity using stochastic character mapping of the categories and patterns of vascular variants. We find that disparate ontogenetic processes determine the stem development in S. piscatoria, which results in vascular variants derived from procambial variants, cambial variants, and ectopic cambia. This diversity underscores the developmental lability of vascular meristems, making the species' vascular system structurally diverse and polymorphic. The complex vascular system observed in S. piscatoria evolved within a lineage composed of species with compound stems. These findings provide evidence for the intricate and labile evolutionary history of stem vasculature in Serjania, and the value of studying vascular variants to unravel the patterns and processes shaping plant diversity.

Phenological growth stages of Amaranthus palmeri according to the extended BBCH scale

AbstractAmaranthus palmeri S. Watson is a problematic weed that has been encountered almost all over the world because of its stronger adaptability, which causes huge economic losses and local plant diversity decline. As an invasive plant, A. palmeri has been found throughout China. We thus make a code system to describe the phenological growth process of A. palmeri according to the extended BBCH scale to better understand the phenological growth of this weed in China. The growth process of A. palmeri was divided into vegetative growth phases and reproductive growth phases. The vegetative growth phases are composed of seed germination (0), leaf development (1), formation of side shoots (2) and main stem elongation (3). Likewise, the reproductive growth phases include inflorescence emergence (5), blooming (6), fruit development (7), seed maturity (8) and senescence (9). Based on the extended BBCH scale, the first digit stands for the primary growth stages, and the third digit represents the secondary growth stages. In particular, the second digit defines the growth progress: the number 0, means the vegetative growth phases, and the number 1 stands for the reproductive growth phases. Owing to the fact that its seed can germinate multiple times within a year, a general illustration of the phenological development stages of A. palmeri germinating in different months was provided here to describe the growth dynamic characteristic at different times. These data are of great significance to develop effective strategies for weed control and management of A. palmeri.

Change in functional trait diversity mediates the effects of nutrient addition on grassland stability

Abstract Nutrient enrichment impacts grassland plant diversity such as species richness, functional trait composition and diversity, but whether and how these changes affect ecosystem stability in the face of increasing climate extremes remains largely unknown. We quantified the direct and diversity‐mediated effects of nutrient addition (by nitrogen, phosphorus, and potassium) on the stability of above‐ground biomass production in 10 long‐term grassland experimental sites. We measured five facets of stability as the temporal invariability, resistance during and recovery after extreme dry and wet growing seasons. Leaf traits (leaf carbon, nitrogen, phosphorus, potassium, and specific leaf area) were measured under ambient and nutrient addition conditions in the field and were used to construct the leaf economic spectrum (LES). We calculated functional trait composition and diversity of LES and of single leaf traits. We quantified the contribution of intraspecific trait shifts and species replacement to change in functional trait composition as responses to nutrient addition and its implications for ecosystem stability. Nutrient addition decreased functional trait diversity and drove grassland communities to the faster end of the LES primarily through intraspecific trait shifts, suggesting that intraspecific trait shifts should be included for accurately predicting ecosystem stability. Moreover, the change in functional trait diversity of the LES in turn influenced different facets of stability. That said, these diversity‐mediated effects were overall weak and/or overwhelmed by the direct effects of nutrient addition on stability. As a result, nutrient addition did not strongly impact any of the stability facets. These results were generally consistent using individual leaf traits but the dominant pathways differed. Importantly, major influencing pathways differed using average trait values extracted from global trait databases (e.g. TRY). Synthesis. Investigating changes in multiple facets of plant diversity and their impacts on multidimensional stability under global changes such as nutrient enrichment can improve our understanding of the processes and mechanisms maintaining ecosystem stability.

Plant cultivation and diversity at the Early Neolithic settlement in Biskupice in Poland

The emergence of the Linear Pottery Culture (LBK) during the Neolithic period within Polish territory 5400–4900 BC, introduced plant cultivation, yet the definitive list of cultivated species remains debated. This study examines plant assemblages (fruits, seeds, pollen, and spores) from the LBK settlement in Biskupice, southern Poland, aiming to identify cultivated and wild species used during the development of the first stable settlements in the Carpathian Foothills. Due to extensive sampling, Biskupice yielded over 11,000 macroscopic plant specimens, enabling detailed analysis of plant diversity, distribution, and implications for agrarian and dietary practices. The analysis revealed a focus on emmer and einkorn wheat cultivation, with barley playing a minor role, alongside evidence of flax and pulses. Radiocarbon dating supported the settlement’s existence in the 6th millennium BCE, and confirmed the use of barley. However, a younger date excluded bread wheat cultivation at this site. The plant assemblage included a diverse array of herbaceous wild plants like black bindweed, fat hen and brome species, suggesting their economic use. Additionally, the presence of cockspur grass, linked with Southeast Asia, indicates alternative migration routes of weeds in Europe, as supported by radiocarbon dating. Palynological analysis suggests existence of nearby cereal plots or the processing of cereals at the settlement, supporting archaeological evidence.

“We are the same, we are equal”: Plant diversity knowledge in Indonesian elementary special school textbooks

“We are the same, we are equal”: Plant diversity knowledge in Indonesian elementary special school textbooks

Resistance of plant diversity to road disturbance: Evidence from the Tibetan Plateau

The expansion of road networks in recent decades has drawn considerable attention due to its impact on biodiversity in high-altitude ecosystems. Here, we conducted a comprehensive field survey to investigate the effects of road disturbance on plant diversity in alpine grasslands on the Tibetan Plateau. Our results indicate that road disturbance caused no significant changes in species richness, Shannon–Wiener’s diversity, or Simpson’s diversity, and the alteration in species composition was limited. These findings demonstrate the robust resistance of alpine grassland plant diversity to road disturbance. Plant diversity exhibited more resistance to road disturbance in regions with more hostile environments, such as plateau sub-frigid regions and alpine steppes. Our study suggests that road construction in the Tibetan Plateau poses limited risk to plant biodiversity.

Subtle changes in plant diversity in the Bavarian Alps over the past eight decades.

Historical resurveys represent a unique opportunity to analyze vegetation dynamics over longer timescales than is typically achievable. Leveraging the oldest historical dataset of vegetation change in the Bavarian Alps, Germany, we address how environmental conditions, vegetation composition, and functional diversity in the calcareous grasslands of the Schachen region have changed across different elevational ranges over an 83-year timeframe. We document changes in regional average temperature and precipitation. We use indicator values (IV) for species' ecological preferences and their palatability to grazers to infer local conditions (temperature, soil moisture/fertility, and grazing regime). We further estimate changes in temporal beta-diversity and functional trait community composition between historical (1936) and contemporary (2019) surveys in two elevational (subalpine and alpine) belts. Both subalpine and alpine sites became drier; subalpine sites also became warmer with more palatable plants. Species occurrence and abundance in the Schachen region has not changed substantially over time despite changing macroclimate and local environmental conditions under anthropogenic change. Yet these grasslands have experienced several "invisible" changes in functional composition over the past 80 years. As the Schachen has become drier, species with traits related to drought tolerance and animal-based dispersal have increased in dominance. Specifically, in alpine sites, community-weighted means revealed that with low fecundity, higher potential for endo- and epizoochory (seed dispersal via animal gut and fur, respectively), higher foliar frost tolerance, and deeper dormancy increased in dominance. Similar trends were found for increasing dominance of low fecundity, epizoochorous species in subalpine sites. Vegetation data from resurveying historical plots in combination with changes in local conditions, classic biodiversity indices, and functional trait indices can provide more holistic insights into changes in the environment and potential impacts of those environmental changes on long-term plant community and functional diversity.

Distribution, species richness, and relative importance of different plant life forms across drylands in China

Studies on plant diversity are usually based on the total number of species in a community. However, few studies have examined species richness (SR) of different plant life forms in a community along large-scale environmental gradients. Particularly, the relative importance (RIV) of different plant life forms in a community and how they vary with environmental variables are still unclear. To fill these gaps, we determined plant diversity of ephemeral plants, annual herbs, perennial herbs, and woody plants from 187 sites across drylands in China. The SR patterns of herbaceous plants, especially perennial herbs, and their RIV in plant communities increased with increasing precipitation and soil nutrient content; however, the RIV of annual herbs was not altered along these gradients. The SR and RIV of ephemeral plants were affected mainly by precipitation seasonality. The SR of woody plants had a unimodal relationship with air temperature and exhibited the highest RIV and SR percentage in plant communities under the harshest environments. An obvious shift emerged in plant community composition, SR and their critical impact factors at 238.5 mm of mean annual precipitation (MAP). In mesic regions (> 238.5 mm), herbs were the dominant species, and the SR displayed a relatively slow decreasing rate with increasing aridity, which was mediated mainly by MAP and soil nutrients. In arid regions (< 238.5 mm), woody plants were the dominant species, and the SR displayed a relatively fast decreasing rate with increasing aridity, which was mediated mainly by climate variables, especially precipitation. Our findings highlight the importance of comparative life form studies in community structure and biodiversity, as their responses to gradients differed substantially on a large scale.

Thriving green havens in baking deserts: Plant diversity and species composition of urban plantations in the Sahara Desert

Thriving green havens in baking deserts: Plant diversity and species composition of urban plantations in the Sahara Desert

Species Diversity And Pollination Ecology Of Bagale Hills Forest Reserve, Girei Local Government Area, Adamawa State - Nigeria

Background: This study assessed the pollination ecology and diversity of the Bagale Hills Forest Reserve (BHFR) in Adamawa State. The aim of the study was to understand if biodiversity conservation of the reserve, as planned by the government, is achieved. The objectives were to: assess angiosperm diversity; determine pollinator diversity; evaluate the interaction between angiosperms-pollinators and assess the period of flowering of angiosperms in the transects of the study area. Materials and Methods: The study adopted the systematic line transect procedure in laying out transects. Four transects of 1 km were laid and four sampled plots of 50 m x 50 m size was alternately laid along each of the transect. Three angiosperms were selected at random for data collection on phenology and the diversity of both plants and its associated pollinators. The studied reserve was traversed on foot for three months and the appearance of flower buds and the presence of pollinators on targeted tree species was observed. Data were analyzed and presented using the Descriptive statistics and the Shannon-Wiener diversity index was used for the determination of biodiversity. Results: The result of the Shannon-Wiener Diversity Index indicated pollinator species diversity of 2.686 and angiosperms diversity index of 2.761591 that indicated a very high biodiversity for both the pollinators and its associated plant species in the study area. The phenology result indicated that the pollinators observed were invertebrates that were not evenly distributed and that only about 3.25 % of the tree species were flowering during the wet season. It was also observed that all sampled tree species were generalist in nature. Conclusion: It was concluded that conservation education must be prioritized for the communities surrounding the study area.

Native Plant Diversity Generates Microbial Legacies That Either Promote or Suppress Non-Natives, Depending on Drought History.

Diverse native plant communities resist non-native plants more than species-poor communities, in part through resource competition. The role of soil biota in diversity-invasibility relationships is poorly understood, although non-native plants interact with soil biota during invasions. We tested the responses of non-native plants to soil biota generated by different native plant diversities. We applied well-watered and drought treatments in both conditioning and response phases to explore the effects of 'historical' and 'contemporary' environmental stresses. When generated in well-watered soils, the microbial legacies from higher native diversity inhibited non-native growth in well-watered conditions. In contrast, when generated in drought-treated soils, the microbial legacies from higher native diversity facilitated non-native growth in well-watered conditions. Contemporary drought eliminated microbial legacy effects on non-native growth. We provide a new understanding of mechanisms behind diversity-invasibility relationships and demonstrate that temporal variation in environmental stress shapes relationships among native plant diversity, soil biota and non-native plants.