Faunal Communities Research Articles

Fire-Derived Charcoal Attracts Microarthropods in the Litter of Boreal Deciduous Forest

Larch forests in the permafrost zone of Eastern Eurasia are exposed to frequent wildfires, which are expected to increase with climate warming. However, little is known about how fire-derived charcoal is linked to the decomposition process in these forests. Fire-derived charcoal can affect the faunal communities in the forest litter. In a two-year field litterbag experiment, we investigated the effect of fire-derived charcoal on the colonisation by microarthropods (Collembola and Acari) of three decomposing litter species dominant in boreal larch forests. Charcoal addition led to an average 15% decrease in body size of collembola but significantly increased their abundance by 5 times throughout the experiment and acari by 1.5 times in the second year of decomposition, and this effect was consistent across all litter species. The increased microarthropod community may have hampered microbial activity and mass loss rate in the presence of charcoal. Charcoal altered the microarthropod community composition, increasing the proportion of collembola up to 20% compared to acari. The difference in abiotic conditions (increased litter water content during dry periods) induced by fire-derived charcoal was a more substantial factor determining the microarthropod community than litter species in the boreal larch forest. Our results indicate that fire-derived charcoal influences the biological drivers of decomposition in boreal larch forests, stimulating the growth of microarthropod community in decomposing litter.

Collembola community contains larger species in frequently flooded soil

Climate change is increasingly affecting biotic communities, including soil fauna. Extreme weather events such as the incidence of heavy rainfall or prolonged drought can cause strong fluctuations in soil moisture. In river floodplains such extreme events determine the flooding intensity of the river bank grassland soils, and their communities. The diversity and distribution of many soil fauna groups depends on soil moisture content, so changes in inundation frequency and duration will impact soil fauna communities. We used the natural fluctuations in water levels of large Dutch rivers to investigate the effect of flooding intensity on the composition and traits of Collembola species, a key group of the soil fauna community. At five locations along large rivers in The Netherlands, we sampled Collembola communities at six levels of decreasing elevation and increasing flooding intensity. We identified all Collembola to species level and calculated species richness, composition and abundance values. Moreover, to understand the observed taxonomic changes across elevation we used the traits body size and life form to explain the change in Collembola community composition. Our results show that high flooding intensity favors larger Collembola species in the community. We hypothesize that high soil moisture in frequently flooded soil favors larger Collembola, which tolerate flooding. Life form, i.e. the preferred depth in the soil column, was significantly correlated with flooding intensity. There is an optimum in species richness and abundance at intermediate flooding intensity. These results can help predict the impact of climate change on soil fauna.

Effects of artificial reef and fishing moratorium on trophic structure of biological community in the Pearl River Estuary marine ranch based on stable isotopes

Deployment of artificial reefs (ARs) has become popular technique to create new hard-bottom habitats, increase biodiversity and richness for fisheries. We compared the faunal community structure and food web structure associated with before and after fishing moratorium between ARs and non-ARs in Wanshan Island, Pearl River Estuary using stable isotope techniques. Community composition showed higher differences between ARs and non-ARs. The range of δ13C and δ15N of different functional groups can distinguish the pelagic and benthic trophic pathways of the food web in reef-or-not area before and after fishing moratorium. The isotopic niches of entire faunal, as well as individual functional groups, overlapped less between ARs and non-ARs in Wanshan Island, which makes the isotopic functional indices non-equivalent. The total convex hull area (TA) of ARs was larger than that of non-ARs, indicating that nutrient pathways of ARs were more diverse. Overall, however, these results suggest that trophic structure was convergence between ARs and non-ARs, and differences before and after fishing moratorium, possibly due to seasonal differences. Finally, it was shown that the construction of ARs had a weak effect on the restoration of fishery resources in this area, which might be related to lack of further management, or even similar community composition to non-ARs areas.

Effects of anthropogenic pressures on the seagrass Halophila stipulacea and its associated macrozoobenthic communities in the northern Gulf of Aqaba

Halophila stipulacea is a tropical seagrass species, native to the Red Sea, Persian Gulf, and Indian Ocean, while invasive to the Mediterranean and Caribbean Seas. The benthic fauna assemblages associated with H. stipulacea in its native habitats and the potential effects of anthropogenic stressors on these assemblages remain unknown. We compared meadow characteristics, associated fauna assemblages and trophic niche structures of H. stipulacea from an impacted and a pristine site in the northern Red Sea. Seagrass cover and biomass were higher in the impacted site, however, the associated fauna community was more abundant and diverse in the pristine site. Both meadows showed comparable trophic niches based on stable isotope analysis. This study provides first insights into the macrozoobenthos associated with H. stipulacea in its native habitat and highlights the importance of better understanding the relationship between seagrasses and their associated biota and the potential effects of urbanization on this relationship.

Bioclimatic inference based on mammal community using machine learning regression models: perspectives for paleoecological studies

Climate has played a significant role in shaping the distribution of mammal species across the world. Mammal community composition can therefore be used for inferring modern and past climatic conditions. Here, we develop a novel approach for bioclimatic inference using machine learning (ML) algorithms, which allows for accurate prediction of a set of climate variables based on the composition of the faunal community. The automated dataset construction process aggregates bioclimatic variables with modern species distribution maps, and includes multiple taxonomic ranks as explanatory variables for the predictions. This yields a large dataset that can be used to produce highly accurate predictions. Various ML algorithms that perform regression have been examined. To account for spatial dependence in our data, we employed a geographical block validation approach for model validation and selection. The random forest (RF) outperformed the other evaluated algorithms. Ultimately, we used unseen modern mammal surveys to assess the high predictive performances and extrapolation abilities achieved by our trained models. This contribution introduces a framework and methodology to construct models for developing models based on neo-ecological data, which could be utilized for paleoclimate applications in the future. The study aimed to satisfy specific criteria for interpreting both modern and paleo faunal assemblages, including the ability to generate reliable climate predictions from faunal lists with varying taxonomic resolutions, without the need for published wildlife inventory data from the study area. This method demonstrates the versatility of ML techniques in climate modeling and highlights their promising potential for applications in the fields of archaeology and paleontology.

Characterizing potential resource use of sargasso-dominant sea wrack by terrestrial invertebrate fauna during sargasso influxes in South Florida

Marine-derived macrophytes primarily compose beach-cast sea wrack that can be used by terrestrial invertebrate fauna in sandy beach system. Since 2011, the inundations of pelagic sargasso would accumulate and decompose at local, nearshore systems across the Tropical Atlantic. While ecological effects of pelagic sargasso influxes were considerably studied on tropical Atlantic nearshore coastal systems, not much has been known about their effects on the intertidal interface or terrestrial faunal communities. This study aims to investigate terrestrial invertebrate communities associated with landed sargasso and the sargasso's potential as habitat or food for these invertebrates. Surveys, sample collection of flora and fauna, and trials of a temperature experiment were conducted at Crandon Park and MJ State Park along Southeast Florida during the 2020 and 2021 sargasso seasons. Invertebrate communities were primarily composed of talitrid amphipods, coleopterans, and dipterans. The quantity of sargasso, dependent on year of sampling session, seemed to have a more discernible effect on invertebrate composition than location. HOBO logger microhabitat experiment trials showed treatments with sargasso-dominant wrack having lower temperatures than treatments with exposed or buried sand. Many invertebrate consumers showed δ13C and δ15N signatures closer to marine macrophytes than terrestrial plants. However, mixing models reveal amphipods and oligochaete worms having a trophic link with pelagic sargasso, while insect fauna had their resource use sourced from other marine macrophytes. However, any consumption of sargasso would likely be attributed to generalist resource use rather than a specific preference to sargasso. The potential uses of sargasso depend on the amount of biomass accumulated on the beach surface and the habitat requirements of specific invertebrate species.

Comparative Phylogeography, Historical Demography, and Population Genetics of Three Common Coastal Fauna in Spartina Marshes of the Northwestern Gulf of Mexico

Coastal wetlands worldwide are experiencing high rates of loss and degradation that may lead to a reduction in diversity in faunal populations. Since salt marsh habitats are subject to a multitude of stressors, evaluations of the genetic diversity, connectivity, and potential resilience of faunal communities within salt marsh habitats are relevant. This study characterizes mitochondrial DNA (mtDNA) diversity for three common faunal residents of salt marshes along the northern Gulf of Mexico. Gulf Killifish (Fundulus grandis) samples were characterized for 1077 bp of the concatenated nucleotide sequence corresponding to the Control Region and Nitrogen Dehydrogenase, Subunits 2 and 5. Daggerblade grass shrimp (Palaemon pugio) samples were characterized using 466 bp of 16sRNA sequence, and phloem-feeding planthoppers (Prokelisia marginata) were characterized using 372 bp of Cytochrome c Oxidase Subunit I (COI) sequence. For F. grandis, our data revealed high levels of haplotypic diversity, evidence of isolation by distance (IBD), and regional population structuring associated with the distribution of two distinct phylogroups and distinct historical demography signatures. P. pugio and P. marginata displayed low levels of haplotypic diversity and evidence of population structure, but both appear to contain only snapshots of the total potential diversity for these species in the Gulf of Mexico. Greater resolution of the patterns of historical demography of Gulf Killifish may be obtained in future studies by including localities from Florida and Mexico. For both P. pugio and planthoppers, future studies would benefit from the characterization of genetic markers with a higher degree of polymorphism. We conclude that despite these three species inhabiting the same habitats along the same stretch of coast, each is subject to a different combination of evolutionary forces, and this study was able to reconstruct differences in how the genetic variation in each of these species emerged, and how it is maintained.

Nitrogen-fixing tree species rather than tree species diversity shape soil nematode communities in subtropical plantations

Positive relationships between tree species diversity and soil communities are reported in many studies. However, the effects of tree species richness and nitrogen (N)-fixing tree species on soil fauna communities are not yet fully understood. Here, we conducted a field experiment to investigate changes in soil nematode communities under a gradient of tree species richness (e.g., 1, 2, 4 and 6 tree species) with N-fixing tree species (absence or presence). We found that N-fixing tree species strongly affected soil nematode trophic groups, and significantly increased the abundance of omnivore-predators and structure index via promoting more trophic links and multi-trophic interactions, leading to a more stable and complex soil food web. In the presence of N-fixing tree species, tree species richness significantly increased the abundance and relative abundance of fungivores and the channel index, with the shift in soil energy channel through increased the C/N ratio of leaf litter. In contrast, tree species richness detrimentally affected the abundance of plant parasites due to the decline of leaf litter N content under the presence of N-fixing tree species. The results revealed that the bottom-up effects of N-fixing tree species on soil nematode community structure were crucial drivers in shaping nematode communities in subtropical plantations. Our study suggests that N-fixing tree species is more important than tree species richness to regulate soil nematode community structure and soil energy channel, and therefore, should be preferentially considered in multispecies forest plantations.

Modeling periodicity in equid serial enamel isotopes as a proxy for precipitation seasonality

Seasonality shapes environments by driving vegetation patterns and faunal community composition, and identifying seasonality patterns in the past can provide unique insight into paleoenvironments and how they changed over time. Many environmental proxies operate on too large a time scale to glean data about intra-annual seasonality. However, serial enamel isotope samples from the teeth of high-crowned ungulates show promise for providing this temporal resolution of data. Interpreting these data remains a challenge due to the complexity of factors related to animal physiology and the isotopic values of environmental inputs. This study seeks to establish a method for interpreting intra-tooth isotopic change in modern equid teeth as a signal of seasonality by applying a linear mixed effect model to the isotope data to detect periodicity in serial enamel isotope values. Using a modern assemblage of zebra (Equus quagga) from Ol Pejeta Conservancy in Kenya, where long-term climate data has been collected, allows us to compare known climatic seasonality patterns to periodicity in the zebra tooth enamel isotopes. The results of the linear mixed effect modeling, in tandem with the climate data from Ol Pejeta, demonstrate the impact high precipitation variability can have on an environment. While our isotope results point towards measured precipitation seasonality patterns at Ol Pejeta, noise in our data and the variation identified by the models illustrate the challenges of working with serial enamel isotope data. Future refinement and application of this model will allow us to better characterize seasonality in both modern and fossil enamel datasets.

Pesticide effects on soil fauna communities—A meta‐analysis

Abstract Soil invertebrate communities represent a significant fraction of global biodiversity and play crucial roles in ecosystems. A number of human activities threaten soil communities, in particular intensive agricultural practices such as pesticide use. However, there is currently no quantitative synthesis of the impacts of pesticides on soil fauna communities. Here, using a meta‐analysis of 54 studies and 294 observations, we quantify pesticide effects on the abundance, biomass, richness and diversity of natural soil fauna communities across a wide range of environmental contexts. We also identify scenarios with the most detrimental effects on soil fauna communities by analysing the effects of different pesticides (herbicides, fungicides, insecticides, broad‐spectrum substances and multiple substances), different application rates and temporal extents (short‐ or long‐term), as well as the response of different functional groups of soil animals (body size categories, presence of exoskeleton). Pesticides overall decreased the abundance and diversity of soil fauna communities across studies (Grand mean effect size (Hedge's g) = −0.30 +/− 0.16) and had stronger effects on soil fauna diversity than abundance. The most detrimental scenarios involved multiple substances, broad‐spectrum substances and insecticides, which significantly decreased soil fauna diversity even at recommended rates. We found no evidence that pesticide effects dampen over time, as short‐term and long‐term studies exhibited similar mean effect sizes. Policy implications: Our study highlights that pesticide use has significant detrimental non‐target effects on soil biodiversity, eroding a substantial part of global biodiversity and threatening ecosystem health. This provides crucial evidence supporting recent policies, such as the European Green Deal, that aim to reduce pesticide use in agriculture to conserve biodiversity. The detrimental effects of multiple substances revealed here are particularly concerning because realistic pesticide use often combines several substances targeting different pests and diseases over the crop season. We suggest that future guidelines for pesticide registration, restrictions and banning should rely on data able to fully capture the long‐term consequences of multiple substances for multiple non‐target species in realistic conditions.

An Assessment of Southeast United States Headwater Tidal Creek Sediment Contamination Over a Twenty-Year Period in Relation to Coastal Development.

Headwater tidal creeks are a primary link between estuarine and upland habitats, serving as conduits for runoff. They are sentinel habitats, providing early warning of potential harm, thus ideal systems to evaluate the effects of coastal suburban and urban development on environmental quality. Estuarine sediments have concentrations of metals, polycyclic aromatic hydrocarbons (PAHs), pesticides, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) that are associated with human activity. High concentrations of contaminants can impair faunal communities, habitat quality, and ecosystem function. Forty-three headwater creeks were sampled between 1994 and 2006 to assess contaminants, and 18 of these were sampled again in 2014/2015. Watersheds were classified as forested, forested to suburban, suburban, or urban land. These values are based on their percent impervious cover (IC) levels and change in IC from 1994-2014. Analyses of temporal data resulted in significant relationships between IC and select metals, PAHs, pesticides, PCBs, and PBDEs. In addition, 11 of the creeks sampled in 2014/2015 have paired data from 1994/1995, allowing for change analysis over the 20 years. Results indicated increasing chemical contamination occurring with increasing levels of development, although only PAHs and total dichloro-diphenyl-trichloroethane (DDT) exhibited a statistically significant increase over time; PAHs also exhibited significantly higher concentrations in developed creeks. Additionally, several metals were deemed enriched in developed creeks based on reference conditions. These results expand our knowledge of how these systems respond to urban development and can inform managers about how human population growth along coastlines may predict altered tidal creek health.

Comparative study of pristine and polluted estuaries in Souss Massa National Park (Morocco): Implications for conservation strategies

Estuaries are among the ecosystems most affected by human actions worldwide. Economic development in Morocco puts pressure on these aquatic systems, making them vulnerable. This study compares the state of benthic communities between a pristine estuary (Massa estuary) and a polluted one (Souss estuary). Both ecosystems belong to the Souss Massa National Park (SMNP), registered in the Ramsar list for its ecological importance as a Marine Protected Area (MPA). Twenty-one benthic species were identified in the pristine estuary, but only six species in the polluted one. Similar differences were detected for the species abundance and biomass. The total organic matter and the water-dissolved oxygen also revealed a notable negative effect of the sewage discharge. The results confirmed human disturbances on faunal communities related to direct wastewater inputs and indirect anthropogenic activities such as the urbanization and the litter generation. A combination of ending wastewater discharge and adding tertiary-level water treatment plants is recommended. The findings highlight the importance of MPAs in conservation strategies if coupled with continuous surveillance of pollution.

Poultry litter and different cover crops and their effects on the edaphic fauna community of an Oxisol

The use of soil cover plants and alternative sources of nitrogen fertilization can promote improvements in the biological characteristics of the soil. The objective of this study was to determine the contribution of the isolated and/or intercropped cultivation of ground cover crops in autumn/winter and the use of poultry litter as a source of N in the wheat crop in succession on the soil mesofauna and macrofauna community. The experimental design was randomized blocks, with split plots, in a factorial arrangement (4 x 4), with three replications. The collections of the edaphic fauna were realized with pitfall traps PROVID in plots of 15 m². The edaphic fauna orders, abundance, Shannon diversity, Simpson dominance, Pielou evenness and the family of organisms of the order Collembola were evaluated. The use of ground cover plants in autumn/winter, induced a greater abundance of edaphic fauna organisms, which were mostly represented by the order Collembola, belonging to the Entomobryidae family. The isolated or intercropped cultivation of cover crops, associated with the use of N via poultry litter, enabled a greater diversity of organisms and a uniform distribution of different groups in the edaphic community.

THE SWAN POINT SITE, ALASKA: THE CHRONOLOGY OF A MULTI-COMPONENT ARCHAEOLOGICAL SITE IN EASTERN BERINGIA

ABSTRACTThe Swan Point site in interior Alaska contains a significant multi-component archaeological record dating back to 14,200 cal BP. The site’s radiocarbon (14C) chronology has been presented in scattered publications that mostly focus on specific archaeological periods in Alaska, in particular its terminal Pleistocene components associated with the East Beringian tradition. This paper synthesizes the site’s 14C data and provides sequential Bayesian models for its cultural zones and subzones. The 14C and archaeological record at Swan Point attests that the location was persistently used over the last 14,000 years, even though major changes are evident within regional vegetation and local faunal communities, reflecting long-term trends culminating in Dene-Athabascan history.

The expansion of evergreen and deciduous shrubs changed the chemical characteristics and biological community of alpine meadows soil

Global warming drives shrubs expansion. However, it is unclear how shrubs expansion affect the nutrients cycling, decomposer diversity and activity of alpine meadows. We selected two dominant shrub species in an alpine forest-Tundra ecotone on the eastern Tibetan Plateau: Rhododendron lapponicum (evergreen shrubs), and Sorbus rufopilosa (deciduous shrubs), the shrub-free tundra site as the control site. The fauna community diversity, microbial biomass, extracellular enzyme activity and enzyme stoichiometry of organic soil and mineral soil layer were determined to explore the effects of shrubs expansion. The soil total nitrogen, microbial biomass carbon and nitrogen, and some extracellular enzyme activity of the two shrubs were higher than those in CK. In addition, deciduous shrub expansion had a stronger effect on meadows ecosystem process than evergreen shrub expansion. However, both of them may alleviate the limitation of nitrogen and phosphorus in alpine meadows ecosystem, and the expansion of evergreen shrubs may also contribute to the accumulation of particulate organic matter. It is of great significance to probe the biogeochemical cycle of alpine meadows ecosystems under climate change.

Climate change decouples dominant tree species in African savannas

To understand how two dominant African savanna trees will continue to respond to climate changes, we examined their regeneration niche and adult tree distributions. Specifically, we wanted to (1) determine if distributional patterns were shifting, (2) predict future distributions under different climate change scenarios and (3) evaluate the realism of predicted future distributions. We randomly placed 40 grids into 6 strata across a climate gradient in the kingdom of Eswatini. Within these grids, we sampled adult and seedling marula (Scelerocarya birrea) and knobthorn (Senegalia nigrecens) trees and used the data to model their abundance. Next, we quantified shifts in distributional patterns (e.g., expansion or contraction) by measuring the current and projected areas of overlap between seedling and adult trees. Finally, we predicted future distributions of abundance based on predicted climate conditions. We found knobthorn seedlings within a small portion of the adult distribution, suggesting it was unlikely to track climate changes. Alternatively, finding marula seedlings on and beyond one edge of the adult distribution, suggested its range would shift toward cooler climates. Predicted future distributions suggest suitable climate for both species would transition out of savannas and into grasslands. Future projections (2041–2070) appeared consistent with observed distributions of marula, but knobthorn predictions were unrealistic given the lack of evidence for regeneration outside of its current range. The idiosyncratic responses of these species to climate change are likely to decouple these keystone structures in the coming decades and are likely to have considerable cascading effects including the potential rearrangement of faunal communities.

Soil fauna community characteristics and driving factors of Pinus tabuliformis in the loess region of northern Shaanxi

This study aimed to examine the characteristics and regulatory mechanisms of the soil fauna community in Pinus tabuliformis plantations at different restoration ages. The study was conducted on the soil fauna of Pinus tabuliformis in different restoration ages (6a, 11a, 18a, and 22a) in Wuqi County. Soil fauna, soil samples, understory herb biomass were collected in the spring, summer, autumn and winter of 2021. The relationship between the soil fauna community characteristics and environmental factors were studied. The results are as follows: (1) The density increased and the number of species decreased in the soil fauna community with an increase in restoration ages, and the composition and structure of the soil fauna community were significantly different at different restoration ages. (2) The diversity of the soil fauna community was highest and the soil food web was the most stable in 6-year-old Pinus tabuliformis plantations. Followed by a 22-year-old Pinus tabuliformis plantation. The lowest soil fauna diversity and the least stable food webs were found at 11- and 18-years-old of Pinus tabuliformis plantations. (3) The understory herb community had the greatest impact on the composition and structure of soil fauna community. SOM, NCP and NHS were the main factors affecting the composition of the soil fauna community. (4) During the restoration of Pinus tabuliformis plantations, the soil fauna community is mainly controlled by the top-down food resources, and the understory herb community driven the evolution process of the soil fauna community, thereby regulating the soil food web. Our research results emphasize the importance of sub-forest herbaceous vegetation to soil animals, which is essential for the formulation of sustainable biodiversity conservation policies for planted forest ecosystems.

Impacts of long-term organic production on soil fauna in boreal dairy and cereal farming

Intensified arable farming results in fewer functional groups of soil biota with decreased biodiversity. Organic farming with slurry fertilization and long crop rotation cycles favors soil fauna diversity under tropical and temperate conditions. Faunal responses to agricultural practices in northern latitudes may, however, differ from those in southern latitudes due to different soil types, climatic conditions, and intensity of management. We investigated the abundance and diversity of soil fauna communities (nematodes, microarthropods, enchytraeids and earthworms) in a boreal sandy soil in replicated organically and conventionally cultivated field blocks that simulated cultivation in a cereal farm and in a forage producing dairy farm. In addition to traditional methods, we investigated nematode diversity using DNA metabarcoding. The results show that organic production system did not unequivocally result in higher abundance and diversity of soil fauna compared with conventional production systems, neither in the cereal nor the dairy farming type. Instead, abundances of all soil fauna groups were typically higher in the dairy than in the cereal farming type irrespective of production system. This holds up for all functional groups of nematodes except omnivores, all four orders of Acari present, two out of the six families of Collembola, the total number of enchytraeids and density of earthworms. Nematode diversity, measured as average ZOTU number, was in conventionally cultivated cereal farming type an order of magnitude lower than in other production and farming type combinations. Of the various differences between farming types, the crop species was the most important one as it defines the management practice and thus the soil conditions where soil biota lives. Our findings underline that when comparing soil faunal communities under organic and conventional cultivation, the differences between farming types need to be considered in addition to the production system as they can have an overriding importance across the food web.

Fire severity as a key determinant of aboveground and belowground biological community recovery in managed even-aged boreal forests.

Changes in fire regime of boreal forests in response to climate warming are expected to impact postfire recovery. However, quantitative data on how managed forests sustain and recover from recent fire disturbance are limited.Two years after a large wildfire in managed even-aged boreal forests in Sweden, we investigated how recovery of aboveground and belowground communities, that is, understory vegetation and soil microbial and faunal communities, responded to variation in the severity of soil (i.e., consumption of soil organic matter) and canopy fires (i.e., tree mortality).While fire overall enhanced diversity of understory vegetation through colonization of fire adapted plant species, it reduced the abundance and diversity of soil biota. We observed contrasting effects of tree- and soil-related fire severity on survival and recovery of understory vegetation and soil biological communities. Severe fires that killed overstory Pinus sylvestris promoted a successional stage dominated by the mosses Ceratodon purpureus and Polytrichum juniperinum, but reduced regeneration of tree seedlings and disfavored the ericaceous dwarf-shrub Vaccinium vitis-idaea and the grass Deschampsia flexuosa. Moreover, high tree mortality from fire reduced fungal biomass and changed fungal community composition, in particular that of ectomycorrhizal fungi, and reduced the fungivorous soil Oribatida. In contrast, soil-related fire severity had little impact on vegetation composition, fungal communities, and soil animals. Bacterial communities responded to both tree- and soil-related fire severity. Synthesis: Our results 2 years postfire suggest that a change in fire regime from a historically low-severity ground fire regime, with fires that mainly burns into the soil organic layer, to a stand-replacing fire regime with a high degree of tree mortality, as may be expected with climate change, is likely to impact the short-term recovery of stand structure and above- and belowground species composition of even-aged P. sylvestris boreal forests.

Diversity of medium and small-sized soil fauna community in different urban-rural green spaces and its influencing factors in Nanchang, China.

Urbanization is one of the important factors leading to biodiversity loss and habitat fragmentation. As an important component of urban ecosystem, soil fauna community plays a key role in improving soil structure and fertility, and promoting material circulation of urban ecosystem. To investigate the distribution characteristics of medium and small-sized soil fauna community in green space and the mechanisms underlying their responses to environmental change during urbanization, we selected 27 green space plots with a gradient of urban, suburban, and rural areas in Nanchang City as study objects, and measured plant parameters, soil physicochemical properties, and distribution characteristics of soil fauna community in these plots. The results showed that a total of 1755 soil fauna individuals were captured, belonging to 2 phyla, 11 classes, and 16 orders. The dominant groups were Collembola, Parasiformes, and Acariformes, which accounting for 81.9% of total soil fauna community. The density, Shannon diversity index, and Simpson dominance index of soil fauna community were significantly higher in suburban area than those in rural area. In the green space of the urban-rural gradient, there were large structure variations in different trophic levels of medium and small-sized soil fauna community. Herbivores and macro-predators occupied the largest proportion in rural area, and less in other areas. Results of the redundancy analysis showed the crown diameter, forest density, soil total phosphorus contents were the main environmental factors affecting soil fauna community distribution, with interpretation rate of 55.9%, 14.0% and 9.7%, respectively. Results of the non-metric multidimensional scale analysis showed that there were variations in soil fauna community characteristics in green space of the urban-rural gradient, and that the aboveground vegetation was the dominant factor for this change. This study improved our understanding of urban ecosystem biodiversity in Nanchang, and provided basis for maintaining soil biodiversity and urban green space construction.