Plant and bacterial diversity co-regulate ecosystem multifunctionality in subtropical grasslands of southwestern China.

The distribution of global biomes has changed during Earth history in response to changes in the climate conditions. We aimed to study how climate change during the Quaternary, a period characterized by periodic transitions between glacials and interglacials and a cooling trend, influenced the expansion of biomes and biome stability. We further studied the hypothesis that biome stability can explain current patterns of plant species richness. We used machine learning and correlative models, current bioclimatic conditions, and an observation-based biome map to model the current global biome distribution. Then, we drove the model with bioclimatic conditions for the last 2.6 million years at a 1000 year temporal resolution to obtain global climate-driven biome suitability maps for this period. Our results indicate that during the study period, biomes were stable in large parts of tropical forests, deserts, boreal and temperate forests, while northern Europe, northern and central America were core areas of biome change. Biome shifts in the far North were caused by regular transitions between boreal vegetation and ice. We analyzed the relation between biome stability and current plant species richness. In tropical rainforests, species richness was positively related to biome stability, but globally the overlap between stable biomes and centers of high species richness was weak. Our modeling framework provides important insights into the stability of biomes during the Quaternary. We suggest that biome stability cannot fully explain species richness, indicating that other factors such as fire or spatial heterogeneity are important. Even though our approach is based on climate only, it is appropriate for further studies due to its general applicability to and spatial and temporal resolution and high computational performance.

Drivers of ecosystem multifunctionality in temperate forests: Carbon-biodiversity coupling in natural forests versus soil-structural control in plantations.

Enhanced rock weathering in grassland: Impacts of basalt dust on hay meadow soil, forage, and floristic diversity.

Urbanization shapes ecological networks and energy flows in depth-stratified wetland soil micro-food web

Soil organic carbon (SOC) plays an essential role in carbon sequestration and climate change mitigation in forest ecosystems. While experimental studies have shown that plant diversity usually increases SOC, it remains unclear whether this positive relationship holds in natural ecosystems across varying climatic conditions. Using a global dataset of 15 large and long-term monitored natural forest sites spanning a wide latitudinal range, we assess the relationship between tree diversity and SOC within and across sites in temperate, subtropical, and tropical regions. We found an overall positive relationship between tree taxonomic diversity and SOC. The relationships between tree taxonomic or functional diversity and SOC became stronger under colder and more arid conditions. Additionally, tree functional composition was linked to SOC only within a subset of sites in more arid climates. These findings suggest that warmer and more humid conditions increase decomposition, offsetting diversity-driven carbon inputs, while colder and more arid conditions enhance SOC through low decomposition and increased inputs through abiotic facilitation and biotic interactions in high-diversity communities. Our findings indicate that conserving plant diversity is critical for enhancing carbon sequestration and mitigating the effects of climatic conditions, particularly in cold climates and regions facing an increase in arid conditions.

Factors influencing spontaneous plant diversity and insect herbivory on extensive green roofs

The Hawaiian Islands are among the most geologically and volcanically active places on Earth. While the Hawaiian Archipelago is known for its animal and plant diversity, much less is known about microbial diversity in the area's diverse habitats. In this study, we focused on steam vent associated biofilms found on the most volcanically active island of Hawai'i, also known as the Big Island. From 46 samples from various biofilms and associated features around fumaroles emitting water steam, we generated amplicon and metagenomic sequences. This represents a total of 276 Gbp of raw sequencing data. From the shotgun metagenomic data, we constructed 363 non-redundant medium- to high-quality metagenome-assembled genomes (MAGs) that are at least 70% complete and with less than 5% contamination. Of these, ten MAGs belong in the domain Archaea, and 353 belong in the domain Bacteria. This dataset could provide valuable insights into microbial diversity and ecology around volcanic features in Hawai'i and elsewhere.

Asymmetric cell division underpins cellular diversity in multicellular plants. These divisions are mechanosensitive, and preprophase band (PPB) formation hinges on cell-wall mechanical properties in plant cells. Yet, the spatial control mechanism governing this process in plants remains elusive. During grass stomatal development, mechanical cues originate from differential growth rates and cell wall modifications at the interface of guard mother cell/subsidiary mother cell (SMC). In this work, we have identified a maize receptor-like protein, KAI1, that functions as a master regulator of subsidiary cell formation within the stomatal complex. KAI1 governs division-plane orientation in SMCs through mechanochemical signaling: It perceives cell wall rigidity via pectin interaction, and subsequently recruits tubulin for PPB positioning, thereby directing division-plane specification. This work uncovers a plant-unique mechanosensitive protein that mediates extracellular matrix cues to cytoskeletal reorganization during asymmetric division for cell diversity. Our findings establish that KAI1 governs a cell wall mechanics-dependent PPB positioning to control the exact division plane alignment of the SMC. This mechanism subsequently mediates the regulation of SMC polarization and subsidiary cell morphogenesis during stomatal development.

Consumptive interactions across trophic levels underpin ecosystem stability. Although theoretical and experimental studies have examined the diversity-stability relationship, empirical evidence linking trophic interactions to ecosystem stability remains limited. Here we evaluate how trophic interactions relate to stability across 430 plant-herbivorous insect networks from temperate and tropical ecosystems. We quantified interaction indicators alongside ecosystem resistance and resilience under drought and wet events. Higher plant diversity was associated with drought resistance but with reduced resilience, and these relationships weakened after accounting for sampling and environmental covariates. In contrast, drought resistance increased with network modularity, whereas resilience decreased with robustness, although these patterns were absent in temperate forests. Diversity and interaction indicators did not predict stability under wet events. Although both directions of trophic interaction-stability relationships were significant, the pathway from trophic interactions to stability (top-down) was stronger than the reverse. Our findings provide large-scale empirical evidence that top-down effects probably dominate the relationship between plant-herbivorous insect interactions and ecosystem stability under climate change.

Invasive alien plants can indirectly suppress native plants by altering soil biota and nutrient cycling through their litter input. The diversity of litter resulting from co-invasion by multiple species may further modulate these impacts. Fluctuating resources are known to favour many invasive plants; however, it is unclear how nutrient fluctuations alter the effects of litter diversity of invasive plants on native communities. Therefore, we grew a native plant community in a control soil without litter, as well as in soils mixed with litter from one, two, three, and six invasive species under constant or pulsed nutrient supply. Invasive species litter altered soil microbial communities, and increased soil total nitrogen concentration and native community biomass. Under pulsed nutrient supply, native community biomass and soil total phosphorus concentration decreased with increasing litter diversity of the invasive species. However, these effects did not occur under constant nutrient supply. A structural equation model indicated that soil phosphorus and fungal community composition were key mediating factors driving the decrease in native community biomass with increasing litter diversity under pulsed nutrient supply. Our findings underscore that the impact of alien invaders on native communities depends on the diversity of the alien plant litter and nutrient fluctuations.

Insect self-medication: exploring nature's pharmacy and its role in insect well-being.

Vertebrate consumers are known to influence plant recruitment and community assembly based on the species they prefer to eat. The enemy release hypothesis (ERH) predicts that invasive introduced plant species may avoid consumption due to a lack of coevolved predators. Herbivores and granivores may also prefer species due to their functional traits, irrespective of species origin. We hypothesized that in a highly invaded plant community, invasive plants would benefit from enemy release and animal consumers would likely decrease plant diversity if they avoided invasive species in favor of native species (Hypothesis 1). Animals were expected to filter the species pool based on preference for palatable functional traits (Hypothesis 2). A factorial experiment combining cage and native seed addition treatments was established in the Voorhis Ecological Reserve, a California sage scrub ecosystem in Southern California. Seed and seedling preference trials were conducted to gather additional evidence of consumer preference at the study site. Although we found little influence of plant functional traits on consumer selection of species, animals created more functionally similar communities. In preference trials, native rodents and birds were found to prefer native plant species and avoid dominant invasive species, and the effects of animal preference were observed in experimental plant communities. Small vertebrates encouraged the success of invasive plants while limiting recruitment of native species, consistent with the ERH. Thus, birds and small mammals may function as an important filter in sage scrub habitat by reducing community diversity and promoting the dominance of competitively superior invasive plant species.

Home gardens (HG), public gardens (PG), road islands (RI), and vacant lots (VL) were the most common urban habitats in Kharga and Dakhla Oases that were analyzed in terms of species distribution patterns. In total, 39 geo-referenced sampling stands were surveyed and were distributed as follows among these habitats: 16 in home gardens (HG), 11 in public gardens (PG), 8 in road islands (RI), and 4 in vacant lots (VL). The total number of recorded species showed variation among habitats: 132 species in HG, followed by PG (112 species), RI (71 species), and VL (58 species). The vegetation structure of the home gardens was characterized by orchard trees, cultivated herbs and xerophytes, while that of public gardens was dominated by ornamentals and wetland plants. On the contrast, the road islands and vacant lots were largely composed of weeds and xerophytes. Eleven variables, including coarse sand (CS), fine sand (FS), clay, moisture content, electrical conductivity, soil reaction, organic matter, carbonates, sodium, sulphates, and phosphates, were used in the CCA analysis after soil variables with high inflation factors were eliminated. After applying cluster analysis to presence /absence dataset of 112 species × 39 sampling stands, 14 vegetation cluster groups were recognized, each was dominated by one or a number of species. Soil characteristics showed significant correlations with the separated cluster groups. The Shannon–Wiener index ranged from 1.93 to 3.27, and species richness ranged from 8 to 27.33 species per stand, with clear separation among vegetation groups along the DCA axes, indicating ecologically meaningful differences even without formal significance testing. Clearly, weeds and ruderal species were most abundant in disturbed habitats impacted by the effects of disturbances and the species invasion in urban habitats. Our results confirmed that managed habitats can act as biodiversity refuges in arid urban ecosystems, while disturbed sites require restoration to limit invasive spread and enhance native plant diversity.

Life cycle impact assessment (LCIA) translates emissions and resource use into a set of environmental impact indicators, forming a key component of life cycle assessments. Current LCIA methods quantify biodiversity loss per pressure-impact pathway separately and at various spatial scales. We developed a new, spatially explicit and scale-consistent LCIA framework and applied it to derive characterization factors (CFs) for the impacts of land use, nitrogen emissions, and greenhouse gas (GHG) emissions on global terrestrial plant diversity. The framework combines the local potentially disappeared fraction of species (LPDF) due to the selected pressures with a multipressure species-area relationship (mp-SAR) model and with information on species endemism to estimate the global PDF (GPDF). For GHG emissions, we provide CFs for 250 GHGs and 20- and 100 year time horizons. Ecoregion-specific CFs of 6 land use types varied by 7 orders of magnitude, while emitting-region-specific CFs of ammonia and nitrogen oxides varied by 2 orders of magnitude. For land use, CF variability was driven almost entirely (>99%) by ecoregion. For nitrogen emissions, emitting region and compound each explained about one-third of the variability. Overall, our LCIA framework allows for consistent scaling of local species loss to global extinction while considering multiple impacts categories.

ABSTRACTGlobal climate change exerts a far‐reaching influence on the geographical distribution, phenological patterns, and genetic diversity of plants, presenting a grave challenge to the survival and evolution of species. Owing to its robust ecological adaptability, restricted dispersal capacity, and abundant intraspecific variation, Cornus kousa subsp. chinensis has emerged as an ideal subject for investigating the responses of woody plants to climate change. Consequently, this study employed the landscape genomics approach to evaluate the survival risks faced by C. kousa under the present and future (2060–2080) climate scenarios (RCP45 and RCP85). A total of 348 leaf samples were gathered from 25 populations of C. kousa spanning diverse regions of China. The research revealed that, under the prevailing climate conditions, the genetic diversity within the populations is remarkably abundant. Nevertheless, the POPs model forecasts that the genetic structure will undergo substantial alterations in future climate scenarios. Notably, 93.6% of the populations will be grouped into a solitary common cluster, and the genetic variation will be conspicuously homogenized. Through BayeScan and Latent Factor Mixed Model (LFMM) analyses, 67 Single Nucleotide Polymorphism (SNP) loci significantly associated with climate factors were identified. Among these loci, 90.3% are closely correlated with the annual mean temperature (Bio 1), suggesting that temperature serves as the primary driving force for adaptive selection at the genomic level. In summary, our findings not only offer valuable perspectives for the conservation of the genetic resources of the C. kousa population but also provide significant reference value for the formulation of subtropical forest conservation strategies.

Desert plant assemblages in southern California provide an opportunity to link patterns of community structure with climate-driven vulnerability in a rapidly changing environment. California sustains an exceptionally diverse flora of approximately 4300 plant species, with 31% identified as endemic. However, desert ecosystems remain comparatively understudied, and additional work is needed to better understand how plant communities may respond to ongoing climate change. We compiled a large occurrence-only data set (~214,000 records) representing 1352 angiosperm species across the Coachella Valley, a heterogeneous region encompassing four desert ecoregions. Using spatial analyses, joint species distribution models, and ecological niche modeling, we evaluated patterns of community structure and projected changes in climatic suitability for representative species under future climate scenarios. Plant diversity hotspots were strongly associated with steep elevational gradients, whereas cold spots were concentrated in lowland and environmentally extreme areas. Representative species exhibited strong co-occurrence patterns, capturing associations with 88% of annual species and 95% of perennial species. Invasive species occurrences were most frequent in highly populated areas across the study region. Future projections indicated substantial declines in suitable habitat for 90% of representative species, with many species predicted to shift northward within the Coachella Valley. Declines in representative species under future climate scenarios are likely to be accompanied by concurrent reductions in many co-occurring taxa. These findings provide a community-level perspective on climate vulnerability in desert plant assemblages and highlight the value of integrating community structure and species distribution models to assess ecological responses to climate change.

Genetic diversity is the foundation of organisms' ability to adapt and survive in changing environments and represents an important element in preserving biodiversity. This research examines genetic diversity in desert plants, focusing on the genetic and environmental factors that influence it. The most important sources of genetic diversity, such as genetic mutations, genetic recombination, and genetic drift, are discussed, as well as their role in the evolution of species and their adaptation to harsh conditions. The characteristics of the Iraqi desert are highlighted as an environment characterized by high temperatures and scarce rainfall, leading to selective pressures that contribute to the emergence of physiological and morphological adaptations in desert plants, such as reduced transpiration, water storage, and the development of deep roots. The research also addresses the importance of these plants in maintaining ecological balance and the possibility of exploiting them in breeding programs and conserving genetic resources. Molecular markers, particularly the RAPD technique, are used as an effective tool for analyzing genetic diversity and revealing genetic relationships among desert plants. The research results confirm that studying the genetic diversity of plants in arid environments is an essential step toward understanding natural adaptation mechanisms and developing effective strategies for conserving and sustaining desert plant species in the face of rapid environmental and climatic changes.

BackgroundThe Guoshan Yao, a subgroup of the Yao ethnic minority in China, inhabit the biodiverse Nanling Mountain region. Their traditional knowledge (TK) of medicinal plants is increasingly threatened by socio-economic development, generational knowledge loss, and conservation policies. This study documents the medicinal plant diversity, and usage trends, analyzes TK transmission pathways, assesses influencing factors on the medicinal plant use knowledge and compares use knowledge with other Yao groups.MethodsA total of 86 respondents (aged 20–90) from Guoshan Yao households were interviewed in the villages of Nanling National Nature Reserve, Guangdong, China. The Relative Importance (RI) index of the recorded plant species was calculated, negative binomial regression was used to assess factors influencing medicinal plant use knowledge, and the Jaccard index of similarity (JI) was used for the cross cultural analysis.ResultsA total of 61.6% of respondents relied on medicinal plants for primary healthcare; however, 41.8% of respondents reported declining trend in this practice. We documented 224 medicinal plants from 188 genera and 90 families. The most common therapeutic use was for traumatic injuries and orthopedic conditions (71 species, 31.7%). Among the recorded species, Polygala japonica had the highest RI value (2). The negative binomial regression indicated that medicinal plant use knowledge was significantly associated with the source of knowledge transfer, with vertical and multiple sources being significant. Cross-cultural analysis with the Yao of Guangxi and Hunan showed that knowledge of medicinal plants is quite similar among the Yao of Gongcheng Guangxi (JI = 0.18) .ConclusionThe Guoshan Yao maintain substantial TK of medicinal plants, the conservation of which depends on vertical and multiple sources knowledge transmission systems. To conserve this knowledge, we recommend promoting the dissemination of knowledge beyond familial boundaries through community awareness programs, and inter-generational interaction.

PremiseDNA barcoding for timber species identification requires comprehensive reference datasets, informative DNA barcodes, and cost‐effective protocols. We developed a workflow leveraging Hyb‐Seq (target capture sequencing and genome skimming) to address these challenges, and we tested it on four genera from the mahogany family (Meliaceae).MethodsWe sequenced up to 350 nuclear and 177 plastid loci from 132 herbarium specimens representing leaf samples of 22 species. We determined the DNA barcoding potential of each locus by looking at species recovery and monophyly in gene trees. We then selected 13 short regions (candidate barcodes) within high‐potential loci and tested their PCR amplification and Sanger sequencing on wood DNA.ResultsThree candidate barcodes emerged as the most reliably sequenced from wood DNA and as providing the most accurate species‐level identifications, with species monophyly rates above 80%. Failure to obtain sequences from some wood DNA extracts was more often associated with potential DNA impurity (as inferred from DNA color) than with DNA degradation.DiscussionOur reference data and candidate barcodes provide a foundation to support the DNA barcoding of mahogany and its relatives. Our workflow illustrates how the wealth of Hyb‐Seq data currently generated from global herbaria may be leveraged to monitor plant diversity.