Growth Habitat Research Articles

Metabolome plasticity in 241 Arabidopsis thaliana accessions reveals evolutionary cold adaptation processes.

Acclimation and adaptation of metabolism to a changing environment are key processes for plant survival and reproductive success. In the present study, 241 natural accessions of Arabidopsis (Arabidopsis thaliana) were grown under two different temperature regimes, 16 °C and 6 °C, and growth parameters were recorded, together with metabolite profiles, to investigate the natural genome × environment effects on metabolome variation. The plasticity of metabolism, which was captured by metabolic distance measures, varied considerably between accessions. Both relative growth rates and metabolic distances were predictable by the underlying natural genetic variation of accessions. Applying machine learning methods, climatic variables of the original growth habitats were tested for their predictive power of natural metabolic variation among accessions. We found specifically habitat temperature during the first quarter of the year to be the best predictor of the plasticity of primary metabolism, indicating habitat temperature as the causal driver of evolutionary cold adaptation processes. Analyses of epigenome- and genome-wide associations revealed accession-specific differential DNA-methylation levels as potentially linked to the metabolome and identified FUMARASE2 as strongly associated with cold adaptation in Arabidopsis accessions. These findings were supported by calculations of the biochemical Jacobian matrix based on variance and covariance of metabolomics data, which revealed that growth under low temperatures most substantially affects the accession-specific plasticity of fumarate and sugar metabolism. Our findings indicate that the plasticity of metabolic regulation is predictable from the genome and epigenome and driven evolutionarily by Arabidopsis growth habitats.

Inventory of the Orchidaceae Family in Jorong Harapan Tinggam Community Forest Talamau Pasaman Barat District West Sumatera

Tinggam Community Forest is a highland tropical forest area in which many types of orchids are found. Orchids generally live as epiphytes, but there are also terrestrial ones. The purpose of this study was to determine the types of natural orchids found in the forest in the Jorong Harapan Tinggam Community Forest, Talamau District, West Pasaman Regency West Sumatera. The research method used is a descriptive survey using a roaming technique by tracing the forest from the outskirts to the forest as a whole. From the results of the study, it was found that there were 16 species, consisting of 13 epiphyte orchids, while the terrestrial orchids obtained were 3 species. The orchid species obtained were: Agrostophyllum lampongense Blume., Arundina graminifolia Hochr., Bulbophyllum sp., Bulbophyllum angustifolium Lindl., Bulbophyllum plavescens Blume., Coelogyne rochussenii Vriese., Cymbidium Rchb.fcrumenatum spp . dayanum De., Eria iridifolia Hook.F., Eria pilifera Ridley., Grammathophyllum speciosum Blume., Phaius tankervilleae Blume. Robiquatia spatulata Blume., Spathoglottis plicata Roxb., Thelasis carinata Blume. It can be concluded that the Jorong Harapan area is an ideal habitat for orchid growth.

Mechanistic insights into dissolved organic matter-driven protistan and bacterial community dynamics influenced by vegetation restoration

Vegetation restoration projects can not only improve water quality by absorbing and transferring pollutants and nutrients from non-vegetation sources, but also protect biodiversity by providing habitat for biological growth. However, the mechanism of the protistan and bacterial assembly processes in the vegetation restoration project were rarely explored. To address this, based on 18 S rRNA and 16 S rRNA high-throughput sequencing, we investigated the mechanism of protistan and bacterial community assembly processes, environmental conditions, and microbial interactions in the rivers with (out) vegetation restoration. The results indicated that the deterministic process dominated the protistan and bacterial community assembly (94.29% and 92.38%), influenced by biotic and abiotic factors. For biotic factors, microbial network connectivity was higher in the vegetation zone (average degree = 20.34) than in the bare zone (average degree = 11.00). For abiotic factors, the concentration of dissolved organic carbon ([DOC]) was the most important environmental factor affecting the microbial community composition. [DOC] was lower significantly in vegetation zone (18.65 ± 6.34 mg/L) than in the bare zone (28.22 ± 4.82 mg/L). In overlying water, vegetation restoration upregulated the protein-like fluorescence components (C1 and C2) by 1.26 and 1.01-folds and downregulated the terrestrial humic-like fluorescence components (C3 and C4) by 0.54 and 0.55-folds, respectively. The different DOM components guided bacteria and protists to select different interactive relationships. The protein-like DOM components led to bacterial competition, whereas the humus-like DOM components resulted in protistan competition. Finally, the structural equation model was established to explain that DOM components can affect protistan and bacterial diversity by providing substrates, facilitating microbial interactions, and promoting nutrient input. In general, our study provides insights into the responses of vegetation restored ecosystems to the dynamics and interactives in the anthropogenically influenced river and evaluates the ecological restoration performance of vegetation restoration from a molecular biology perspective.

Rhodopseudomonas palustris PSB06 agent enhance pepper yield and regulating the rhizosphere microecological environment

The Rhodopseudomonas palustris (R. palustris) PSB06 can promote crop growth, as it maybe regulates microbial communities in plant root soil, soil physicochemical properties, thus creating a favorable habitat for the crop growth. However, there are few studies on the yields and rhizosphere microbial community of R. palustris PSB06 agent. In the study, the high-throughput sequencing was used to study the changes of rhizosphere soil bacterial community after PSB06 treatment. The results indicated R. palustris PSB06 agent increased the pepper yield by 33.45% when compared to control group, with better effect than other treatments. And it also significantly increased soil nitrogen concentration. R. palustris PSB06 agent had improved pepper rhizosphere bacterial α diversity and changed the community structure. Acidobacteria, Proteobacteria, Actinomycetes and Firmicutes were dominant phyla in all the pepper rhizosphere soil samples. The results showed that soil bacterial community were significantly positively correlated with pH (R = 0.8537, P = 0.001) and total nitrogen (R = 0.4347, P = 0.003). The nine significantly enriched OTU in R.palustris PSB06 treatment (PB) group belong to Nitrososphaera (OTU_109, OTU_14, OTU_18, OTU_8), Lysobacter (OTU_2115, OTU_13), Arenimonas (OTU_26), Luteimonas (OTU_49), and Ramlibacter (OTU_70) were significantly positively correlated with the total yield of pepper (R > 0.5, P < 0.05). Overall, our results provide a theoretical basis for studying the microbial regulation of R.palustris PSB06 on rhizosphere soil.

Pengelolaan dan Konservasi Vegetasi Tanaman Gumi Banten di Desa Besakih, Kecamatan Rendang, Karangasem

Taman Gumi Banten is an area that is utilized as a habitat for plant growth. An important background that supports Taman Gumi Banten is the preservation of rare plants classified as ceremonial plants, usada, and puspa dewata. This research aims to manage and conserve vegetation in the Taman Gumi Banten Besakih, as an effort to preserve ceremonial plants, usada, and puspa dewata. This research was conducted in Taman Gumi Banten Besakih with an area of 2 hectares, conducted for 3 months (May-July 2021). Sampling method with plot method. Primary data, both vegetation data and soil data were taken at the observation site, while secondary data were taken from the Karangasem BMKG office. Data analysis was carried out with vegetation analysis, namely the importance value index, diversity index and species distribution pattern, and vegetation rarity status based on PERMENLHK No. 20 of 2018. While soil data will be analyzed at the Soil Science Laboratory, Faculty of Agriculture, UNUD. The results concluded that the number of species found was 101 species, consisting of 2297 individuals, with low diversity and uniform distribution patterns. There are 2 species classified as rare, namely the kasna kasna (Anaphalis javanica) and gegirang tree (Leontopodium alpinum), soil conditions especially high levels of organic carbon and soil texture all sandy loam are very supportive of vegetation development, and the number of plants in Taman Gumi Banten has only been fulfilled 2297 individuals while the shortage of 2703 individuals (being pursued).

Eels as natural samplers highlight spatial heterogeneity in energy flow in an estuary

The high spatiotemporal heterogeneity makes it difficult to ensure the representation of samples in estuarine studies. Using Japanese eels as natural samplers (n = 881), we revealed the spatial heterogeneity of energy flow among three successive estuarine segments (upper, middle, and lower estuaries) of the Hamana Lake−Miyakoda River system on the Pacific side of central Honshu, Japan. In the upper estuary which serves as the nursery ground for eels, the predominant small eels (body weight <30 g) fed mainly on polychaetes (58.8% IRI [index of relative importance]), mainly Hediste atoka. This polychaete species depends on the detritus food chain driven by terrestrial inputs, and the detritus food chain appears to be predominant in the upper estuary. However, large eels (body weight >150 g) fed directly on terrestrial subsidies in the form of fallen insects (49.0% IRI) and earthworms (20.2% IRI), indicating that the detritus food chain does not directly affect the diet of large eels. Terrestrial subsidies in the form of living organisms do not contribute to the diet of eels in the adjacent middle estuary, which is the main growth habitat for eels within an estuary. However, small eels depend on terrestrial subsidies by feeding on oysters (71.6% IRI), which assimilate terrestrial particulate organic matter. The predominant medium eels were highly dependent on the high diversity and biomass of prey groups, as indicated by the high % IRI values of several groups, such as infaunal bivalves (31.7% IRI), oysters (19.0% IRI), amphipods (22.6% IRI), and polychaetes (16.4% IRI). Eelgrass beds usually serve as shelters and foraging areas for medium and large eels in the lower estuary. Despite the high species diversity around seagrass meadows, the eels concentrated on infaunal bivalves (85.4% IRI) with high biomass, predominantly Anadara sp. In addition to being tools for monitoring fauna, eels as natural samplers provide insights into the energy flow in ecosystems.

Migration Behavior of Anguilla celebesensis Silver Eels within their Tomini Bay Spawning Area.

The tropical Celebes eel, Anguilla celebesensis, has a short migration between its spawning and growth habitats. Its spawning areas were hypothesized to be in Tomini Bay and the Celebes Sea after collecting their small leptocephali. However, there is no information about the silver eel oceanic spawning migration behavior of A. celebesensis. To better understand their short-distance spawning migration behavior, four large female silver eels (Eel 1-4) were equipped with pop-up satellite archival tags (PSATs) and released near the mouth of the Poso River in Tomini Bay of Sulawesi Island on 22 February (Eel 1-3) and 11 March 2010 (Eel 4). All PSATs ascended in Tomini Bay and transmitted their data. Eel 3 and 4 provided clear records of consistent diel vertical migration (DVM: eight days-Eel 3, 13 days-Eel 4) with daytime dives to mean depths of 444.7 m (Eel 3) and 539.0 m (Eel 4), where mean temperatures were 9.1°C (Eel 3) and 7.7°C (Eel 4), and nighttime ascents to mean depths of 132.8 m (Eel 3) and 112.4 m (Eel 4), where mean temperatures were 20.6°C (Eel 3) and 23.4°C (Eel 4). Eel 3 and 4 started to dive to deeper water around nautical dawn and swam up to shallower water around sunset. During nighttime, both eels swam in deeper and colder water during nights with moonlight than during nights without moonlight, and there was a negative linear relationship between experienced water temperatures with the moon in the sky and the lunar age for the eels. The A. celebesensis daily rhythm of DVM behaviors was similar to spawning-migration DVM behaviors of other anguillid species. Essential life history characteristics of A. celebesensis appear to be a short migration between freshwater growth habitat and ocean spawning habitat, and high GSI values with advanced gonadal development in downstream-migrating silver eels.

Morphological Characterization and Recognition of New Traits of Soybean [Glycine max (L.) Merrill

Distinctness, Uniformity, and Stability (DUS) characterization of ninety recently evolved soybean genotypes including three national checks were carried out at JNKVV, Jabalpur, during Kharif 2021. Sixteen DUS traits were evaluated as described by National DUS test guidelines. Observations were made on Hypocotyl Pigmentation, Growth type, Growth habitat, Leaf shape, Leaf size, Leaf colour, Flower colour, Flower colour, Pod hairiness, Pod pub colour, Pod intensity of brown colour, Seed size, Seed shape, Seed coat colour, Hilum colour, Seed coat Lustre and Colour of funicle at various phases. It revealed that there was a lot of variation in the soybean genotypes for DUS characters. Frequency distribution of data exhibited that presence of Hypocotyl: anthocyanin pigmentation (65.55 %), Semi-Determinate Growth type (75.55 %), Semi-erect Growth habitat (90.0 %), Pointed Ovate Leaf shape (83.33 %), Pod hairiness pubescent (84.44%), Seed size medium (64.44%), Seed coat colour yellow (84.44%), Seed coat Lustre intermediate (77.77%) and Colour of funicle brown (100%) were dominating traits in present set of genotypes. This soybean germplasm has a wide range of features and morphological variation, which may assist a breeder in further improvement of soybean. This will be extremely helpful in identifying, conserving and developing ideal plant type on the basis of distinguishing morphological characters.

Microbial exploration from two different ecosystems in Central Sulawesi, Indonesia

Abstract. Ratnawati, Sudewi S, Jaya K, Saleh AR. 2022. Microbial exploration from two different ecosystems in Central Sulawesi, Indonesia. Biodiversitas 23: 6191-6198. A supportive growing environment and the presence of microbes in the soil are considered good habitats for plant growth. Endophytic microbes live in symbiosis (mutual benefit) with their host plants, both in the stem and root tissues of plants, providing defense services in biotic and abiotic stress situations. This study was aimed to identify various microbes that exist in various agricultural cultivation ecosystems in Central Sulawesi. Microbial sampling was obtained from healthy plant tissues (endophytes) and rhizosphere in lowland rice and shallot plantation ecosystems. The sample obtained was then weighed as much as 5 g and surface sterilized for further isolation by serial dilution method to be spread on NA (Nutrient Agar) media for bacteria, and PDA (Potato Dextrose Agar) for fungi. The microbes that had grown were re-isolated to obtain pure isolate culture of microbes. The results showed that 8 isolates from the rhizosphere and 4 isolates as endophytes in the ecosystem of organic rice fields were recorded. The fungal isolates from the shallot plantation “Lembah Palu” found as many as 12 isolates from rhizosphere and 4 isolates as endophytes. The results of macroscopic and microscopic characteristics on fungal isolates identified as the species of Trichoderma, Fusarium, Penicillium, Gliocladium and Aspergillus.

Metatranscriptional characterization of metabolic dynamics in anaerobic membrane bioreactor producing methane from low-strength wastewater

An anaerobic membrane bioreactor (AnMBR) with media is an emerging carbon–neutral biotechnology for low-strength wastewater (LSWW) treatment and methane recovery. Understanding metabolic dynamics among methanogens and syntrophic bacteria is important in optimizing the design and operation of AnMBR. However, little is known about it, especially in media-attached microbial communities. This study explored metabolic dynamics to compare media-attached and suspended conditions. Accordingly, metagenomes and metatranscriptomes from AnMBRs with polymeric media and fed with different influent concentrations (350 and 700 mg-COD/L) were analyzed. Metabolic dynamics were profoundly influenced by the different growth habitats and influent conditions, although the applied influent concentrations are within the range of typical LSWW. Metabolic dynamics prediction results suggest that media-attached-growth habitats may have provided a more favorable microenvironment for methanogens to grow and produce methane, especially under low influent conditions. These findings provide significant implications for optimizing floating media design and operation of AnMBR-producing methane from LSWW.

Impact of earthworm species and growth habitats on the quality of vermicompost

Impact of earthworm species and growth habitats on the quality of vermicompost

Genome-Wide Identification and Expression Analysis of the Aquaporin Gene Family in Lycium barbarum during Fruit Ripening and Seedling Response to Heat Stress.

Plant-water relations mediated by aquaporins (AQPs) play vital roles in both key plant growth processes and responses to environmental challenges. As a well-known medicinal and edible plant, the harsh natural growth habitat endows Lycium plants with ideal materials for stress biology research. However, the details of their molecular switch for water transport remain unclear. In the present work, we first identified and characterized AQP family genes from Lycium (L.) barbarum at the genome scale and conducted systemic bioinformatics and expression analyses. The results showed that there were 38 Lycium barbarum AQPs (LbAQPs) in L.&amp;nbsp;barbarum, which were classified into four subfamilies, including 17 LbPIP, 9 LbTIP, 10 LbNIP, and 2 LbXIP. Their encoded genes were unevenly distributed on all 12 chromosomes, except chromosome 10. Three of these genes encoded truncated proteins and three genes underwent clear gene duplication events. Cis-acting element analysis indicated that the expression of LbAQPs may be mainly regulated by biotic/abiotic stress, phytohormones and light. The qRT-PCR assay indicated that this family of genes presented a clear tissue-specific expression pattern, in which most of the genes had maximal transcript levels in roots, stems, and leaves, while there were relatively lower levels in flowers and fruits. Most of the LbAQP genes were downregulated during L. barbarum fruit ripening and presented a negative correlation with the fruit relative water content (RWC). Most of their transcripts presented a quick and sharp upregulation response to heat stress following exposure of the 2-month-old seedlings to a 42 °C temperature for 0, 1, 3, 12, or 24 h. Our results proposed that LbAQPs were involved in L. barbarum key development events and abiotic stress responses, which may lay a foundation for further studying the molecular mechanism of the water relationship of Lycium plants, especially in harsh environments.

Habitat use and growth of yellow-stage European eel in coastal and freshwater ecosystems in Norway

Many anguillid eel species display facultative catadromy. Some eel spend their entire life cycle in marine coastal areas, but the geographical extent of this, especially at the extremes of their distributional ranges, is unknown. We analysed otolith Sr:Ca and Ba:Ca from yellow-stage European eel ( Anguilla anguilla) sampled along the coast of Norway and in several freshwater lakes (58°N–63°N), to infer their initial settlement and later life movement patterns with regards to habitat salinity. Most eel (80%) sampled in marine habitats ( n = 371) had settled and remained in marine water, but 20% had moved between marine and freshwater habitats and were hence classified as inter-habitat shifters. Among freshwater sampled eel ( n = 99), 80% had settled and remained in fresh water, but 20% were classified as inter-habitat shifters. The average growth rates for marine water residents, inter-habitat shifters, and freshwater residents were 35, 27, and 17 mm·year–1, respectively. Northern European shallow marine habitats may serve as important yellow eel growth habitats and may be critical to buffer the European eel population against the general decrease in continental recruitment.

Temperature-mediated flower size plasticity in Arabidopsis

Organisms can rapidly mitigate the effects of environmental changes by changing their phenotypes, known as phenotypic plasticity. Yet, little is known about the temperature-mediated plasticity of traits that are directly linked to plant fitness such as flower size. We discovered substantial genetic variation in flower size plasticity to temperature both among selfing Arabidopsis thaliana and outcrossing A.arenosa individuals collected from a natural growth habitat. Genetic analysis using a panel of 290 A. thaliana accession and mutant lines revealed that MADS AFFECTING FLOWERING (MAF) 2-5 gene cluster, previously shown to regulate temperature-mediated flowering time, was associated to the flower size plasticity to temperature. Furthermore, our findings pointed that the control of plasticity differs from control of the trait itself. Altogether, our study advances the understanding of genetic and molecular factors underlying plasticity on fundamental fitness traits, such as flower size, in response to future climate scenarios.

Middle Miocene (Serravallian) rhodoliths and coralline algal debris in carbonate ramps (Betic Cordillera, S Spain)

Serravallian (middle Miocene) coralline algal assemblages at the southern margin of the Guadalquivir Basin (southern Spain) occur as rhodoliths preserved in situ or very close to their growth habitats (autochthonous–parautochthonous assemblages) and also as reworked remains (allochthonous assemblages). The former assemblages consist of spherical rhodoliths built up by encrusting to warty plants and also of large fragments of branches, whereas the latter are mostly unrecognizable small fragments occurring in channeled packstone–grainstone beds. In both cases, the most abundant components are members of the order Hapalidiales (Mesophyllum roveretoi, Mesophyllum sp., Lithothamnion ramosissimum, and less frequently Phymatolithon group calcareum and Lithothamnion group corallioides). Laminar growths of Lithoporella minus and branches of Spongites group fruticulosus and Sporolithon sp. occur very rarely. There are also anecdotal records of Subterraniphyllum thomasii, extending its upper stratigraphic range up to the Serravallian in the western Tethys. The autochthonous–parautochthonous coralline algal assemblages formed in a middle ramp, at several tens of meters of water depth, as suggested by the dominance of Hapalidiales. The allochthonous assemblages represent fragments of coralline algae derived from the middle ramp and redeposited in deeper settings, most likely the outer ramp, due to storm-generated currents.

Which soil properties affect soil mite (Acari, Mesostigmata) communities in stands with various shares of European ash (Fraxinus excelsior L.)?

European ash (Fraxinus excelsior L.) is an important tree species and a critical component of European forests. Its share has gradually decreased due to the global climate crisis or fungal diseases. Therefore, it may influence dependent plant communities and soil organisms. Hence, we aimed to describe soil properties among different habitats where ash may grow and assess how these habitats affect abundance, species richness, and diversity of soil mite (Mesostigmata) communities. The study was conducted in eight stands (western Poland) grouped in four habitats differing in terms of soil conditions and stand species composition. Stands represented: (1) optimal habitats for ash growth with >90 % ash in the tree layer, (2) optimal habitats without ash in the tree layer, (3) suboptimal habitats with >60 % ash and co-dominance of Quercus robur L., and (4) transformed habitats with >60 % ash and co-dominance of Pinus sylvestris L. Soil environments within the research plots (circular plot area in each stand = 400 m2) were characterized by the description of the soil profile and 17 soil parameters provided for each of 72 soil samples. Mesostigmatid mites were extracted from 72 additionally collected samples into Berlese-Tullgren funnels, then mounted on slides and classified to species or genus levels.In total, 362 mites were classified into 39 taxa. The most numerous taxa were Paragamasus sp. (13.0 % of all mites), Oodinychus ovalis (C. L. Koch) (11.3 %), and Paragamasus runcatellus (Berlese) (8.6 %). We found that decreasing nitrate‑nitrogen was accompanied by increasing mite abundance, species richness, and diversity. Furthermore, mesostigmatid mite abundance and species richness increased with increasing soil pH. Although soil moisture, pH of forest litter, magnesium, calcium, potassium, total nitrogen, and C/N mass ratio differed between all habitats, they did not affect Mesostigmatid abundance, species richness, and diversity. Nevertheless, analysis of variance conducted for the Canonical Correspondence Analysis model showed that habitat and pH of forest litter significantly impacted the community species composition of mesostigmatid mites. Our study provides a better understanding of the habitat requirements of soil mesostigmatid mites and, therefore, leads to improving the use of mesostigmatid mite taxa as effective bioindicators of soil and environmental quality.

Analysis of the Population Structure and Dynamic of Endemic Salvia ceratophylloides Ard. (Lamiaceae)

Understanding how changes of any origin interact with the structure and survival of entire populations is very important for the protection and conservation of threatened, rare and/or endemic species. In this study, structure and population dynamics of Salvia ceratophylloides Ard., a precious endemic species, belonging to the subgenus Sclarea (Moench) Benth., section Plethiosphace Benth. (Lamiaceae) exclusive to the suburban environments of Reggio Calabria (Southern Italy), was analysed. Interactions between this species and its different growth habitats were examined. Moreover, the disturbance factors which directly affect the demographic viability of the species, influencing its growth, reproduction and distribution in its distribution area were identified. From 2019 to 2021, a census by counting individuals of all the known stations, recorded according to a specific protocol, was carried out. The recorded data were statistically analysed and compared with those of the phytosociological surveys carried out using the Braun-Blanquet method and summarised in phytosociological classes, in accordance with the hierarchical floristic classification system of vascular plant communities, accepted at national and European levels. The structure of the different populations was also related to the different threat factors that afflict S. ceratophylloides. It was observed that the most structured populations of S. ceratophylloides were found in natural and semi-natural environments where the anthropogenic disturbance was minor, while populations with an irregular structure were found in sites exposed to disturbances of various origins. The different phytosociological classes do not interact directly on population structure. The most important factors affecting structure and distribution are disturbances of various origins, in particular anthropogenic and phytosanitary disturbances. In order to keep populations balanced and stable over time, it would be useful to adopt conservation measures for the species and the habitat in which they live, with practical solutions for the following: (a) to limit infestations by insects that parasitize stems and seeds; (b) to prevent mowing, fires, grazing and the introduction of invasive alien species.

Glass eel (Anguilla anguilla L. 1758) feeding behaviour during upstream migration in an artificial waterway

The transition from marine to fresh water is a challenging task for juvenile eels. This critical step in the early eels' life is preceded by a metamorphosis from the oceanic larval to the continental glass eel stage, requiring major energy-demanding morphological, physiological and behavioural modifications during which time these animals do not feed. The success of the glass eels' inland migration after metamorphosis will largely depend on remaining energy levels, which can be supplemented only by resuming food uptake. Although it is crucial for their survival and the maintenance of the population, the feeding behaviour of glass eels is still an understudied aspect of the eels' complex life cycle. Many uncertainties about the phenology, diet, potential prey preferences and their relation with migration modus (migratory vs. sedentary) still remain. In this study, the authors analysed the stomach and gut contents of 458 European glass eels (Anguilla anguilla L. 1758) captured in a drainage canal connecting a small mesotidal estuary with an adjacent polder area during the spring migration seasons of 2016 and 2017. They demonstrated that although glass eels started feeding briefly upon arrival in the estuary, food uptake for early arrivals was restricted to a minority that sparsely feed on detritus and some worm-like benthic invertebrates. Along the season, food uptake intensified eventually engaging all glass eels and their dietary palette diversified including a wide array of planktonic and benthic organisms. Crustacean plankton (mainly cyclopoid copepods) was an important part of the glass eel diet, whereas benthic oligochaetes were less abundant as food source in spite of their high presence in the sediments. No clear differences in feeding behaviour could be observed between migratory and sedentary glass eels. This study showed that glass eels can use highly artificial and dynamic drainage canals as feeding ground during their critical marine/freshwater transition. This outcome is also a plea to improve the accessibility of alternative (unnatural) migration routes between the ocean and suitable freshwater growth habitats for the European eel.

Photosynthetic regulation in fluctuating light under combined stresses of high temperature and dehydration in three contrasting mosses

Photosynthesis regulation is fundamental for the response to environmental dynamics, especially for bryophytes during their adaptation to terrestrial life. Alternative electron flow mediated by flavodiiron proteins (FLV) and cyclic electron flow (CEF) around photosystem I (PSI) play seminal roles in the response to abiotic stresses in mosses; nevertheless, their correlation and relative contribution to photoprotection of mosses exposed to combined stresses remain unclear. In the present study, the photosynthetic performance and recovery capacity of three moss species from different growth habitats were examined during heat and dehydration with fluctuating light. Our results showed that dehydration at 22 °C for 24 h caused little photodamage, and most of the parameters recovered to their original values after rehydration. In contrast, dehydration at 38 °C caused drastic injuries, especially to PSII, which was mainly caused by the inactivation of non-photochemical quenching (NPQ). Dehydration also induced a high accumulation of O2- and H2O2. A consistently higher CEF as well as a positive correlation between CEF and FLV was observed in resistant R. japonicum, implying CEF played a more important protective role for R. japonicum. In H. plumaeforme and P. cuspidatum, the positive relationship under mild stress switched to negative when stress became severe. Therefore, FLV pathway was sensitive to environmental fluctuations and maybe less efficient than CEF thus, readily to be lost during land colonization and evolution in angiosperms. Our work provides insights into the coordination of various pathways to fine-tune photosynthetic protection and can be used as a basis for species screening and development of breeding strategies for degraded ecosystem restoration with pioneering mosses.

Tracking microplastics biodegradation through CO2 emission: Role of photoaging and mineral addition

Once microplastics (MPs) enter the terrestrial ecosystem, they may affect the assessment of soil carbon storage and the fluxes of greenhouse gases. This study showed microbial incubation diminished the size and dissolved organic carbon (DOC) content of MPs and introduced more oxygen-containing functional groups to MPs potentially through microbial colonization. The aged MPs generally showed higher carbon mineralization ratio (0.010–0.876 %) than the pristine MPs (0.007–0.189 %), which was supported by their higher enzyme activities and DOC content. Interestingly, four model minerals increased the DOC release and CO2 emission from MPs by altering MPs physicochemical properties and shaping the habitat for microbial growth. The higher enzyme activities in mineral artificial soils, except for montmorillonite, served as a potential valid explanation for their higher mineralization. The high CO2 emission but low enzyme activity in montmorillonite artificial soil was due to most DOC being already mineralized. Aging and minerals altered the microflora and enhanced the expression of some C metabolism- and N-related functional genes, which supplemented the cause of higher CO2 and N2O emissions from the corresponding artificial soils. Overall, the increased biomineralization of MPs carbon by minerals was divergent from the protective role of minerals on soil organic carbon.