Structure Of Animal Communities Research Articles

The influence of forest types including native and non‐native tree species on soil macrofauna depends on site conditions

AbstractThe ongoing climate change calls for managing forest ecosystems in temperate regions toward more drought‐resistant and climate‐resilient stands. Yet ecological consequences of management options such as planting non‐native tree species and mixing coniferous and deciduous tree species have been little studied, especially on soil animal communities, key in litter decomposition and pest control. Here, we investigated the taxonomic and trophic structure of soil macrofauna communities in five forest types including native European beech (Fagus sylvatica), range‐expanding Norway spruce (Picea abies) and non‐native Douglas fir (Pseudotsuga menziesii) as well as conifer‐beech mixtures across loamy and sandy sites in northern Germany. Abundance of primary decomposers (feeding predominantly on litter) was high in Douglas fir and beech forests, benefiting from less acidic soil and more favorable litter resources compared to spruce forests, while secondary decomposers (feeding predominantly on microorganisms and microbial residues) reached highest densities in spruce forests. Differences in abundance and species richness among forest types generally varied between regions and were most pronounced in Douglas fir of the sandy region. However, trophic guilds differed more between regions than between forest types, indicating that environmental factors outweigh the importance of forest type on soil macrofauna communities. The analysis of stable isotopes (δ15N and δ13C values) supported the general robustness in trophic position of macrofauna trophic guilds against variations in forest types and regions, but indicated reduced detrital shifts and food‐chain lengths in coniferous compared to European beech forests with mixtures mitigating these effects. Overall, for evaluating consequences of future forest management practices on the structure and functioning of soil animal communities, regional factors need to be considered, but in particular at loamy sites the taxonomic and trophic structure of soil macrofauna communities are resistant against changes in forest types.

Functional traits in soil-living oribatid mites unveil trophic reorganization in belowground communities by introduced tree species

Biodiversity loss and its potential threat on ecosystem functions call for a critical evaluation of human impacts on forest ecosystems. Management practices based on stand diversification offer a possible solution to biodiversity loss due to monoculture plantations, and these practices often involve planting introduced tree species. Although introduced non-native tree species may provide high economic returns, they may also form novel ecosystems and threaten local biodiversity, but this has been little studied. Here, we combined a taxonomic and trait-based approach and investigated communities of oribatid mites (Oribatida, Acari) across forest types of both native and introduced tree species in Northern Germany. Both trophic and life-history traits of oribatid mites were evaluated using native European beech (Fagus sylvatica) as reference, compared to native Norway spruce (Picea abies), introduced Douglas fir (Pseudotsuga menziesii) and beech-conifer mixtures. The abundance and diversity of oribatid mites were generally similar among monocultures of European beech, Norway spruce and Douglas fir. By contrast, species and trait compositions of oribatid mite communities were shifted to include more primary decomposers and more surface-living oribatid mites in Douglas fir, resulting in a trophic reorganization with less predators than in European beech forests. These results suggest that oribatid mites maintain a similar level of trait diversity regardless of forest type, but the changes in trophic guild composition and vertical distribution indicate greater availability of litter-based resources in Douglas fir than in European beech forests. The similar abundance and diversity of oribatid mite communities in Douglas fir mixed stands as in native European beech forests points to mixed forests as a promising management option for future forestry. Overall, our trait-based analyses provided insights into the changes of soil biota composition, revealing the impact of introduced tree species on the structure and functions of soil animal communities.

Refining spider guilds for arid environments

ABSTRACT Guilds have been used to assess how vegetation or environmental perturbations influence the community structure of animal communities. Spiders use a variety of hunting strategies. In arid environments they are the main predators of arthropods. Despite this, spider guilds have not been studied in desert ecosystems. Our study was carried out in one area of the Chihuahuan Desert. We used ramp-type traps and manual collection to capture the spiders. After identifying the specimens caught, we used a classification based on 20 and 23 traits to group the species into guilds. We used new traits for classification (eg horizontal web, triangular web, vertical web, threads coming out of the retreat). As a result, we obtained 11 guilds. Some species of the same family (e.g Gnaphosidae, Oxyopidae, Philodromidae, Theridiidae, Thomisidae) were positioned in different guilds. In addition to the classification, we provide information on the natural history of the species found. This information can be used to understand the differences between spider communities in desert vegetation types and those in other biomes.

Long-term changes in water quality and structure of benthic animal communities in the Neva estuary under anthropogenic stress

In the Neva River estuary, 188 species and taxa of a higher rank of benthic animals were found, of which 129 were found in the eastern part of the Gulf of Finland. At present, the zoobenthos of the estuary is dominated by eurybiont species inhabiting polluted waters. We used integrated index IP' specially devised for water-bodies and rivers of the north-western Russia to assess the water quality and a state of ecosystems of the Neva estuary. It is based on structural parameters of zoobenthic communities and makes it possible to take into consideration the pollution by toxic and organic substances. On average the water quality of the Neva Bay assessed from IP′ values was relatively stable during 1994–2021. It was assessed as “polluted” with the exception of 2006 and 2015 caused by large-scale dredging works. In the period 1982–2021, the average number of zoobenthos species at one station in the Neva Bay almost doubled, from 12 ± 1 species in 1982 to 23±2 species in 2020. In the resort area of the eastern Gulf of Finland, the values of species richness and the Shannon index were much lower than in the Neva Bay, and on average for one station varied from 5±0.6 to 14±4 species and from 1.1±0.2 to 2.3±0.2 bit/ind. This is caused by the influence of salinity, eutrophication and pollution, and invasion of alien species. In addition to intense anthropogenic impact, the dynamics of the state of zoobenthos in this part of the estuary was determined by climate fluctuations.

Historical and dispersal processes drive community assembly of multiple aquatic taxa in glacierized catchments in the Qinghai-Tibet plateau

Understanding the relative role of dispersal dynamics and niche constraints is not only a core task in community ecology, but also becomes an important prerequisite for bioassessment. Despite the recent progress in our knowledge of community assembly in space and time, patterns and processes underlying biotic communities in alpine glacierized catchments remain mostly ignored. To fill this knowledge gap, we combined the recently proposed dispersal-niche continuum index (DNCI) with traditional constrained ordinations and idealized patterns of species distributions to unravel community assembly mechanisms of different key groups of primary producers and consumers (i.e., phytoplankton, epiphytic algae, zooplankton, macroinvertebrates, and fishes) in rivers in the Qinghai-Tibet Plateau, the World's Third Pole. We tested whether organismal groups with contrasting body sizes differed in their assembly processes, and discussed their applicability in bioassessment in alpine zones. We found that community structure of alpine river biotas was always predominantly explained in terms of dispersal dynamics and historical biogeography. These patterns are most likely the result of differences in species-specific functional attributes, the stochastic colonization-extinction dynamics driven by multi-year glacier disturbances and the repeated hydrodynamic separation among alpine catchments after the rising of the Qilian mountains. Additionally, we found that the strength of dispersal dynamics and niche constraints was partially mediated by organismal body sizes, with dispersal processes being more influential for microscopic primary producers. Finding that zooplankton and macroinvertebrate communities followed clumped species replacement structures (i.e., Clementsian gradients) supports the notion that environmental filtering also contributes to the structure of high-altitude animal communities in glacierized catchments. In terms of the applied fields, we argue that freshwater bioassessment in glacierized catchments can benefit from incorporating the metacommunity perspective and applying novel approaches to (i) detect the optimal spatial scale for species sorting and (ii) identify and eliminate the species that are sensitive to dispersal-related processes.

The macroevolutionary singularity of snakes.

Snakes and lizards (Squamata) represent a third of terrestrial vertebrates and exhibit spectacular innovations in locomotion, feeding, and sensory processing. However, the evolutionary drivers of this radiation remain poorly known. We infer potential causes and ultimate consequences of squamate macroevolution by combining individual-based natural history observations (>60,000 animals) with a comprehensive time-calibrated phylogeny that we anchored with genomic data (5400 loci) from 1018 species. Due to shifts in the dynamics of speciation and phenotypic evolution, snakes have transformed the trophic structure of animal communities through the recurrent origin and diversification of specialized predatory strategies. Squamate biodiversity reflects a legacy of singular events that occurred during the early history of snakes and reveals the impact of historical contingency on vertebrate biodiversity.

Long-term recovery of Mediterranean ant and bee communities after fire in southern Spain

Wildfires play a determinant role in the composition and structure of animal communities, especially for groups closely associated with the vegetation and soil, such as bees or ants. The effects of fire on animal communities depend on the functional traits of each group. Here, we assessed the impacts of fire and time since fire on the taxonomic and functional responses of ant and bee communities. We sampled 35 pine forests in Andalusia (southern Spain) that had experienced fire in the past (0 to 41 years ago). Specifically, we explored whether a) fire increased taxonomic and functional diversity and changed community composition in communities in the short term and b) fire influence (increase or decrease) on ant communities would be dependent on time since fire. We found that ant and bee taxonomic richness increased regardless of time since fire. Different approaches gave the same result, such as taxonomic diversity indexes (ant abundance, ant richness and ant Shannon diversity index), the changes in species richness in ant and bee communities, as well as the higher number of ant and bee species prone to the burned habitat than to the unburned habitat, using the Ihabitat Index. Besides environmental variables (such as the effects of different Pinus species or elevation), time since fire changed the taxonomic composition of ant communities and the functional composition of bee communities. Moreover, six of the 13 ant functional traits explored differed between burned and unburned areas, with the degree of difference declining as time since fire increased. For example, burned areas contained ant communities with more ground-nesting species and strictly diurnal species, functional traits that are characteristic of open areas. In contrast, other traits persisted in burned areas over the long term, notably a higher degree of worker polymorphism and species monogyny. Our study shows how much short- and long-term effects of fire on ant and bee communities differ; while richness increases in the long-term, some functional traits are also filtered in the short-term. We suggest that fire in Mediterranean coniferous ecosystems could have a positive effect on these groups and should not be overlooked.

The Biological and Anthropogenic Soundscape of an Urbanized Port - the Charleston Harbor Estuary, South Carolina, USA.

Soundscape ecology provides a long-term, noninvasive approach to track animal behavior, habitat quality, and community structure over temporal and spatial scales. Using soniferous species as an indicator, biological soundscapes provide information about species and ecosystem health as well as their response and resiliency to potential stressors such as noise pollution. Charleston Harbor, South Carolina, USA provides important estuarine habitat for an abundance of marine life and is one of the busiest and fastest growing container ports in the southeast USA. Six passive acoustic recorders were deployed in the Charleston Harbor from December 2017 to June 2019 to determine biological patterns and human-associated influences on the soundscape. Anthropogenic noise was detected frequently across the estuary, especially along the shipping channel. Despite this anthropogenic noise, biological sound patterns were identified including snapping shrimp snaps (Alpheus spp. and Synalpheus spp.), fish calling and chorusing (Sciaenidae and Batrachoididae families), and bottlenose dolphin vocalizations. Biological response to anthropogenic activity varied among trophic levels, with decreased detection of fish calling when anthropogenic noise occurred and increased dolphin vocalizations in the presence of anthropogenic noise. Statistically, fine-scale, temporal patterns in biological sound were not clearly identified by sound pressure levels (SPLs), until files with anthropogenic noise presence were removed. These findings indicate that SPL patterns may be limited in their interpretation of biological activity for noisy regions and that the overall acoustic signature that we find in more pristine estuaries is lost in Charleston Harbor.

Community Study of Brachyuran Crab at Setiu Lagoon, Terengganu, Malaysia

Brachyuran crab of Setiu Lagoon was systematically sampled between July 2011 and May 2012 to determine the community structure of animals and their relationship with environmental parameters. The semiterrestrial crabs were collected from a 100 m2 quadrat at eight stations. In addition, fishing devices were used to collect true aquatic crabs employed at the subtidal habitat. Forty-four species and 13 families were identified representing semiterrestrial and true aquatic crabs (i.e., Sesarmidae, Varunidae, Grapsidae, Ocypodidae, Macropthalmidae, Dotillidae, Camptandriidae, Pilumnidae, Portunidae, Eriphiidae, Oziidae, Dorippidae and Leucosiidae). Parasesarma plicatum, Perisesarma eumolpe, Clistocoeloma merguiense, Haberma sp., Uca (Austruca) annulipes, Uca (Gelasimus) vocans, and Moguai aloutos) were widely distributed in this lagoon. ST5 (at mix mangrove forest) recorded the highest number of species with density (12 ind.m-2), species richness (D = 2.68 ± 0.72), species evenness; (J’ = 0.90 ± 0.06) and species diversity (H’ = 2.17 ± 0.32) as compared to other stations. The results indicated that water salinity, pH and sediment grain size influence the community pattern of brachyuran in this lagoon.

The Białowieża Forest as a Key Area for Understanding the History of European Forest Bird Communities

The last remnants of pristine forests in Europe, especially in the nemoral belt of deciduous and mixed deciduous coniferous trees, are unique for understanding the history, composition and structure of plant and animal communities. This is especially true for the Białowieża forest, NE Poland. The biogeographical history of emblematic forest clades of birds, e.g. woodpeckers, tits and nuthatches, is analyzed from molecular phylogenies which allow to determine their pace and mode of origination and differentiation. The flyways which connect temperate and tropical realms played a major role in the origination and differentiation of many extant lineages. Then, large differences in the structure of bird communities between North American and European forests are discussed and explained in the light of the geographic configuration of major land masses and past climatic changes and upheavals throughout the Neogene. From long term in depth studies in this forest, the composition and structure of bird communities may be used as references for understanding and measuring the processes and mechanisms of change in communities of the western managed forests.

Characterization and Dynamics of the Gut Microbiota in Rice Fishes at Different Developmental Stages in Rice-Fish Coculture Systems.

The rice-fish system (RFS), a traditional coculture farming model, was selected as a "globally important agricultural heritage system." Host-associated microbiota play important roles in development, metabolism, physiology, and immune function. However, studies on the gut microbiota of aquatic animals in the RFS are scarce, especially the lack of baseline knowledge of the dynamics of gut microbial communities in rice fish during different developmental stages. In this study, we characterized the microbial composition, community structure, and functions of several sympatric aquatic animals (common carp (Cyprinus carpio), crucian carp (Carassius carassius), and black-spotted frogs (Pelophylax nigromaculatus)), and the environment (water) in the RFS using 16S rRNA gene sequencing. Moreover, we investigated stage-specific signatures in the gut microbiota of common carp throughout the three developmental stages (juvenile, sub-adult, and adult). Our results indicated that the Fusobacteriota, Proteobacteria, and Firmicutes were dominant gut microbial phyla in rice fish. The differences in gut microbial compositions and community structure between the three aquatic species were observed. Although no significant differences in alpha diversity were observed across the three developmental stages, the microbial composition and community structure varied with development in common carp in the RFS, with an increase in the relative abundance of Firmicutes in sub-adults and a shift in the functional features of the community. This study sheds light on the gut microbiota of aquatic animals in the RFS. It deepens our understanding of the dynamics of gut microflora during common carp development, which may help improve aquaculture strategies in the RFS.

Urbanization and greenspace type as determinants of species and functional composition of collembolan communities

Urban regions are rapidly expanding worldwide resulting in biotic homogenization and loss of ecological functions in urban ecosystems due to management practices targeting at satisfying aesthetic and health demands of urban residents. These practices also modify living conditions and food recourses of soil invertebrates thereby affecting the structure and functional diversity of soil animal communities including collembolans. Here, we assessed the response of the community composition and functional diversity of collembolans as a major component of soil food webs to urbanization (suburban vs urban region) and greenspace types (including forest and four park-associated greenspaces: lawn, lawn with shrubs, lawn with trees, and lawn with shrubs and trees). Our results highlight that both urbanization and greenspace type significantly affect soil properties and community structure of collembolans. The negative effect of urbanization and park-associated greenspaces on species and functional composition of collembolan communities were likely due to both changes in soil abiotic conditions and bacterial community composition, whereas the reduction of collembolan functional traits likely resulted from changes in soil abiotic conditions and fungal community composition. In park-associated greenspaces richness and diversity of bacterial communities were highest in lawns with trees and lowest in forests. By contrast, species richness and diversity of fungal communities were highest in lawns with shrubs, but, similar to bacteria, lowest in forests. Community composition and functional traits of collembolans were more homogeneous in urban than suburban greenspaces pointing to reduced functioning of collembolan assemblages in urban areas. Overall, our results suggest that changes in soil properties and bacterial communities caused by urbanization and greenspace type are important factors contributing to taxonomic homogenization of collembolan communities, while the loss of functional traits of collembolan communities in urban greenspaces is likely caused by changes in soil properties and fungal community composition.

Some results of the research of mammals and birds inhabiting the Polar Ural Mountains foothills

This paper describes some results of the research of mammals and birds fauna and population structure as ecosystem condition indicators, and provides an investigation of flora and soil to establish habitats structural peculiarities. The research covered an area of a future road from Kharp Village through a ski resort to the Snowflake International Arctic Station (Priuralsky District, Yamal-Nenets Autonomous Okrug, Russia). Our study aims at assessing the environmental impact of the project. In the areas typical habitats, we registered two small mammal species (Clethrionomys (= Myodes) rutilus, Sorex araneus), 25 bird species, traces of three medium and large mammal species presence (Lepus timidus, Vulpes vulpes, Rangifer tarandus). Micromammals show very low abundance, low indices of small mammal communities diversity and sustainability, Cl. rutilus being an absolute dominant. The bird species show a relatively low level of abundance. The composition and structure of animal and bird communities are in line with natural and climate conditions of the Polar Urals foothills. The investigation results revealed low resource capacity, sustainability and biotic communities vulnerability to any impact. The study materials suggest that the future road from Kharp Village to the Snowflake International Arctic Station will not significantly harm mammal and bird population of the area, and will provide facilities for recreational and tourist activities, and will mitigate risks of anthopogenic impact on these vulnerable ecosystems.

Fear as an enemy? Behavioral changes of Ananteris mauryi (Scorpiones: Buthidae) triggered by chemical cues from an intraguild predator

Fear level and intraguild predation are factors that act together to directly influence animal behavior, population dynamics, and community structure. These factors trigger stress, which promotes behavioral, morphological, physiological, and demographic changes, especially in the prey. Some invertebrates, such as scorpions, are known to have a refined chemoreception system to perceive both prey and predators. Therefore, we investigated the ability of an intraguild prey, the scorpion Ananteris mauryi Lourenço, 1982, to detect chemical traces of its predator, the scorpion Tityus pusillus Pocock, 1893. Our goal was to verify whether A. mauryi exhibits antipredator behavior induced exclusively by chemical cues from its predator. Ananteris mauryi specimens were subjected to two experimental treatments: one with and one without traces of T. pusillus. The results showed that A. mauryi tended to avoid substrates with chemical traces of T. pusillus, confirming its capacity for chemical detection. As a result of this perception, changes in behavioral frequencies were triggered, generating an antipredator behavioral repertoire. These findings were supported by behavioral changes, such as tail wagging, which is performed exclusively by scorpions in the presence of a predator and at imminent risk of predation.

Environmental risks of antibiotics in soil and the related bioremediation technologies

Antibiotics are widely used and prevalently distributed in the environment. The issue of antibiotic resistance genes has posed a huge threat to the global public health. Soil is an important sink of antibiotics in the environment. Antibiotic exposure may introduce adverse effects on soil organisms, and bring indirect but potential risks to human health. Therefore, it is urgent to take actions to remediate antibiotics-contaminated soil. This review summarized effects of antibiotics on phenotype growth of plants, physiological characteristics and community structure of animals, composition and structure of microbial communities, and transmission of antibiotic resistance genes among organisms in soil. Additionally, the potential and prospects of employing antibiotic-resistant soil plants, animals, microorganisms, and their combinations to treat antibiotics-contaminated soil were illustrated. Last but not least, the unaddressed issues in this area were proposed, which may provide insights into relevant research directions in the future.

Community structure and ecological distribution of benthic animals in Tien Hai mangrove forest, Northern Vietnam

Mangroves are a diverse and rich ecosystem, in which many animals are associated, including benthos. Species composition and occurrence of these animals are driven by the mangroves and tidal conditions. To examine how the benthic animal is distributed in mangrove habitats from northern Vietnam, two surveys in 2019 were conducted in Tien Hai Wetland Nature Reserve, which resulted in a total of 89 species, belonging to 56 genera and 35 families of zoobenthos. This is the first publication of these animals in the study site. The two major groups of benthic animals in the ecosystem were Crustacea and Mollusca, which occupy 54.02% and 36.78% of the total species, respectively. There are several new records of these animals from the coastal mangroves of Vietnam. Two species were new data for northern Vietnam (Scopimera curtelsoma and Parasesarma eumolpe), and four species were new records for Vietnam (Laemodonta punctigera, Cassidula nucleus, Pythia cecillei and Microtralia alba). Also, the present study shows distributional characteristics of the benthic animal community in mangrove forests. The present study indicates that benthic animals show an increase in species diversity and density from the river mouth to the continent. Seasonally quantitative data of benthic from the study site are the first work in mangrove forests of Vietnam. Recent findings are fundamental data for further studies on zoobenthos and related issues to preserve biodiversity in the mangrove forests in Vietnam.

Abstract 927: Gut microbiome changes are associated with the efficacy of Delta-24-RGDOX viroimmunotherapy against malignant glioma

Abstract Malignant gliomas are devastating diseases that require new and more effective treatments. To improve clinical outcomes, our laboratories have developed an oncolytic adenovirus armed with the T-cell activator OX40L, named Delta-24-RGDOX. Here, we evaluated changes to gut microbiome in glioma bearing mice treated with viroimmunotherapy. GL261 glioblastoma cells were implanted in the brain of immunocompetent C57BL/6 mice. Then mice were treated with intratumoral injections of control (PBS) or a combination of Delta-24-RGDOX and Indoximod, an inhibitor of the immune modulator IDO. The combined immunotherapy prolonged mice overall survival with the production of long-term survivors (>100 days). We also performed a similar set of experiments in mice with depleted CD4+ T cell. Genomic DNA was isolated with the Powerlyzer kit from fecal pellets collected from glioma-bearing mice (n=15), followed by sequencing of the 16S ribosomal RNA V4 region (prokaryotes) and ITS-2 region (for fungi) using the Illumina platform. Data was analyzed at first and deposited in Qiita, the taxonomic reference was the SILVA database, and community analyses were performed in QIIME and R with a rarefaction depth of 27,000 reads for 16S and 500 reads for ITS. We found significant differences in the gut microbiome community structure of viroimmunotherapy-treated animals compared to those with depleted CD4+ T cells and controls which shared similarities (PERMANOVA p<0.001). The highest gut diversity was observed in viroimmunotherapy in animals in which the T cell populations were not depleted which also corresponded to long-term survivors (KW p=0.006). The gut bacterial community structure of viroimmunotherapy-treated animals without T-cell depletion showed an increase in Actinobacteria compared to control-treated mice and those with shorter survival. In fact, we found significantly higher amounts of Bifidobacterium and Lactobacillus in the viroimmunotherapy-treated mice while Moryella were more dominant in the control groups (WRST p<0.05). We did not find significant differences in structure nor diversity of the fungal communities which were dominated by Ascomycota with Alternaria and Fusarium. However, control-treated animals had higher amounts of Aspergillus while Trichoderma were increased in viroimmunotherapy-treated mice.Our data suggests that bacterial communities play an important role in modulating viroimmunotherapy against glioma in immunocompetent animal glioma models. Importantly, increase in Bifidobacterium and Lactobacillus was associated with a better response to the therapy, likely strengthening antitumor immunity and raising efficacy in viroimmunotherapy-treated mice. This reveals the benefits of gut microbiome therapeutics in positively influencing the final clinical outcome of viroimmunotherapy. Sponsored by NCI's 2U54CA096297-16. Citation Format: Candelaria Gomez-Manzano, Natalie M. Melendez-Vazquez, Teresa Nguyen, Ashley Ossimetha, Hong Jiang, Juan Fueyo, Filipa Godoy-Vitorino. Gut microbiome changes are associated with the efficacy of Delta-24-RGDOX viroimmunotherapy against malignant glioma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 927.

Fire and Its Interactions With Other Drivers Shape a Distinctive, Semi-Arid ‘Mallee’ Ecosystem

Fire shapes ecosystems globally, including semi-arid ecosystems. In Australia, semi-arid ‘mallee’ ecosystems occur primarily across the southern part of the continent, forming an interface between the arid interior and temperate south. Mallee vegetation is characterized by short, multi-stemmed eucalypts that grow from a basal lignotuber. Fire shapes the structure and functioning of mallee ecosystems. Using the Murray Mallee region in south-eastern Australia as a case study, we examine the characteristics and role of fire, the consequences for biota, and the interaction of fire with other drivers. Wildfires in mallee ecosystems typically are large (1000s ha), burn with high severity, commonly cause top-kill of eucalypts, and create coarse-grained mosaics at a regional scale. Wildfires can occur in late spring and summer in both dry and wet years. Recovery of plant and animal communities is predictable and slow, with regeneration of eucalypts and many habitat components extending over decades. Time since the last fire strongly influences the distribution and abundance of many species and the structure of plant and animal communities. Animal species display a discrete set of generalized responses to time since fire. Systematic field studies and modeling are beginning to reveal how spatial variation in fire regimes (‘pyrodiversity’) at different scales shapes biodiversity. Pyrodiversity includes variation in the extent of post-fire habitats, the diversity of post-fire age-classes and their configuration. At regional scales, a desirable mix of fire histories for biodiversity conservation includes a combination of early, mid and late post-fire age-classes, weighted toward later seral stages that provide critical habitat for threatened species. Biodiversity is also influenced by interactions between fire and other drivers, including land clearing, rainfall, herbivory and predation. Extensive clearing for agriculture has altered the nature and impact of fire, and facilitated invasion by pest species that modify fuels, fire regimes and post-fire recovery. Given the natural and anthropogenic drivers of fire and the consequences of their interactions, we highlight opportunities for conserving mallee ecosystems. These include learning from and fostering Indigenous knowledge of fire, implementing actions that consider synergies between fire and other processes, and strategic monitoring of fire, biodiversity and other drivers to guide place-based, adaptive management under climate change.

Elevational gradients strongly mediate habitat selection patterns in a nocturnal predator

AbstractMountain ecosystems contain strong elevational gradients in climate and vegetation that shape species distributions and the structure of animal communities. Nevertheless, studies of habitat selection for individual species rarely account for such gradients that often result in species being managed uniformly across their range, which may not improve conservation as intended. Therefore, we characterized variation in nocturnal habitat selection by 18 GPS‐tagged California spotted owls (Strix occidentalis occidentalis) along a 1400‐m elevational gradient in the Sierra Nevada, California. We characterized three‐dimensional forest structure with light detection and ranging data that we used in mixed‐effects resource‐ and step‐selection analyses of owl habitat selection. At lower elevations, owls selected stands with shorter trees, sites closer to hard edges between tall forests and open areas, sites with less diversity in forest seral types and sites with more ridge and southwest aspects. In contrast, owls at higher elevations selected the opposite. Within public forests that had taller trees and within their home range core (45% kernel density estimate of GPS points) areas, owls selected forests with less and more canopy cover at low and high elevations, respectively. Outside of their core areas, owls selected areas with fewer and more tall trees at low and high elevations, respectively. These findings may be explained by elevational gradients in prey distribution and variation in owl diet because owls consume more woodrats (Neotoma spp; earlier seral species) at lower elevations and more flying squirrels (Glaucomys sabrinus; older forest species) at higher elevations. Thus, at low elevations and in areas unlikely to support nesting, spotted owls could benefit from management that promotes woodrat habitat by encouraging oak regeneration and creating small brushy openings within forests with shorter (younger) trees. Conversely, at higher elevations, (1) enhancing flying squirrel habitat by promoting large trees and denser canopy on mesic sites and (2) managing for greater cover type diversity on southwest‐facing slopes and ridgetops is more likely to improve foraging habitat quality for spotted owls. The patterns of owl selection over elevational gradients has not been explicitly considered in most habitat management plans but clearly would improve management throughout mountain ecosystems.

Diversity and functional structure of soil animal communities suggest soil animal food webs to be buffered against changes in forest land use

Forest soil and litter is inhabited by a diverse community of animals, which directly and indirectly rely on dead organic matter as habitat and food resource. However, community composition may be driven by biotic or abiotic forces, and these vary with changes in habitat structure and resource supply associated with forest land use. To evaluate these changes, we compiled comprehensive data on the species composition of soil animal communities and environmental factors in forest types varying in land-use intensity in each of three regions in Germany, i.e., coniferous, young managed, old managed, and unmanaged beech forests. Coniferous forests featured high amounts of leaf litter and low microbial biomass concentrations contrasting in particular unmanaged beech forests. However, soil animal diversity and functional community composition differed little between forest types, indicating resilience against disturbance and forest land use. Structural equation modelling suggested that despite a significant influence of forest management on resource abundance and quality, the biomass of most soil fauna functional groups was not directly affected by forest management or resource abundance/quality, potentially because microorganisms hamper the propagation of nutrients to higher trophic levels. Instead, detritivore biomass depended heavily on soil pH. Macrofauna decomposers thrived at high pH, whereas mesofauna decomposers benefitted from low soil pH, but also from low biomass of macrofauna decomposers, potentially due to habitat modification by macrofauna decomposers. The strong influence of soil pH shows that decomposer communities are structured predominantly by regional abiotic factors exceeding the role of local biotic factors such as forest type.