Researchers sampled 10 sites for each invasive goldenrod across western, southern and central Slovakia during summer 2021. At each site, they established three permanent plots measuring 2 by 2 metres: an uninvaded control, a transitional plot with 20–50% goldenrod cover, and a heavily invaded plot with more than 50% cover. Populations had been established and self-reproducing for at least five years, and sites containing mixed goldenrod populations were excluded.

The invaded and control plots were placed close together, with similar topographic position and management, and embedded within a larger rectangle. Researchers treated adjacent control plots as an approximation of pre-invasion conditions. Mixed-effects models accounted for sampling locality as a random effect and considered slope, soil depth and clay content. Sample completeness exceeded 90% for the plots associated with each goldenrod species, while a descriptive rarefaction analysis compared richness across increasing numbers of plots.

All three measured diversity metrics—species richness, Hill–Shannon diversity and Hill–Simpson diversity—declined significantly in the herb layer at the heavily invaded level compared with control and transitional plots. The guild-specific analysis showed a different pattern. Forb richness was lowest in heavily invaded plots regardless of which goldenrod dominated, although control and transitional plots did not differ significantly. No significant invasion-level effect was detected for graminoid richness or either diversity index, or for any bryophyte diversity measure.

Model predictions for forb Hill–Shannon and Hill–Simpson diversity moved in opposite directions under the two invaders: the predicted values increased from control to heavily invaded plots at S. canadensis sites and decreased at S. gigantea sites. Pairwise comparisons within each species were not statistically significant, but a contrast-in-contrast analysis indicated that the invasion effect differed between species, with a stronger effect for S. canadensis. Supplementary rarefaction curves also showed declining forb richness with increasing invasion at S. gigantea sites, whereas no corresponding decline was detected for the three guilds at S. canadensis sites.

Permutational multivariate analysis detected an association between invasion level and plant species composition, but its marginal explanatory power was low, at 0.018–0.019. Goldenrod species identity was not significant. The full models explained 24.8% of variation in herb-layer composition, 27.2% among forbs and 20.6% among graminoids. Multivariate dispersion differed among invasion levels for the herb layer and forbs, and ordination showed pronounced overlap among groups. Indicator-species analysis identified no species whose association with an invasion level remained significant after false-discovery-rate correction, so the results did not establish a distinct set of indicator species.

Vegetation structure also changed along the gradient. Cumulative herb-layer cover, including the invasive goldenrods, was highest in heavily invaded plots, while cumulative cover of forbs excluding Solidago and of graminoids declined. Moss-layer cover was lower at heavily invaded levels, although clay content was also a significant covariable. Litter was thicker at S. canadensis sites than at S. gigantea sites. Bare soil cover declined with increasing invasion at S. gigantea sites but showed no significant change at S. canadensis sites.

Soil responses also depended on the invader. In heavily invaded S. gigantea plots, soil pH was lower and nitrogen concentration higher than in controls, with a lower carbon-to-nitrogen ratio. No comparable invasion-level differences in pH or nitrogen were detected at S. canadensis sites; the discussion reports declining nitrogen and a higher carbon-to-nitrogen ratio there. Soil potassium and the carbon-to-nitrogen ratio showed significant species-by-invasion interactions, although within-species pairwise contrasts were not consistently significant. Invasion level affected calcium and magnesium concentrations, but multiplicity-adjusted comparisons did not identify significant differences among levels.

The authors proposed possible mechanisms involving litter accumulation, altered light availability, belowground growth, nutrient cycling and soil stoichiometry, but these mechanisms were not directly tested. The spatial gradient design cannot fully separate invasion effects from environmental heterogeneity, management history or invasion age, and exact residence times were unavailable at some sites. Goldenrod cover therefore served as a proxy for invasion intensity. A single summer sampling period may also have underrepresented seasonal plants whose biomass persists briefly. The findings consequently describe associations in the sampled Slovak grasslands rather than uniform effects across other soils, regions or management regimes.

Subject of Research: Guild-specific effects of Solidago canadensis and S. gigantea invasion on plant diversity and soil properties in Slovak semi-natural grasslands

Article Title: Invasion impact of two goldenrods ( Solidago canadensis and S. gigantea ) on species diversity of plant guilds and soil environment

Article References: Slezák, M., Jarčuška, B., Šingliarová, B., Španiel, S., Hrivnák, R., Májeková, J., Gömöryová, E., Širka, P., Hodálová, I., Mereďa Jr., P., Galvánek, D., Janišová, M., Kochjarová, J., & Skokanová, K. (2026). Invasion impact of two goldenrods (Solidago canadensis and S. gigantea) on species diversity of plant guilds and soil environment. NeoBiota, 107, 105-130. https://doi.org/10.3897/neobiota.107.179300

Image Credits: AI Generated

DOI: 10.3897/neobiota.107.179300

Keywords: Solidago canadensis, Solidago gigantea, plant invasion, semi-natural grasslands, species diversity, forbs, graminoids, soil chemistry, Slovakia, Invasion, impact, goldenrods

The research team deployed a dual-locus DNA metabarcoding approach, amplifying two chloroplast gene regions, trnL(UAA) and rbcL, from faecal DNA collected at Welverdiend, a rural communal rangeland village in the Lowveld Bioregion, and at the Syferkuil Experimental Farm of the University of Limpopo in the Central Bushveld Bioregion. Samples were taken in October, directly before the first rains of the new season, when forage from the grass layer is particularly scarce. Approximately 10 grams of fresh faecal material was collected after defecation from each animal without disturbing them, and DNA was isolated using a plant DNA extraction kit. The two barcodes were then amplified and sequenced on an Illumina MiSeq platform, generating millions of sequences that were filtered, curated and matched against custom, study-area-specific plant DNA reference libraries built specifically for these savanna sites.

The choice of barcodes matters enormously in plant metabarcoding. Unlike animals, which have the near-universal COI barcode, plants possess no single marker that works equally well across all taxa. The rbcL region offers highly universal primers and reliable family-level identification, while trnL yields small DNA fragments suited to the degraded, low-copy-number DNA found in faeces. Neither locus has particularly high species-level discrimination, so the researchers evaluated diets to genus level. Crucially, the two markers proved complementary: trnL exhibited higher diversity in family and genus identification at both sites, uniquely recovering families such as Apocynaceae, Asteraceae and Euphorbiaceae, while rbcL exclusively identified Combretaceae and Annonaceae. Only by combining both loci could the team capture a comprehensive account of the cattle diets.

The results revealed a striking seasonal shift in foraging behaviour. At Welverdiend, where cattle forage on communal rangelands, the trnL marker showed Malvaceae — a family dominated by forbs and non-woody shrubs — as the most frequently ingested plant family, with a frequency of occurrence of 92 percent. Ebenaceae, representing woody taxa such as Euclea, and Poaceae, the grasses, followed closely at 84 percent each. Key forb genera in the Welverdiend diets included Malvastrum, Asparagus and Ipomoea, while woody taxa from Fabaceae, Combretaceae, Ebenaceae and Malvaceae — including genera such as Albizia, Combretum, Euclea and Vachellia — made substantial contributions. Grasses such as Setaria and Eragrostis were present but did not dominate individual diets.

At Syferkuil, where rotational grazing is practised on open thorn bush savanna, a different pattern emerged. Grasses dominated both marker datasets, with Poaceae showing a frequency of occurrence of 96 percent in the trnL dataset and 88 percent in the rbcL dataset. Setaria was the most common genus at 88 percent, followed by the woody Vachellia at 58 percent. Yet even here, forbs were actively foraged: Pollichia and Indigofera each recorded a 25 percent frequency of occurrence, and the succulent shrub Adenium appeared in half of the sampled individuals. The forb family Caryophyllaceae emerged as one of the most frequently utilised families in the trnL dataset, and in one sample it was the only family detected.

Phylogenetic and diversity analyses reinforced the superiority of the dual-locus strategy. The sum of branch lengths — a measure of phylogenetic distance among detected food items — was higher for trnL than rbcL at both sites, and Shannon index calculations showed the highest diversity of consumed plants at Syferkuil, especially for trnL. Plant species richness differed significantly between bioregions and markers. The researchers note that the differing success of the two barcodes is partly explained by the completeness of the reference libraries: the Combretaceae family, for instance, was represented by 12 unique species in the combined reference libraries, of which only three were barcoded with trnL, while rbcL covered all 12 — explaining why trnL systematically missed this family.

The study also exposed gaps in existing plant DNA reference databases for South African savannas. A substantial number of sequence variants remained unassigned after comparison with the custom libraries and could not be matched to any plant species in NCBI’s non-redundant nucleotide database, indicating the presence of unknown or poorly characterised plant species in the region. The rbcL reference library consisted of 1,238 sequences representing 318 genera and 562 species, while the trnL library held 921 sequences representing 270 genera and 461 species. The authors argue that expanded, multi-barcode reference records from South African savannas are needed not only to improve dietary reconstructions but to support the wider field of plant metabarcoding in the region.

The ecological implications extend beyond livestock nutrition. African savannas cover almost half the continent, and the replacement of functionally diverse native herbivore communities by single-species livestock has substantially altered savanna vegetation structure. Traditional rangeland management has focused on grass biomass productivity, with limited recognition of the role of forbs. Yet previous studies of bison showed that under nutritional pressure these grazers increased their intake of shrubs and forbs to access higher protein content — a pattern the new cattle data now confirm for African livestock. With drought events projected to increase in frequency and intensity, understanding alternative indigenous forage items is key to future ecosystem management in dryland rangelands.

The researchers caution that the method has inherent limitations. PCR bias may selectively amplify certain taxa, leading to over- or underrepresentation of specific plants, and faecal samples represent a snapshot of what an individual consumed immediately before sampling rather than long-term dietary habits. They recommend incorporating multiple sampling points over time and integrating dietary observations or tracking methods alongside genetic analyses for a more holistic understanding of foraging behaviour.

Nevertheless, the findings carry a clear message for rangeland managers facing a drier future: conserving the diversity of not only grasses but also shrubs and forbs in grazing areas supports the flexible foraging strategies cattle need to survive periods of scarcity. The study underscores that cattle possess a remarkable dietary adaptability, shifting from grass-based forage to higher inclusions of forbs and woody taxa during the dry season to maintain nutritional balance despite changing environmental conditions. Recognising these shifts, the authors argue, can guide adaptive management practices — from rotational grazing to supplemental feeding — that ensure the sustainable use of semi-arid landscapes while sustaining livestock productivity in communities that depend on it.

Subject of Research: A DNA metabarcoding study of cattle dung from two South African savanna sites reveals that livestock shift from grass-based diets to forbs and woody taxa during the dry season, highlighting the hidden dietary importance of small flowering herbs and the value of a dual-locus trnL and rbcL approach with site-specific reference libraries.

Article Title: Application of a dual-locus metabarcoding approach for a more comprehensive account of cattle dietary items in a semi-arid African savanna with special reference to forbs

Article References: Botha, D., Barnard, S., Du Plessis, M., Allam, M., Behn, K., Ismail, A., Linstädter, A., Mokoka, M. V., Mnisi, Z. T. H., & Siebert, F. (2024). Application of a dual-locus metabarcoding approach for a more comprehensive account of cattle dietary items in a semi-arid African savanna with special reference to forbs. Metabarcoding and Metagenomics, 8, Article e127959. https://doi.org/10.3897/mbmg.8.127959

Image Credits: AI Generated

DOI: 10.3897/mbmg.8.127959

Keywords: DNA metabarcoding, cattle diets, forbs, semi-arid savanna, South Africa, drought, rangeland management, trnL, rbcL, livestock, Application, dual-locus

The team assembled 128 miniature grassland communities in pots at the University of Alicante, each containing four individuals drawn from sixteen common European grassland species. Eight were grasses, including meadow fescue, perennial ryegrass, and timothy; eight were forbs, the broad-leaved wildflowers of the meadow, including yarrow, daisy, ribwort plantain, and dandelion. By varying the proportion of grasses from zero to one hundred percent, the researchers created a gradient of functional diversity, a coarse but informative proxy for how differently the species in each pot made their living. Half the pots received living inoculum of four AMF species commonly found in European grasslands, cultured at Agroscope’s Swiss Collection of Arbuscular Mycorrhizal Fungi; the other half received the same inoculum after sterilization. Every pot also received a microbial filtrate to equalize the background soil community, isolating the effect of the fungi themselves.

Then came the twist that reshaped the entire study. When the researchers checked their controls, they found that the supposedly fungus-free pots were anything but. Root colonization averaged 53 percent in sterilized controls versus 61 percent in inoculated pots, and the proportion of AMF DNA reads among all fungal sequences was essentially identical in both treatments. Airborne spores, incomplete substrate sterilization, or fungal propagules hitchhiking on surface-sterilized seeds most likely seeded the control pots. A truly AMF-free control, the authors concluded, was unattainable, which is arguably more realistic: in nature, soils are never fungus-free, and plants always respond against a backdrop of resident mycorrhizal communities.

Rather than scrapping the experiment, the team pivoted. DNA extracted from the soils of 96 pots was amplified with fungal ITS2 primers and sequenced on an Illumina NovaSeq platform, yielding nearly 5.7 million quality-filtered reads. After clustering at 97 percent identity and screening against the UNITE and FungalTraits databases, the researchers identified 233 AMF operational taxonomic units among 6355 fungal OTUs. Crucially, the living inoculum had not simply added fungi; it had restructured the community. Rarefied AMF richness was significantly lower in inoculated pots, apparently because the four introduced strains, known competitors such as Rhizoglomus and Claroideoglomus, monopolized root and soil niches and excluded the background taxa. Inoculation had inadvertently created a gradient of fungal diversity rather than a simple presence-versus-absence contrast.

That gradient told an unexpected story. Contrary to the complementarity hypothesis, which predicts that diverse fungal communities should boost plant productivity through differentiated resource uptake, biomass production declined as AMF richness rose. Root biomass showed the clearest signal, decreasing significantly with fungal richness regardless of the grass proportion in the community. Aboveground production also fell with richness, though the effect was weaker and moderated by community composition. The most productive communities were grass-dominated pots carrying the engineered low-diversity inoculum, a result that directly contradicts the expectation that diversity begets function at every level of the soil food web.

The explanation the authors favor is one of dominance rather than diversity. Fungal taxa differ enormously in how effectively they deliver nutrients to their hosts, and the four inoculated species are among the best-documented performers in the literature. By concentrating the community around a few highly functional, highly competitive strains, inoculation produced more biomass per plant even as it squeezed out the broader fungal repertoire. In other words, a few excellent traders beat a large crowd of mediocre ones, at least for total biomass. This mechanism echoes findings from agricultural soils, where competitive inoculant strains can lift crop yields while eroding the indigenous mycorrhizal diversity that underpins long-term ecosystem resilience.

Yet the biomass ledger concealed a deeper asymmetry between plant types. When the researchers examined how the response to fungal richness varied with grass dominance, a pattern emerged: the negative effect of fungal richness on leaf production weakened as the proportion of forbs increased. Communities dominated by forbs benefited more from a diverse AMF community than grass-dominated ones, which thrived instead under the low-diversity inoculum. Although this interaction was statistically marginal, the authors attribute it to fundamental differences in resource economy. Grasses, with their fast growth and fine root architecture, are often less dependent on mycorrhizal supply, whereas many forbs, particularly non-nitrogen-fixing species with higher carbon demands from multiple symbioses, rely more heavily on fungal partners and may profit from a wider menu of fungal strategies.

The study also revealed a striking division of labor between the aboveground and belowground worlds. Aboveground biomass was governed primarily by plant functional composition: grass-dominated communities produced the most shoot material, likely because grasses’ upright growth form allows them to escape competition for light, while forbs with broad horizontal leaves shade more easily. Belowground biomass, by contrast, was governed primarily by fungal diversity, with almost no influence of plant composition. This split suggests that AMF act chiefly through root-mediated resource acquisition and allocation, a finding consistent with recent large-scale evidence that mycorrhizal symbiosis enhances soil carbon storage by pushing biomass investment underground. The hyphal networks that flourish under such investment may in turn improve soil structure, water retention, and nutrient availability for the whole community.

For the booming industry in commercial mycorrhizal biofertilizers, the implications are sobering. Inoculants are increasingly marketed as a green alternative to chemical fertilizers, and they can indeed raise yields. But this experiment demonstrates that adding fungi is not the same as adding fungal diversity, and that the two can move in opposite directions. A commercial treatment that concentrates the community around a few productive strains may boost short-term biomass in grass-dominated systems while sacrificing the native diversity that forb-rich, biodiverse grasslands depend on. The authors argue that sustainable land management requires understanding the specific interactions between plant functional groups and fungal community composition, not simply dosing soils with spores.

The broader lesson is that the relationship between biodiversity and ecosystem function, one of ecology’s most celebrated patterns, is not a simple staircase. Context matters at every scale: which plants are present, which fungi are present, and how their resource economies match. By coupling DNA-based assessments of fungal richness with experimental gradients of plant functional diversity, this study offers a template for disentangling those mechanisms in semi-arid grasslands and beyond. The next step, the authors suggest, is to extend the joint assessment of plant and fungal functional diversity to ecosystem processes such as nutrient cycling, where their models already hinted at treatment-dependent shifts in soil nitrogen and phosphorus availability. In the hidden economy beneath our feet, it seems, diversity is currency, but who gets rich depends entirely on who is trading.

Subject of Research: Effects of arbuscular mycorrhizal fungal diversity and plant functional composition on biomass production in semi-arid grassland communities

Article Title: Forb species benefit more than grasses from a diverse arbuscular mycorrhizal fungal community in semi-arid grasslands

Article References: Shpilkina, Y., Vasar, M., Asensio, S., Ochoa, V., Gozalo, B., Enste, K., Zobel, M., de Bello, F., van der Heijden, M., Maestre, F. T., & Neuenkamp, L. (2026). Forb species benefit more than grasses from a diverse arbuscular mycorrhizal fungal community in semi-arid grasslands. Web Ecology, 26(2), 119-155. https://doi.org/10.5194/we-26-119-2026

Image Credits: AI Generated

DOI: 10.5194/we-26-119-2026

Keywords: arbuscular mycorrhizal fungi, soil biodiversity, grasslands, forbs, grasses, plant functional diversity, biomass production, fungal inoculants, root colonization, DNA metabarcoding, semi-arid ecosystems, sustainable agriculture

Global electricity demand is growing at roughly twice the rate of overall energy demand, and the expansion of transmission networks shows no sign of slowing. While linear infrastructure is often associated with habitat loss and fragmentation, ecologists have increasingly recognized that power line corridors can act as novel habitats, supporting diverse plant communities and providing forage for pollinators such as bees and butterflies. What has been missing, the authors argue, is a mechanistic understanding of how these corridors shape vegetation—not simply how many species they contain, but what ecological strategies those species represent.

To address this gap, a research team led by Samuel Roy Proulx of Université du Québec à Chicoutimi, working with colleagues including Évelyne Thiffault, David Paré, Jean-François Boucher, Yann Chavaillaz, and Maude Larochelle, surveyed 18 power line rights-of-way across an enormous territory spanning roughly 205,000 square kilometers of Québec. Their sites ranged from the northern mixed forest biome in the south to the edge of the continuous boreal forest in the north, crossing four distinct bioclimatic domains and a mean annual temperature gradient from 4.6 °C down to −1.6 °C. Corridor widths ranged from 30 to 160 meters, and the lines had been installed at various points between 1927 and 2021.

At each site, the team laid out a transect of seven circular sampling plots running perpendicular to the corridor: three within the cleared right-of-way itself, two in the forest edge approximately 20 meters from the corridor margin, and two in control forest interiors about 60 meters away. Vegetation was surveyed in three strata—trees, shrubs, and forbs—using nested plots of different sizes, from 400-square-meter circles for mature trees down to one-square-meter quadrats for low-growing herbs. In total, the surveys recorded 139 plant species across the study area.

Rather than relying solely on species counts, the researchers assembled functional traits for each species, drawing on the TOP and TRY plant trait databases. The traits included specific leaf area, plant height, foliage persistence, flower color, inflorescence type, and flowering period—characteristics that together capture how plants respond to disturbance and how they might support pollinators. From these traits, the team calculated four complementary functional diversity indices: functional richness, which measures the volume of trait space occupied; functional evenness, which describes how evenly abundances are distributed within that space; functional dispersion, the mean trait distance of species from the community centroid; and Rao’s quadratic entropy, which combines abundance and functional differences. A Shannon diversity index provided a taxonomic benchmark for comparison.

The statistical analysis used linear mixed models with bioclimatic domain and site identity as random effects, and candidate predictors including corridor position, right-of-way width, installation year, topographic wetness, growing degree-days above 5 °C, seasonal precipitation, and soil clay and silt content. Model selection via the corrected Akaike Information Criterion produced a striking result: the position relative to the right-of-way, and its interaction with climatic variables, dominated the patterns—while the corridor’s own attributes, such as width and age, mattered far less than the researchers had hypothesized.

For the forb layer, forest edges emerged as functional hotspots. Every functional index except evenness peaked at the edge, followed by control forests, with corridors scoring lowest. Functional richness of forbs was strongly and positively related to growing degree-days interacting with position, with edge and forest predictions substantially exceeding corridor values as thermal sums increased. Functional evenness told a subtler story: within corridors, evenness remained stable as seasonal precipitation rose from 430 to 640 millimeters, whereas it declined sharply in edge and control forests over the same gradient. Rao’s quadratic entropy was roughly 63 percent higher at forest edges and 50 percent higher in control forests than in corridors.

The shrub stratum showed an even clearer positional signature. Functional evenness in corridors averaged 0.31 compared with 0.74 in control forests, and functional dispersion and Rao’s entropy were dramatically lower inside corridors—expected consequences of mechanical clearing that removes woody vegetation on a four-to-ten-year cycle to prevent electrical arcing and fire. Notably, corridor characteristics such as installation year and width had little explanatory power for shrub diversity, suggesting that the recurring management regime, rather than corridor history, is the dominant filter. For trees, which were entirely absent from corridors, the only significant effects were higher functional richness at edges with increasing degree-days and a decline in functional dispersion as corridor width increased from 30 to 91 meters—a hint that very wide clearings homogenize the surrounding forest’s tree communities.

Why did corridors, with their open, sun-drenched conditions, fail to show the highest functional diversity? The authors point to several mechanisms. Repeated cutting leaves behind accumulated trunks, branches, and twigs that can create suboptimal seedbeds for forbs, while decomposing woody debris and canopy openings elevate soil inorganic nitrogen, favoring a narrow set of nitrophilous species such as raspberry and strawberry. Recurrent disturbance may also act as an environmental filter, culling species whose traits do not tolerate regular removal and thereby compressing the community’s functional trait space even when species richness persists. Notably, the study found little evidence that corridors promote invasives: of the 139 species recorded, only six were exotic or invasive, and their mean cover across plots was a mere 0.52 percent.

The broader significance lies in what functional diversity implies for ecosystem services. Because floral traits such as flower color, inflorescence type, and flowering period are known predictors of pollinator communities, the high functional diversity of forbs and shrubs at forest edges suggests these transitional zones may offer particularly suitable pollinator habitat—consistent with European studies linking corridor vegetation traits to bee and butterfly diversity. The authors are careful to note that pollinators were not directly surveyed, so their results indicate habitat potential rather than demonstrated biodiversity support. Still, the message for land managers is clear: the forest edge, not the corridor interior, is where the richest functional vegetation persists, and management strategies that maintain diverse, low-growing communities while removing cut biomass could enhance the ecological value of these ubiquitous linear infrastructures across boreal and temperate forests.

Subject of Research: Vegetation functional diversity across power line rights-of-way, forest edges, and control forests in eastern Canadian boreal and temperate forests.

Article Title: Vegetation functional diversity along power line rights-of-way in eastern Canadian forests

Article References: Proulx, S. R., Thiffault, É., Paré, D., Boucher, J.-F., Chavaillaz, Y., & Larochelle, M. (2026). Vegetation functional diversity along power line rights-of-way in eastern Canadian forests. Environmental and Sustainability Indicators, 32, Article 101507. https://doi.org/10.1016/j.indic.2026.101507

Image Credits: AI Generated

DOI: 10.1016/j.indic.2026.101507

Keywords: functional diversity, power line rights-of-way, plant functional traits, boreal forest, forest edges, Québec, pollinator habitat, vegetation management, forbs, shrubs, boreal forest ecology, linear infrastructure