Biotic Habitat Research Articles

Determinants of microbial community structure in supraglacial pool sediments of monsoonal Tibetan Plateau.

Supraglacial pools are prevalent on debris-covered mountain glaciers, yet only limited information is available on the microbial communities within these habitats. Our research questions for this preliminary study were: (1) What microbes occur in supraglacial pool sediments of monsoonal Tibet?; (2) Which abiotic and biotic habitat variables have the most influence on the microbial community structure?; and (3) Does microbial composition of supraglacial pool sediments differ from that of glacial-melt stream pool sediments? We collected microbial samples for 16S rRNA sequencing and invertebrates for enumeration and identification and measured 14 abiotic variables from 46 supraglacial pools and nine glacial-melt stream pools in 2018 and 2019. Generalized linear model analyses, small sample Akaike information criterion, and variable importance scores were used to identify the best predictor variables of microbial community structure. Multi-response permutation procedure (MRPP) was used to compare taxa composition between supraglacial pools and stream pools. The most abundant phyla in supraglacial pool sediments were Proteobacteria, Actinobacteria, Bacteroidota, Chloroflexi, and Cyanobacteria. Genera richness, indicator genera richness, and Polaromonas relative abundance were best predicted by Chironomidae larvae abundance. Angustibacter and Oryzihumus relative abundance were best predicted by pH, Acidiphilium relative abundance was best predicted by turbidity, and Sphingomonas relative abundance was best predicted by glacier zone. Taxa composition was similar between supraglacial and stream pools at the class, genus, and ASV taxonomic levels. Our results indicate that Chironomidae larvae may play a keystone species role in shaping bacterial communities of supraglacial pools on debris-covered glaciers.IMPORTANCEGlacier meltwater habitats (cryoconite holes, supraglacial pools, supraglacial ponds and lakes, glacial streams) and their biota have not been well-studied, especially on debris-covered glaciers in temperate monsoonal regions. Our study is the first to document the microbial community-habitat relationships in supraglacial pools on a debris-covered glacier in Tibet. Microbial genera richness, indicator genera richness, and Polaromonas relative abundance declined with increasing larval Chironomidae abundance, which is a novel finding that highlights the importance of larval insects in structuring microbial communities in supraglacial pools.

Spatial Distribution and Status of Biota Habitats in the Forest Reserves of Omo and Ago-Owu in Ogun State, Oluwa in Ondo State, and Ife and Shaha in Osun State, Southwestern Nigeria

Spatial Distribution and Status of Biota Habitats in the Forest Reserves of Omo and Ago-Owu in Ogun State, Oluwa in Ondo State, and Ife and Shaha in Osun State, Southwestern Nigeria

Seagrass Meadow Conditions in Coastal Waters of Siwak Bay Central Lombok

Seagrass is a flowering plant thriving in shallow sea waters and estuaries. Seagrass ecosystems are essential in supporting life in shallow seas as primary producers, biota habitats, sediment trappers, and nutrient trappers. Environmental factors affecting seagrass growth include temperature, salinity, pH, and substrate. The study was conducted in March-June 2023. This study aimed to determine the type and condition of seagrass beds in the waters of Siwak Bay. The method used in this study is the quadrant transect method at three research stations. There are seven types of seagrass identified, namely Thalassia hemprichii, Halophila ovalis, Cymodocea rotundata, Cymodocea serrulata, Halodule pinifolia, Halodule uninervis, and Syringodium isoetifolium. The percentage of total seagrass cover is at a value of 37%-61%, indicating that the condition of seagrass beds in the waters of Siwak Bay is included in the unhealthy category. The highest species density found at station III in Halodule pinifolia was 483.5 stands/m², and the lowest was found at stations II and III in Thalassia hemprichii and Cymodocea serrulata with 0 stands/m². The average density value of seagrass beds in the waters of Siwak Bay is very dense. The highest type frequency was found in Cymodocea rotundata, with a value of 2.53. The tallest species diversity and diversity index was found at station II with values of 1.56 and 0.8, respectively. In contrast, the highest dominance index was found at station I, with a value of 0.44.

Spatial and Temporal Dynamics of the Vegetation Cover from the Bijagual Massif, Boyacá, Colombia, during the 1986-2021 Period.

Landscape changes based on spectral responses allow showing plant cover changes through diversity, composition, and ecological connectivity. The spatial and temporal vegetation dynamics of the Bijagual Massif from 1986 to 2021 were analyzed as a measure of ecological integrity, conservation, and territory. The covers identified were high open forest (Hof), dense grassland of non-wooded mainland (Dgnm), a mosaic of pastures and crops (Mpc), lagoons (Lag), and bare and degraded lands (Bdl). The Bijagual Massif has 8574.1 ha. In 1986, Dgnm occupied 42.6% of the total area, followed by Mpc (32.8%) and Hof (24.5%); by 2000, Mpc and Hof increased (43.7 and 28.1%, respectively), while Dgnm decreased (28%); by 2021, Dgnm was restricted to the northeastern zone and continued to decrease (25.2%), Mpc occupied 52.9%, Hof 21.7% and Bdl 0.1%. Of the three fractions of the connectivity probability index, only dPCintra and dPCflux contribute to ecological connectivity. Hof and Dgnm show patches with biota habitat quality and availability. Between 1986 and 2021, Dgnm lost 1489 ha (41%) and Hof 239.5 ha (11%). Mpc replaced various covers (1722.2 ha; 38%) in 2021. Bijagual has a valuable biodiversity potential limited by Mpc. Territorial planning and sustainable agroecological and ecotourism proposals are required due to the context of the ecosystems.

The impacts of non-native watercress in Oklahoma spring ecosystems

Watercress (Nasturtium officinale) has spread widely from Europe and commonly occurs in Oklahoma (USA) springs. Watercress is usually an emergent plant and affects water flow patterns and may provide habitat for biota. Although watercress is not considered an invasive species, its impacts in springs have not been reported. With a goal to describe possible impacts of watercress in springs, 14 karst-associated springs (12 with watercress) were surveyed for sediment characteristics, macroinvertebrates, and diatoms in July 2021. The effects of watercress were evident. Sediment particle size was unaffected by the presence of watercress but sediment organic matter was higher under watercress beds than outside of beds. Although there was no difference in total benthic macroinvertebrate density or richness, higher organic matter was associated with slightly higher abundances of detritivorous and predatory macroinvertebrates (SIMPER). Submerged portions of watercress had significantly much lower diatom density than other spring substrates, with diatom composition similar to other plants but different from that of rocks. Self-shading or possible allelopathy may cause the low diatom density. The significantly lower macroinvertebrate density within watercress mats relative to that of other plants may result from a reduced food source because the plant’s low diatom density. Only predatory damselflies were more common in watercress than in other plants, which had more abundant grazers. Although watercress can increase heterogeneity in sediments and is sometimes valued as an edible plant, watercress supports low algal and macroinvertebrate densities, such that extensive growth of watercress can have an overall negative impact on spring ecosystems.

Seasonal Variation Analysis of Microplastic Distribution in the Estuary of Brantas River

Every year, 0.48-1.29 million tonnes of plastic waste is estimated to enter the waters due to poor plastic waste management in Indonesia. Plastic waste has the potential to be degraded into smaller particles through ultraviolet (UV) radiation, weathering process, water currents, physical-mechanical and biodegradation. Plastics with particle sizes between >1 μm and <5 are categorized as microplastics (MP). Microplastic particles are mainly distributed in surface waters. Rivers are considered as the main route of plastic transportation from the land to the ocean. The Brantas River in Surabaya is the main downstream section of the Brantas River and plays an important role in providing clean water for Surabaya City, aquatic biota habitat, and irrigation. With extreme weather conditions such as long dry seasons and high rainfall in the rainy season distribution and abundance of microplastics in water bodies/rivers tend to vary. The study's goal is to determine the effect of seasonal water volume (dry and rainy) on the abundance and characteristics of microplastics in water and sediment samples from the downstream Brantas River (Surabaya city). Observations of the abundance of microplastics in water and sediment at three stations during the dry season revealed a trend of increasing abundance downstream. Microplastics were abundant in the water at sta 1 with an average of 0.8 particles/L, sta 2 with 1.25 particles/L, and sta 3 with 1.02 particles/L. The abundance of microplastics in the sediment at sta 1 averaged 0.2 particles/gr, sta 2 0.51 particles/gr, and sta3 0.25 particles/gr. Meanwhile, in the rainy season, the abundance of microplastics in water and sediment shows a higher abundance compared to the dry season. Abundance of microplastics in the water at sta 1 with an average of 0.9 particles/L, sta 2 1.24 particles/L, and sta3 1.17 particles/L. The abundance of microplastics in the sediment at sta 1 averaged 0.55 particles/gr, sta 2 0.56 particles/gr, and sta3 0.60 particles/gr.

Shipwreck ecology: Understanding the function and processes from microbes to megafauna.

An estimated three million shipwrecks exist worldwide and are recognized as cultural resources and foci of archaeological investigations. Shipwrecks also support ecological resources by providing underwater habitats that can be colonized by diverse organisms ranging from microbes to megafauna. In the present article, we review the emerging ecological subdiscipline of shipwreck ecology, which aims to understand ecological functions and processes that occur on shipwrecks. We synthesize how shipwrecks create habitat for biota across multiple trophic levels and then describe how fundamental ecological functions and processes, including succession, zonation, connectivity, energy flow, disturbance, and habitat degradation, manifest on shipwrecks. We highlight future directions in shipwreck ecology that are ripe for exploration, placing a particular emphasis on how shipwrecks may serve as experimental networks to address long-standing ecological questions.

How does trait variance partitioning help us to understand plant community assembly? The example of pond communities in the Kerguelen Islands

AbstractQuestionIn the current context of biodiversity erosion, functional approaches to the examination of community assembly mechanisms and better prediction of plant species fates have emerged. The assessment of trait variation patterns should be a powerful means of identifying community assembly mechanisms. However, most studies of trait variations and their consequences for individual performance (i.e., vegetative biomass) are usually incomplete as they focused on single ecological scales or filters, with no consideration of relationships between traits. Such research has provided a fragmented view of plant community assembly.LocationWe examined macrophyte communities living in ponds of the sub‐Antarctic Iles Kerguelen.MethodsWe measured traits related to resource acquisition and conservation in all occurring species, and examined their variation across temporal (years), spatial (sites), and taxonomic (between and within species) scales and in response to multiple abiotic and biotic habitat variables. The consequences of these trait variations and the effects of their correlation for plant individual performance were also explored.ResultsTrait distributions were fairly conserved among sites, whereas we observed a large amount of intraspecific trait variation enabling individuals to resist filters. Responses to biotic and/or abiotic variables were trait‐dependent, and simultaneous trait responses should enable individual plants to face several simultaneous constraints. Almost all traits had direct or indirect effects on individual performance, indicating the need to consider trait relationships.ConclusionThe partitioning of trait variance is a relevant approach to the identification of the scale at which the most decisive processes for plant community assembly operate without the interference of scale dependency issues, and should orient further research. In addition, several biotic and abiotic variables should be considered in future studies to better understand the effects of environmental changes on plant communities.

High resolution lidar data shed light on inter-island translocation of endangered bird species in the Hawaiian Islands.

Translocation, often a management solution reserved for at-risk species, is a highly time-sensitive intervention in the face of a rapidly changing climate. The definition of abiotic and biotic habitat requirements is essential to the selection of appropriate release sites in novel environments. However, field-based approaches to gathering this information are often too time intensive, especially in areas of complex topography where common, coarse-scale climate models lack essential details. We apply a fine-scale remote sensing-based approach to study the 'akikiki (Oreomystis bairdi) and 'akeke'e (Loxops caeruleirostris), Hawaiian honeycreepers endemic to Kaua'i that are experiencing large-scale population declines due to warming-induced spread of invasive disease. We use habitat suitability modeling based on fine-scale light detection and ranging (lidar)-derived habitat structure metrics to refine coarse climate ranges for these species in candidate translocation areas on Maui. We found that canopy density was consistently the most important variable in defining habitat suitability for the two Kaua'i species. Our models also corroborated known habitat preferences and behavioral information for these species that are essential for informing translocation. We estimated a nesting habitat that will persist under future climate conditions on east Maui of 23.43 km2 for 'akikiki, compared to the current Kaua'i range of 13.09 km2 . In contrast, the novel nesting range for 'akeke'e in east Maui was smaller than its current range on Kaua'i (26.29 vs. 38.48 km2 , respectively). We were also able to assess detailed novel competitive interactions at a fine scale using models of three endemic Maui species of conservation concern: 'ākohekohe (Palmeria dolei), Maui 'alauahio (Paroreomyza montana), and kiwikiu (Pseudonestor xanthophrys). Weighted overlap areas between the species from both islands were moderate (<12 km2 ), and correlations between Maui and Kaua'i bird habitat were generally low, indicating limited potential for competition. Results indicate that translocation to east Maui could be a viable option for 'akikiki but would be more uncertain for 'akeke'e. Our novel multifaceted approach allows for the timely analysis of both climate and vegetation structure at informative scales for the effective selection of appropriate translocation sites for at-risk species.

Composition of Soil Bacterial and Nematode Communities within Soil Aggregates in a Kiwifruit Orchard under Cover Crop Treatment

Soil, which exhibits difference in nutrient contents and aggregate sizes, provides spatially distinct habitats for biota. Cover crops influence the compositions of soil organism communities, playing an indispensable role in regulation of underground food webs and ecosystem functions. However, the effect of cover crops on soil microbes and nematodes distribution within different aggregate sizes remains unknown. Thus, a field experiment in a kiwifruit orchard with cover crops was conducted to estimate the distribution of soil nematodes and bacteria with different soil aggregate sizes (mega-aggregate (&gt;2 mm, LMA), macro-aggregate (0.25–2 mm, SMA), and micro-aggregate (&lt;0.25 mm, MA)) and cover crop treatments (four cover crop species (CC) and no cover crop as control (CK)). The results showed that bacterial compositions varied with both aggregate sizes and cover crop treatments. The composition of bacterial community was significantly different between mega-aggregate and micro-aggregate, and bacterial community diversity was significantly higher in micro-aggregate compared with mega-aggregate. Moreover, cover crop treatment dramatically changed the compositions of bacterial communities. However, the nematode communities were mainly impacted by soil aggregate sizes. Larger aggregates (mega- and macro-aggregates) contained higher abundance of omnivores/predators and lower abundance of fungivores. In contrast to bacterial community, the richness of nematode community was lower in micro-aggregates compared with larger aggregates (mega- and macro-aggregates). Redundancy analysis (RDA) and structural equation model (SEM) showed soil organic carbon (SOC) was the main soil factor that directly and indirectly affected both bacterial and nematode communities. The investigations of both bacterial and nematode communities could provide a better understanding on carbon and nutrient cycling across aggregate size fractions.

Habitat selection and population status of breeding Wood Snipe Gallinago nemoricola in an alpine meadow in Sichuan, China

Summary The Wood Snipe Gallinago nemoricola is one of the least known shorebird species, and its habitat associations are very poorly understood. Here we provide the first assessment of the habitat use of the Wood Snipe during the breeding season. Between May and July 2021 at a 4-km2 alpine meadow in Sichuan province, China, we conducted population surveys and behavioural observations to identify sites where breeding Wood Snipe occurred and foraged. We quantified the habitat characteristics and food resource availability of these sites and compared them with randomly selected “background” sites. Comparison between 34 occurrence sites and 25 background sites indicated that during the breeding season, Wood Snipes are not distributed evenly across alpine meadow habitats, but preferred habitats in the lower part (3,378–3,624 m) of the alpine meadow with intermediate levels of soil moisture. In addition, comparison between 17 foraging sites and 24 background sites showed that the Wood Snipe tended to forage at sites with higher soil fauna abundance. We found weak evidence for denser vegetation cover at its height and no evidence for other biotic habitat variables such as vegetation composition or other abiotic habitat variables such as slope, soil penetrability, or disturbance level to influence Wood Snipe habitat associations. Our results suggest that the actual distribution range of the Wood Snipe during the breeding season may be smaller than expected from the extent of apparently suitable habitat. We advise caution in evaluating the potential habitat availability and distribution of the Wood Snipe, and call for further research to better understand the ecology of this rare species to inform its conservation.

Toxicity of sediments in eight urban stormwater management ponds: bioassessment by oligochaete community metrics used in the sediment quality triad.

Implemented for decades as part of the 'best management practices (BMPs)' for controlling urban runoff impacts on receiving waters, stormwater management ponds (SMPs) have been increasingly viewed as potential habitats for urban wildlife. However, since SMPs are subject to a lot of environmental constraints, research toward assessing their ecological quality and their actual benefits as habitats for biota is needed. In this study, the sediment toxicity of eight SMPs located in Southern Ontario, Canada was assessed using the sediment quality triad (SQT) approach. Sediment samples were collected for chemical, ecotoxicological and biological analyses. An oligochaete-based index approach (Oligochaete Index of Lake Bioindication and percentage of pollution-sensitive species) was used as the biological endpoint and integrated into a weight-of-evidence approach to assessing the general sediment quality of the ponds. Our results showed that (i) heavy metals in the sediment and (ii) chloride concentrations in the sediment interstitial water caused detrimental effects on the ecological quality of the sediments in the ponds studied. The oligochaete indices applied in this study showed value as biological endpoints to be integrated into the SQT and used for setting up sediment ecological quality goals.

DNA barcode of seven species coral from Sepulu, Madura Island, Indonesia

Abstract. Insafitri, Nursalim N, Kholilah N, Kurniasih EM, Cahyani NKD, Nugraha WA, Ambariyanto A. 2023. DNA barcode of seven species coral from Sepulu, Madura Island, Indonesia. Biodiversitas 24: 317-323. Diversity of coral species is needed because it affects the disruption of coral reef ecosystems, nutrient recycling, coral reef growth and the habitat of biota that live in these ecosystems. The main constituents of coral reef ecosystems are coral animals that belong to the Anthozoa class. Sepulu waters (Madura Island), Bangkalan District, East Java Province, Indonesia, has a percentage of coral cover that is in the bad category, management of coral reefs in this area has not been the main focus and it is feared that the situation will get worse so efforts are needed to maintain coral reefs to be sustainable and better. This management effort requires an analysis of species identification. DNA barcoding of corals has never been done on corals of Sepulu waters. The purpose of this study is to find out the DNA of barcoding coral species on Sepulu waters. Genetic marker Cytochrome Oxidase I of the mitochondrial genome DNA (mtDNA) was used to analyze genetic diversity. Reconstruction of phylogenetic tree and genetic diversity were done by using software MEGA X. Research results showed that sample DBP011101 closely related to Dipsatraea maxima 99.55%, DBP011102 closely related to Porites rus 99.4%, DBP011103 closely related to Acropora hyacinthus 99.11%, DBP011104 closely related to Porites cf lichen 98.66%, DBP011106 closely related to Dipsastraea rotumana 95.37%, DBP011107 closely related to Porites horrisoni 98.81%, and DBP011108 closely related to Acropora valida 98.38%. The results of the study are the first coral barcode DNA on Sepulu waters that can help in determining coral species that are useful in managing the sustainability of coral resources, especially on Sepulu waters.

Applying a hybrid model to support management of the endangered Topeka shiner in oxbow habitats

IntroductionHabitat restoration aims at reinstating abiotic and biotic habitat conditions to support long-term species persistence and viability. This management practice is commonly part of recovery plans developed for species listed as threatened or endangered under the Endangered Species Act. The endangered Topeka shiner (Notropis topeka) inhabits off-channel habitats, such as oxbow lakes which are increasingly the focus of restoration, but the exact abiotic conditions conducive to its persistence in this habitat are not fully understood. In this study, a hybrid model consisting of an individual-based model of the Topeka shiner and an aquatic ecosystem model representing the oxbow habitat was applied to identify optimal environmental conditions for the persistence of Topeka shiner populations.Materials and methodsEnvironmental conditions that correlated with Topeka shiner presence were gathered from published studies and included water temperature, turbidity, oxbow depth, light intensity (as a function of riparian vegetation presence), dissolved nitrogen, and dissolved phosphorus. Selected conditions were systematically varied in simulations and results were analyzed with a partial rank correlation method that quantifies the relative influence on model output from multiple factors.ResultsConducted simulations identified water temperature, depth, and dissolved inorganic nitrogen to be the most influential for Topeka shiner population biomass and additional simulations were conducted exploring the magnitudes and directions of effects of these three factors. Water temperature had the largest positive impact on population biomass followed by oxbow depth and nitrogen reduction.DiscussionWe recommend that the three identified factors be further explored in a combination of empirical and modeling approaches to advise management for the endangered Topeka shiner. This study demonstrated how ecological models could inform recovery plans by identifying factors that enhance species persistence. Ultimately, models should support management practices that result in long-term population viability of listed species and could facilitate their timely delisting.

Habitat associations of juvenile Atlantic cod (Gadus morhua L.) and sympatric demersal fish communities within shallow inshore nursery grounds

Resolving the relationship between demersal fish and sublittoral biotic habitats and substrates is a key element in the protection of important nursery grounds for strengthening fish recruitment. In Norway, coastal Atlantic cod (Gadus morhua L.) is a commercially and culturally important demersal fish for Norwegian coastal communities, and in recent decades the stock has declined to such an extent that a plan to rebuild the stock to biologically safe limits has been implemented. Yet, little is known about the specific biotic and abiotic habitat associations of the early-life stages of coastal cod, which is important for the management and protection of the species. The same shallow, sublittoral zones are inhabited by juveniles and adults of other commercial demersal gadoids and wrasses. This study presents novel findings on associations between juvenile coastal cod and other demersal fish species with seafloor substrates and biological habitats, inferred from five years of extensive fyke net surveys. Newly settled 0-group cod were typically associated with eel grass and red algae biotic habitats on sand and shell sand substrates. However, there was an ontogenic habitat shift amongst one year old (1-group) individuals that became more ubiquitous with their biotic habitat or substrate type choices. The juvenile gadoids saithe (Pollachius virens) and pollack (Pollachius pollachius), were most associated with hard bottom dominated sites with saithe being more abundant at exposed sites, compared to pollack. Goldsinny wrasse (Ctenolabrus rupestris) and corkwing wrasse (Symphodus melops) appeared to favor sugar kelp forests and red algae. Overall, the study identifies the specific sublittoral biotic habitats and substrates important to different early life stages of juvenile coastal cod and other commercially important demersal fish, providing critical information needed for identifying candidate coastal habitats for protection.

Are protected areas working for endangered frogs in the Peruvian Andes?

Assessments of the performance of protected-area (PA) networks for aquatic biodiversity conservation are rare yet essential for successful conservation of species. This is especially crucial in highly biodiverse, developing tropical countries where biodiversity loss is most pronounced. We assessed a PA network in the central Andes of Peru that encompasses parts of the geographical distribution of two endangered, endemic, high-elevation Telmatobius frogs. Sites within and beyond PA boundaries were classified into three different PA types: (a) strict-use (prohibits use by local inhabitants), (b) multi-use (allows some use by local inhabitants), and (c) unprotected (no restrictions). We conducted spatial analysis of species distributions, quantified species abundances and population trends, and measured potential threats and ecological integrity in each PA type. Spatial analysis indicated range contractions of 57.7% (T. macrostomus) and 69.0% (T. brachydactylus). Defaunation rates and species abundances in PAs were similar to those outside PAs. Poaching, livestock, and solid waste were the predominant threats. Analysis of ecological integrity indicated that strict-use sites had greater biotic index and habitat assessment scores compared to multi-use sites. These results suggest that despite benefits of greater ecological integrity in strict-use PAs, protection type has little effect on the conservation of aquatic species by itself. Protected areas are unlikely to be effective without better management of the trade-offs between cultural activities and biodiversity conservation. For PA networks to be of better conservation value for aquatic biodiversity in the developing world, they should be community-oriented and connect high-quality habitats, with their borders defined by catchments.

Soil and Vegetation Drive Sesquiterpene Lactone Content and Profile in Arnica montana L. Flower Heads From Apuseni-Mountains, Romania.

Arnica montana L. (AM, Asteraceae) is a perennial, herbaceous vascular plant species of commercial importance. The flower heads’ pharmacological properties are attributed mainly to sesquiterpene lactones (SLs), with phenolic acids and flavonoids also considered of relevance. The botanical drug is still partly collected in different European mountain regions. The SL content can be influenced by genetic factors and environmental conditions (altitude, temperature and rainfall). Surprisingly, the influence of the soil on SL-content have rarely been investigated. However, the soil determines the occurrence, distribution and overall fitness of AM. Equally, environmental factors are crucial determinants for the biosynthesis and fluctuations in plant secondary metabolites. Therefore, different abiotic (pH, C/N ratio, base saturation, cation exchange capacity) and biotic (species richness, vegetation cover) parameters need to be assessed as potential drivers of the variable content of AM’s secondary metabolites. Consequently, we developed an in situ experimental design aiming to cover a wide range of soil pH conditions. We detected and investigated different AM populations growing in grassland on acidic soils, on siliceous as well as calcareous geologies within the same geographical region and altitudinal belt. The total SL content and most single SL contents of the AM flower heads differed significantly between the two geologies. AM flower heads of plants growing on loam on limestone showed a significant higher total SL content than the flower heads of plants growing in siliceous grasslands. Furthermore, the SL contents were significantly correlated with geobotanical species richness and vegetation cover pointing toward an effect of species interactions on the production of SLs. Moreover, the ratios of the main SLs helenalin to dihydrohelenalin esters were significantly correlated to environmental parameters indicating that SL composition might be a function of habitat conditions. The findings of this study shed light upon the often ignored, complex interactions between environmental conditions and plant secondary metabolites. We highlight the importance of both abiotic and biotic habitat parameters for SLs in AM.

Using eDNA presence/non‐detection data to characterize the abiotic and biotic habitat requirements of a rare, elusive amphibian

AbstractThe environmental DNA (eDNA) approach has already been established as a valuable tool for the detection and monitoring of rare and elusive species. However, its application is not limited to assessing whether or not a species is present in a given area. In this study, we collected environmental data from 48 aquatic locations that had previously been investigated in an eDNA‐based study. We sought to determine the abiotic and biotic factors that could explain the presence or non‐detection of Hula painted frog DNA at those locations, in order to characterize this rare species’ little studied habitat requirements. We found that the detection probability of this species decreased substantially with increasing phosphorus loads as well as in the presence of the wetland plant Lythrum salicaria. By contrast, the detection probability increased markedly when Phragmites australis or Ludwigia stolonifera constituted part of the dominant aquatic vegetation. Our results expand the knowledge on this elusive frog species and contribute valuable information for future habitat restoration plans. They further show that eDNA data can also be used to characterize the putative habitats of species where such data are scarce or even totally lacking.

Disentangling the Effects of Biotic Neighbors and Habitat Heterogeneity on Seedling Survival in a Deciduous Broad-Leaved Forest

Disentangling the Effects of Biotic Neighbors and Habitat Heterogeneity on Seedling Survival in a Deciduous Broad-Leaved Forest

Using the background of fish photographs to quantify habitat composition in marine ecosystems

Citizen science initiatives that collect opportunistic photos, or recordings, of living organisms (e.g. iNaturalist) are increasingly recognized for their importance in monitoring biodiversity. These projects are focussed primarily on recording the occurrence of individual species in space and time. Each photo potentially also contains additional valuable information. Here, we explored the amount and potential value of background information captured in fish photographs as a method to characterise reef habitats. The habitat in the background of fish photographs shared on iNaturalist was analysed for 6 sites across Australia. To measure accuracy of the habitat data captured in the iNaturalist photos, the habitat composition of each site was compared to standardised photo-quadrats from the citizen science project Reef Life Survey (RLS). Across all sites, 70-85% of the fish photographs from iNaturalist contained discernible biotic habitat in the background. Habitat composition as measured from the background of opportunistic fish photographs was similar to those of standardised surveys from RLS. In the face of rapid environmental change, opportunistic photographs collected by recreational divers represent a complementary way to rapidly and cost-effectively collect habitat data at more reefs and more frequently than is generally feasible with standardised scientific surveys.