Published in Environmental Monitoring and Assessment, the research by Şahin Palta, Eren Baş, and Zekeriya Yavaşcı of Bartın University examined AMF spore density, community composition, and rhizosphere soil properties across five plant families in a natural rangeland. The findings challenge the assumption that soil chemistry alone dictates which mycorrhizal fungi thrive where. Instead, plant family identity emerges as a decisive driver, shaping fungal abundance and diversity in patterns that could reshape how we manage rangelands worldwide.

The numbers tell a dramatic story. AMF spore density peaked in soils beneath Asteraceae, the daisy family, at 609.8 spores per 50 grams of soil. At the opposite extreme, Urticaceae, the nettle family, hosted just 77.6 spores per 50 grams, a nearly eightfold difference. That gap is not a minor variation; it suggests that the plant above ground exerts a powerful influence on the reproductive output of fungi below, possibly through differences in root architecture, carbon allocation, or the chemical signals each family releases into the rhizosphere.

Correlation analysis added another layer of intrigue. AMF spore density showed a positive association with soil pH (r = 0.47), hinting that slightly alkaline conditions favor sporulation. But the fungi responded negatively to electrical conductivity (r = −0.49), available potassium (r = −0.44), and total nitrogen (r = −0.40). In other words, richer soils with more nitrogen and potassium actually hosted fewer spores. This counterintuitive pattern aligns with a growing body of evidence that mycorrhizal fungi invest less in reproduction when plants, flush with nutrients, depend less on fungal partners for mineral acquisition.

Five fungal species appeared in the rhizosphere soils of all five plant families: Acaulospora tuberculata, Claroideoglomus etunicatum, Funneliformis geosporum, Glomus sp., and Rhizophagus clarus. Their broad distribution across host groups suggests these are generalist symbionts, capable of partnering with a wide range of plants. Yet the study also found that community structure varied among plant families, indicating that host identity filters which species dominate even when the same core species are present everywhere.

Diversity metrics revealed further complexity. Species richness was highest in Urticaceae, despite that family hosting the fewest spores overall. Shannon diversity and evenness peaked in Lamiaceae, the mint family. Fabaceae and Asteraceae showed lower diversity values, and Jaccard similarity was highest between Fabaceae and Asteraceae, meaning their fungal communities overlapped more than any other pair. These patterns suggest that plant family identity shapes not just how many fungi are present, but which species coexist and how evenly they are distributed.

Soil organic carbon, total nitrogen, available potassium, and CaCO₃ content also varied among the sampled plant groups, reinforcing the idea that each plant family modifies its own rhizosphere environment. These modifications, in turn, feed back into fungal community dynamics. The result is a complex interplay between biotic and abiotic factors, where plant identity and soil chemistry jointly determine the belowground fungal landscape.

The implications extend far beyond Turkish rangelands. Mycorrhizal fungi are increasingly recognized as critical components of belowground biotic networks, influencing plant productivity, soil carbon sequestration, and ecosystem resilience. If plant family identity drives fungal community structure, then shifts in vegetation composition, whether from grazing, climate change, or land-use conversion, could cascade through soil food webs in unpredictable ways. Rangeland managers may need to consider not just which plants are present, but which families, to maintain healthy fungal communities.

The study also highlights the value of natural rangelands as living laboratories for understanding mycorrhizal ecology. Unlike agricultural systems, where fertilization and tillage disrupt soil structure, natural rangelands preserve the intricate relationships between plants and fungi that have evolved over millennia. By sampling across five plant families in a single rangeland, the researchers isolated the effect of host identity from broader environmental gradients, offering a cleaner test of how plant families shape their fungal partners.

As climate change and land degradation threaten rangelands globally, understanding the drivers of mycorrhizal fungal communities becomes ever more urgent. This study adds a crucial piece to the puzzle: the plant family above ground is not a passive backdrop but an active architect of the fungal world below. The next chapter in this research will likely explore the mechanisms behind these patterns, from root exudates to carbon allocation, unlocking new strategies for restoring degraded soils and sustaining the invisible partnerships that keep rangelands alive.

One reason spore counts offer such a revealing window into mycorrhizal ecology is that spores are not simply byproducts of fungal activity but the principal propagules through which many AMF species persist between growing seasons and disperse to new hosts. A spore is a thick-walled resting structure, often packed with lipid reserves, that can survive in soil for months or years until favorable conditions and a suitable host root coincide. When researchers count spores in a soil sample, they are therefore measuring not just fungal presence but the accumulated reproductive investment of the fungal community over time. The wet sieving and decanting approach traditionally used to extract these spores, first formalized in the 1960s, remains a standard technique because it separates spores from soil particles by density differences, allowing morphological identification under a microscope based on wall structure, color, and size.

It is worth noting that spore abundance does not always track the total amount of fungal activity inside roots. A plant family might support extensive hyphal colonization of its root system while producing relatively few spores, or conversely, a modest root infection might coincide with heavy sporulation. Different fungal genera follow different strategies in this respect. Some members of the Glomeraceae, for example, are known for rapid colonization of root tissue and abundant spore production, whereas species of Acaulospora tend to sporulate more slowly and may peak in abundance at different times of year. This means the patterns observed in the rangeland study reflect a snapshot of community structure that could shift with season, and repeated sampling across a full growing cycle would help establish whether the family-level differences are stable or transient.

The negative association between spore density and soil nitrogen deserves particular attention because it connects to a well-documented feedback in plant-fungal economics. When soil nitrogen and phosphorus are plentiful, plants can reduce the carbon they allocate to root exudates and to the fungal partners themselves, since the marginal benefit of the symbiosis declines. Fungi, receiving less carbon subsidy, may respond by reducing both vegetative growth inside roots and the production of spores. The rangeland soils beneath families associated with higher fertility may therefore have hosted fungi that were metabolically active but reproductively restrained, while the poorer soils beneath other families pushed fungi toward sporulation as a survival strategy. This trade-off between growth and reproduction helps explain why the most spore-rich soils were not necessarily the most nutrient-rich ones.

Electrical conductivity, which reflects the total concentration of dissolved salts in the soil solution, has long been recognized as a constraint on mycorrhizal communities. Studies from saline environments, including work in the salt-affected soils of Iran and semiarid Mediterranean regions, have shown that elevated salinity can suppress sporulation and shift community composition toward salt-tolerant fungal taxa. The negative correlation observed in the Turkish rangeland, though modest in magnitude, is consistent with this broader literature and suggests that even moderate variation in salinity within a single landscape can leave a measurable imprint on the fungal community.

The presence of the same five fungal species across all five plant families raises interesting questions about what ecologists call assembly rules. If host identity were the only filter operating, one might expect entirely distinct fungal suites beneath each family. Instead, the data suggest a two-tier structure: a cosmopolitan core of generalist symbionts present everywhere, overlaid by family-specific differences in the relative abundance of species and in the occurrence of rarer taxa. This layered pattern mirrors findings from other ecosystems, where a handful of dominant AMF species often account for most of the community while a long tail of infrequent species contributes to differences between habitats. The higher Jaccard similarity between Fabaceae and Asteraceae hints that these two families, despite their very different biology, may impose similar rhizosphere filters, perhaps through comparable root traits or exudate chemistry.

The contrast between richness and abundance in Urticaceae is especially instructive. Hosting the greatest number of species while producing the fewest spores suggests that many fungal taxa persisted there at low densities, possibly as opportunistic residents rather than dominant partners. Nettle family plants are often associated with nitrogen-rich soils, and the nutrient conditions they create may suppress the competitive dominance of a few aggressive sporulators, allowing more species to coexist at low levels. This decoupling of richness from abundance illustrates why diversity indices must be interpreted alongside raw counts, since a community can be diverse precisely because no single species thrives.

Future work building on these findings would benefit from molecular approaches, such as sequencing of fungal DNA directly from roots and soils, which can detect species that never sporulate during the sampling period and can quantify relative abundance more precisely than spore counts alone. Combining morphological spore identification with molecular community profiling, along with measurements of root colonization intensity and hyphal length in soil, would paint a fuller picture of how plant families shape not only fungal reproduction but the entire symbiotic economy of the rangeland belowground.

Subject of Research: Soil Microbiology

Article Title: Plant family identity drives arbuscular mycorrhizal fungal spore abundance and community structure in natural rangelands

Article References: Palta, Ş., Baş, E., & Yavaşcı, Z. (2026). Plant family identity drives arbuscular mycorrhizal fungal spore abundance and community structure in natural rangelands. Environmental Monitoring and Assessment, 198(11), Article 1214. https://doi.org/10.1007/s10661-026-16087-2

Image Credits: AI Generated

DOI: 10.1007/s10661-026-16087-2

Keywords: mycorrhizal fungi, rangelands, soil ecology, plant-fungal symbiosis, rhizosphere, biodiversity, Plant, family, identity, drives, arbuscular, mycorrhizal